U.S. patent application number 17/583333 was filed with the patent office on 2022-07-07 for prodrugs of modulators of the nmda receptor.
This patent application is currently assigned to H. Lundbeck A/S. The applicant listed for this patent is H. Lundbeck A/S. Invention is credited to Erhad Ascic, Laurent David, John Paul Kilburn, Mauro Marigo.
Application Number | 20220213117 17/583333 |
Document ID | / |
Family ID | 1000006227185 |
Filed Date | 2022-07-07 |
United States Patent
Application |
20220213117 |
Kind Code |
A1 |
Kilburn; John Paul ; et
al. |
July 7, 2022 |
PRODRUGS OF MODULATORS OF THE NMDA RECEPTOR
Abstract
The present invention is directed to novel prodrugs of
modulators of the NMDA receptor. Separate aspects of the inventions
are directed to pharmaceutical compositions comprising said
compounds and uses of the compounds to treat neurological disorders
or neuropsychiatric disorders such as depression.
Inventors: |
Kilburn; John Paul; (Valby,
DK) ; Ascic; Erhad; (Valby, DK) ; Marigo;
Mauro; (Valby, DK) ; David; Laurent; (Valby,
DK) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
H. Lundbeck A/S |
Valby |
|
DK |
|
|
Assignee: |
H. Lundbeck A/S
Valby
DK
|
Family ID: |
1000006227185 |
Appl. No.: |
17/583333 |
Filed: |
January 25, 2022 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
16916681 |
Jun 30, 2020 |
|
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17583333 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C07D 495/04
20130101 |
International
Class: |
C07D 495/04 20060101
C07D495/04 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 3, 2019 |
DK |
PA201900822 |
Claims
1-36. (canceled)
37. A method for the treatment of depression comprising the
administration of a therapeutically effective amount of a compound
having the formula Ia: ##STR00211## wherein: R.sup.5 is selected
from the group consisting of C.sub.1-5 alkyl, C.sub.1-4 haloalkyl,
hydroxyalkyl, C.sub.1-4 hydroxyhaloalkyl, R.sup.8, WR.sup.8, and
W(OR.sup.9); W is selected from the group consisting of C.sub.1-3
alkylene and --CH.sub.2C(O)--; R.sup.8 is selected from the group
consisting of C.sub.3-6 cycloalkyl, phenyl, a 4, 5, or 6 membered
heterocycle, and a 5 or 6 membered heteroaryl, wherein said
cycloalkyl, phenyl, heterocycle or heteroaryl are independently
unsubstituted or substituted with 1, 2 or 3 substituents
independently selected from halogen, C.sub.1-3 alkyl, C.sub.1-3
alkoxy, wherein said C.sub.1-3 alkyl and C.sub.1-3 alkoxy are
independently unsubstituted or substituted with 1, 2 or 3 F; and
R.sup.9 is C.sub.1-3 alkyl unsubstituted or substituted with 1, 2
or 3 F; or pharmaceutically acceptable salt thereof, to a patient
in need thereof.
38. The method according to claim 37, wherein R.sup.5 is selected
from the group consisting of methyl, ethyl, propyl, isopropyl,
cyclopropyl, butyl, isobutyl, --CH.sub.2-cyclopropyl,
2-methoxyethyl, isopentyl, benzyl, cyclohexyl,
2-oxo-2-(pyrrolidin-1-yl)ethyl, and phenyl.
39. The method according to claim 37, wherein R.sup.5 is C.sub.1-5
alkyl.
40. The method according to claim 37, wherein R.sup.5 is selected
from the group consisting of methyl, ethyl, propyl, butyl, and
isopropyl.
41. The method according to claim 37, wherein R.sup.5 is selected
from the group consisting of methyl, ethyl, propyl, and butyl.
42. The method according to claim 37, wherein R.sup.5 is selected
from the group consisting of methyl and ethyl.
43. The method according to claim 37, wherein R.sup.5 is
methyl.
44. The method according to claim 37, wherein R.sup.5 is ethyl.
45. The method according to claim 37, wherein the compound is
selected from the group consisting of: methyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate;
ethyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoa-
te; propyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)prop-
anoate; isopropyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate;
cyclopropyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate;
butyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoa-
te; isobutyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate;
cyclopropylmethyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate;
2-methoxyethyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate;
isopentyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)prop-
anoate; benzyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate;
cyclohexyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate;
and phenyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate;
or a pharmaceutically acceptable salt thereof.
46. The method according to claim 37, wherein the compound is
selected from the group consisting of: methyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate;
ethyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoa-
te; propyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)prop-
anoate; and isobutyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate;
and pharmaceutically acceptable salts thereof.
47. The method according to claim 37, wherein the compound is
methyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate,
or a pharmaceutically acceptable salt thereof.
48. The method according to claim 37, wherein the compound is ethyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate,
or a pharmaceutically acceptable salt thereof.
49. The method according to claim 37, wherein the compound is
propyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate,
or a pharmaceutically acceptable salt thereof.
50. The method according to claim 37, wherein the compound is
isobutyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate,
or a pharmaceutically acceptable salt thereof.
51. The method for the treatment of depression according to claim
37, wherein the depression is selected from the group consisting of
major depressive disorder, treatment-resistant depression,
catatonic depression, melancholic depression, atypical depression,
psychotic depression, perinatal depression, postpartum depression,
bipolar depression, including bipolar I depression and bipolar II
depression, and mild, moderate or severe depression.
52. The method for the treatment of depression according to claim
47, wherein the depression is selected from the group consisting of
major depressive disorder, treatment-resistant depression,
catatonic depression, melancholic depression, atypical depression,
psychotic depression, perinatal depression, postpartum depression,
bipolar depression, including bipolar I depression and bipolar II
depression, and mild, moderate or severe depression.
53. The method for the treatment of depression according to claim
48, wherein the depression is selected from the group consisting of
major depressive disorder, treatment-resistant depression,
catatonic depression, melancholic depression, atypical depression,
psychotic depression, perinatal depression, postpartum depression,
bipolar depression, including bipolar I depression and bipolar II
depression, and mild, moderate or severe depression.
54. The method for the treatment of depression according to claim
49, wherein the depression is selected from the group consisting of
major depressive disorder, treatment-resistant depression,
catatonic depression, melancholic depression, atypical depression,
psychotic depression, perinatal depression, postpartum depression,
bipolar depression, including bipolar I depression and bipolar II
depression, and mild, moderate or severe depression.
55. The method for the treatment of depression according to claim
50, wherein the depression is selected from the group consisting of
major depressive disorder, treatment-resistant depression,
catatonic depression, melancholic depression, atypical depression,
psychotic depression, perinatal depression, postpartum depression,
bipolar depression, including bipolar I depression and bipolar II
depression, and mild, moderate or severe depression.
56. A method of treatment of a condition selected from suicidal
ideation, bipolar disorder (including bipolar depression),
obsessive compulsive disorder and status epilepticus comprising the
administration of a therapeutically effective amount of a compound
having the formula Ia: ##STR00212## wherein: R.sup.5 is selected
from the group consisting of C.sub.1-5 alkyl, C.sub.1-4 haloalkyl,
hydroxyalkyl, C.sub.1-4 hydroxyhaloalkyl, R.sup.8, WR.sup.8, and
W(OR.sup.9); W is selected from the group consisting of C.sub.1-3
alkylene and --CH.sub.2C(O)--; R.sup.8 is selected from the group
consisting of C.sub.3-6 cycloalkyl, phenyl, a 4, 5, or 6 membered
heterocycle, and a 5 or 6 membered heteroaryl, wherein said
cycloalkyl, phenyl, heterocycle or heteroaryl are independently
unsubstituted or substituted with 1, 2 or 3 substituents
independently selected from halogen, C.sub.1-3 alkyl, C.sub.1-3
alkoxy, wherein said C.sub.1-3 alkyl and C.sub.1-3 alkoxy are
independently unsubstituted or substituted with 1, 2 or 3 F; and
R.sup.9 is C.sub.1-3 alkyl unsubstituted or substituted with 1, 2
or 3 F; or pharmaceutically acceptable salt thereof, to a patient
in need thereof.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation application of U.S.
application Ser. No. 16/916,681, filed Jun. 30, 2020, which claims
priority to Danish Application No. PA201900822, filed Jul. 3, 2019,
the entire contents of the aforementioned application is hereby
incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention is directed to compounds that are
prodrugs of modulators of the NMDA receptor, pharmaceutical
compositions comprising said compounds, and their use in the
treatment of neurological disorders or neuropsychiatric disorders
such as depression, in particular major depressive disorder (MDD)
and treatment-resistant depression (TRD).
BACKGROUND OF THE INVENTION
[0003] The World Health Organization estimates 350 million people
will be affected with MDD and has projected that depression will
constitute the largest health burden on society worldwide by 2030.
A rough working estimate of prevalence is that depression affects
1/5th of the population at some point, affecting women in a higher
proportion than men (5-9% and 2-3% incidence respectively in the
US, representing an overall incidence of 6.6%). The North-American
Center for Disease Control has reported that from 2005-2008, 8.9%
of the US population was prescribed an antidepressant during any
given month, antidepressants being also prescribed for anxiety,
pain, and other non-mood disorders [Global Burden of Disease Study.
Lancet. May 17, 1997; 349(9063): 1436-1442].
[0004] Antidepressants are marketed and thus known to the skilled
person. Examples of different types of antidepressant are but not
limited to, selective serotonin reuptake inhibitors (SSRIs),
Serotonin-norepinephrine reuptake inhibitors (SNRIs), Monoamine
oxidase inhibitors (MAOIs), and Tricyclic antidepressants. Typical
limitations of known antidepressants are delayed onset of efficacy
and low remission rates after multiple courses of pharmacotherapy,
and for some antidepressants severe side-effects [Antidepressants
and the risk of suicidal behaviours. Jama. Jul. 21, 2004;
292(3):338-343].
[0005] In recent years, modulators of the N-Methyl-D-Aspartate
(NMDA) receptors have received more attraction in treatment MDD, in
particular treatment-resistant depression (TRD). Especially,
ketamine, an antagonist of the NMDA receptor, is used for treating
MMD due to its antidepressant effect and fast onset. However, MDD
treatment with ketamine has the drawback of psychometric side
effects and requirement of intravenous administration.
[0006] NMDA receptors are tetrameric ligand-gated ion channels
which are also involved in essential physiological processes such
as synaptic plasticity and development. NMDA receptors are
heterotetramers comprising two GluN1 subunits and two GluN2/GluN3
subunits. This means that they assemble as either diheteromeric or
triheteromeric receptors. The majority of native NMDA receptors
consist of two GluN1 subunits and two GluN2 subunits. Activation of
the NMDA receptors requires simultaneous binding at two different
binding sites. Glutamate, the major excitatory neurotransmitter in
the central nervous system, binds to the GluN2 subunits and glycine
binds to the GluN1 and GluN3 subunits.
[0007] Another known modulator of the NMDA receptor is
D-cycloserine, which is a partial glycine site agonist.
D-cycloserine has been intensively studied due to its neuroactive
properties and potential utility in treatment of depression and
depression disorders such as MDD [Heresco-Levy, U., Javitt, D. C.,
Gelfin, Y., Gorelik, E., Bar, M., Blanaru, M., Kremer, I., 2006.
Controlled trial of d-cycloserine adjuvant therapy for
treatment-resistant major depressive disorder. J. Affect. Disord.
93, 239-243] and PTSD [Olden, M., Wyka, K., Cukor, J., Peskin, M.,
Altemus, M., Lee, F. S., Finkelstein-Fox, L., Rabinowitz, T.,
Difede, J., 2017. Pilot study of a telehealth-delivered medication
augmented exposure therapy protocol for PTSD. J. Nerv. Ment. Dis.
205, 154-160]. However, treatment of D-cycloserine suffers from
frequent complaints of psychopathological stimulation such as
anxiety, euphoria, agitation, feeling stimulated,
dizziness/drowsiness, fatigue, headache, and gastrointestinal
disturbance [Schade, S., Paulus, W., 2016. D-Cycloserine in
neuropsychiatric diseases: a systematic review. Int. J.
Neuropsychopharmacol]
[0008] Urwyler et al., J. Med. Chem. 2009, 52, 5093-5107 discloses
3-acylamino-2-amonipropionic acid derivatives with affinity for the
glycine site of the NMDA receptor.
[0009] Despite the longstanding interest in the field, there is
evidently still an unmet need as regards developing efficient, well
tolerated and active drugs for the treatment of depression in
particular MDD and TRD. A prodrug of a compound being a modulator
of the NMDA receptor, with improved permeability and brain exposure
compared to the parent compound may fulfil such unmet needs.
SUMMARY OF THE INVENTION
[0010] With this background, it is an object of the invention to
provide a prodrug of modulators of the NMDA receptor. Accordingly,
the present invention relates to compounds of formula I, or a
pharmaceutically acceptable salt thereof, wherein:
##STR00001##
[0011] R.sup.1 is selected from the group consisting of a hydrogen,
halogen, C.sub.1-4 haloalkyl, cyano, C.sub.3-6 cycloalkyl, and
C.sub.1-4 alkyl;
[0012] R.sup.2 is selected from the group consisting of hydrogen,
halogen, C.sub.1-4 haloalkyl, cyano, C.sub.3-6 cycloalkyl, and
C.sub.1-4 alkyl;
[0013] R.sup.3 is selected from the group consisting of hydrogen,
halogen, C.sub.1-4 haloalkyl, cyano, C.sub.3-6 cycloalkyl, and
C.sub.1-4 alkyl;
[0014] R.sup.4 is selected from the group consisting of hydrogen,
halogen, C.sub.1-4 alkyl, C.sub.1-4 haloalkyl, C.sub.1-4
hydroxyalkyl, C.sub.1-4 hydroxyhaloalkyl, cyano, NR.sup.aR.sup.b,
SR.sup.cR.sup.d, OR.sup.6, L-(OR.sup.6), and R.sup.7;
[0015] R.sup.a and R.sup.b are independently selected from the
group consisting of hydrogen, and C.sub.1-4 alkyl;
[0016] R.sup.c and R.sup.d are independently selected from the
group consisting of hydrogen, and C.sub.1-4 alkyl;
[0017] R.sup.6 is selected from the group consisting of hydrogen,
halogen, C.sub.1-4 alkyl, C.sub.1-4 haloalkyl, C.sub.1-4
hydroxyalkyl, and C.sub.1-4 hydroxyhaloalkyl;
[0018] L represents C.sub.1-3 alkylene;
[0019] R.sup.7 is selected from the group consisting of C.sub.3-6
cycloalkyl, phenyl, a 4, 5, or 6 membered heterocycle, and a 5 or 6
membered heteroaryl, wherein said cycloalkyl, phenyl, heterocycle
or heteroaryl are independently unsubstituted or substituted with
1, 2 or 3 substituents independently selected from halogen,
C.sub.1-3 alkyl, C.sub.1-3 alkoxy, wherein said C.sub.1-3 alkyl and
C.sub.1-3 alkoxy are independently unsubstituted or substituted
with 1, 2 or 3 F;
[0020] R.sup.5 is selected from the group consisting of C.sub.1-5
alkyl, C.sub.1-4 haloalkyl, hydroxyalkyl, C.sub.1-4
hydroxyhaloalkyl, R.sup.8, WR.sup.8, and W(OR.sup.9);
[0021] W is selected from the group consisting of C.sub.1-3
alkylene and --CH.sub.2C(O)--;
[0022] R.sup.8 is selected from the group consisting of C.sub.3-6
cycloalkyl, phenyl, a 4, 5, or 6 membered heterocycle, and a 5 or 6
membered heteroaryl, wherein said cycloalkyl, phenyl, heterocycle
or heteroaryl are independently unsubstituted or substituted with
1, 2 or 3 substituents independently selected from halogen,
C.sub.1-3 alkyl, C.sub.1-3 alkoxy, wherein said C.sub.1-3 alkyl and
C.sub.1-3 alkoxy are independently unsubstituted or substituted
with 1, 2 or 3 F; and
[0023] R.sup.9 is C.sub.1-3 alkyl unsubstituted or substituted with
1, 2 or 3 F.
[0024] In a further aspect is provided a pharmaceutical composition
comprising a compound of formula I or a pharmaceutically acceptable
salt thereof, and one or more pharmaceutically acceptable carrier
or diluents.
[0025] In a further aspect is provided a method for the treatment
of depression comprising the administration of a therapeutically
effective amount of a compound of formula I, or acceptable salt
thereof, or a pharmaceutical composition to a patient in need
thereof.
[0026] In a further aspect is provided a compound of formula I, or
a pharmaceutically acceptable salt thereof for use as a
medicament.
[0027] In a further aspect is provide a compound of formula I, or a
pharmaceutically acceptable salt thereof, or a pharmaceutical
composition for use in the treatment of depression.
[0028] In a further aspect is provided a use of a compound of
formula I, or a pharmaceutically acceptable salt thereof, or a
pharmaceutical composition comprising a compound of formula I, or a
pharmaceutically acceptable salt thereof for the manufacture of a
medicament for use in the treatment of depression.
[0029] These and other aspects of the invention will become
apparent upon reference to the following detailed description. It
should be understood that the various aspects, embodiments,
implementations and features of the invention mentioned herein may
be claimed separately, or in any combination.
[0030] All references, including publications, patent applications
and patents, cited herein are hereby incorporated by reference in
their entirety and to the same extent as if each reference were
individually and specifically indicated to be incorporated by
reference and were set forth in its entirety.
[0031] Headings and sub-headings are used herein for convenience
only and should not be construed as limiting the invention in any
way.
BRIEF DESCRIPTION OF DRAWINGS
[0032] FIG. 1: Effects of compound 2c in the MEST model.
[0033] Y-axis: Estimated seizure threshold (CC.sub.50) current
(mA); X-axis: bar furthest to the left: vehicle 10% HP.beta.CD; bar
second to the left: 3 mg/kg of compound 2c; bar third to the left:
10 mg/kg of compound 2c; bar furthest to the right: 30 mg/kg of
compound 2c.
[0034] Significance levels for post-hoc comparisons (relative to
the vehicle group) are indicated: *<0.05, **<0.01,
***<0.001.
[0035] FIG. 2: Effects of compound 2c and ketamine in the forced
swim test model.
[0036] Y-axis: Immobility time (s); X-axis: bar furthest to the
left: Vehicle; bar second to the left: ketamine (5 mg/kg); bar in
the middle: compound 2c (3 mg/kg); bar second to the right:
compound 2c (10 mg/kg); bar furthest to the right: compound 2c (30
mg/kg)
[0037] Significance levels for post-hoc comparisons (relative to
the vehicle group) are indicated: *<0.05, **<0.01,
***<0.001.
[0038] FIGS. 3A-3D: Effects of compound 2c and ketamine in Resting
state Electroencephalography (rsEEG).
[0039] Y-axis: Baseline-normalized power (dB); X-axis: Frequency
(Hz);
[0040] FIG. 3A: rsEEG obtained in the prelimbic cortex ML 0.7;
30-40 min after dosing of compound 2c (20 mg/kg in 10% HP.beta.CD);
ketamine (10 mg/kg in saline); or 10% HP.beta.CD.
[0041] +: compound 2c; *: ketamine; O: 10% HP.beta.CD.
[0042] FIG. 3B: rsEEG obtained in the prelimbic cortex ML-0.7;
30-40 min after dosing of compound 2c (20 mg/kg in 10% HP.beta.CD);
ketamine (10 mg/kg in saline); or 10% HP.beta.CD.
[0043] +: compound 2c; *: ketamine; O: 10% HP.beta.CD.
[0044] FIG. 3C: rsEEG obtained in the Thalamus ML-0.7; 30-40 min
after dosing of compound 2c (20 mg/kg in 10% HP.beta.CD); ketamine
(10 mg/kg in saline); or 10% HP.beta.CD.
[0045] +: compound 2c; *: ketamine; O: 10% HP.beta.CD.
[0046] FIG. 3D: rsEEG obtained in the Vertex ML 2.0; 30-40 min
after dosing of compound 2c (20 mg/kg in 10% HP.beta.CD); ketamine
(10 mg/kg in saline); or 10% HP.beta.CD.
[0047] +: compound 2c; *: ketamine; O: 10% HP.beta.CD.
[0048] Significance levels for post-hoc comparisons (relative to
the vehicle group) are indicated: *<0.05, **<0.01,
***<0.001.
[0049] FIG. 4: Micro dialysis studies in rats after systemic
administration of compound 1c.
[0050] X-axis: time (minutes); Y-axis: concentration of tested
compound in the rat ventral hippocampus (.mu.M); O: Compound 1c;
.cndot.: Compound 2c.
DETAILED DESCRIPTION OF THE INVENTION
[0051] The present invention relates to ester prodrugs of the
parent compounds with the Formula V or a pharmaceutically
acceptable salt thereof, wherein:
##STR00002##
[0052] R.sup.1 is selected from the group consisting of a hydrogen,
halogen, C.sub.1-4 haloalkyl, cyano, C.sub.3-6 cycloalkyl, and
C.sub.1-4 alkyl;
[0053] R.sup.2 is selected from the group consisting of hydrogen,
halogen, C.sub.1-4 haloalkyl, cyano, C.sub.3-6 cycloalkyl, and
C.sub.1-4 alkyl;
[0054] R.sup.3 is selected from the group consisting of hydrogen,
halogen, C.sub.1-4 haloalkyl, cyano, C.sub.3-6 cycloalkyl, and
C.sub.1-4 alkyl;
[0055] R.sup.4 is selected from the group consisting of hydrogen,
halogen, C.sub.1-4 alkyl, C.sub.1-4 haloalkyl, C.sub.1-4
hydroxyalkyl, C.sub.1-4 hydroxyhaloalkyl, cyano, NR.sup.aR.sup.b,
SR.sup.cR.sup.d, OR.sup.6, L-(OR.sup.6), and R.sup.7;
[0056] R.sup.a and R.sup.b are independently selected from the
group consisting of hydrogen and C.sub.1-4 alkyl;
[0057] R.sup.c and R.sup.d are independently selected from the
group consisting of hydrogen and C.sub.1-4 alkyl;
[0058] R.sup.6 is selected from the group consisting of hydrogen,
C.sub.1-4 alkyl, C.sub.1-4 haloalkyl, C.sub.1-4 hydroxyalkyl, and
C.sub.1-4 hydroxyhaloalkyl;
[0059] L represents a C.sub.1-3 alkylene; and
[0060] R.sup.7 is selected from the group consisting of C.sub.3-6
cycloalkyl, phenyl, 4, 5, or 6 membered heterocycle, and 5 or 6
membered heteroaryl, wherein said cycloalkyl, phenyl, heterocycle
or heteroaryl are independently unsubstituted or substituted with
1, 2 or 3 substituents independently selected from halogen,
C.sub.1-3 alkyl, C.sub.1-3 alkoxy, wherein said C.sub.1-3 alkyl and
C.sub.1-3 alkoxy are independently unsubstituted or substituted
with 1, 2 or 3 F.
[0061] The inventors observed that dosing of the prodrug of the
invention gave a significant response in the forced swim test and
Maximal Electro Shock Threshold test compared to vehicle.
[0062] The inventors observed that the prodrugs of the invention
have an improved permeability compared to the parent compounds of
the invention as shown in table 3a and 3b.
[0063] The inventors observed that the administration of compound
2c dosed at 20 mg/kg subcutaneously showed significant effects in
resting state Electroencephalography and showing similarities to
that observed with ketamine as shown in FIGS. 3A-3D.
1. Definitions
[0064] As used herein, the terms "C.sub.1-3 alkyl", "C.sub.1-4
alkyl", "C.sub.1-5 alkyl", "C.sub.1-6 alkyl", "C.sub.1-7 alkyl" and
"C.sub.1-8 alkyl" refers to a linear (i.e. unbranched) or branched
saturated hydrocarbon having from one up to eight carbon atoms,
inclusive. Examples of such groups include, but are not limited to
methyl, ethyl, 1-propyl, 2-propyl, 1-butyl, 2-butyl,
2-methyl-2-propyl, 2-methyl-1-butyl, n-hexyl, isopropyl, isobutyl,
isopentyl, n-heptyl and n-octyl.
[0065] As used herein, the term "alkoxy" refers to a moiety of the
formula --OR', wherein R' indicates alkyl as defined above. In
particular "C.sub.1-4 alkoxy" refers to such moiety wherein the
alkyl part has 1, 2, 3 or 4 carbon atoms. Examples of "C.sub.1-4
alkoxy" include methoxy, ethoxy, n-butoxy and tert-butoxy.
[0066] As used herein, the term "alkoxyalkyl," as used herein,
refers to an alkoxy group, as defined herein, appended to the
parent molecular moiety through an alkyl group, as defined herein.
Examples include, but are not limited to, methoxymethyl and
ethoxymethyl.
[0067] As used in the context of the present invention, the terms
"halo" and "halogen" are used interchangeably and refer to an atom
of the group consisting of F, Cl, I and Br.
[0068] As used herein, the term "C.sub.1-6 fluoroalkyl" refers to a
straight chained or branched saturated hydrocarbon having from one
to six carbon atoms inclusive substituted with one or more fluorine
atoms. Examples include, but are not limited to, trifluoromethyl,
pentafluoroethyl, 1-fluoroethyl, 1,2-difluoroethyl and 3,4
difluorohexyl.
[0069] Similarly, the term "C.sub.1-4 fluoroalkyl" refers to a
saturated hydrocarbon of straight chained or branched C.sub.1-4
fluoroalkyl having from one to four carbon atoms inclusive
substituted with one or more fluorine atoms per carbon atom.
[0070] As used herein, the term "cyano", refers to a CN group
appended to the parent molecule through the carbon atom of the CN
group.
[0071] The term "phenyl" is intended to mean a benzene radical,
with one H removed at the attachment point.
[0072] The term "heteroaryl," as used herein, refers to an aromatic
monocyclic ring. The aromatic monocyclic rings are five or six
membered rings containing at least one heteroatom independently
selected from the group consisting of N, O and S (e.g. 1, 2, 3, or
4 heteroatoms independently selected from O, S, and N). The five
membered aromatic monocyclic rings have two double bonds and the
six membered aromatic monocyclic rings have three double bonds.
Representative examples of heteroaryl include, but are not limited
to, indolyl, pyridinyl (including pyridin-2-yl, pyridin-3-yl,
pyridin-4-yl), pyrimidinyl, pyrazinyl, pyridazinyl, pyrazolyl,
pyrrolyl.
[0073] The term "heterocycle" or "heterocyclic," as used herein,
means a monocyclic heterocycle, a bicyclic heterocycle, or a
tricyclic heterocycle. The monocyclic heterocycle is a three-,
four-, five-, six-, seven-, or eight-membered ring containing at
least one heteroatom independently selected from the group
consisting of O, N, and S. The three- or four-membered ring
contains zero or one double bond, and one heteroatom selected from
the group consisting of O, N, and S. The five-membered ring
contains zero or one double bond and one, two or three heteroatoms
selected from the group consisting of O, N and S. The six-membered
ring contains zero, one or two double bonds and one, two, or three
heteroatoms selected from the group consisting of O, N, and S. The
seven- and eight-membered rings contains zero, one, two, or three
double bonds and one, two, or three heteroatoms selected from the
group consisting of O, N, and S. Representative examples of
monocyclic heterocycles include, but are not limited to,
pyrrolidinyl, azetidinyl, azepanyl, aziridinyl, diazepanyl,
1,3-dioxanyl, 1,3-dioxolanyl, 1,3-dithiolanyl, 1,3-dithianyl,
imidazolinyl, imidazolidinyl, isothiazolinyl, isothiazolidinyl,
isoxazolinyl, and isoxazolidinyll.
[0074] The term "cycloalkyl," as used herein, refers to a
carbocyclic ring system containing three to ten carbon atoms, zero
heteroatoms and zero double bonds. The cycloalkyl may be monocyclic
or bicyclic, wherein the two rings are bridged, fused, or
spirocyclic. Representative examples of cycloalkyl include, but are
not limited to, cyclopropyl, cyclobutyl, cyclopentyl,
cyclohexyl.
[0075] For compounds described herein, groups and substituents
thereof may be selected in accordance with permitted valence of the
atoms and the substituents, such that the selections and
substitutions result in a stable compound, e.g., which does not
spontaneously undergo transformation such as by rearrangement,
cyclization, elimination, etc.
[0076] The use of the terms "a" and "an" and "the" and similar
referents in the context of describing the invention are to be
construed to cover both the singular and the plural, unless
otherwise indicated herein or clearly contradicted by context. For
example, the phrase "the compound" is to be understood as referring
to various "compounds" of the invention or particular described
aspect, unless otherwise indicated.
[0077] The description herein of any aspect or aspect of the
invention using terms such as "comprising", "having," "including,"
or "containing" with reference to an element or elements is
intended to provide support for a similar aspect or aspect of the
invention that "consists of", "consists essentially of", or
"substantially comprises" that particular element or elements,
unless otherwise stated or clearly contradicted by context (e.g., a
composition described herein as comprising a particular element
should be understood as also describing a composition consisting of
that element, unless otherwise stated or clearly contradicted by
context).
[0078] In the present context, the term an NMDA receptor partial
glycine agonist is intended to indicate a compound that binds to
and activates the NMDA receptor through the orthosteric glycine
binding site and elicits partial efficacy relative to glycine.
[0079] In the present context, the term "therapeutically effective
amount" of a compound is intended to indicate an amount sufficient
to cure, alleviate or partially arrest the clinical manifestations
of a given disease (e.g. depression) and its complications in a
therapeutic intervention comprising the administration of said
compound. An amount adequate to accomplish this is defined as
"therapeutically effective amount". Effective amounts for each
purpose will depend on the severity of the disease (e.g.
depression) or injury as well as the weight and general state of
the subject. It will be understood that determining an appropriate
dosage may be achieved using routine experimentation, e.g. by
constructing a matrix of values and testing different points in the
matrix, which is all within the ordinary skills of a trained
physician.
[0080] In the present context, the term "treatment" and "treating"
means the management and care of a patient for the purpose of
combating a disease. The term is intended to include the full
spectrum of treatments for a given disease (e.g. depression) from
which the patient is suffering, such as administration of the
active compound to alleviate the symptoms or complications, to
delay the progression of the disease (e.g. depression), to
alleviate or relief the symptoms and complications, and/or to cure
or eliminate the depression disease. The patient to be treated is
preferably a mammal, in particular a human being. In the present
context, "disease" can be used synonymous with disorder, condition,
malfunction, dysfunction and the like.
[0081] In the present context, the terms "prodrug" or "prodrug
derivative" indicates a compound that, after administration to a
living subject, such as a mammal, preferably a human is converted
within the body into a pharmacologically active moiety. The
conversion preferably takes place within a mammal, such as in a
mouse, rat, dog, minipig, rabbit, monkey and/or human.
[0082] In the present context, the terms "parent compound" and
"parent molecule" indicate the pharmacologically active moiety
obtained upon conversion of a corresponding prodrug or administered
as the active moiety to the patient. For example, the "parent
compound" is to be understood as a compound of formula V
exemplified with compound 1a, 1b, 1c, 1d, 1e, 1f, 1g, 1h, 1i, 1j,
1k, 1l, 1m, 1n, 1o, or 1p.
2. Embodiments of the Invention
[0083] In the following, embodiments of the invention are
disclosed. The first embodiment is denoted E1, the second
embodiment is denoted E2 and so forth.
[0084] E1. A compound of Formula I, or a pharmaceutically
acceptable salt thereof, wherein:
##STR00003##
[0085] R.sup.1 is selected from the group consisting of a hydrogen,
halogen, C.sub.1-4 haloalkyl, cyano, C.sub.3-6 cycloalkyl, and
C.sub.1-4 alkyl;
[0086] R.sup.2 is selected from the group consisting of hydrogen,
halogen, C.sub.1-4 haloalkyl, cyano, C.sub.3-6 cycloalkyl, and
C.sub.1-4 alkyl;
[0087] R.sup.3 is selected from the group consisting of hydrogen,
halogen, C.sub.1-4 haloalkyl, cyano, C.sub.3-6 cycloalkyl, and
C.sub.1-4 alkyl;
[0088] R.sup.4 is selected from the group consisting of hydrogen,
halogen, C.sub.1-4 alkyl, C.sub.1-4 haloalkyl, C.sub.1-4
hydroxyalkyl, C.sub.1-4 hydroxyhaloalkyl, cyano, NR.sup.aR.sup.b,
SR.sup.cR.sup.d, OR.sup.6, L-(OR.sup.6), and R.sup.7;
[0089] R.sup.a and R.sup.b are independently selected from the
group consisting of hydrogen, and C.sub.1-4 alkyl;
[0090] R.sup.c and R.sup.d are independently selected from the
group consisting of hydrogen, and C.sub.1-4 alkyl;
[0091] R.sup.6 is selected from the group consisting of hydrogen,
halogen, C.sub.1-4 alkyl, C.sub.1-4 haloalkyl, C.sub.1-4
hydroxyalkyl, and C.sub.1-4 hydroxyhaloalkyl;
[0092] L represents C.sub.1-3 alkylene;
[0093] R.sup.7 is selected from the group consisting of C.sub.3-6
cycloalkyl, phenyl, a 4, 5, or 6 membered heterocycle, and a 5 or 6
membered heteroaryl, wherein said cycloalkyl, phenyl, heterocycle
or heteroaryl are independently unsubstituted or substituted with
1, 2 or 3 substituents independently selected from halogen,
C.sub.1-3 alkyl, C.sub.1-3 alkoxy, wherein said C.sub.1-3 alkyl and
C.sub.1-3 alkoxy are independently unsubstituted or substituted
with 1, 2 or 3 F;
[0094] R.sup.5 is selected from the group consisting of C.sub.1-5
alkyl, C.sub.1-4 haloalkyl, hydroxyalkyl, C.sub.1-4
hydroxyhaloalkyl, R.sup.8, WR.sup.8, and W(OR.sup.9);
[0095] W is selected from the group consisting of C.sub.1-3
alkylene and --CH.sub.2C(O)--;
[0096] R.sup.8 is selected from the group consisting of C.sub.3-6
cycloalkyl, phenyl, a 4, 5, or 6 membered heterocycle, and a 5 or 6
membered heteroaryl, wherein said cycloalkyl, phenyl, heterocycle
or heteroaryl are independently unsubstituted or substituted with
1, 2 or 3 substituents independently selected from halogen,
C.sub.1-3 alkyl, C.sub.1-3 alkoxy, wherein said C.sub.1-3 alkyl and
C.sub.1-3 alkoxy are independently unsubstituted or substituted
with 1, 2 or 3 F; and
[0097] R.sup.9 is C.sub.1-3 alkyl unsubstituted or substituted with
1, 2 or 3 F.
[0098] E2. The compound according to embodiment E1, or a
pharmaceutically acceptable salt thereof, wherein:
[0099] R.sup.1 is selected from the group consisting of a hydrogen,
halogen, and C.sub.1-4 alkyl;
[0100] R.sup.2 is selected from the group consisting of hydrogen,
halogen, and C.sub.1-4 alkyl; R.sup.3 is selected from the group
consisting of hydrogen, halogen, and C.sub.1-4 alkyl;
[0101] R.sup.4 is selected from the group consisting of hydrogen,
halogen, C.sub.1-4 alkyl, C.sub.1-4 haloalkyl, C.sub.1-4
hydroxyalkyl, OR.sup.6, and R.sup.7;
[0102] R.sup.6 is selected from the group consisting of hydrogen,
C.sub.1-4 alkyl, and C.sub.1-4 haloalkyl;
[0103] R.sup.7 is selected from the group consisting of C.sub.3-6
cycloalkyl and phenyl, wherein said cycloalkyl and phenyl is
independently unsubstituted or substituted with 1, 2 or 3
substituents independently selected from halogen, C.sub.1-3 alkyl,
C.sub.1-3 alkoxy, wherein said C.sub.1-3 alkyl and C.sub.1-3 alkoxy
are independently unsubstituted or substituted with 1, 2 or 3
F;
[0104] R.sup.5 is selected from the group consisting of C.sub.1-5
alkyl, R.sup.8, WR.sup.8, and W(OR.sup.9);
[0105] W is C.sub.1-3 alkylene;
[0106] R.sup.8 is selected from the group consisting of C.sub.3-6
cycloalkyl, phenyl, wherein said cycloalkyl and phenyl are
independently unsubstituted or substituted with 1, 2 or 3
substituents independently selected from halogen, C.sub.1-3 alkyl,
C.sub.1-3 alkoxy, wherein said C.sub.1-3 alkyl and C.sub.1-3 alkoxy
are independently unsubstituted or substituted with 1, 2 or 3 F;
and
[0107] R.sup.9 is C.sub.1-3 alkyl unsubstituted or substituted with
1, 2 or 3 F.
[0108] E3. The compound according to any one of embodiments E1 to
E2, or a pharmaceutically acceptable salt thereof, wherein R.sup.1
is hydrogen.
[0109] E4. A compound according to any one of embodiments E1 to E3,
or a pharmaceutically acceptable salt thereof, wherein R.sup.2 is
hydrogen.
[0110] E5. A compound according to any one of embodiments E1 to E4,
or a pharmaceutically acceptable salt thereof, wherein R.sup.3 is
selected from the group consisting of hydrogen, C.sub.1-4 alkyl,
and halogen.
[0111] E6. The compound according to embodiment E5, or a
pharmaceutically acceptable salt thereof, wherein R.sup.3 is
selected from the group consisting of hydrogen, fluoro, and
methyl.
[0112] E7. The compound according to embodiment E6, or a
pharmaceutically acceptable salt thereof, wherein R.sup.3 is
hydrogen.
[0113] E8. The compound according to any of embodiments E1 to E2,
or a pharmaceutically acceptable salt thereof, wherein R.sup.1,
R.sup.2, and R.sup.3 are hydrogen.
[0114] E9. The compound according to any one of embodiments E1 to
E8, or a pharmaceutically acceptable salt thereof, wherein R.sup.4
is C.sub.1-4 alkyl.
[0115] E10. The compound according to any one of embodiments E1 to
E9, or a pharmaceutically acceptable salt thereof, wherein R.sup.4
is methyl.
[0116] E11. The compound according to any one of embodiments E1 to
E8, or a pharmaceutically acceptable salt thereof, wherein R.sup.4
is C.sub.1-4 fluoroalkyl.
[0117] E12. The compound according to any one of embodiments E1 to
E8, or a pharmaceutically acceptable salt thereof, wherein R.sup.4
is halogen.
[0118] E13. The compound according to any one of embodiments E1 to
E8, or a pharmaceutically acceptable salt thereof, wherein R.sup.4
is phenyl unsubstituted or substituted with C.sub.1-3 alkyl.
[0119] E14. The compound according to any one of embodiments E1 to
E8, or a pharmaceutically acceptable salt thereof, wherein R.sup.4
is C.sub.1-4 alkoxy.
[0120] E15. The compound according to any one of embodiments E1 to
E7, or a pharmaceutically acceptable salt thereof, wherein R.sup.4
is selected from the group consisting of C.sub.1-4 alkyl, C.sub.1-4
fluoroalkyl, NR.sup.aR.sup.b, SR.sup.cR.sup.d, C.sub.1-4
hydroxyalkyl C.sub.1-4 alkoxy, halogen, and phenyl unsubstituted or
substituted with ethyl.
[0121] E16. The compound according to embodiment E15, or a
pharmaceutically acceptable salt thereof, wherein R.sup.4 is
selected from the group consisting of methyl, ethyl, isopropyl,
cyclopropyl, fluoromethyl, difluoromethyl, trifluoromethyl,
hydroxymethyl, isopropoxy, ethoxy, methoxy, bromo, fluoro,
dimethylamino, methylthio, and ethylphenyl.
[0122] E17. A compound according to claim 1, having the formula Ia,
or a pharmaceutically acceptable salt thereof, wherein:
##STR00004##
[0123] E18. The compound according to any one of embodiments E1 to
E17, or a pharmaceutically acceptable salt thereof, wherein R.sup.5
is selected from the group consisting of methyl, ethyl, propyl,
isopropyl, cyclopropyl, butyl, isobutyl, --CH.sub.2-cyclopropyl,
2-methoxyethyl, isopentyl, benzyl, cyclohexyl,
2-oxo-2-(pyrrolidin-1-yl)ethyl and phenyl.
[0124] E19. The compound according to any one of embodiments E1 to
E18, or a pharmaceutically acceptable salt thereof, wherein R.sup.5
is a C.sub.1-5 alkyl.
[0125] E20. The compound according to any one of embodiments E1 to
E19, or a pharmaceutically acceptable salt thereof, wherein R.sup.5
is selected from the group consisting of methyl, ethyl, propyl,
butyl and isopropyl.
[0126] E21. The compound according to any one of embodiments E1 to
E20, or a pharmaceutically acceptable salt thereof, wherein R.sup.5
is selected from the group consisting of methyl, ethyl, propyl, and
butyl.
[0127] E22. The compound according to any one of embodiments E1 to
E21, or a pharmaceutically acceptable salt thereof, wherein R.sup.5
is selected from the group consisting of methyl and ethyl.
[0128] E23. The compound according to any one of embodiments E1 to
E22, or a pharmaceutically acceptable salt thereof, wherein R.sup.5
is methyl.
[0129] E24. The compound according to any one of embodiments E1 to
E22, or a pharmaceutically acceptable salt thereof, wherein R.sup.5
is ethyl.
[0130] E25. The compound according to any one of embodiments E1 to
E24 selected from the group consisting of: [0131] methyl
(R)-2-amino-3-(7-(difluoromethyl)thieno[3,2-b]pyridine-2-carboxamido)prop-
anoate; [0132] methyl
(R)-2-amino-3-(7-cyclopropylthieno[3,2-b]pyridine-2-carboxamido)propanoat-
e; [0133] methyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate;
[0134] ethyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate;
[0135] propyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate;
[0136] isopropyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate;
[0137] cyclopropyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate;
[0138] butyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate;
[0139] isobutyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate;
[0140] cyclopropylmethyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate;
[0141] 2-Methoxyethyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate;
[0142] isopentyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate;
[0143] benzyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate;
[0144] cyclohexyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate;
[0145] phenyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate;
[0146] (2-oxo-2-pyrrolidin-1-yl-ethyl)
(R)-2-amino-3-[(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate;
[0147] methyl
(R)-2-amino-3-(7-(2-ethylphenyl)thieno[3,2-b]pyridine-2-carboxamido)propa-
noate; [0148] methyl
(R)-2-amino-3-(7-methoxythieno[3,2-b]pyridine-2-carboxamido)propanoate;
[0149] methyl
(R)-2-amino-3-(7-(trifluoromethyl)thieno[3,2-b]pyridine-2-carboxamido)pro-
panoate; [0150] methyl
(R)-2-amino-3-(7-isopropoxythieno[3,2-b]pyridine-2-carboxamido)propanoate-
; [0151] methyl
(R)-2-amino-3-(7-bromothieno[3,2-b]pyridine-2-carboxamido)propanoate;
[0152] methyl
(R)-2-amino-3-(7-(hydroxymethyl)thieno[3,2-b]pyridine-2-carboxamido)propa-
noate; [0153] methyl
(R)-2-amino-3-(7-(fluoromethyl)thieno[3,2-b]pyridine-2-carboxamido)propan-
oate; [0154] methyl
(R)-2-amino-3-(6-fluoro-7-methyl-thieno[3,2-b]pyridine-2-carboxamido)prop-
anoate; and [0155] methyl
(R)-2-amino-3-(6,7-dimethylthieno[3,2-b]pyridine-2-carboxamido)propanoate-
; or a pharmaceutically acceptable salt thereof.
[0156] E26. The compound according to embodiment E1 selected from
the group consisting of: [0157] methyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate;
[0158] ethyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate;
[0159] propyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate;
[0160] isopropyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate;
[0161] cyclopropyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate;
[0162] butyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate;
[0163] isobutyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate;
[0164] cyclopropylmethyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate;
[0165] 2-Methoxyethyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate;
[0166] isopentyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate;
[0167] benzyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate;
[0168] cyclohexyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate;
and [0169] phenyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate;
or a pharmaceutically acceptable salt thereof.
[0170] E27. The compound according to embodiment E1 selected from
the group consisting of: [0171] methyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate;
[0172] ethyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate;
[0173] propyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate;
and [0174] isobutyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate;
or a pharmaceutically acceptable salt thereof.
[0175] E28. A pharmaceutical composition comprising a compound, or
a pharmaceutically acceptable salt thereof, according to any one of
embodiments E1 to E27, and one or more pharmaceutically acceptable
carriers or diluents.
[0176] E29. A compound or a pharmaceutically acceptable salt
thereof according to any one of embodiments E1 to E27 for use as a
medicament.
[0177] E30. A compound, or a pharmaceutically acceptable salt
thereof, or a pharmaceutical composition according to any one of
embodiments E1 to E28 for use in the treatment of depression.
[0178] E31. The compound or a pharmaceutical composition according
to embodiment E30, wherein the depression is selected of major
depressive disorder, treatment-resistant depression, catatonic
depression, melancholic depression, atypical depression, psychotic
depression, perinatal depression, postpartum depression, bipolar
depression, including bipolar I depression and bipolar II
depression, and mild, moderate or severe depression.
[0179] E32. A compound, or a pharmaceutically acceptable salt
thereof, or a pharmaceutical composition according to any one of
embodiments E1 to E28 for use in the treatment of a condition
selected from suicidal ideation, bipolar disorder (including
bipolar depression), obsessive compulsive disorder and status
epilepticus.
[0180] E33. A method for the treatment of depression comprising the
administration of a therapeutically effective amount of a compound
or a pharmaceutically acceptable salt thereof, or a pharmaceutical
composition according to any one of embodiments E1 to E28 to a
patient (e.g. a human patient) in need thereof.
[0181] E34. The method for the treatment of depression according to
embodiment E33, wherein depression is selected from major
depressive disorder, treatment-resistant depression, catatonic
depression, melancholic depression, atypical depression, psychotic
depression, perinatal depression, postpartum depression, bipolar
depression, including bipolar I depression and bipolar II
depression, and mild, moderate or severe depression.
[0182] E35. Use of a compound or a pharmaceutically acceptable salt
thereof, or a pharmaceutical composition according to any one of
embodiments E1 to E28 for the manufacture of a medicament for use
in the treatment of depression.
[0183] E36. The use of a compound or pharmaceutical composition
according to embodiment E35, wherein the depression is selected
from the group consisting of major depressive disorder,
treatment-resistant depression, catatonic depression, melancholic
depression, atypical depression, psychotic depression, perinatal
depression, postpartum depression, bipolar depression, including
bipolar I depression and bipolar II depression, and mild, moderate
or severe depression.
[0184] Reference to compounds encompassed by the invention includes
the free substance of compounds of the invention, pharmaceutically
acceptable salts of compounds of the invention, such as acid
addition salts or base addition salts, and polymorphic and amorphic
forms of compounds of the invention and of pharmaceutically
acceptable salts thereof. Furthermore, the compounds of the
invention and pharmaceutically acceptable salts thereof may
potentially exist in unsolvated as well as in solvated forms with
pharmaceutically acceptable solvents such as water, ethanol and the
like. Both solvated and unsolvated forms are encompassed by the
present invention.
[0185] Compound names can be assigned by using the Struct=Name
naming algorithm as part of CHEMDRAW.RTM..
[0186] It should be understood that the compounds of the invention
may possess tautomeric forms, stereoisomers, geometric isomers, and
that these also constitute embodiments of the invention.
[0187] Racemic forms may be resolved into the optical antipodes by
known methods, for example, by separation of diastereomeric salts
thereof with an optically active acid, and liberating the optically
active amine compound by treatment with a base. Separation of such
diastereomeric salts can be achieved, e.g. by fractional
crystallization. The optically active acids suitable for this
purpose may include, but are not limited to d- or l-tartaric,
mandelic or camphorsulfonic acids. Another method for resolving
racemates into the optical antipodes is based upon chromatography
on an optically active matrix. The compounds of the present
invention may also be resolved by the formation and chromatographic
separation of diastereomeric derivatives from chiral derivatizing
reagents, such as, chiral alkylating or acylating reagents,
followed by cleavage of the chiral auxiliary. Any of the above
methods may be applied either to resolve the optical antipodes of
the compounds of the invention per se or to resolve the optical
antipodes of synthetic intermediates, which can then be converted
by methods described herein into the optically resolved final
products which are the compounds of the invention. Additional
methods for the resolution of optical isomers, known to those
skilled in the art, may be used. Such methods include those
discussed by J. Jaques, A. Collet and S. Wilen in Enantiomers,
Racemates, and Resolutions, John Wiley and Sons, New York, 1981.
Optically active compounds can also be prepared from optically
active starting materials.
[0188] Included in this invention are also isotopically labelled
compounds, which are similar to those claimed in formula I, wherein
one or more atoms are represented by an atom of the same element
having an atomic mass or mass number different from the atomic mass
or mass number usually found in nature (e.g., .sup.2H, .sup.3H,
.sup.11C, .sup.13C, .sup.15N, .sup.18F and the like). Particular
mention is made of .sup.2H substituted compounds i.e. compounds
wherein one or more H atoms are represented by deuterium.
[0189] In one embodiment of the invention one or more of the
hydrogen atoms of the compound of formula I are represented by
deuterium. It is recognized that elements are present in natural
isotopic abundances in most synthetic compounds, and result in
inherent incorporation of deuterium. However, the natural isotopic
abundance of hydrogen isotopes such as deuterium is immaterial
(about 0.015%) relative to the degree of stable isotopic
substitution of com-pounds indicated herein. Thus, as used herein,
designation of an atom as deuterium at a position indicates that
the abundance of deuterium is significantly greater than the
natural abundance of deuterium. Any atom not designated as a
particular isotope is intended to represent any stable isotope of
that atom, as will be apparent to the ordinarily skilled
artisan.
[0190] In one embodiment, designation of a position as "D" in a
compound has a minimum deuterium incorporation of greater than
about 60% at that position such as greater than about 70% at that
position such as greater than about 80% at that position such as
greater than about 85% at that position. In a further embodiment,
designation of a position as "D" in a compound has a minimum
deuterium incorporation of greater than about 90% at that position
such as greater than about 95% at that position such as greater
than about 97% at that position such as greater than about 99% at
that position.
[0191] a. Pharmaceutically Acceptable Salts
[0192] The compounds of this invention (parent compounds and their
respective prodrugs) are generally utilized as the free substance
or as a pharmaceutically acceptable salt thereof. When a compound
of the invention contains a free base such salts may be prepared in
a conventional manner by treating a solution or suspension of a
free base of a compound of the invention with a molar equivalent of
a pharmaceutically acceptable acid. Representative examples of
suitable organic and inorganic acids are described below.
[0193] Pharmaceutically acceptable salts in the present context is
intended to indicate non-toxic, i.e. physiologically acceptable
salts.
[0194] The term "pharmaceutically acceptable salts" include salts
formed with inorganic and/or organic acids on the nitrogen atoms in
the parent molecule. Said acids may be selected from for example
hydrochloric acid, hydrobromic acid, phosphoric acid, nitrous acid,
sulphuric acid, benzoic acid, citric acid, gluconic acid, lactic
acid, maleic acid, succinic acid, tartaric acid, acetic acid,
propionic acid, oxalic acid, maleic acid, fumaric acid, glutamic
acid, pyroglutamic acid, salicylic acid, saccharin, and sulfonic
acids such as methanesulfonic acid, ethanesulfonic acid,
toluenesulfonic acid and benzenesulfonic acid.
[0195] In an embodiment of the invention, the pharmaceutically
acceptable salt is a hydrogen chloride salt.
[0196] In an embodiment of the invention, the pharmaceutically
acceptable salt is a hydrogen bromide salt.
[0197] The term pharmaceutically acceptable salts also include
salts formed with inorganic and/or organic bases on the acidic
groups of compounds of the invention. Said bases may be selected
from for example alkali metal bases, such as sodium hydroxide,
lithium hydroxide, potassium hydroxide, alkaline earth bases, such
as calcium hydroxide and magnesium hydroxide, and organic bases,
such as trimethylamine.
[0198] Additional examples of useful acids and bases to form
pharmaceutically acceptable salts can be found e.g. in Stahl and
Wermuth (Eds) "Handbook of Pharmaceutical salts. Properties,
selection, and use", Wiley-VCH, 2008.
3. Conditions for Treatment
[0199] The invention encompasses use of the compounds of the
invention for treatment of all diseases and disorders listed
above.
[0200] As described above the present invention may be useful in
the treatment of depression and depressive disorders. Hence in one
embodiment, a compound of the invention is used for the treatment
of depression.
[0201] The diagnosis of depression usually follows a clinical
evaluation by a psychiatrist or other mental health professionals.
The two most recognized sets of diagnostic criteria for major
depressive disorder and other depressive, or mood disorders, are
outlined in the DSM, Diagnostic and Statistical Manual of Mental
Disorders, Fourth Edition, (DSM IV) published by the American
psychiatric association and the ICD (ICD-10: International
Statistical Classification of Diseases and Related Health
Problems--10th Revision, published periodically by the World Health
Organization) or any other psychiatric classification system.
[0202] Signs and symptoms of depression are for example depressed
mood, loss of interest (anhedonia), weight or appetite changes,
sleep problems, psychomotor activity (objective or subjective),
fatigability, worthlessness, concentration difficulty, suicidal
ideation, loss of confidence, sexual dysfunction and
self-reproach.
[0203] Thus in an embodiment of the invention, treatment with
compounds of the invention prevent, alter, reduce or alleviate one
or more signs or symptoms of depression selected from the group
consisting of depressed mood, loss of interest (anhedonia), weight
or appetite changes, sleep problems, psychomotor activity
(objective or subjective), fatigability, worthlessness,
concentration difficulty, suicidal ideation, loss of confidence,
sexual dysfunction and self-reproach.
[0204] The skilled person is familiar with various test for
measuring the improvement of depressive symptoms. Examples of test
for measuring the improvements are but not limited to the HAM-D or
MADRS scale.
[0205] In an embodiment the depression is major depressive
disorder
[0206] In a further embodiment the depression is
treatment-resistant depression.
[0207] In a further embodiment the depression is selected from
major depressive disorder, treatment-resistant depression,
catatonic depression, melancholic depression, atypical depression,
psychotic depression, perinatal depression, postpartum depression,
bipolar depression, including bipolar I depression and bipolar II
depression, and mild, moderate or severe depression.
[0208] In an embodiment of the invention, compound of the invention
is used in the treatment of pain [Expert Rev Clin Pharmacol. 2011
May 1; 4(3): 379-388].
[0209] In a further embodiment the pain is neuropathic pain.
[0210] Preclinical animal models has demonstrated pro-cognitive and
antidepressant-like effects with the use of NDMA glycine site
modulators[Peyrovian et al., Progress in Neuropsychopharmacology
& Biological Psychiatry. 92 (2019) 387-404].
[0211] Hence, in an embodiment of the invention, a compound of
formula I or a pharmaceutically acceptable salt thereof is used in
the treatment of a condition selected from suicidal ideation,
bipolar disorder (including bipolar depression), obsessive
compulsive disorder and status epilepticus
[0212] In a further embodiment, the condition is suicidal
ideation.
[0213] In an embodiment of the invention, compound of the invention
is used the treatment of a neurological disorder or
neuropsychiatric disorder.
[0214] a. Combination Treatment
[0215] In one embodiment of the invention, the compounds of the
invention are for use as stand-alone treatment as the sole active
compound. In another embodiment of the invention, the compounds of
the invention may be used in combination with other agents useful
in the treatment of disorders such as depression. The terms
"combined use", "in combination with" and "a combination of" and
the like as used herein in the context of the method of the
invention comprising the combined administration of therapeutically
effective amounts of a compound of the invention, and another
compound, which compound is useful in the treatment a
neurodegenerative disease or disorder, is intended to mean the
administration of a compound of the invention simultaneously or
sequentially, in any order, together with said other compound.
[0216] The two compounds may be administered simultaneously or
sequentially with a time gap between the administrations of the two
compounds. The two compounds may be administered either as part of
the same pharmaceutical formulation or composition, or in separate
pharmaceutical formulations or compositions. The two compounds may
be administered on the same day or on different days. They may be
administered by the same route, such for example by oral
administration, by depot, by intramuscular injection or intravenous
injection; or by different routes wherein one compound is for
example administered orally or placed by depot and the other
compound is for example injected. The two compounds may be
administered by the same dosage regime or interval, such as once or
twice daily, weekly, or monthly; or by different dosage regimes for
example wherein one is administered once daily and the other is
administered twice daily or weekly or monthly.
[0217] In some instances, the patient to be treated may already be
in treatment with one or more other compounds useful in the
treatment of depression when treatment with a compound of the
invention initiated. In other instances, the patient may already be
in treatment with a compound of the invention when treatment with
one or more other compounds useful in the treatment of a depression
or psychosis is initiated. In other instances, the treatment with a
compound of the invention and treatment with one or more other
compounds useful in the treatment of psychosis initiated at the
same time.
[0218] b. Compounds for Combination Treatment
[0219] Examples of therapeutically active compounds which may
advantageously be combined with compounds of the invention include
sedatives or hypnotics, such as benzodiazepines; anticonvulsants,
such as lamotrigine, valproic acid, topiramate, gabapentin,
carbamazepine; mood stabilizers such as lithium; dopaminergic
drugs, such as dopamine agonists and L-Dopa; drugs to treat ADHD,
such as atomoxetine; psychostimulants, such as modafinil, ketamine,
methylphenidate and amphetamine; other antidepressants, such as
mirtazapine, mianserin, vortioxetine, cipralex, and buproprion;
hormones, such as T3, estrogen, DHEA and testosterone; atypical
antipsychotics, such as olanzapine, brexpiprazole and aripiprazole;
typical antipsychotics, such as haloperidol; drugs to treat
Alzheimer's diseases, such as cholinesterase inhibitors and
memantine, folate; S-Adenosyl-Methionine; immunmodulators, such as
interferons; opiates, such as buprenorphine; angiotensin II
receptor 1 antagonists (AT1 antagonists); ACE inhibitors; statins;
and alpha1 adrenergic antagonist, such as prazosin.
[0220] c. Administration Routes
[0221] The pharmaceutical compositions comprising a compound of the
invention, either as the sole active compound or in combination
with another active compound, may be specifically formulated for
administration by any suitable route such as the oral, rectal,
nasal, buccal, sublingual, pulmonal, transdermal and parenteral
(e.g. subcutaneous, intramuscular, and intravenous) route.
[0222] It will be appreciated that the route will depend on the
general condition and age of the subject to be treated, the nature
of the condition to be treated and the active ingredient.
[0223] d. Doses
[0224] In one embodiment, the compound of the present invention is
administered in an amount from about 0.5 mg/kg body weight to about
50 mg/kg body weight per day. In particular, daily dosages may be
in the range of 1 mg/kg body weight to about 30 mg/kg body weight
per day. The exact dosages will depend upon the frequency and mode
of administration, the sex, the age, the weight, and the general
condition of the subject to be treated, the nature and the severity
of the condition to be treated, any concomitant diseases to be
treated, the desired effect of the treatment and other factors
known to those skilled in the art.
[0225] In an embodiment the frequency of administration is 1, 2, 3,
4, or 5 times per day
[0226] In an embodiment the frequency of administration is once
weekly.
[0227] In an embodiment the frequency of administration is twice
weekly.
[0228] A typical oral dosage for adults will be in the range of
500-3000 mg/day of a compound of the present invention, such as
700-2800 mg/day, such as 1000-2000 mg/day or 1200-1700 mg/day.
Conveniently, the compounds of the invention are administered in a
unit dosage form containing said compounds in an amount of about
100 to 1000 mg, such as 100 mg, 150 mg, 200 mg, 250 mg, 300 mg, 350
mg, 400 mg, 450 mg, 500 mg, 750 mg or up to 1000 mg of a compound
of the present invention.
[0229] In an embodiment the frequency of administration is 1, 2, 3,
4, or 5 times per day.
[0230] In one embodiment the frequency of administration is once
weekly.
[0231] In an embodiment the frequency of administration is twice
weekly.
[0232] A typical IV dosage for adults will be in the range of
20-300 mg/day of a compound of the present invention, such as
50-200 mg/day, such as 70-150 mg/day or 75-125 mg/day.
Conveniently, the compounds of the invention are administered in a
unit dosage form containing said compounds in an amount of about 10
to 300 mg, such as 10 mg, 20 mg, 50 mg, 100 mg, 150 mg, 200 mg, 250
mg, 300 mg of a compound of the present invention.
[0233] In an embodiment the frequency of administration is once
weekly.
[0234] In an embodiment the frequency of administration is twice
weekly.
4. Pharmaceutical Formulations and Excipients
[0235] In the following, the term, "excipient" or "pharmaceutically
acceptable excipient" refers to pharmaceutical excipients
including, but not limited to, fillers, antiadherents, binders,
coatings, colours, disintegrants, flavours, glidants, lubricants,
preservatives, sorbents, sweeteners, solvents, vehicles and
adjuvants.
[0236] The present invention also provides a pharmaceutical
composition comprising a compound of the invention, such as one of
the compounds disclosed in the Experimental Section herein.
[0237] The present invention also provides a process for making a
pharmaceutical composition comprising a compound of the invention.
The pharmaceutical compositions according to the invention may be
formulated with pharmaceutically acceptable excipients in
accordance with conventional techniques such as those disclosed in
Remington, "The Science and Practice of Pharmacy", 22.sup.th
edition (2013), Edited by Allen, Loyd V., Jr.
[0238] Pharmaceutical compositions for oral administration include
solid oral dosage forms such as tablets, capsules, powders and
granules; and liquid oral dosage forms such as solutions,
emulsions, suspensions and syrups as well as powders and granules
to be dissolved or suspended in an appropriate liquid.
[0239] Solid oral dosage forms may be presented as discrete units
(e.g. tablets or hard or soft capsules), each containing a
predetermined amount of the active ingredient, and preferably one
or more suitable excipients. Where appropriate, the solid dosage
forms may be prepared with coatings such as enteric coatings or
they may be formulated so as to provide modified release of the
active ingredient such as delayed or extended release according to
methods well known in the art. Where appropriate, the solid dosage
form may be a dosage form disintegrating in the saliva, such as for
example an oral-dispersible tablet.
[0240] Examples of excipients suitable for solid oral formulation
include, but are not limited to, microcrystalline cellulose, corn
starch, lactose, mannitol, povidone, croscarmellose sodium,
sucrose, cyclodextrin, talcum, gelatin, pectin, magnesium stearate,
stearic acid and lower alkyl ethers of cellulose. Similarly, the
solid formulation may include excipients for delayed or extended
release formulations known in the art, such as glyceryl
monostearate or hypromellose. If solid material is used for oral
administration, the formulation may for example be prepared by
mixing the active ingredient with solid excipients and subsequently
compressing the mixture in a conventional tableting machine; or the
formulation may for example be placed in a hard capsule e.g. in
powder, pellet or mini tablet form. The amount of solid excipient
will vary widely but will typically range from about 25 mg to about
1 g per dosage unit.
[0241] Liquid oral dosage forms may be presented as for example
elixirs, syrups, oral drops or a liquid filled capsule. Liquid oral
dosage forms may also be presented as powders for a solution or
suspension in an aqueous or non-aqueous liquid. Examples of
excipients suitable for liquid oral formulation include, but are
not limited to, ethanol, propylene glycol, glycerol,
polyethylenglycols, poloxamers, sorbitol, poly-sorbate, mono and
di-glycerides, cyclodextrins, coconut oil, palm oil, and water.
Liquid oral dosage forms may for example be prepared by dissolving
or suspending the active ingredient in an aqueous or non-aqueous
liquid, or by incorporating the active ingredient into an
oil-in-water or water-in-oil liquid emulsion.
[0242] Further excipients may be used in solid and liquid oral
formulations, such as colourings, flavourings and preservatives
etc.
[0243] Pharmaceutical compositions for parenteral administration
include sterile aqueous and nonaqueous solutions, dispersions,
suspensions or emulsions for injection or infusion, concentrates
for injection or infusion as well as sterile powders to be
reconstituted in sterile solutions or dispersions for injection or
infusion prior to use. Examples of excipients suitable for
parenteral formulation include, but are not limited to water,
coconut oil, palm oil and solutions of cyclodextrins. Aqueous
formulations should be suitably buffered if necessary and rendered
isotonic with sufficient saline or glucose.
[0244] Other types of pharmaceutical compositions include
suppositories, inhalants, creams, gels, dermal patches, implants
and formulations for buccal or sublingual administration.
[0245] It is requisite that the excipients used for any
pharmaceutical formulation comply with the intended route of
administration and are compatible with the active ingredients.
5. Compounds of the Invention
TABLE-US-00001 [0246] TABLE 1 Exemplified parent compounds of the
invention Example Name structure Compound 1a (R)-2-amino-3-(7-
(difluoromethyl)thieno[3,2- b]pyridine-2- carboxamido)propanoic
acid ##STR00005## Compound 1b (R)-2-amino-3-(7-
cyclopropylthieno[3,2-b] pyridine-2-carboxamido) propanoic acid
##STR00006## Compound 1c (R)-2-amino-3-(7- methylthieno[3,2-
b]pyridine-2- carboxamido)propanoic acid ##STR00007## Compound 1d
(R)-2-amino-3-(7-(2- ethylphenyl)thieno[3,2- b]pyridine-2-
carboxamido)propanoic acid ##STR00008## Compound 1e
(R)-2-amino-3-(7- methoxythieno[3,2- b]pyridine-2-
carboxamido)propanoic acid ##STR00009## Compound 1f
(R)-2-amino-3-(7- (trifluoromethyl)thieno [3,2-b]pyridine-2-
carboxamido)propanoic acid ##STR00010## Compound 1g
(R)-2-amino-3-(7- isopropoxythieno[3,2- b]pyridine-2-carboxamido)
propanoic acid ##STR00011## Compound 1h (R)-2-amino-3-[(7-
bromothieno[3,2- b]pyridine-2-carboxamido) propanoic acid
##STR00012## Compound 1i (R)-2-amino-3-[(7-
hydroxymethylthieno[3,2- b]pyridine-2-carboxamido) propanoic acid
##STR00013## Compound 1j (R)-2-amino-3-[[7-
(fluoromethyl)thieno[3,2- b]pyridine-2-carboxamido] propanoic acid
##STR00014## Compound 1k (R)-2-amino-3-[(6-fluoro-7-
methyl-thieno[3,2- b]pyridine-2-carboxamido) propanoic acid
##STR00015## Compound 1l (R)-2-amino-3-[(6,7- dimethylthieno[3,2-
b]pyridine-2-carboxamido) propanoic acid ##STR00016##
TABLE-US-00002 TABLE 2 Exemplified prodrugs of the invention
Example Name Structure Compound 2a Methyl (R)-2-amino-3-(7-
(difluoromethyl)thieno[3,2- b]pyridine-2- carboxamido)propanoate
##STR00017## Compound 2b Methyl (R)-2-amino-3-(7-
cyclopropylthieno[3,2- b]pyridine-2-carboxamido) propanoate
##STR00018## Compound 2c Methyl (R)-2-amino-3-(7-
methylthieno[3,2-b]pyridine-2- carboxamido)propanoate ##STR00019##
Compound 2d Ethyl (R)-2-amino-3-(7- methylthieno[3,2-b]pyridine-2-
carboxamido)propanoate ##STR00020## Compound 2e Propyl
(R)-2-amino-3-(7- methylthieno[3,2-b]pyridine-2-
carboxamido)propanoate ##STR00021## Compound 2f Isopropyl
(R)-2-amino-3-(7- methylthieno[3,2-b]pyridine-2-
carboxamido)propanoate ##STR00022## Compound 2g Cyclopropyl
(R)-2-amino-3-(7- methylthieno[3,2-b]pyridine-2-
carboxamido)propanoate ##STR00023## Compound 2h Butyl
(R)-2-amino-3-(7- methylthieno[3,2-b]pyridine-2-
carboxamido)propanoate ##STR00024## Compound 2i Isobutyl
(R)-2-amino-3-(7- methylthieno[3,2-b]pyridine-2-
carboxamido)propanoate ##STR00025## Compound 2j Cyclopropylmethyl
(R)-2- amino-3-(7-methylthieno[3,2- b]pyridine-2-
carboxamido)propanoate ##STR00026## Compound 2k 2-Methoxyethyl
(R)-2-amino-3- (7-methylthieno[3,2-b] pyridine-2-carboxamido)
propanoate ##STR00027## Compound 2l Isopentyl (R)-2-amino-3-(7-
methylthieno[3,2-b]pyridine-2- carboxamido)propanoate ##STR00028##
Compound 2m Benzyl (R)-2-amino-3-(7- methylthieno[3,2-b]pyridine-2-
carboxamido)propanoate ##STR00029## Compound 2n Cyclohexyl
(R)-2-amino-3-(7- methylthieno[3,2-b]pyridine-2-
carboxamido)propanoate ##STR00030## Compound 2o Phenyl
(R)-2-amino-3-(7- methylthieno[3,2-b]pyridine-2-
carboxamido)propanoate ##STR00031## Compound 2p
2-Oxo-2-(pyrrolidin-1-yl)ethyl (R)-2-amino-3-(7-
methylthieno[3,2-b]pyridine-2- carboxamido)propanoate ##STR00032##
Compound 2q Methyl (R)-2-amino-3-(7-(2- ethylphenyl)thieno[3,2-
b]pyridine-2- carboxamido)propanoate ##STR00033## Compound 2r
Methyl (R)-2-amino-3-(7- methoxytheino[3,2-b]
pyridine-2-carboxamido) propanoate ##STR00034## Compound 2s Methyl
(R)-2-amino-3-(7- (trifluoromethyl)thieno[3,2- b]pyridine-2-
carboxamido)propanoate ##STR00035## Compound 2t Methyl
(R)-2-amino-3-(7- isopropoxythieno[3,2- b]pyridine-2-
carboxamido)propanoate ##STR00036## Compound 2u Methyl
(R)-2-amino-3-(7- bromothieno[3,2-b]pyridine-2-
carboxamido)propanoate ##STR00037## Compound 2v Methyl
(R)-2-amino-3-(7- (hydroxymethyl)thieno[3,2-
b]pyridine-2-carboxamido) propanoate ##STR00038## Compound 2w
Methyl (R)-2-amino-3-(7- (fluoromethyl)thieno[3,2- b]pyridine-2-
carboxamido)propanoate ##STR00039## Compound 2x Methyl
(R)-2-amino-3-(6- fluoro-7-methyl-thieno[3,2- b]pyridine-2-
carboxamido)propanoate ##STR00040## Compound 2y Methyl
(R)-2-amino-3-(6,7- dimethylthieno[3,2-b]pyridine-
2-carboxamido)propanoate ##STR00041##
6. Experimental Section
[0247] a. Preparation of the compounds of the invention
[0248] The compounds of the present invention of the general
formula I, wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5
are as defined above can be prepared by the methods outlined in the
following reaction Schemes 1-18 and in the examples. In the
described methods, it is possible to make use of variants or
modifications, which are themselves known to chemists skilled in
the art or could be apparent to the person of ordinary skill in
this art. Furthermore, other methods for preparing compounds of the
invention will be readily apparent to the person skilled in the art
in light of the following reaction schemes and examples.
[0249] The schemes may involve the use of selective protecting
groups during the synthesis of the compounds of the invention. One
skilled in the art would be able to select the appropriate
protecting group for a particular reaction. It may be necessary to
incorporate protection and de-protection strategies for
substituents such as amino, amido, carboxylic acid and hydroxyl
groups in the synthetic methods described below to synthesize the
compounds of Formula I. Methods for protection and de-protection of
such groups are well known in the art, and may be found in T.
Green, et al., Protective Groups in Organic Synthesis, 1991, 2nd
Edition, John Wiley & Sons, New York.
[0250] The schemes in this section are representative of methods
useful in synthesizing the compounds of the present invention. They
are not intended to constrain the scope of the invention in any
way.
##STR00042##
[0251] Compounds of general formula I (Scheme 1) may be prepared
from compounds with general formula IV by standard de-protection
procedures. As an example, compounds of general formula I (Scheme
1) may be prepared from compounds with general formula IV where
Pg.sup.1 is a N-Carbobenzyloxy group (Cbz) and R.sup.5 is defined
as in general formula I.
[0252] Compounds with general formula IV may be prepared by
compounds of general formula III with carboxylic acids (or salt
thereof) of general formula II by standard peptide coupling such as
using O-(Benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium
tetrafluoroborate in the presence of a base such as
N,N-diisopropylethylamine in a solvent such as
N,N-dimethylformamide.
##STR00043##
[0253] Compounds of general formula I (Scheme 2) may be prepared
from compounds with general formula V by standard esterification
procedures. As an example, compounds of general formula I (Scheme
2) may be prepared from compounds with general formula V by
treatment with a reagent such as thionyl chloride in methanol
(R.sup.5=Me). Compounds of general formula V may be prepared from
compounds with general formula IV by standard de-protection
procedures. As an example, compounds of general formula V (Scheme
2) may be prepared from compounds with general formula IV where
Pg.sup.1 is Cbz and Pg.sup.2 is benzyl using conditions such as HBr
in acetic acid.
[0254] Compounds with general formula IV may be prepared by
compounds of general formula III with carboxylic acids (or salt
thereof) of general formula II by standard peptide coupling such as
using O-(Benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium
tetrafluoroborate in the presence of a base such as
N,N-diisopropylethylamine in a solvent such as
N,N-dimethylformamide.
##STR00044##
[0255] Thieno[3,2-b]pyridine-2-carboxylic acid (or salt thereof) of
general formula II (Scheme 3), can be obtained from
thieno[3,2-b]pyridine of general formula VI by deprotonation at low
temperature using a base such as lithium diisopropylamide (LDA) in
a solvent such as tetrahydrofuran (THF) followed by the addition of
carbon dioxide VII and allowing the reaction mixture to reach room
temperature.
##STR00045##
[0256] Thieno[3,2-b]pyridine of general formula VI where R.sup.4 is
Cl, is commercially available. Thieno[3,2-b]pyridine of general
formula VI where R.sup.4 is Br (Scheme 4) can be obtained by
treatment of compound Via with a reagent such as Phosphorus(V)
oxybromide VIII at elevated temperature.
##STR00046##
[0257] Thieno[3,2-b]pyridine of general formula VIc (Scheme 5), can
be obtained by treatment of compound VIb under reaction conditions
such as HI in water at elevated temperature.
##STR00047##
[0258] Thieno[3,2-b]pyridine of general formula VI (Scheme 6) where
R.sup.4 is C.sub.1-6 alkoxy can be obtained by treatment of
compound VIb under reaction conditions such as in the presence of
an alcohol ROH X, deprotonated by a base such as sodium, at
elevated temperature.
##STR00048##
[0259] Thieno[3,2-b]pyridine of general formula VI (Scheme 7) where
R.sup.4 can be trifluoromethyl as described in general Formula I
can be obtained by treatment of compound VIc, under reaction
conditions such as in the presence of metal catalyst such as copper
iodide, a reagent such as potassium fluoride, and a perfluorinated
precursor such as trimethyl(trifluoromethyl)silane (TMSCF.sub.3)
XI.
##STR00049##
[0260] Thieno[3,2-b]pyridine of general formula VI (Scheme 8) where
R.sup.4 can be --CH.sub.2OH as described in general Formula I can
be obtained from compound XIII, by treatment with a reducing agent
such as sodium borohydride. Compound XIII can be obtained from
compound XII in reaction conditions such as hydrochloric acid in
methanol. Compound XII can be obtained from compound VI busing a
reagent such as zinc cyanide in the presence of metal catalysts
such as
[1,1'-Bis(diphenylphosphino)ferrocene]dichloropalladium(II),
complex with dichloromethane and bis(dibenzylideneacetone)palladium
and zinc.
##STR00050##
[0261] Thieno[3,2-b]pyridine-2-carboxylic acid of general formula
II (or salt thereof), (Scheme 9) where R.sup.4 can be as described
in general Formula I can be prepared from the corresponding ester
where Pg can be methyl as in compounds of general formula XVII by
hydrolysis under aqueous conditions in a variety of conditions
known to chemists skilled in the art. Compounds of general formula
XVII can be obtained from compounds of general formula XVI under
reaction conditions such as hydrogenation in the presence of a
catalyst such as palladium on carbon. Compounds of general formula
XVI can be obtained by reacting compounds of general formula XIV
with reagents of general formula XV under reaction conditions such
as in the presence of a catalyst such as
[1,1'-Bis(diphenylphosphino)ferrocene]dichloropalladium(II),
complex with dichloromethane and a base such as potassium
carbonate. Compounds of general formula XIV where Pg is methyl can
be obtained from compounds of general formula IIa by treatment with
a reagent such as thionyl chloride in methanol as solvent.
##STR00051##
[0262] Compounds of general formula II (or salt thereof) where
R.sup.4 is as described for Formula I (Scheme 10) can be obtained
reacting compounds of general formula IIb, with reagents of general
formula XVIII in the presence of a catalyst such as
[1,1'-Bis(diphenylphosphino)ferrocene]dichloropalladium(II),
complex with dichloromethane or
[1,1'-Bis(di-tert-butylphosphino)ferrocene]dichloropalladium(II)
and a base such as sodium carbonate.
##STR00052##
[0263] Thieno[3,2-b]pyridine-2-carboxylic acid (or salt thereof) of
general formula II (Scheme 11) where R.sup.4 can be difluoromethyl
as described in general Formula I can be prepared from the
corresponding ester where Pg can be methyl as in compounds of
general formula XX by hydrolysis in aqueous conditions in a variety
of conditions known to chemists skilled in the art. Compounds of
general formula XX where R.sup.4 can be difluoromethyl can be
prepared by treatment of a compound of general formula XIX with
reagents such as (diethylamino)sulfur trifluoride. Compounds of
general formula XIX can be prepared from compounds of general
formula XVI, in the presence of ozone followed by treatment with a
reagent such as triphenyl phosphine.
##STR00053##
[0264] Thieno[3,2-b]pyridine-2-carboxylic acid of general formula
II, where R.sup.1 is hydrogen (or salt thereof) (Scheme 12) can be
prepared from the corresponding ester where Pg can be methyl as in
compounds of general formula XXIII by hydrolysis under aqueous
conditions known to chemists skilled in the art. Compounds of
general formula XXIII can be prepared by reaction of aldehydes of
general formula XXI with a reagent of general formula XXII in the
presence of a base such as triethylamine.
##STR00054##
[0265] Aldehydes of general formula XXI (Scheme 13) can be prepared
from compounds of general formula XXVI using a reducing reagent
such as diisobutylaluminum hydride. Compounds of general formula
XXVI can be prepared from compounds of general formula XXIV, where
X is an halogen such as iodine, by reaction with a reagent such as
XXV in the presence of a catalyst such as
[1,1'-Bis(diphenylphosphino)ferrocene]dichloropalladium(II),
complex with dichloromethane and a base such as potassium
phosphate. Compounds of general formula XXIV can be prepared from
compounds of general formula XXIII, via deprotonation using a base
such as lithium diisopropylamide followed by the addition of an
electrophilic halogen species, such as molecular iodine.
##STR00055##
[0266] Aldehydes of general formula XXI (Scheme 14) can be prepared
from compounds of general formula XXX, under reaction conditions
such in the presence of ozone followed by treatment with reagent
such as triphenyl phosphine. Compounds of general formula XXX can
be obtained reacting compounds of general formula XXIX with
reagents of general formula XVa, under reaction conditions such as
in the presence of a catalyst such as
[1,1'-Bis(diphenylphosphino)ferrocene]dichloropalladium(II),
complex with dichloromethane and a base such as potassium
carbonate. Compounds of general formula XXIX can be prepared from
compounds of general formula XXVIII, where X is an halogen such as
iodine, by reaction with a reagent such as XXV in the presence of a
catalyst such as
[1,1'-Bis(diphenylphosphino)ferrocene]dichloropalladium(II),
complex with dichloromethane and a base such as potassium carbonate
Compounds of general formula XXVIII can be prepared from compounds
of general formula XXVII, via deprotonation using a base such as
lithium diisopropylamide followed by the addition of an
electrophilic halogen species such as molecular iodine.
##STR00056##
[0267] Compounds of general formula IV (Scheme 15) where
R.sup.4.dbd.--CH.sub.2F may be prepared from compounds of general
formula IV where R.sup.4.dbd.--CH.sub.2OH using reagents such as
(diethylamino)sulfur trifluoride.
##STR00057##
[0268] Compounds of general formula V (Scheme 16) may be prepared
from compounds with general formula XXXII under reaction conditions
such as hydrogenation in the presence of a catalyst such as
palladium on carbon. Compounds with general formula XXXII may be
prepared by reacting protected amines such as IIIa with carboxylic
acids of general formula XXXI by standard peptide coupling methods
such as using O-(Benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium
tetrafluoroborate in the presence of a base such as
N,N-diisopropylethylamine in a solvent such as
N,N-dimethylformamide. Compounds of general formula XXXI can be
obtained reacting compounds of general formula IIa where X is Cl or
Br, with reagent of formula XVb under reaction conditions such as
in the presence of a catalyst such as
[1,1'-Bis(di-tert-butylphosphino)ferrocene]dichloropalladium(II)
and a base such as potassium carbonate.
##STR00058##
[0269] Compounds of general formula III where R.sup.5 is as defined
herein (Scheme 17) may be prepared by reacting carboxylic acids of
formula XXXIII with alcohols of formula XXXIV using standard
esterification procedures.
##STR00059##
[0270] Compounds of general formula III where R.sup.5 is as defined
herein (Scheme 18) may be prepared by deprotection of compounds of
general formula XXXVI where Pg.sup.3 could be a
tert-butyloxycarbonyl protecting group (Boc) and Pg.sup.1 could be
a benzyloxy carbamate (Cbz). Compounds of general formula XXXVI
where R.sup.5 is as in general formula I may be prepared by
reacting carboxylic acids of formula XXXV with alcohols of formula
XXXIV using standard esterification procedures. Compounds of
general formula XXXV where Pg.sup.3 could be a
tert-butyloxycarbonyl protecting group (Boc) may be prepared by
protection of compounds of general formula XXXIII using standard
procedures.
[0271] b. General Methods
[0272] LC-MS methods
[0273] Analytical LC-MS Data were obtained using one of the methods
identified below.
[0274] Method AA: A Waters Acquity UPLC-MS was used. Column:
Acquity UPLC BEH C18 1.7 .mu.m; 2.1.times.50 mm; Column
temperature: 60.degree. C.; Solvent system: A=water/trifluoroacetic
acid (99.965:0.035) and B=acetonitrile/water/trifluoroacetic acid
(94.965:5:0.035); Method: Linear gradient elution with A:B=90:10 to
0:100 in 1.0 minutes and with a flow rate of 1.2 mL/min.
[0275] Method BB: A Waters Acquity UPLC-MS was used. Column:
Acquity UPLC BEH C18 1.7 .mu.m; 2.1.times.50 mm; Column
temperature: 60.degree. C.; Solvent system: A=water/trifluoroacetic
acid (99.5:0.5) and B=acetonitrile/water/trifluoroacetic acid
(94.965:5:0.035); Method: Linear gradient elution with A:B=90:10 to
0:100 in 1.0 minutes and with a flow rate of 1.2 mL/min.
[0276] Preparative HPLC
[0277] Preparative-HPLC (Method A): Instrument: Gilson GX-281
Liquid Handler, SHIMADZU LC-8A LCMS2010; Column: YMC-Actus Triart
C18 150*30 5 .mu.m; Mobile Phase A: water (0.05% HCl v/v); Mobile
phase B: MeCN; Gradient: B from 5% to 35% in 10 min then hold at
100% for 3 min; FlowRate(ml/min): 25; Column temperature:
35.degree. C. and Wavelength: 220 nm 254 nm.
[0278] Preparative HPLC (Method B): Instrument: Gilson GX-215,
Gilson 322 Pump, Gilson 156 UV Detector; Column: YMC-Actus Triart
C18 150*30 5 .mu.m; Mobile Phase A: water (0.05% HCl v/v); Mobile
phase B: MeCN; Gradient: B from 0% to 28% in 10 min then hold at
100% for 3 min; FlowRate(ml/min): 25; Column temperature:
40.degree. C. and Wavelength: 220 nm 254 nm.
[0279] Preparative HPLC (Method C): Instrument: Gilson GX-281
Liquid Handler, Gilson 322 Pump, Gilson 156 UV Detector; Column:
Xtimate C18 150*25 mm*5 .mu.m; Mobile Phase A: water (0.05% ammonia
hydroxide v/v); Mobile phase B: MeCN; Gradient: from 42% to 72% in
10 min then hold at 100% for 2.5 min; Flow Rate (ml/min): 25;
Column temperature: 25.degree. C. and Wavelength: 220 nm 254
nm.
[0280] Preparative HPLC (Method D): Instrument: Gilson GX-281,
Gilson 322 Pump, Gilson 156 UV Detector; Column: Gemini 150*25 mm*5
.mu.m; Mobile Phase A: water (0.05% ammonia hydroxide v/v); Mobile
phase B: MeCN; Gradient: B from 52% to 82% in 10 min then hold at
100% for 2 min; FlowRate(ml/min): 25; Column temperature:
30.degree. C. and Wavelength: 220 nm 254 nm.
[0281] Preparative HPLC (Method E): Instrument: Gilson GX-215,
Gilson 322 Pump, Gilson 156 UV Detector; Column: Venusil ASB Phenyl
250*50 10 .mu.m; Mobile Phase A: water (0.05% HCl); Mobile phase B:
MeCN; Gradient: B from 15% to 45% in 10 min then hold 100% B for 1
min; Flow Rate (mL/min): 25; Column temperature: 40.degree. C.,
Wavelength: 220 nm 254 nm.
[0282] Preparative HPLC (Method F): Instrument: Gilson GX-281
Liquid Handler, Gilson 322 Pump, Gilson 156 UV Detector; Column:
Venusil ASB Phenyl 250*50 mm*10 .mu.m; Mobile Phase A: water (0.05%
HCl); Mobile phase B: MeCN; Gradient: B from 18% to 48% in 10 min
then hold at 100% for 1 min; Flow Rate(ml/min): 25; Column
temperature: 40.degree. C.; Wavelength: 220 nm, 254 nm.
[0283] Preparative HPLC (Method G): Instrument: Gilson GX-281
Liquid Handler, Gilson 322 Pump, Gilson 156 UV Detector; Column:
Xtimate C18 150*25 mm*5 .mu.m; Mobile Phase A: water (0.05% ammonia
hydroxide v/v); Mobile phase B: MeCN; Gradient: B from 64% to 94%
in 10 min then hold at 100% for 2.5 min; Flow Rate (ml/min): 25;
Column temperature: 25.degree. C. and Wavelength: 220 nm 254
nm.
[0284] Preparative HPLC (Method H): HPLC Instrument: Gilson GX-281
Liquid Handler, Gilson 322 Pump, Gilson 156 UV Detector; Column:
Xtimate C18 150*25 mm*5 .mu.m; Mobile Phase: A: water (0.05%
ammonia hydroxide v/v); Mobile phase B: MeCN; Gradient: B from 34%
to 64% in 10 min then hold at 100% for 2.5 min; FlowRate (ml/min):
25; Column temperature: 25.degree. C.; Wavelength: 220 nm 254
nm.
[0285] Preparative HPLC (Method I): Instrument: Gilson GX-215,
Gilson 322 Pump, Gilson 156 UV Detector; Column: Waters Xbridge
150*25 mm*5 .mu.m; Mobile Phase: A: water (10 mM
NH.sub.4HCO.sub.3); Mobile phase B: MeCN; Gradient: B from 21% to
51% in 10 min then hold at 100% for 2.5 min; FlowRate (ml/min): 25;
Column temperature: 30.degree. C.; Wavelength: 220 nm 254 nm.
[0286] Preparative HPLC (Method J): Instrument: Gilson GX-215
Liquid Handler, Gilson 322 Pump, Gilson 156 UV Detector; Column:
DYA-5 C18 150*25 mm*5 .mu.m; Mobile Phase A: water (0.05% HCl v/v);
Mobile phase B: MeCN; Gradient: B from 6% to 36% in 10 min then
hold at 100% for 3 min; Flow Rate (ml/min): 25; Column temperature:
35.degree. C. and Wavelength: 220 nm 254 nm.
[0287] Preparative HPLC (Method K): Instrument: Gilson GX-281,
Gilson 322 Pump, Gilson 156 UV Detector; Column: Phenomenex Gemini
C18 250*50*10 .mu.m; Mobile Phase A: water (10 mM
NH.sub.4HCO.sub.3); Mobile phase B: MeCN; Gradient: B from 10% to
40% in 11.2 min holds at 100% for 2.5 min; FlowRate(ml/min): 22;
Column temperature: 40.degree. C. and Wavelength: 220 nm 254
nm.
[0288] Preparative HPLC (Method L): Instrument: Gilson GX-281
Liquid Handler, Gilson 322 Pump, Gilson 156 UV Detector; Column:
Waters Xbridge 150*25 5 .mu.m; Mobile Phase A: water (10 mM
NH.sub.4HCO.sub.3); Mobile phase B: MeCN; Gradient: B from 25% to
55% in 10 min then hold at 100% for 1.5 min; FlowRate(ml/min): 25;
Column temperature: 30.degree. C.; Wavelength: 220 nm 254 nm.
[0289] Preparative HPLC (Method M): HPLC Instrument: Gilson GX-281
Liquid Handler, Gilson 322 Pump, Gilson 156 UV Detector; Column:
Venusil ASB Phenyl 250*50 10 .mu.m; Mobile Phase A: water (0.05%
HCl); Mobile phase B: MeCN; Gradient: B from 0% to 20% in 10 min
then hold at 100% for 3 min; FlowRate(ml/min): 25; Column
temperature: 40.degree. C.; Wavelength: 220 nm 254 nm.
[0290] Preparative HPLC (Method N): Instrument: Gilson GX-281
Liquid Handler, Gilson 322 Pump, Gilson 156 UV Detector; Column:
Agela Durashell C18 150 mm.times.25 mm.times.5 .mu.m; Mobile Phase
A: water (0.225% FA, v/v); Mobile phase B: MeCN; Gradient: B from
32% to 62% in 10 min, hold 100% B for 2 min; Flow Rate (ml/min):
25; Column temperature: 40.degree. C. and Wavelength: 220 nm 254
nm.
[0291] Preparative HPLC (Method 0): Instrument: Gilson GX-281,
Gilson 322 Pump, Gilson 156 UV Detector; Column: Waters Xbridge
150*25*5 .mu.m; Mobile Phase A: water (10 mM NH.sub.4HCO.sub.3);
Mobile phase B: MeCN; Gradient: B from 40% to 66% in 8.4 min then
hold at 100% for 2 min; FlowRate(ml/min): 25; Column temperature:
30.degree. C. and Wavelength: 220 nm 254 nm.
[0292] Preparative HPLC (Method P): Instrument: Gilson GX-281
Liquid Handler, Gilson 322 Pump, Gilson 156 UV Detector; Column:
Agela ASB 150*25 mm*5 .mu.m; Mobile Phase A: water (0.05% HCl);
Mobile phase B: MeCN; Gradient: B from 0% to 30% in 8 min then hold
at 100% for 0 min; FlowRate(ml/min): 25; Column temperature:
40.degree. C.; Wavelength: 220 nm 254 nm.
[0293] Preparative HPLC (Method Q): Instrument: Gilson GX-281
Liquid Handler, Gilson 322 Pump, Gilson 156 UV Detector; Column:
Agela ASB 150*25 mm*5 .mu.m; Mobile Phase A: water (0.05% HCl);
Mobile phase B: MeCN; Gradient: B from 0% to 25% in 8 min then hold
at 100% for 0 min; Flow Rate (ml/min): 25; Column temperature:
40.degree. C. and Wavelength: 220 nm 254 nm.
[0294] Preparative HPLC (Method R): Instrument: Gilson GX-281
Liquid Handler, Gilson 322 Pump, Gilson 156 UV Detector; Column:
Agela ASB 150*25 mm*5 .mu.m; Mobile Phase A: water (0.05% HCl);
Mobile phase B: MeCN; Gradient: B from 0% to 25% in 8 min then hold
at 100% for 0 min; Flow Rate (ml/min): 25; Column temperature:
40.degree. C. and Wavelength: 220 nm 254 nm.
[0295] Preparative HPLC (Method S): Instrument: Gilson GX-281
Liquid Handler, Gilson 322 Pump, Gilson 156 UV Detector; Column:
Agela Durashell C18 150 mm.times.25 mm.times.5 .mu.m; Mobile Phase
A: water (0.225% FA, v/v); Mobile phase B: MeCN; Gradient: B from
40% to 70% in 10 min, hold 100% B for 0 min; Flow Rate (ml/min):
25; Column temperature: 40.degree. C. and Wavelength: 220 nm 254
nm.
[0296] Preparative SFC (Method SFC1): Instrument: Berger, MULTIGR
AM-II; Column: DAICEL CHIRALPAK AS-H(250 mm*30 mm, 5 .mu.m); Mobile
phase: CO2/IPA (0.1% NH.sub.3 in H2O)=35/35; Flow Rate: 60 mL/min;
Column Temperature: 38.degree. C.; Nozzle Pressure: 100 bar; Nozzle
Temperature: 60.degree. C.; Evaporator Temperature: 20.degree. C.;
Trimmer Temperature: 25.degree. C.; Wavelength: 220 nm.
[0297] .sup.1H NMR spectra were recorded at 300, 400, 500 or 600
MHz on Bruker Avance instruments. TMS was used as internal
reference standard. Chemical shift values are expressed in ppm. The
following abbreviations are used for multiplicity of NMR signals:
s=singlet, d=doublet, t=triplet, q=quartet, qui=quintet, h=heptet,
dd=double doublet, dt=double triplet, dq=double quartet, tt=triplet
of triplets, m=multiplet, br s=broad singlet and br=broad
signal.
[0298] Abbreviations are in accordance with to the ACS Style Guide:
"The ACS Style guide--A manual for authors and editors" Janet S.
Dodd, Ed. 1997, ISBN: 0841234620
[0299] c. Preparation of the intermediates
Intermediate 1
(R)-3-(Benzyloxy)-2-(((benzyloxy)carbonyl)amino)-3-oxopropan-1-aminium
chloride
##STR00060##
[0301] To phenylmethanol (56.0 mL) was added thionyl chloride (2.1
g, 17.6 mmol) dropwise at 28.degree. C. After completion of the
addition, (R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoic acid
(3.8 g, 15.9 mmol) was added in several portions and the reaction
was stirred for 24 h at 28.degree. C. LCMS showed the reaction was
completed. The excess benzyl alcohol was removed
at 80.degree. C./0.02 bar and the residue was stirred in
cyclohexane (35 mL) for 16 h. Filtration and trituration of the
filter cake with methyl tert-butyl ether (50 mL) afforded the title
compound (3.0 g, yield: 51.6%). LCMS (m/z) 329.2 [M+H+],
t.sub.R=(min, Method AA)=0.52.
Intermediate 2
(R)-2-(((benzyloxy)carbonyl)amino)-3-((tert-butoxycarbonyl)amino)propanoic
acid
##STR00061##
[0303] To a solution of
(R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoic acid (4.5 g,
18.9 mmol) in 10% sodium carbonate aqueous solution (50 mL) were
added dioxane (30 mL) and di-tert-butyl dicarbonate (6.18 g, 28.32
mmol) at 0.degree. C. The reaction mixture was stirred at
20.degree. C. for 16 h. The mixture was diluted with water (100 mL)
and washed with methyl tert-butyl ether (50 mL.times.3). The
aqueous layer was acidified with 2N HCl to pH to 5.sup..about.6 and
extracted with ethyl acetate (80 mL.times.3). The combined organic
layers were dried over sodium sulfate, filtered and concentrated.
The residue was slurried in diisopropyl ether (40 mL) and collected
to give compound
(R)-2-(((benzyloxy)carbonyl)amino)-3-((tert-butoxycarbonyl)amino)propanoi-
c acid (5.5 g).
[0304] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. ppm 7.43-7.28
(m, 5H), 5.20-5.09 (m, 2H), 4.52-4.28 (m, 1H), 3.69-3.40 (m, 2H),
1.43 (s, 9H).
Intermediate 3
Methyl (R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoate
##STR00062##
[0306] To a solution of
(R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoic acid (200 g,
839 mmol) in methanol (1 L) was added dropwise thionyl chloride
(656 g, 5.5 mol) at 0.degree. C. The mixture was allowed to warm to
25.degree. C. and stirred for 18 h. The reaction was concentrated
and the residue washed with MTBE (500 mL.times.2) to give methyl
(R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoate (240 g) as HCl
salt.
[0307] .sup.1H NMR (400 MHz, MeOD) .delta. 7.31-7.39 (m, 5H), 5.13
(s, 2H), 4.50-4.54 (m, 1H), 3.77 (s, 3H), 3.43-3.48 (m, 1H),
3.24-3.27 (m, 1H)
Intermediate 4
Ethyl (R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoate
##STR00063##
[0309] To a solution of
(R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoic acid (5 g, 21
mmol) in ethanol (60 mL) was added dropwise thionyl chloride (4.99
g, 42 mmol). The mixture was stirred at 30.degree. C. for 16 h. The
reaction was concentrated to give ethyl
(R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoate (6.0 g) as HCl
salt.
[0310] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 8.38 (br s, 3H),
7.94 (d, 1H), 7.41-7.30 (m, 5H), 5.07 (s, 2H), 4.46-4.37 (m, 1H),
4.12 (q, 2H), 3.25-3.15 (m, 1H), 3.11-2.99 (m, 1H), 1.18 (t,
3H).
Intermediate 5
(R)-propyl 3-amino-2-(((benzyloxy)carbonyl)amino)propanoate
##STR00064##
[0312] To a solution of
(R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoic acid (2.0 g,
8.4 mmol) in n-PrOH (30 mL) was added thionyl chloride (2.0 g,
16.78 mmol) at 0.degree. C. The mixture was stirred at 25.degree.
C. for 16 h. The reaction mixture was concentrated. The residue was
treated with methyl tert-butyl ether (5 mL) and hexane (15 mL). The
solid was collected by filtration and washed with hexane (15
mL.times.2) and dried to give (R)-propyl
3-amino-2-(((benzyloxy)carbonyl)amino)propanoate (2.2 g) as a HCl
salt.
[0313] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 8.12 (br s, 3H),
7.88 (br d, 1H), 7.40-7.32 (m, 5H), 5.11-5.03 (m, 2H), 4.42-4.36
(m, 1H), 4.04 (t, 2H), 3.28-3.22 (m, 1H), 3.13-3.01 (m, 1H),
1.61-1.54 (m, 2H), 0.87 (t, 3H).
Intermediate 6
Isopropyl (R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoate
hydrochloride
##STR00065##
[0315] To a solution of
(R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoic acid (5 g, 21
mmol) in i-PrOH (60 mL) was added drop wise thionyl chloride (5.0
g, 42 mmol). The mixture was stirred at 30.degree. C. for 16 h.
Then additional thionyl chloride (3 mL) was added, the reaction was
then stirred at 30.degree. C. for 24 h. The mixture was
concentrated to give 10 g crude product. The crude product was
treated with cyclohexane (30 mL) and stirred for 3 h. The solid was
collected and dried to give isopropyl
(R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoate (6.3 g) as HCl
salt.
[0316] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 8.38 (br, 3H),
7.92 (d, J=8.0 Hz, 1H), 7.39-7.29 (m, 5H), 5.06 (s, 2H), 4.95-4.86
(m, 1H), 4.39-4.31 (m, 1H), 3.22-3.12 (m, 1H), 3.10-2.99 (m, 1H),
1.17 (dd, J=9.2, 6.4 Hz, 6H).
Intermediate 7
Cyclopropyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-((tert-butoxycarbonyl)amino)propanoa-
te
##STR00066##
[0318] To a mixture of
(R)-2-(((benzyloxy)carbonyl)amino)-3-((tert-butoxycarbonyl)amino)propanoi-
c acid (1.1 g, 3.25 mmol) and cyclopropanol (208 mg, 3.58 mmol) in
DMF (25 mL) was added N,N-diisopropylethylamine (1.26 g, 9.75 mmol)
and HATU (1.85 g, 4.88 mmol). The reaction mixture was stirred at
50.degree. C. for 16 h. The mixture was diluted with water (20 mL)
and extracted with ethyl acetate (30 mL.times.3). The combined
organic layers were washed with brine (30 mL.times.3) and
concentrated. The residue was purified by Combi Flash on silica gel
to give cyclopropyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-((tert-butoxycarbonyl)amino)propanoa-
te (1.1 g).
[0319] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 7.40-7.30 (m, 5H),
5.75 (br s, 1H), 5.12 (s, 2H), 4.80 (br s, 1H), 4.40-4.34 (m, 1H),
4.20-4.15 (m, 1H), 3.57-3.50 (m, 2H), 1.43 (s, 9H), 0.78-0.70 (m,
4H).
Intermediate 8
Cyclopropyl
(R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoate
##STR00067##
[0321] A mixture of (R)-cyclopropyl
2-(((benzyloxy)carbonyl)amino)-3-((tert-butoxycarbonyl)amino)propanoate
(1.0 g, 2.64 mmol) in HCl/Ethyl acetate (15 mL) was stirred at
15.degree. C. for 1 hour. The mixture was concentrated below
40.degree. C. to give (R)-cyclopropyl
3-amino-2-(((benzyloxy)carbonyl)amino)propanoate (810 mg) as HCl
salt.
[0322] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 8.00 (br s, 3H),
7.86 (br d, J=8.4 Hz, 1H), 7.42-7.31 (m, 5H), 5.07 (s, 2H),
4.37-4.30 (m, 1H), 4.15-4.09 (m, 1H), 3.25-3.00 (m, 2H), 0.74-0.57
(m, 4H).
Intermediate 9
Butyl (R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoate
##STR00068##
[0324] To a mixture of
(R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoic acid (8 g, 33.6
mmol) and butan-1-ol (30 mL) was added thionyl chloride (12 g, 101
mmol) dropwise at 0.degree. C. over 30 minutes. The resulting
mixture was stirred at 30.degree. C. for 15.5 h. The reaction was
concentrated in vacuo. The residue was purified by washing with
petroleum ether (50 mL) at 25.degree. C. to give butyl
(R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoate hydrochloride
(11 g).
[0325] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 8.37 (s, 3H),
7.92 (d, 1H), 7.30-7.38 (m, 5H), 5.04 (s, 2H), 4.36-4.43 (m, 1H),
4.05 (t, 2H), 3.18 (m, 1H), 3.04 (m, 1H), 1.47-1.55 (m, 2H),
1.23-1.32 (m, 2H), 0.82-0.87 (t, 3H).
Intermediate 10
Cyclohexyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-((tert-butoxycarbonyl)amin-
o)propanoate
##STR00069##
[0327] A mixture of
(R)-2-(((benzyloxy)carbonyl)amino)-3-((tert-butoxycarbonyl)amino)propanoi-
c acid (1 g, 2.96 mmol), HATU (1.69 g, 4.43 mmol) and
N,N-diisopropylethylamine (1.15 g, 8.9 mmol) in DMF (25 mL) was
stirred at 20.degree. C. for 30 min, cyclohexanol (326 mg, 3.25
mmol) was added and the resulting mixture was stirred at 50.degree.
C. for 16 h. The mixture was diluted with water (25 mL) and
extracted with ethyl acetate (50 mL.times.2). The combined organic
phases were washed with brine (50 mL.times.2), dried over anhydrous
sodium sulfate and concentrated. The residue was purified by Combi
Flash (silica gel, from 0 to 30%, Ethyl acetate in petroleum ether)
to give cyclohexyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-((tert-butoxycarbonyl)amino)propanoa-
te (520 mg).
[0328] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 7.41-7.28 (m, 5H),
5.89-5.65 (m, 1H), 4.92-4.70 (m, 2H), 4.49-4.33 (m, 1H), 3.68-3.47
(m, 2H), 1.91-1.73 (m, 4H), 1.61-1.34 (m, 15H).
Intermediate 11
Cyclohexyl (R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoate
hydrochloride
##STR00070##
[0330] A solution of (R)-cyclohexyl
2-(((benzyloxy)carbonyl)amino)-3-((tert-butoxycarbonyl)amino)propanoate
(520 mg, 1.24 mmol) in HCl/Ethyl acetate (4 mL, 4 M) was stirred at
20.degree. C. for 1 hour. The mixture was concentrated to give
cyclohexyl (R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoate
(440 mg) as HCl salt.
[0331] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 8.44-8.06 (m, 3H),
7.34-7.13 (m, 5H), 6.58 (br d, J=6.8 Hz, 1H), 5.03 (s, 2H),
4.78-4.33 (m, 2H), 3.59-3.23 (m, 2H), 1.89-1.19 (m, 10H).
Intermediate 12
Phenyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-((tert-butoxycarbonyl)amino)pr-
opanoate
##STR00071##
[0333] To a solution of
(R)-2-(((benzyloxy)carbonyl)amino)-3-((tert-butoxycarbonyl)amino)propanoi-
c acid (1 g, 2.9 mmol) in DMF (25 mL) was added HATU (1.69 g, 4.4
mmol), N,N-diisopropylethylamine (1.15 g, 8.9 mmol) and phenol (306
mg, 3.25 mmol). The mixture was stirred at 50.degree. C. for 16 h.
The mixture was diluted with water (10 mL) and extracted with ethyl
acetate (20 mL.times.3). The combined organic layers were washed
with brine (20 mL.times.3) and concentrated. The residue was
purified by Combi Flash on silica gel (petroleum ether:ethyl
acetate with ethyl acetate from 0 to 25%) to give compound phenyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-((tert-butoxycarbonyl)amino)propanoa-
te (890 mg).
[0334] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 7.42-7.32 (m, 7H),
7.27-7.21 (m, 1H), 7.19-7.09 (m, 2H), 5.91 (br s, 1H), 5.15 (s,
2H), 4.91 (br s, 1H), 4.72-4.62 (m, 1H), 3.88-3.76 (m, 1H),
3.74-3.63 (m, 1H), 1.44 (s, 9H).
Intermediate 13
Phenyl (R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoate
##STR00072##
[0336] A mixture of (R)-phenyl
2-(((benzyloxy)carbonyl)amino)-3-((tert-butoxycarbonyl)amino)propanoate
(890 mg, 2.15 mmol) in HCl/Ethyl acetate (4 M, 15 mL) was stirred
at 15.degree. C. for 1 hour. The mixture was concentrated below
40.degree. C. to give compound phenyl
(R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoate (870 mg) as
HCl salt.
[0337] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 8.35 (br s, 3H),
8.19 (br d, J=8.0 Hz, 1H), 7.46-7.27 (m, 8H), 7.11 (d, J=7.6 Hz,
2H), 5.22-5.03 (m, 2H), 4.74-4.62 (m, 1H), 3.30-3.14 (m, 1H).
Intermediate 14
2-Oxo-2-(pyrrolidin-1-yl)ethyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-((tert-butoxycarbonyl)amino)propanoa-
te
##STR00073##
[0339] To a solution of
(R)-2-(((benzyloxy)carbonyl)amino)-3-((tert-butoxycarbonyl)amino)propanoi-
c acid (1 g, 2.96 mmol), HATU (1.69 g, 4.43 mmol) and
N,N-diisopropylethylamine (1.15 g, 8.87 mmol) in DMF (15 mL) was
added 2-hydroxy-1-(pyrrolidin-1-yl)ethanone (382 mg, 2.96 mmol).
The mixture was stirred at 50.degree. C. for 16 h. The mixture was
diluted with water (20 mL) and extracted with ethyl acetate (20
mL.times.3). The combined organic layers were washed with brine (20
mL.times.3) and concentrated. The residue was purified by Combi
Flash on silica gel (petroleum ether:ethyl acetate with ethyl
acetate from 0 to 54%) to give 2-oxo-2-(pyrrolidin-1-yl)ethyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-((tert-butoxycarbonyl)amino)propanoa-
te (700 mg).
[0340] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 7.41-7.29 (m, 5H),
6.20 (br, 1H), 6.11 (d, J=6.8 Hz, 1H), 5.18-5.07 (m, 2H), 5.01 (d,
J=14.4 Hz, 1H), 4.55-4.39 (m, 2H), 3.90-3.70 (m, 1H), 3.65-3.31 (m,
5H), 2.05-1.97 (m, 2H), 1.92-1.85 (m, 2H), 1.43 (s, 9H).
Intermediate 15
2-Oxo-2-(pyrrolidin-1-yl)ethyl
(R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoate
##STR00074##
[0342] To a solution of (R)-2-oxo-2-(pyrrolidin-1-yl)ethyl
2-(((benzyloxy)carbonyl)amino)-3-((tert-butoxycarbonyl)amino)propanoate
(700 mg, 1.56 mmol) in ethyl acetate (4 mL) was added HCl/Ethyl
acetate (4 M, 10 mL). The mixture was stirred at 15.degree. C. for
1 hour. The mixture was concentrated in vacuo to give
2-oxo-2-(pyrrolidin-1-yl)ethyl
(R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoate (600 mg) as
HCl salt.
[0343] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 8.39 (br s, 3H),
8.03 (d, J=8.0 Hz, 1H), 7.39-7.32 (m, 5H), 5.07 (s, 2H), 4.98 (d,
J=15.2 Hz, 1H), 4.76 (d, J=15.2 Hz, 1H), 4.60-4.51 (m, 1H), 3.39
(t, J=6.4 Hz, 2H), 3.30 (t, J=7.2 Hz, 2H), 3.26-3.14 (m, 2H),
1.92-1.86 (m, 2H), 1.81-1.72 (m, 2H).
Intermediate 16
Isopentyl (R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoate
##STR00075##
[0345] To a solution of
(R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoic acid (5 g, 21
mmol) in 3-methylbutan-1-ol (50 mL) was added thionyl chloride (5
g, 42 mmol) at 0.degree. C. The mixture was stirred at 25.degree.
C. for 16 h. The 3-methylbutan-1-ol was removed at 80.degree.
C./0.02 bar, the residue was dissolved in water (30 mL), and washed
with ethyl acetate (20 mL.times.3). The aqueous layers were
concentrated to give a isopentyl
(R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoate hydrochloride
(6 g).
[0346] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 8.50 (br, 3H),
7.97 (d, 1H), 7.38-7.30 (m, 5H), 5.10-4.99 (m, 2H), 4.48-4.38 (m,
1H), 4.10 (t, 2H), 3.24-3.16 (m, 1H), 3.12-3.02 (m, 1H), 1.58-1.67
(m, 1H), 1.45 (q, 2H), 0.87-0.83 (m, 6H).
Intermediate 17
2-Methoxyethyl
(R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoate
##STR00076##
[0348] To a solution of
(R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoic acid (5 g, 21
mmol) in 2-methoxyethanol (50 mL) was added thionyl chloride (5 g,
42 mmol). The mixture was stirred at 20.degree. C. for 16 h. The
mixture was concentrated to give 2-methoxyethyl
(R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoate (7 g) as HCl
salt.
[0349] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 8.35 (br, 3H),
7.95 (d, 1H), 7.38-7.31 (m, 5H), 5.11-5.00 (m, 2H), 4.49-4.40 (m,
1H), 4.25-4.15 (m, 2H), 3.50 (m, 2H), 3.25 (m, 4H), 3.05 (m,
1H).
Intermediate 18
Lithium 7-chlorothieno[3,2-b]pyridine-2-carboxylate
##STR00077##
[0351] To a solution of 7-chlorothieno[3,2-b]pyridine (10.0 g, 58.9
mmol) in THF (150 mL) was added drop wise n-butyllithium (n-BuLi)
(2.5 M in hexane, 23.6 mL) at -78.degree. C. The mixture was
stirred at -78.degree. C. for 30 minutes. Then gaseous carbon
dioxide (15 psi) was bubbled through the reaction solution and the
mixture was allowed to warm to 20.degree. C. over a period of 16 h.
The mixture was diluted with THF (20 mL) and filtered to give
lithium 7-chlorothieno[3,2-b]pyridine-2-carboxylate (12 g).
[0352] d. Preparation of the exemplified compounds of the
invention
Compound 1a
(R)-2-amino-3-(7-(difluoromethyl)thieno[3,2-b]pyridine-2-carboxamido)propa-
noic acid
[0353] The overall synthesis scheme for the preparation of
(R)-2-amino-3-(7-(difluoromethyl)thieno[3,2-b]pyridine-2-carboxamido)prop-
anoic acid is shown below.
##STR00078##
Step 1: Methyl 7-formylthieno[3,2-b]pyridine-2-carboxylate
##STR00079##
[0355] Ozone was bubbled through a solution of methyl
7-vinylthieno[3,2-b]pyridine-2-carboxylate (700 mg, 3.19 mmol) in
MeOH (30 mL) at -78.degree. C. for 10 min, then the mixture was
warmed to 25.degree. C. PPh.sub.3 (1.26 g, 4.79 mmol) was added,
and the mixture was stirred at 25.degree. C. for 2 h. The mixture
was concentrated under reduced pressure. The residue was purified
by CombiFlash (petroleum ether:ethyl acetate with ethyl acetate
from 0 to 30%) to give methyl
7-formylthieno[3,2-b]pyridine-2-carboxylate (550 mg).
[0356] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 10.35 (s, 1H),
9.10 (d, J=4.4 Hz, 1H), 8.33 (s, 1H), 7.82 (d, J=4.4 Hz, 1H), 4.02
(s, 3H).
Step 2: Methyl
7-(difluoromethyl)thieno[3,2-b]pyridine-2-carboxylate
##STR00080##
[0358] To a solution of methyl
7-formylthieno[3,2-b]pyridine-2-carboxylate (550 mg, 2.49 mmol) in
dichloromethane (DCM) (15 mL) was added diethylaminosulfur
trifluoride (DAST) (602 mg, 3.74 mmol) at 0.degree. C. The mixture
was stirred at 25.degree. C. for 2 h. The mixture was quenched with
water (0.5 mL) and concentrated under reduced pressure. The residue
was purified by CombiFlash (petroleum ether:ethyl acetate with
ethyl acetate from 0 to 30%) to give methyl
7-(difluoromethyl)thieno[3,2-b]pyridine-2-carboxylate (350 mg).
[0359] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 8.89 (d, J=4.4 Hz,
1H), 8.30 (s, 1H), 7.48 (d, J=4.4 Hz, 1H), 7.17-6.73 (m, 1H), 4.01
(s, 3H).
Step 3: 7-(difluoromethyl)thieno[3,2-b]pyridine-2-carboxylic
acid
##STR00081##
[0361] To a solution of methyl
7-(difluoromethyl)thieno[3,2-b]pyridine-2-carboxylate (440 mg, 1.81
mmol) in MeOH (10 mL) was added LiOH.H.sub.2O (228 mg, 5.43 mmol)
dissolved in water (1 mL). The mixture was stirred at 25.degree. C.
for 3 h. The mixture was concentrated under reduced pressure. The
residue was dissolved in water (10 mL) and washed with ethyl
acetate (10 mL). The aqueous layer was acidified by 2N HCl (2 mL)
and the precipitate was collected to give
7-(difluoromethyl)thieno[3,2-b]pyridine-2-carboxylic acid (320
mg).
[0362] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 8.94 (d, J=4.4
Hz, 1H), 8.22 (s, 1H), 7.73 (d, J=4.4 Hz, 1H), 7.63-7.32 (m,
1H).
Step 4: benzyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-(difluoromethyl)thieno
[3,2-b]pyridine-2-carboxamido)propanoate
##STR00082##
[0364] To a solution of
7-(difluoromethyl)thieno[3,2-b]pyridine-2-carboxylic acid (320 mg,
1.40 mmol) and benzyl
(R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoate (511 mg, 1.40
mmol, HCl salt) in DMF (8 mL) was added
O-(Benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium
tetrafluoroborate (674 mg, 2.10 mmol) and N,N-diisopropylethylamine
(543 mg, 4.20 mmol). The mixture was stirred at 25.degree. C. for
16 h. The mixture was diluted with water (10 mL) and extracted with
ethyl acetate (10 mL.times.3). The combined organic layers were
washed with water (20 mL) and brine (20 mL) and concentrated under
reduced pressure. The residue was purified by Combi Flash
(petroleum ether:ethyl acetate with ethyl acetate from 0 to 60%) to
give benzyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-(difluoromethyl)thieno[3,2-b]pyri-
dine-2-carboxamido)propanoate (600 mg).
[0365] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 8.85 (d, J=4.4 Hz,
1H), 7.90 (s, 1H), 7.46 (d, J=4.4 Hz, 1H), 7.39-7.27 (m, 10H),
7.06-6.76 (m, 1H), 6.05 (br d, 1H), 5.22 (s, 2H), 5.12 (s, 2H),
4.68-4.59 (m, 1H), 4.01-3.92 (m, 1H), 3.91-3.82 (m, 1H).
Step 5: Preparation of
(R)-2-amino-3-(7-(difluoromethyl)thieno[3,2-b]pyridine-2-carboxamido)prop-
anoic acid
##STR00083##
[0367] A mixture of benzyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-(difluoromethyl)thieno
[3,2-b]pyridine-2-carboxamido)propanoate (200 mg, 0.37 mmol) in 33%
HBr in AcOH (4 mL) was stirred at 50.degree. C. for 16 h. The
mixture was concentrated under reduced pressure. The residue was
purified by preparative HPLC (Method A) to give
(R)-2-amino-3-(7-(difluoromethyl)thieno[3,2-b]pyridine-2-carboxamido)prop-
anoic acid (86 mg) as HCl salt.
[0368] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 9.58 (br t,
J=6.0 Hz, 1H), 8.91 (d, J=4.8 Hz, 1H), 8.66-8.58 (m, 3H), 8.55 (s,
1H), 7.69 (d, J=4.8 Hz, 1H), 7.63-7.31 (m, 1H), 4.22-4.12 (m, 1H),
3.94-3.76 (m, 2H)
[0369] LCMS (MH+): m/z=316.2, t.sub.R (min, Method BB)=0.29.
[0370] [.alpha.].sup.20D=-6.5, (c=2 mg/mL, DMSO).
Compound 2a
Methyl
(R)-2-amino-3-(7-(difluoromethyl)thieno[3,2-b]pyridine-2-carboxamid-
o)propanoate
##STR00084##
[0372] To a solution of
(R)-2-amino-3-(7-(difluoromethyl)thieno[3,2-b]pyridine-2-carboxamido)
propanoic acid (380 mg, 0.74 mmol, HBr salt) in MeOH (5 mL) was
added thionyl chloride (263 mg, 2.21 mmol). The mixture was stirred
at 50.degree. C. for 16 h. The mixture was concentrated under
reduced pressure. The residue was dissolved in water (5 mL) and
adjusted to pH=8 with saturated aqueous sodium carbonate and
extracted with ethyl acetate (10 mL.times.4). The combined organic
layers were washed with brine (15 mL) and dried over anhydrous
sodium sulfate, filtered and concentrated under reduced pressure.
The residue was purified by Combi Flash (DCM: MeOH with MeOH from 0
to 15%) to give methyl
(R)-2-amino-3-(7-(difluoromethyl)thieno[3,2-b]pyridine-2-carboxamido)prop-
anoate (145 mg).
[0373] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 8.86 (d, J=4.8 Hz,
1H), 8.00 (s, 1H), 7.46 (d, J=4.8 Hz, 1H), 7.08 (brs, 1H),
7.06-6.73 (t, 1H), 3.97-3.88 (m, 1H), 3.83-3.74 (m, 4H), 3.61-3.51
(m, 1H)
[0374] LCMS (MH+): m/z=330.2, t.sub.R (min, Method BB)=0.34
min.
[0375] [.alpha.].sup.20D=-39.7, (c=1 mg/mL, CH.sub.3OH).
Compound 1b
(R)-2-amino-3-(7-cyclopropylthieno[3,2-b]pyridine-2-carboxamido)
propanoic acid
[0376] The overall synthesis scheme for the preparation of
(R)-2-amino-3-(7-cyclopropylthieno[3,2-b]pyridine-2-carboxamido)
propanoic acid is shown below.
##STR00085##
Step 1: 7-cyclopropylthieno[3,2-b]pyridine-2-carboxylic acid
##STR00086##
[0378] A mixture of lithium
7-chlorothieno[3,2-b]pyridine-2-carboxylate (500 mg, 2.46 mmol),
cyclopropylboronic acid (423 mg, 4.92 mmol) and K.sub.3PO.sub.4
(1.04 g, 4.92 mmol) in dioxane (10 mL) and water (2 mL) was stirred
under N.sub.2. Then
[1,1'-Bis(di-tert-butylphosphino)ferrocene]dichloropalladium(II)
(PdCl.sub.2(dtbpf)) (80 mg, 0.123 mmol) was added and the mixture
was stirred at 110.degree. C. for 16 h in a sealed tube. The
mixture was poured into water (15 mL), extracted with ethyl acetate
(20 mL). The aqueous was adjusted pH (4.sup..about.5) by HCl aq.
(3M) and concentrated to afford
7-cyclopropylthieno[3,2-b]pyridine-2-carboxylic acid (700 mg).
Step 2: benzyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-cyclopropylthieno
[3,2-b]pyridine-2-carboxamido)propanoate
##STR00087##
[0380] A mixture of crude
7-cyclopropylthieno[3,2-b]pyridine-2-carboxylic acid (650 mg, 2.89
mmol), benzyl (R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoate
(1.05 g, 2.89 mmol, HCl salt), N,N-diisopropylethylamine (1.12 g,
8.67 mmol) and O-(Benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium
tetrafluoroborate (1.39 g, 4.34 mmol) in DMF (5 mL) was stirred at
30.degree. C. for 16 h. The mixture was poured into water (20 mL)
and extracted with ethyl acetate (20 mL.times.2). The combined
organic phases were washed with brine (30 mL.times.3), dried over
anhydrous sodium sulfate and concentrated. The residue was purified
by combiFlash (Ethyl acetate: Petroleum ether=0.sup..about.50%) to
give benzyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-cyclopropylthieno[3,2-b]pyridine--
2-carboxamido)propanoate (260 mg).
[0381] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 9.05 (br, 1H),
8.60 (d, 1H), 8.18 (s, 1H), 7.89 (br d, 1H), 7.36-7.22 (m, 10H),
7.04 (d, J=5.2 Hz, 1H), 5.11 (d, J=5.2 Hz, 2H), 5.06 (m, 2H),
4.47-4.42 (m, 1H), 3.77-3.65 (m, 2H), 2.10-2.18 (m, 1H), 1.24-1.17
(m, 2H), 1.05-0.96 (m, 2H).
Step 3:
(R)-2-Amino-3-(7-cyclopropylthieno[3,2-b]pyridine-2-carboxamido)
propanoic acid
##STR00088##
[0383] A mixture of benzyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-cyclopropylthieno
[3,2-b]pyridine-2-carboxamido)propanoate (80.0 mg, 0.15 mmol) and
HBr/AcOH (3 mL, 33%) was stirred at 50.degree. C. for 16 h. The
mixture was concentrated on vacuo. The residue was purified by
preparative-HPLC (Method B) to give
(R)-2-amino-3-(7-cyclopropylthieno
[3,2-b]pyridine-2-carboxamido)propanoic acid (15 mg) as HCl
salt.
[0384] .sup.1H NMR (400 MHz, D.sub.2O) .delta. 8.59-8.52 (m, 1H),
8.09-8.02 (m, 1H), 7.24-7.14 (m, 1H), 4.21-4.12 (m, 1H), 3.95 (dd,
1H), 3.85 (dd, 1H), 2.26 (m, 1H), 1.45 (dd, 2H), 1.24-1.14 (m,
2H).
[0385] LCMS (MH+): m/z=306.2, tR (min, Method BB)=0.22.
[0386] [.alpha.].sup.20D=12.0 (c=0.25 mg/mL, CH.sub.3OH).
Compound 2b
Methyl
(R)-2-amino-3-(7-cyclopropylthieno[3,2-b]pyridine-2-carboxamido)pro-
panoate
[0387] The overall synthesis scheme for the preparation of methyl
(R)-2-amino-3-(7-cyclopropylthieno[3,2-b]pyridine-2-carboxamido)propanoat-
e is shown below.
##STR00089##
Step 1: Methyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-cyclopropylthieno[3,2-b]pyridine--
2-carboxamido)propanoate
##STR00090##
[0389] A mixture of 7-cyclopropylthieno[3,2-b]pyridine-2-carboxylic
acid (980 mg, 4.47 mmol), (R)-methyl
3-amino-2-(((benzyloxy)carbonyl)amino)propanoate (1.29 g, 4.47
mmol, HCl salt),
2-(1H-Benzotriazole-1-yl)-1,1,3,3-tetramethylaminium
tetrafluoroborate (TBTU) (2.15 g, 6.7 mmol) and
N,N-diisopropylethylamine (2.89 g, 22.35 mmol) in DMF (20 mL) was
stirred at 25.degree. C. for 16 h. The mixture was diluted with
water (30 mL) and extracted with ethyl acetate (10 mL.times.3). The
organic phase was washed with brine (10 mL.times.2), dried over
anhydrous sodium sulfate and concentrated. The residue was purified
by CombiFlash (Petroleum ether: Ethyl acetate=0.sup..about.80%) to
give methyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-cyclopropylthieno[3,2-b]pyridine--
2-carboxamido)propanoate (600 mg).
[0390] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 8.59 (d, J=4.8 Hz,
1H), 7.90 (s, 1H), 7.37-7.26 (m, 6H), 6.83 (d, J=4.8 Hz, 1H), 5.99
(br d, J=6.8 Hz, 1H), 5.12 (s, 2H), 4.66-4.52 (m, 1H), 3.99-3.83
(m, 2H), 3.80 (s, 3H), 2.18-2.04 (m, 1H), 1.25-1.16 (m, 2H),
1.01-0.93 (m, 2H).
Step 2: Methyl
(R)-2-amino-3-(7-cyclopropylthieno[3,2-b]pyridine-2-carboxamido)propanoat-
e
##STR00091##
[0392] A mixture of methyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-cyclopropylthieno[3,2-b]pyridine--
2-carboxamido)propanoate (700 mg, 1.54 mmol) and HBr/AcOH (10 mL,
30%) was stirred at 25.degree. C. for 16 h. The mixture was diluted
with methyl tert-butyl ether (20 mL). The precipitate was filtered.
The filter cake was dried to give the crude product. The crude
product was washed with CH.sub.3OH (10 mL). The product was
filtered to give methyl
(R)-2-amino-3-(7-cyclopropylthieno[3,2-b]pyridine-2-carboxamido)propanoat-
e (230 mg) as HBr salt.
[0393] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 9.53 (br t, 1H),
8.84 (d, 1H), 8.55 (br s, 3H), 8.41 (s, 1H), 7.34 (d, 1H),
3.88-3.73 (m, 5H), 2.39-2.28 (m, 1H), 1.38 (m, 2H), 1.20 (br s,
2H).
[0394] LCMS (MH+): m/z=320.0, t.sub.R (min, Method BB)=0.31.
[0395] [.alpha.].sup.20D=-1.0, (c=1.0 mg/mL, CH.sub.3OH).
Compound 1c
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoic
acid
[0396] The overall synthesis scheme for the preparation of
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoic
acid is shown below.
##STR00092##
Step 1: 7-Methylthieno[3,2-b]pyridine-2-carboxylic acid
##STR00093##
[0398] A mixture of lithium
7-chlorothieno[3,2-b]pyridine-2-carboxylate (300 mg, 1.37 mmol),
2,4,6-trimethyl-1,3,5,2,4,6-trioxatriborinane (344 mg, 2.74 mmol,
0.4 mL), PdCl.sub.2(dtbpf) (90 mg, 0.14 mmol) and K.sub.3PO.sub.4
(727 mg, 3.43 mmol) in water (4 mL) and dioxane (12 mL) in a sealed
tube was heated to 80.degree. C. for 16 h under N.sub.2. The
mixture was filtered. The aqueous phase was adjusted to
pH=3.sup..about.4 with HCl (2M, 4 mL). The mixture was concentrated
to give 7-methylthieno[3,2-b]pyridine-2-carboxylic acid (260 mg).
The crude product was used for the next step without any further
purification.
Step 2: benzyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-methylthieno[3,2-b]pyridine-2-car-
boxamido)propanoate
##STR00094##
[0400] To a solution of 7-methylthieno[3,2-b]pyridine-2-carboxylic
acid (300 mg, crude) in DMF (10 mL) was added TBTU (748 mg, 2.33
mmol), N,N-diisopropylethylamine (602 mg, 4.66 mmol) and benzyl
(R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoate (566 mg, 1.55
mmol, HCl salt). The mixture was stirred at 20.degree. C. for 15 h.
The mixture was diluted with water (30 mL) and extracted with ethyl
acetate (25 mL.times.3). The combined organic layers were washed
with brine (30 mL) and concentrated. The residue was purified by
Combi Flash on silica gel (petroleum ether:ethyl acetate with ethyl
acetate from 0 to 100%) to give 390 mg crude product. The crude
product was triturated with DCM (15 mL) and isolated by filtration
and dried to give benzyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-methylthieno[3,2-b]pyridine-2-car-
boxamido)propanoate (230 mg).
[0401] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 9.04 (br t,
J=5.6 Hz, 1H), 8.64 (d, J=4.8 Hz, 1H), 8.19 (s, 1H), 7.89 (br d,
J=8.4 Hz, 1H), 7.37-7.22 (m, 11H), 5.17-5.00 (m, 4H), 4.48-4.39 (m,
1H), 3.76-3.62 (m, 2H), 2.57 (s, 3H).
Step 3:
(R)-2-Amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propano-
ic acid
##STR00095##
[0403] A mixture of benzyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-methylthieno[3,2-b]pyridine-2-car-
boxamido)propanoate (100 mg, 0.20 mmol) and HBr/AcOH (3 mL, 33%)
were stirred at 50.degree. C. for 16 h. The mixture was diluted
with methyl tert-butyl ether (3 mL) and water (3 mL). The aqueous
phase was extracted with methyl tert-butyl ether (3 mL.times.2).
The aqueous phase was lyophilized to give
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoic
acid (50 mg) as HBr salt.
[0404] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 9.42 (br s, 1H),
8.91-8.80 (m, 1H), 8.54-8.32 (m, 4H), 7.61 (br s, 1H), 4.20-4.10
(m, 1H), 3.90-3.69 (m, 2H), 2.71 (s, 3H).
[0405] LCMS (MH+): m/z=280.1, t.sub.R (min, Method BB)=0.17.
[0406] [.alpha.].sup.20D=-11.0, (c=1.0 mg/mL, CH.sub.3OH).
Compound 2c
Methyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoa-
te
[0407] The overall synthesis scheme for the preparation of methyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate
is shown below.
##STR00096##
Step 1: Methyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-methylthieno[3,2-b]pyridine-2-car-
boxamido)propanoate
##STR00097##
[0409] A mixture of 7-methylthieno[3,2-b]pyridine-2-carboxylic acid
(800 mg, 4.14 mmol), (R)-methyl
3-amino-2-(((benzyloxy)carbonyl)amino)propanoate (1.2 g, 4.14 mmol,
HCl salt), TBTU (1.99 g, 6.21 mmol) and N,N-diisopropylethylamine
(2.68 g, 20.7 mmol, 3.6 mL) in DMF (20 mL) was stirred at
25.degree. C. for 16 h. The mixture was diluted with water (90 mL)
and extracted with ethyl acetate (20 mL.times.3). The organic phase
was washed with brine (20 mL.times.2), dried over anhydrous sodium
sulfate and concentrated. The residue was purified by CombiFlash
(Petroleum ether: Ethyl acetate=0.sup..about.90%) to give methyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate
(1.1 g).
[0410] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 8.61 (d, J=4.8 Hz,
1H), 7.91 (s, 1H), 7.40-7.25 (m, 6H), 7.13 (d, 4.4 Hz, 1H), 6.02
(br d, J=6.8 Hz, 1H), 5.11 (s, 2H), 4.63-4.55 (m, 1H), 3.98-3.83
(m, 2H), 3.79 (s, 3H), 2.58 (s, 3H).
Step 2: Methyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate
##STR00098##
[0412] A mixture of methyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate
(600 mg, 1.4 mmol) and HBr/AcOH (6 mL, 33%) was stirred at
25.degree. C. for 16 h. The mixture was diluted with methyl
tert-butyl ether (6 mL). The precipitate was filtered and dried to
give the crude product (0.6 g). The crude product was washed with
MeOH (5 mL) and filtered. The filter cake was dried to give methyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)
propanoate (400 mg) as HBr salt.
[0413] .sup.1H NMR (400 MHz, CD.sub.3OD) .delta. 8.91 (d, J=6.4 Hz,
1H), 8.45 (s, 1H), 7.91-7.86 (m, 1H), 4.39 (t, J=4.8 Hz, 1H),
4.10-4.03 (m, 1H), 3.97-3.91 (m, 1H), 3.90 (s, 3H), 2.93 (s,
3H).
[0414] LCMS (MH+): m/z=294.4, t.sub.R (min, Method BB)=0.27.
[0415] [.alpha.].sup.20D=-2.0, (c=1.0 mg/mL, CH.sub.3OH).
Compound 2d
Ethyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoat-
e
[0416] The overall synthesis scheme for the preparation of ethyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate
is shown below.
##STR00099##
Step 1: Ethyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-methylthieno[3,2-b]pyridine-2-car-
boxamido)propanoate
##STR00100##
[0418] To a solution of 7-methylthieno[3,2-b]pyridine-2-carboxylic
acid (2.5 g, crude) in DMF (30 mL) was added TBTU (6.23 g, 19.4
mmol), N,N-diisopropylethylamine (5.02 g, 38.8 mmol) and (R)-ethyl
3-amino-2-(((benzyloxy)carbonyl)amino)propanoate (3.45 g, 11.38
mmol, HCl salt). The mixture was stirred at 20.degree. C. for 16 h.
The mixture was diluted with water (50 mL) and extracted with ethyl
acetate (40 mL.times.3). The combined organic layer was washed with
water (50 mL.times.2) and brine (50 mL.times.2), dried over
anhydrous sodium sulfate, filtered and concentrated. The residue
was purified by Combi Flash on silica gel (petroleum ether:ethyl
acetate with ethyl acetate from 0 to 100%) twice to give ethyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-methylthieno[3,2-b]pyridine-2-car-
boxamido)propanoate (2.6 g). .sup.1H NMR (400 MHz, CDCl.sub.3)
.delta. 8.62 (d, J=4.8 Hz, 1H), 7.93 (s, 1H), 7.49 (br s, 1H),
7.36-7.24 (m, 5H), 7.14 (d, J=4.8 Hz, 1H), 6.06 (br d, J=6.4 Hz,
1H), 5.12 (s, 2H), 4.63-4.55 (m, 1H), 4.25 (m, 2H), 4.00-3.82 (m,
2H), 2.59 (s, 3H), 1.29 (t, J=7.2 Hz, 3H).
Step 2: Ethyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate
##STR00101##
[0420] A mixture of ethyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-methylthieno[3,2-b]pyridine-2-car-
boxamido)propanoate (1.6 g, 3.62 mmol) in 30% HBr in AcOH (20 mL)
was stirred at 20.degree. C. for 3 h. The mixture was concentrated.
To the residue was added water (35 mL) and washed with methyl
tert-butyl ether (30 mL). The aqueous layer was lyophilized to give
ethyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate
(1.55 g) as 2HBr salt.
[0421] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 9.47 (br s, 1H),
8.86 (d, J=4.8 Hz, 1H), 8.54 (br s, 3H), 8.41 (s, 1H), 7.64 (m,
1H), 4.28-4.22 (m, 1H), 4.18 (q, J=7.2 Hz, 2H), 3.85-3.72 (m, 2H),
2.71 (s, 3H), 1.18 (t, J=7.2 Hz, 3H).
[0422] LCMS (MH+): m/z=308.4, t.sub.R (min, Method BB)=0.30.
[0423] [.alpha.].sup.20D=2.1, (c=7.6 mg/mL, MeOH).
Compound 2e
Propyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoa-
te
[0424] The overall synthesis scheme for the preparation of propyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate
is shown below.
##STR00102##
Step 1: Propyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-methylthieno[3,2-b]pyridine-2-car-
boxamido)propanoate
##STR00103##
[0426] To a mixture of 7-methylthieno[3,2-b]pyridine-2-carboxylic
acid (300 mg, crude), TBTU (748 mg, 2.33 mmol) and
N,N-diisopropylethylamine (602 mg, 4.66 mmol) in DMF (6 mL) was
added (R)-propyl 3-amino-2-(((benzyloxy)carbonyl)amino)propanoate
(479 mg, 1.71 mmol, HCl salt). The mixture was stirred at
20.degree. C. for 14 h. The reaction mixture was added water (10
mL), extracted with ethyl acetate (10 mL.times.3). The combined
organic layers were washed with brine (10 mL.times.3), dried over
anhydrous sodium sulfate and concentrated. The residue was purified
by Combi Flash on silica gel (petroleum ether/ethyl acetate with
ethyl acetate from 0% to 80%) twice to give propyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-methylthieno[3,2-b]pyridine-2-car-
boxamido)propanoate (140 mg).
[0427] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 8.64 (d, J=4.8 Hz,
1H), 7.93 (s, 1H), 7.36-7.27 (m, 6H), 7.15 (d, J=4.8 Hz, 1H), 5.96
(br d, J=5.6 Hz, 1H), 5.14 (s, 2H), 4.64-4.55 (m, 1H), 4.16 (m,
2H), 4.03-3.78 (m, 2H), 2.61 (s, 3H), 1.75-1.68 (m, 2H), 0.95 (t,
J=7.2 Hz, 3H).
Step 2: Propyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate
##STR00104##
[0429] A mixture of propyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-methylthieno[3,2-b]pyridine-2-car-
boxamido)propanoate (140 mg, 0.31 mmol) in 30% HBr in AcOH (6 mL)
was stirred at 20.degree. C. for 1 hour. The reaction mixture was
concentrated. The residue was added MeCN (2 mL) and washed with
methyl tert-butyl ether (10 mL.times.3). The solid was collected by
filtration, added water (10 mL) and lyophilized to give propyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate
(98 mg) as HBr salt.
[0430] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 9.32 (br t,
J=6.0 Hz, 1H), 8.76 (d, J=5.2 Hz, 1H), 8.50 (m, 3H), 8.32 (s, 1H),
7.50 (d, J=4.8 Hz, 1H), 4.30-4.21 (m, 1H), 4.18-4.05 (m, 2H), 2.65
(s, 3H), 1.64-1.54 (m, 2H), 0.85 (t, J=7.2 Hz, 3H).
[0431] LCMS (MH+): m/z=322.1, t.sub.R (min, Method BB)=0.36.
[0432] [.alpha.].sup.20D=-0.57 (c=4.6 mg/mL, CH.sub.3OH).
Compound 2f
Isopropyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propa-
noate
[0433] The overall synthesis scheme for the preparation of
isopropyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate
is shown below.
##STR00105##
Step 1: Isopropyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-methylthieno[3,2-b]pyridine-2-car-
boxamido)propanoate
##STR00106##
[0435] To a solution of 7-methylthieno[3,2-b]pyridine-2-carboxylic
acid (2.5 g, crude) in DMF (30 mL) was added TBTU (6.23 g, 19.41
mmol), N,N-diisopropylethylamine (5.02 g, 38.82 mmol) and isopropyl
(R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoate (3.5 g, 11.0
mmol, HCl salt). The mixture was stirred at 20.degree. C. for 16 h.
The mixture was diluted with water (50 mL) and extracted with ethyl
acetate (40 mL.times.3). The combined organic layer was washed with
water (50 mL.times.2) and brine (50 mL.times.2), dried over
anhydrous sodium sulfate, filtered and concentrated. The residue
was purified by Combi Flash on silica gel (petroleum ether: ethyl
acetate with ethyl acetate from 0 to 100%) twice to give isopropyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-methylthieno[3,2-b]pyridine-2-car-
boxamido)propanoate (2.4 g).
[0436] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 8.62 (d, J=4.8 Hz,
1H), 7.93 (s, 1H), 7.48 (br s, 1H), 7.36-7.24 (m, 5H), 7.14 (d,
J=4.8 Hz, 1H), 6.03 (br d, J=6.8 Hz, 1H), 5.15-5.05 (m, 3H),
4.61-4.51 (m, 1H), 3.97-3.82 (m, 2H), 2.60 (s, 3H), 1.27 (d, J=6.0
Hz, 6H).
Step 2: Isopropyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate
##STR00107##
[0438] Isopropyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-methylthieno[3,2-b]pyridine-2-car-
boxamido)propanoate (1.6 g, 3.51 mmol) in 30% HBr in AcOH (15 mL)
was stirred at 20.degree. C. for 2 h. The mixture was concentrated.
The residue was added water (35 mL) and washed with methyl
tert-butyl ether (30 mL). The aqueous layer was lyophilized to give
compound Isopropyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-methylthieno[3,2-b]pyridine-2-car-
boxamido)propanoate (1.6 g) as HBr salt.
[0439] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 9.36 (m, 1H),
8.79 (d, J=5.2 Hz, 1H), 8.55-8.40 (m, 3H), 8.35 (s, 1H), 7.55 (d,
J=5.2 Hz, 1H), 5.04-4.93 (m, 1H), 4.24-4.15 (m, 1H), 3.80-3.70 (m,
2H), 2.68 (s, 3H), 1.20 (dd, J=15.6, 6.0 Hz, 6H).
[0440] LCMS (MH+): m/z=322.4, t.sub.R (min, Method BB)=0.34.
[0441] [.alpha.].sup.20D=1.8, (c=7.0 mg/mL, MeOH).
Compound 2g
Cyclopropyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate
[0442] The overall synthesis scheme for the preparation of
cyclopropyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate
is shown below.
##STR00108##
Step 1: Cyclopropyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-methylthieno[3,2-b]pyridine-2-car-
boxamido)propanoate
##STR00109##
[0444] To a solution of 7-methylthieno[3,2-b]pyridine-2-carboxylic
acid (200 mg, crude) in DMF (3 mL) was added cyclopropyl
(R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoate (326 mg, 1.04
mmol, HCl salt), TBTU (499 mg, 1.55 mmol) and
N,N-diisopropylethylamine (401 mg, 3.11 mmol). The reaction mixture
was stirred at 10.degree. C. for 3 h. The reaction mixture was
added water (10 mL), extracted with ethyl acetate (10 mL.times.3).
The combined organic layers were washed with brine (10 mL.times.3),
dried over anhydrous sodium sulfate and concentrated. The residue
was purified by column chromatography on silica gel (petroleum
ether/ethyl acetate with ethyl acetate from 70% to 80%) to give
cyclopropyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-methylthieno[3,2-b]pyridine-2-car-
boxamido)propanoate (150 mg).
[0445] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 8.97 (br t,
J=5.6 Hz, 1H), 8.60 (d, J=4.8 Hz, 1H), 8.16 (s, 1H), 7.79 (d, J=8.0
Hz, 1H), 7.33-7.21 (m, 6H), 5.07-4.97 (m, 2H), 4.35-4.24 (m, 1H),
4.02-3.99 (m, 1H), 3.66-3.53 (m, 2H), 2.54 (s, 3H), 0.65-0.46 (m,
4H).
Step 2: Cyclopropyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate
##STR00110##
[0447] A solution of cyclopropyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-methylthieno[3,2-b]pyridine-2-car-
boxamido)propanoate (120 mg, 0.26 mmol) in AcOH (5 mL) were added
30% HBr in AcOH (0.5 mL). The reaction mixture was stirred at
10.degree. C. for 2 h. The mixture was added methyl tert-butyl
ether (6 mL) and stirred for 5 minutes and then allowed to stand
for 5 minutes and then the organic solvent was discarded. The
residue was concentrated. The residue was then washed with methyl
tert-butyl ether (5 mL.times.2) to give cyclopropyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate
(100 mg) as HBr salt.
[0448] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 9.36 (br t,
J=5.6 Hz, 1H), 8.80 (d, J=5.2 Hz, 1H), 8.52 (br s, 3H), 8.34 (s,
1H), 7.55 (d, J=4.8 Hz, 1H), 4.28-4.21 (m, 1H), 4.20-4.14 (m, 1H),
3.80-3.75 (m, 2H), 2.68 (s, 3H), 0.75-0.61 (m, 4H).
[0449] LCMS (MH+): m/z=319.8, t.sub.R (min, Method BB)=0.32.
[0450] [.alpha.].sup.20D=2 (c=1 mg/mL, MeOH).
Compound 2h
Butyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoat-
e
[0451] The overall synthesis scheme for the preparation of
cyclopropyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate
is shown below.
##STR00111##
Step 1: Butyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-methylthieno[3,2-b]pyridine-2-car-
boxamido)propanoate
##STR00112##
[0453] To a solution of butyl
(R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoate (428 mg, 1.29
mmol, HCl salt), N,N-diisopropylethylamine (502 mg, 3.88 mmol) and
7-methylthieno[3,2-b]pyridine-2-carboxylic acid (250 mg, crude) in
DMF (50 mL) was added TBTU (623 mg, 1.94 mmol) under N.sub.2. The
mixture was stirred at 20.degree. C. for 16 h. The reaction was
added water (100 ml) and extracted with ethyl acetate (30
mL.times.3). The organic layers were concentrated. The residue was
purified by Combi Flash (silica gel, Petroleum ether: Ethyl
acetate, Ethyl acetate from 0% to 70%) to give butyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-methylthieno[3,2-b]pyridine-
-2-carboxamido)propanoate (120 mg).
[0454] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 8.63 (d, J=4.8 Hz,
1H), 7.92 (s, 1H), 7.41-7.27 (m, 6H), 7.15 (d, J=4.8 Hz, 1H), 5.96
(br d, J=6.8 Hz, 1H), 5.13 (s, 2H), 4.65-4.51 (m, 1H), 4.26-4.13
(m, 2H), 4.04-3.89 (m, 1H), 3.88-3.77 (m, 1H), 2.60 (s, 3H),
1.66-1.55 (m, 2H), 1.42-1.32 (m, 2H), 0.92 (t, J=7.2 Hz, 3H).
Step 2: Butyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate
##STR00113##
[0456] A solution of butyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-methylthieno[3,2-b]pyridine-2-car-
boxamido)propanoate (120 mg, 0.26 mmol) in 30% HBr in AcOH (10 mL)
was stirred at 20.degree. C. for 2 h. The reaction was
concentrated. The residue was added MeCN (1 mL) and methyl
tert-butyl ether (20 mL) and stirred at 20.degree. C. for 1 hour,
filtered and dried to give butyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate
(95 mg) as HBr salt.
[0457] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 9.43 (br t,
J=5.6 Hz, 1H), 8.84 (d, J=5.6 Hz, 1H), 8.53 (br s, 3H), 8.39 (s,
1H), 7.61 (d, J=5.2 Hz, 1H), 4.26-4.24 (m, 1H), 4.20-4.08 (m, 2H),
3.84-3.76 (m, 2H), 2.71 (s, 3H), 1.59-1.47 (m, 2H), 1.35-1.22 (m,
2H), 0.78 (t, J=7.2 Hz, 3H).
[0458] LCMS (MH+): m/z=336.1, t.sub.R (min, Method BB)=0.41.
[0459] [.alpha.].sup.20D=3 (c=2 mg/mL, MeOH).
Compound 2i
Isobutyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propan-
oate
[0460] The overall synthesis scheme for the preparation of isobutyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate
is shown below.
##STR00114##
Step 1: Isobutyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-methylthieno[3,2-b]pyridine-2-car-
boxamido)propanoate
##STR00115##
[0462] To a solution of 7-methylthieno[3,2-b]pyridine-2-carboxylic
acid (200 mg, crude) in DMF (3 mL) were added isobutyl
(R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoate (377 mg, 1.14
mmol, HCl salt), TBTU (499 mg, 1.55 mmol) and
N,N-diisopropylethylamine (401 mg, 3.11 mmol). The reaction mixture
was stirred at 15.degree. C. for 2 h. The reaction mixture was
added water (10 mL), and was extracted with ethyl acetate (10
mL.times.3). The combined organic layers were washed with brine (10
mL.times.3), dried over anhydrous sodium sulfate and concentrated.
The residue was purified by column chromatography on silica gel
(petroleum ether/ethyl acetate with ethyl acetate from 50% to 60%)
to give isobutyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-methylthieno[3,2-b]pyridine-2-car-
boxamido)propanoate (130 mg).
[0463] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 8.64 (d, J=4.8 Hz,
1H), 7.92 (s, 1H), 7.39-7.27 (m, 6H), 7.15 (d, J=4.0 Hz, 1H), 5.95
(d, J=6.4 Hz, 1H), 5.13 (s, 2H), 4.65-4.55 (m, 1H), 4.06-3.92 (m,
3H), 3.87-3.80 (m, 1H), 2.60 (s, 3H), 2.00-1.90 (m, 1H), 0.94 (d,
J=6.8 Hz, 6H).
Step 2: Isobutyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate
##STR00116##
[0465] A solution of isobutyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-methylthieno[3,2-b]pyridine-2-car-
boxamido)propanoate (120 mg, 0.26 mmol) in 30% HBr in AcOH (3 mL)
was stirred at 10.degree. C. for 1 hour. The solvent was removed.
The residue was washed with a mixture of MeCN (1 mL) and methyl
tert-butyl ether (5 mL). The organic layer was decanted, then the
residue was lyophilized to give isobutyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate
(110 mg) as HBr salt.
[0466] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 9.32 (br s, 1H),
8.78 (br s, 1H), 8.51 (br s, 3H), 8.35 (br s, 1H), 7.53 (br s, 1H),
4.35-4.25 (m, 1H), 4.03-3.89 (m, 2H), 3.81 (t, J=5.6 Hz, 2H), 2.67
(s, 3H), 1.97-1.82 (m, 1H), 0.88 (dd, J=2.0, 6.8 Hz, 6H).
[0467] LCMS (MH+): m/z=336.1, t.sub.R (min, Method BB)=0.41.
[0468] [.alpha.].sup.20D=2 (c=1 mg/mL, MeOH).
Compound 2J
Cyclopropylmethyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate
##STR00117##
[0470] To a solution of
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoic
acid (150 mg, 0.42 mmol, HBr salt) in cyclopropylmethanol (5 mL)
was added thionyl chloride (99 mg, 0.83 mmol). The mixture was
stirred at 40.degree. C. for 16 h. The reaction mixture was
concentrated. The residue was washed with methyl tert-butyl ether
(10 mL.times.3). The solid was collected by filtration and dried.
The product was purified by preparative HPLC (Method E) and
lyophilized to give cyclopropylmethyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate
(49 mg) as HCl salt.
[0471] .sup.1H NMR (400 MHz, MeOD) .delta. 8.91 (d, J=5.6 Hz, 1H),
8.46 (s, 1H), 7.87 (d, J=5.6 Hz, 1H), 4.39 (t, J=5.6 Hz, 1H),
4.20-3.95 (m, 4H), 2.93 (s, 3H), 1.34-1.09 (m, 1H), 0.63-0.54 (m,
2H), 0.40-0.31 (m, 2H).
[0472] LCMS (MH+): m/z=333.8, t.sub.R (min, Method BB)=0.37.
[0473] [.alpha.].sup.20D=4.1 (c=7.8 mg/mL, CH.sub.3OH).
Compound 2k
2-methoxyethyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate
[0474] The overall synthesis scheme for the preparation of
2-methoxyethyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate
is shown below.
##STR00118##
Step 1: 2-methoxyethyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-methylthieno[3,2-b]pyridine-2-car-
boxamido)propanoate
##STR00119##
[0476] To a solution of 7-methylthieno[3,2-b]pyridine-2-carboxylic
acid (800 mg, 4.14 mmol) and 2-methoxyethyl
(R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoate (2.07 g, 6.21
mmol, HCl salt) in DMF (20 mL) was added TBTU (1.60 g, 4.97 mmol)
and N,N-diisopropylethylamine (1.61 g, 12.42 mmol). The mixture was
stirred at 20.degree. C. for 16 h. The reaction mixture was
quenched with water (10 mL), and extracted with ethyl acetate (20
mL.times.3). The combined organic layers were washed with brine (10
mL.times.3), dried over anhydrous sodium sulfate and concentrated.
The residue was purified by Combi Flash on silica gel (ethyl
acetate/Petroleum ether with ethyl acetate from 0% to 100%) to give
2-methoxyethyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-methylthieno[3,2-b]pyridine-2-car-
boxamido)propanoate (800 mg).
[0477] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 9.01 (t, J=5.6
Hz, 1H), 8.63 (d, J=4.8 Hz, 1H), 8.20 (s, 1H), 7.83 (d, J=8.0 Hz,
1H), 7.37-7.24 (m, 6H), 5.09-4.99 (m, 2H), 4.42-4.34 (m, 1H),
4.20-4.12 (m, 2H), 3.74-3.57 (m, 2H), 3.50-3.42 (m, 2H), 3.17 (s,
3H), 2.57 (s, 3H).
Step 2: 2-methoxyethyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate
##STR00120##
[0479] To a solution of 2-methoxyethyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-methylthieno[3,2-b]pyridine-2-car-
boxamido)propanoate (400 mg, 0.85 mmol) in AcOH (10 mL) was added
30% HBr in AcOH (1 mL), the mixture was stirred at 20.degree. C.
for 16 h. The mixture was concentrated. The residue was purified by
preparative HPLC (Method E) to give 2-methoxyethyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate
(170 mg) as HCl salt.
[0480] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 9.72 (t, J=5.6
Hz, 1H), 8.88-8.74 (m, 4H), 8.54 (s, 1H), 7.60 (d, J=5.2 Hz, 1H),
4.33-4.18 (m, 3H), 3.54-3.48 (m, 2H), 3.17 (s, 3H), 2.70 (s,
3H).
[0481] LCMS (MH+): m/z=338.1, t.sub.R (min, Method BB)=0.3.
[0482] [.alpha.].sup.20D=-14 (c=3 mg/mL, DMSO).
Compound 21
Isopentyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propa-
noate
[0483] The overall synthesis scheme for the preparation of
isopentyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate
is shown below.
##STR00121##
Step 1: Isopentyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-methylthieno[3,2-b]pyridine-2-car-
boxamido)propanoate
##STR00122##
[0485] To a mixture of 7-methylthieno[3,2-b]pyridine-2-carboxylic
acid (200 mg, crude) and isopentyl
(R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoate (393 mg, 1.14
mmol, HCl salt) in DMF (5 mL) was added TBTU (499 mg, 1.55 mmol)
and N,N-diisopropylethylamine (401 mg, 3.11 mmol), the mixture was
stirred at 20.degree. C. for 1 hour. The mixture was added water
(10 mL) and extracted with ethyl acetate (20 mL.times.3), the
organic layers were washed with brine (20 mL.times.3), dried over
anhydrous sodium sulfate, filtered and concentrated. The residue
was purified by Combi Flash on silica gel chromatography (Petroleum
ether: Ethyl acetate, Ethyl acetate from 0% to 70%) twice to give
isopentyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-methylthieno[3,2-b]pyridine-2-car-
boxamido)propanoate (250 mg).
[0486] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 8.65 (d, J=4.8 Hz,
1H), 7.92 (s, 1H), 7.38-7.28 (m, 6H), 7.16 (d, J=4.4 Hz, 1H), 5.92
(br d, J=6.4 Hz, 1H), 5.14 (s, 2H), 4.64-4.55 (m, 1H), 4.29-4.19
(m, 2H), 4.01-3.79 (m, 2H), 2.61 (s, 3H), 1.73-1.65 (m, 1H),
1.59-1.52 (m, 2H), 0.92 (d, J=6.4 Hz, 6H).
Step 2: Isopentyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate
##STR00123##
[0488] A solution of isopentyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-methylthieno[3,2-b]pyridine-2-car-
boxamido)propanoate (200 mg, 0.41 mmol) in 30% HBr in AcOH (6 mL)
was stirred at 20.degree. C. for 1 hour. The sample was added water
(15 mL) and lyophilized. The obtained solid was further purified by
preparative-HPLC (Method F) to give isopentyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate
(105 mg) as HCl salt.
[0489] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 9.66 (br t,
J=5.6 Hz, 1H), 8.82-8.75 (m, 4H), 8.52 (s, 1H), 7.54 (d, J=4.8 Hz,
1H), 4.15-4.12 (t, 2H), 3.92-3.73 (m, 2H), 2.67 (s, 3H), 1.65-1.54
(m, 1H), 1.45-1.38 (m, 2H), 0.77 (t, J=6.8 Hz, 6H).
[0490] LCMS (MH+): m/z=349.8, t.sub.R (min, Method BB)=0.45.
[0491] [.alpha.].sup.20D=+2.5 (c=4.0 mg/mL, CH.sub.3OH).
Compound 2m
Benzyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoa-
te
[0492] The overall synthesis scheme for the preparation of benzyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate
is shown below.
##STR00124##
Step 1: Benzyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-methylthieno[3,2-b]pyridine-2-car-
boxamido)propanoate
##STR00125##
[0494] To a solution of 7-methylthieno[3,2-b]pyridine-2-carboxylic
acid (300 mg, crude) in DMF (10 mL) was added TBTU (748 mg, 2.33
mmol), N,N-diisopropylethylamine (602 mg, 4.66 mmol) and benzyl
(R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoate (566 mg, 1.55
mmol, HCl salt). The mixture was stirred at 20.degree. C. for 15 h.
The mixture was diluted with water (30 mL) and extracted with ethyl
acetate (25 mL.times.3). The combined organic layers were washed
with brine (30 mL) and concentrated. The residue was purified by
Combi Flash on silica gel (petroleum ether:ethyl acetate with ethyl
acetate from 0 to 100%) to give 390 mg crude product. The crude
product was triturated with DCM (15 mL) and the solid was collected
and dried to give benzyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-methylthieno[3,2-b]pyridine-2-car-
boxamido)propanoate (230 mg).
[0495] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 9.04 (br t,
J=5.6 Hz, 1H), 8.64 (d, J=4.8 Hz, 1H), 8.19 (s, 1H), 7.89 (br d,
J=8.4 Hz, 1H), 7.37-7.22 (m, 11H), 5.17-5.00 (m, 4H), 4.48-4.39 (m,
1H), 3.76-3.62 (m, 2H), 2.57 (s, 3H).
Step 2: Benzyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate
##STR00126##
[0497] To a solution of benzyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-methylthieno[3,2-b]pyridine-2-car-
boxamido)propanoate (100 mg, 0.20 mmol) in AcOH (5 mL) was added
30% HBr in AcOH (0.5 mL). The mixture was stirred at 20.degree. C.
for 1 hour 40 min. The mixture was diluted with methyl tert-butyl
ether (6 mL) and a precipitate was formed. The organic layer was
discarded and the precipitate was collected. The residue was washed
with MeCN (5 mL) and dried to give benzyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate
(82 mg) as HBr salt.
[0498] .sup.1H NMR (400 MHz, CD.sub.3OD) .delta. 8.92 (d, J=6.0 Hz,
1H), 8.33 (s, 1H), 7.88 (d, J=5.6 Hz, 1H), 7.44-7.37 (m, 2H),
7.29-7.15 (m, 3H), 5.38-5.32 (m, 1H), 5.30-5.24 (m, 1H), 4.44 (t,
J=5.6 Hz, 1H), 4.09-4.01 (m, 1H), 3.99-3.90 (m, 1H), 2.93 (s,
3H).
[0499] LCMS (MH+): m/z=370, t.sub.R (min, Method BB)=0.42.
[0500] [.alpha.].sup.20D=8.6 (c=3.2 mg/mL, CH.sub.3OH).
Compound 2n
Cyclohexyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)prop-
anoate
[0501] The overall synthesis scheme for the preparation of
cyclohexyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate
is shown below.
##STR00127##
Step 1: cyclohexyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-methylthieno[3,2-b]pyridine-2-car-
boxamido)propanoate
##STR00128##
[0503] A mixture of 7-methylthieno[3,2-b]pyridine-2-carboxylic acid
(300 mg, 1.55 mmol), cyclohexyl
(R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoate (590 mg, 1.65
mmol, HCl salt), TBTU (747.77 mg, 2.33 mmol) and
N,N-diisopropylethylamine (602 mg, 4.66 mmol) in DMF (10 mL) was
stirred at 20.degree. C. for 16 h. The mixture was diluted with
water (10 mL) and extracted with ethyl acetate (10 mL.times.2). The
organic phase was washed with brine (10 mL.times.2), dried over
anhydrous sodium sulfate and concentrated. The residue was purified
by Combi Flash (silica gel, from 0 to 60%, Ethyl acetate in
petroleum ether) to give 350 mg of the crude product. The compound
was purified by SFC separation (Method SFC1) to give cyclohexyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-methylthieno[3,2-b]pyridine-2-car-
boxamido)propanoate (270 mg).
[0504] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 8.63 (d, J=4.8 Hz,
1H), 7.94 (s, 1H), 7.51-7.41 (m, 1H), 7.37-7.27 (m, 5H), 7.14 (d,
J=4.4 Hz, 1H), 6.03 (d, J=6.8 Hz, 1H), 5.12 (s, 2H), 4.90-4.81 (m,
1H), 4.62-4.50 (m, 1H), 4.00-3.77 (m, 2H), 2.60 (s, 3H), 1.91-1.64
(m, 4H), 1.57-1.28 (m, 6H).
Step 2: cyclohexyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate
##STR00129##
[0506] A solution of cyclohexyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-methylthieno[3,2-b]pyridine-2-car-
boxamido)propanoate (150 mg, 0.30 mmol) in 30% HBr in AcOH (2 mL)
was stirred at 20.degree. C. for 40 min. The mixture was
concentrated. The residue was washed with CH.sub.3CN (2 mL.times.3)
and the organic layer was decanted. The residue was lyophilized to
give cyclohexyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate
(98 mg) as HBr salt.
[0507] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 9.40 (m, 1H),
8.83 (d, J=5.2 Hz, 1H), 8.61-8.40 (m, 3H), 8.37 (s, 1H), 7.59 (d,
J=5.2 Hz, 1H), 4.86-4.73 (m, 1H), 4.33-4.17 (m, 1H), 3.84-3.71 (m,
2H), 2.70 (s, 3H), 1.85-1.72 (m, 2H), 1.69-1.55 (m, 2H), 1.49-1.14
(m, 6H).
[0508] LCMS (MH+): m/z=361.8, t.sub.R (min, Method BB)=0.45.
[0509] [.alpha.].sup.20D=1.50 (c=4.0 mg/mL, CH.sub.3OH).
Compound 2o
Phenyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoa-
te
[0510] The overall synthesis scheme for the preparation of phenyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate
is shown below.
##STR00130##
Step 1: Phenyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-methylthieno[3,2-b]pyridine-2-car-
boxamido)propanoate
##STR00131##
[0512] To a solution of 7-methylthieno[3,2-b]pyridine-2-carboxylic
acid (150 mg, crude) in DMF (5 mL) was added TBTU (374 mg, 1.16
mmol), N,N-diisopropylethylamine (301 mg, 2.33 mmol) and phenyl
(R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoate (272 mg,
crude, HCl). The mixture was stirred at 15.degree. C. for 16 h. The
mixture was diluted with water (15 mL) and extracted with ethyl
acetate (20 mL.times.3). The combined organic layers were washed
with brine (20 mL.times.3) and concentrated. The residue was
purified by Combi Flash on silica gel (petroleum ether: ethyl
acetate with ethyl acetate from 0 to 100%) to give 240 mg of the
product. The product was further triturated with DCM (3 mL). The
solid was collected by filtration to give compound phenyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-methylthieno[3,2-b]pyridin-
e-2-carboxamido)propanoate (100 mg).
[0513] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 9.16 (br t,
J=5.6 Hz, 1H), 8.63 (d, J=4.8 Hz, 1H), 8.24 (s, 1H), 8.06 (d, J=7.6
Hz, 1H), 7.44-7.26 (m, 9H), 7.09 (d, J=7.6 Hz, 2H), 5.16-5.05 (m,
2H), 4.65-4.54 (m, 1H), 3.88-3.78 (m, 2H), 2.57 (s, 3H).
Step 2: Phenyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate
##STR00132##
[0515] A mixture of phenyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-methylthieno[3,2-b]pyridine-2-car-
boxamido)propanoate (90 mg, 0.18 mmol) and 30% HBr in AcOH (3 mL)
was stirred at 15.degree. C. for 1 hour. The mixture was
concentrated. The residue was triturated with MeCN (2 mL) and
methyl tert-butyl ether (5 mL). The solid was collected and dried
to give phenyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate
(65 mg) as HBr salt.
[0516] .sup.1H NMR (400 MHz, CD.sub.3OD) .delta. 8.91 (d, J=5.6 Hz,
1H), 8.45 (s, 1H), 7.88 (d, J=5.6 Hz, 1H), 7.48-7.42 (m, 2H),
7.35-7.27 (m, 3H), 4.68 (t, J=5.2 Hz, 1H), 4.21-4.15 (m, 2H), 2.94
(s, 3H).
[0517] LCMS (MH+): m/z=355.8, t.sub.R (min, Method BB)=0.41.
[0518] [.alpha.].sup.20D=-9.3 (c=2.5 mg/mL, CH.sub.3OH).
Compound 2p
2-Oxo-2-(pyrrolidin-1-yl)ethyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate
[0519] The overall synthesis scheme for the preparation of
2-Oxo-2-(pyrrolidin-1-yl)ethyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate
is shown below.
##STR00133##
Step 1: 2-Oxo-2-(pyrrolidin-1-yl)ethyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-methylthieno[3,2-b]pyridine-2-car-
boxamido)propanoate
##STR00134##
[0521] To a solution of 7-methylthieno[3,2-b]pyridine-2-carboxylic
acid (150 mg, crude) in DMF (10 mL) was added TBTU (374 mg, 1.16
mmol), N,N-diisopropylethylamine (301 mg, 2.33 mmol) and
2-oxo-2-(pyrrolidin-1-yl)ethyl
(R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoate (300 mg,
crude, HCl salt). The mixture was stirred at 15.degree. C. for 16
h. The mixture was diluted with water (15 mL) and extracted with
ethyl acetate (20 mL.times.3). The combined organic layers were
washed with brine (20 mL.times.3) and concentrated. The residue was
purified by Combi Flash on silica gel (petroleum ether:ethyl
acetate with ethyl acetate from 0 to 100% then MeOH: ethyl acetate
with MeOH from 0% to 15%) twice to give
2-oxo-2-(pyrrolidin-1-yl)ethyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-methylthieno[3,2-b]pyridine-2-car-
boxamido)propanoate (170 mg).
[0522] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 9.18-9.07 (m, 1H),
8.60 (d, J=4.8 Hz, 1H), 8.20 (s, 1H), 7.40-7.31 (m, 5H), 7.11 (d,
J=4.8 Hz, 1H), 6.12 (br d, J=6.8 Hz, 1H), 5.19-5.06 (m, 3H),
4.67-4.61 (m, 1H), 4.53 (d, J=14.8 Hz, 1H), 4.42-4.31 (m, 1H),
3.85-3.77 (m, 1H), 3.71-3.59 (m, 2H), 3.46-3.37 (m, 2H), 2.60 (s,
3H), 2.07-2.02 (m, 2H), 1.96-1.88 (m, 2H).
Step 2: 2-Oxo-2-(pyrrolidin-1-yl)ethyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate
##STR00135##
[0524] To a solution of 2-oxo-2-(pyrrolidin-1-yl)ethyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-methylthieno[3,2-b]pyridine-2-car-
boxamido)propanoate (120 mg, 0.23 mmol) in AcOH (5 mL) was added
30% HBr in AcOH (0.5 mL). The mixture was stirred at 15.degree. C.
for 2 h. The mixture was added methyl tert-butyl ether (6 mL) and
stirred for 5 min and allowed to stand for 5 min and then the
organic solvent was decanted. The residue was concentrated. The
residue was then washed with methyl tert-butyl ether (5 mL.times.2)
to give compound 2-oxo-2-(pyrrolidin-1-yl)ethyl
(R)-2-amino-3-(7-methylthieno[3,2-b]pyridine-2-carboxamido)propanoate
(102 mg) as HBr salt.
[0525] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 9.40 (br t,
J=5.6 Hz, 1H), 8.81 (d, J=5.2 Hz, 1H), 8.62 (br s, 3H), 8.35 (s,
1H), 7.57 (d, J=4.8 Hz, 1H), 5.09 (d, J=15.2 Hz, 1H), 4.92 (d,
J=15.2 Hz, 1H), 4.55-4.46 (m, 1H), 3.48-3.36 (m, 4H), 2.69 (s, 3H),
1.96-1.88 (m, 2H), 1.86-1.78 (m, 2H).
[0526] LCMS (MH+): m/z=390.8, t.sub.R (min, Method BB)=0.34
min.
[0527] [.alpha.].sup.20D=14.5 (c=4.6 mg/mL, CH.sub.3OH).
Compound 1d
(R)-2-Amino-3-(7-(2-ethylphenyl)thieno[3,2-b]pyridine-2-carboxamido)propan-
oic acid
[0528] The overall synthesis scheme for the preparation of
(R)-2-Amino-3-(7-(2-ethylphenyl)thieno[3,2-b]pyridine-2-carboxamido)propa-
noic acid is shown below.
##STR00136##
Step 1: 7-(2-Ethylphenyl)thieno[3,2-b]pyridine-2-carboxylic
acid
##STR00137##
[0530] Lithium 7-chlorothieno[3,2-b]pyridine-2-carboxylate (1.0 g,
4.55 mmol), (2-ethylphenyl)boronic acid (1.16 g, 7.74 mmol),
Na.sub.2CO.sub.3 (1.45 g, 13.6 mmol) and Pd(dppf)Cl.sub.2 (333 mg,
0.46 mmol) in water (10 mL) and dioxane (20 mL) was de-gassed and
then heated to 110.degree. C. for 16 h under N.sub.2. The mixture
was concentrated, and the residue was diluted with water (10 mL),
and extracted with ethyl acetate (10 mL.times.2). The aqueous phase
was adjusted to pH=3.sup..about.4 with HCl (2M, 5 mL). The
precipitate was filtered and dried to give
7-(2-ethylphenyl)thieno[3,2-b]pyridine-2-carboxylic acid (700
mg).
[0531] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 8.86 (d, 1H),
8.18 (s, 1H), 7.51-7.47 (m, 2H), 7.45 (d, 1H), 7.40-7.36 (m, 1H),
7.35-7.32 (m, 1H), 2.45-2.43 (m, 2H), 0.97 (t, 3H)
Step 2: Benzyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-(2-ethylphenyl)thieno[3,2-b]pyrid-
ine-2-carboxamido)propanoate
##STR00138##
[0533] A mixture of
7-(2-ethylphenyl)thieno[3,2-b]pyridine-2-carboxylic acid (200 mg,
0.71 mmol), benzyl
(R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoate (258 mg, 0.71
mmol, HCl salt), O-(Benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium
tetrafluoroborate (340 mg, 1.06 mmol) and N,N-diisopropylethylamine
(456 mg, 3.53 mmol) in DMF (10 mL) was stirred at 25.degree. C. for
16 h. The mixture was diluted with water (30 mL) and extracted with
ethyl acetate (10 mL.times.3). The organic phase was washed with
brine (10 mL.times.2), dried over anhydrous sodium sulfate and
concentrated. The residue was purified by preparative-HPLC (Method
G) to give benzyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-(2-ethylphenyl)thieno[3,2-b]pyrid-
ine-2-carboxamido)propanoate (200 mg).
[0534] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 8.78 (d, 1H), 7.89
(s, 1H), 7.47-7.38 (m, 2H), 7.36-7.25 (m, 12H), 7.22 (d, 1H), 7.08
(br s, 1H), 5.97 (br s, 1H), 5.19 (s, 2H), 5.10 (s, 2H), 4.60-4.59
(m, 1H), 3.98-3.78 (m, 2H), 2.55-2.42 (m, 2H), 1.04 (t, 3H).
Step 3:
(R)-2-Amino-3-(7-(2-ethylphenyl)thieno[3,2-b]pyridine-2-carboxamid-
o)propanoic acid
##STR00139##
[0536] A mixture of benzyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-(2-ethylphenyl)thieno[3,2-b]pyrid-
ine-2-carboxamido)propanoate (60 mg, 0.10 mmol) and HBr/AcOH (3 mL,
33%) were stirred at 50.degree. C. for 16 h. The mixture was
diluted with MTBE (3 mL), filtered and washed with MTBE (3.times.3
mL). The filter cake was dried to give
(R)-2-amino-3-(7-(2-ethylphenyl)thieno[3,2-b]pyridine-2-carboxamido)propa-
noic acid (43 mg) as HBr salt.
[0537] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 9.24-9.22 (m,
1H), 8.87 (d, 1H), 8.41-8.26 (m, 4H), 7.54-7.44 (m, 3H), 7.41-7.36
(m, 1H), 7.35-7.30 (m, 1H), 4.24-4.07 (m, 1H), 3.82-3.77 (m, 1H),
3.74-3.69 (m, 1H), 2.45-2.43 (m, 2H), 0.96 (t, 3H).
[0538] LCMS (MH+): m/z=370.1, t.sub.R (min, Method BB)=0.46.
[0539] [.alpha.].sup.20D=-6.67, (c=1.5 mg/mL, CH.sub.3OH).
Compound 2q
Methyl
(R)-2-amino-3-(7-(2-ethylphenyl)thieno[3,2-b]pyridine-2-carboxamido-
)propanoate
##STR00140##
[0541] To a mixture of
(R)-2-amino-3-(7-(2-ethylphenyl)thieno[3,2-b]pyridine-2-carboxamido)
propanoic acid (295 mg, 555.28 mmol, HBr salt) in MeOH (10 mL) was
added thionyl chloride (199 mg, 1.67 mmol) dropwise at 0.degree. C.
After completion of the addition, the reaction stirred for 42 hr at
30.degree. C. The mixture was concentrated. The residue was
purified by Preparative-HPLC (Method H) to give the crude product
(0.2 g). The crude product was purified by Preparative-HPLC (Method
I) to give methyl
(R)-2-amino-3-(7-(2-ethylphenyl)thieno[3,2-b]pyridine-2-carboxamido)propa-
noate (45 mg).
[0542] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 8.99 (br s, 1H),
8.81 (d, J=4.8 Hz, 1H), 8.31 (s, 1H), 7.54-7.26 (m, 5H), 3.61 (s,
3H), 3.57-3.52 (m, 1H), 3.49-3.42 (m, 2H), 2.44-2.42 (m, 2H), 0.96
(t, J=7.6 Hz, 3H).
[0543] LCMS (MH+): m/z=384.4, t.sub.R (min, Method BB)=0.49
min.
[0544] [.alpha.].sup.20D=-12.0, (c=0.5 mg/mL, CH.sub.3OH).
Compound 1e
(R)-2-amino-3-(7-methoxythieno[3,2-b]pyridine-2-carboxamido)propanoic
acid
[0545] The overall synthesis scheme for the preparation of
(R)-2-amino-3-(7-methoxythieno[3,2-b]pyridine-2-carboxamido)propanoic
acid is shown below.
##STR00141##
Step 1: 7-methoxythieno[3,2-b]pyridine
##STR00142##
[0547] To MeOH (5.0 mL) was added Na (135 mg, 0.59 mmol). The
mixture was stirred at room temperature for 1 hour, and
7-chlorothieno[3,2-b]pyridine (200 mg, 1.18 mmol) was added. The
mixture was stirred at 110-120.degree. C. for another 15 h. The
reaction mixture was concentrated under reduced pressure to give
7-methoxythieno[3,2-b]pyridine (160 mg).
[0548] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 8.57 (d, 1H), 7.67
(d, 1H), 7.50 (d, 1H), 6.70 (d, 1H), 4.04 (s, 3H).
Step 2: 7-methoxythieno[3,2-b]pyridine-2-carboxylic acid
##STR00143##
[0550] To a solution of 7-methoxythieno[3,2-b]pyridine (150 mg,
0.90 mmol) in THF (15 mL) was added n-BuLi (2.5 M in hexane, 0.5
mL) at -78.degree. C. The mixture was stirred at -78.degree. C. for
0.5 hour. CO.sub.2 was bubbled into the solution for 0.5 hour. The
mixture was warmed to room temperature and stirred for another 15
h. The reaction mixture was concentrated under reduced pressure to
remove the solvent. The residue was diluted with water (20 mL) and
HCl (2M, to pH.sup..about.5), filtered and dried to give
7-methoxythieno[3,2-b]pyridine-2-carboxylic acid (120 mg).
[0551] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 8.56 (br, 1H),
7.86 (s, 1H), 7.04 (br, 1H), 4.01 (s, 3H).
Step 3: Benzyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-methoxythieno[3,2-b]pyridine-2-ca-
rboxamido)propanoate
##STR00144##
[0553] To a solution of 7-methoxythieno[3,2-b]pyridine-2-carboxylic
acid (120 mg, 0.57 mmol) and benzyl (R)-3-amino-2-(((benzyloxy)
carbonyl)amino) propanoate (207 mg, 0.63 mmol, HCl salt) in DMF (5
mL) was added O-(Benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium
tetrafluoroborate (276 mg, 0.86 mmol) and N,N-diisopropylethylamine
(370 mg, 2.87 mmol). The mixture was stirred at 20-30.degree. C.
for 16 h. The residue was diluted with water (20 mL) and extracted
with ethyl acetate (20 mL.times.2). The combined organic layers
were washed with brine (10 mL), dried over MgSO.sub.4, filtered and
concentrated under reduced pressure to give a residue. The residue
was purified by flash silica gel chromatography (Eluent of 0'100%
Ethyl acetate/Petroleum ether) to give benzyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-methoxythieno[3,2-b]pyridi-
ne-2-carboxamido)propanoate (48 mg).
Step 4:
(R)-2-amino-3-(7-methoxythieno[3,2-b]pyridine-2-carboxamido)propan-
oic acid
##STR00145##
[0555] A solution of benzyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-methoxythieno[3,2-b]pyridine-2-ca-
rboxamido)propanoate (125 mg, 0.24 mol) in HBr/AcOH (5 mL,
.sup..about.33%) was stirred at 50.degree. C. for 16 h. The
reaction mixture was concentrated under reduced pressure to give
(R)-2-amino-3-(7-methoxythieno[3,2-b]pyridine-2-carboxamido)
propanoic acid (100 mg) as HBr salt.
[0556] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 9.52 (t, Hz,
1H), 9.00 (d, 1H), 8.40-8.30 (m, 4H), 7.52 (d, 1H), 4.22 (s, 3H),
4.15-4.13 (m, 1H), 3.84-3.72 (m, 2H).
[0557] LCMS (MH+): m/z=296.2, t.sub.R (min, Method BB)=0.28.
[0558] [.alpha.].sup.20D=-1.45, (c=2.75 g/mL, CH.sub.3OH).
Compound 2r
Methyl (R)-2-amino-3-(7-methoxythieno[3,2-b]pyridine-2-carboxamido)
propanoate
##STR00146##
[0560] To a solution of
(R)-2-amino-3-(7-methoxythieno[3,2-b]pyridine-2-carboxamido)
propanoic acid (35 mg, 0.12 mmol) in MeOH (15 mL) was added thionyl
chloride (1 mL) at 0.degree. C. and stirred at 15-30.degree. C. for
16 h. The reaction mixture was concentrated under reduced pressure
to remove solvent. The residue was diluted with t-BuOMe/MeOH (15 mL
V: V=15:1) and filtered and the filter cake was dried under reduced
pressure to give a residue. The residue was diluted with water (15
mL) and sodium carbonate (sat. aq) to pH.sup..about.9 extracted
with ethyl acetate (15 mL.times.3). The combined organic layers
were washed with brine (10 mL), dried over magnesium sulfate,
filtered and concentrated under reduced pressure to give a residue.
The residue was diluted with water (15 mL) and HCl (2M) to
pH.sup..about.4 and was freeze-dried to give methyl
(R)-2-amino-3-(7-methoxythieno[3,2-b]pyridine-2-carboxamido)propanoate
(35 mg) as HCl salt.
[0561] .sup.1H NMR (400 MHz, D.sub.2O) .delta. 8.74 (d, J=6.8 Hz,
1H), 8.09 (s, 1H), 7.41 (d, J=6.8 Hz, 1H), 4.42 (t, J=5.2 Hz, 1H),
4.40 (s, 3H). 4.25-3.99 (m, 2H), 3.94 (s, 3H)
[0562] LCMS (MH+): m/z=310.2, t.sub.R (min, Method BB)=0.31.
[0563] [.alpha.]20D=4 (c=1 mg/mL, CH.sub.3OH).
Compound 1f
(R)-2-amino-3-(7-(trifluoromethyl)thieno[3,2-b]pyridine-2-carboxamido)
propanoic acid
[0564] The overall synthesis scheme for the preparation of
(R)-2-amino-3-(7-(trifluoromethyl)thieno[3,2-b]pyridine-2-carboxamido)
propanoic acid is shown below.
##STR00147##
Step 1: 7-Iodothieno[3,2-b]pyridine
##STR00148##
[0566] A solution of 7-chlorothieno[3,2-b]pyridine (1.00 g, 5.90
mmol) in HI (10 mL, 45% in water) was stirred at 130.degree. C. for
16 h. The reaction mixture was cooled to room temperature,
carefully quenched with sat.aq. Na.sub.2CO.sub.3 to
pH=6.sup..about.7, and extracted with ethyl acetate (3.times.10
mL). The combined organic layers were washed with brine (3.times.10
mL), dried over anhydrous sodium sulfate and concentrated. The
residue was purified by CombiFlash (petroleum ether/ethyl acetate
with ethyl acetate from 5% to 10%) to give
7-iodothieno[3,2-b]pyridine (1.2 g).
[0567] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 8.32 (d, J=4.8 Hz,
1H), 7.85-7.77 (m, 2H), 7.66 (d, J=5.2 Hz, 1H).
Step 2: 7-(Trifluoromethyl)thieno[3,2-b]pyridine
##STR00149##
[0569] To a solution of 7-iodothieno[3,2-b]pyridine (500 mg, 1.92
mmol) in DMF (5 mL) were added CuI (401 mg, 2.11 mmol), KF (334 mg,
5.75 mmol) and TMSCF.sub.3 (327 mg, 2.30 mmol). The reaction
mixture was stirred at 80.degree. C. for 16 h. The reaction mixture
was quenched with water (10 mL), and extracted with ethyl acetate
(3.times.10 mL). The combined organic layers were washed with brine
(3.times.10 mL), dried over anhydrous sodium sulfate and
concentrated.
[0570] The residue was purified by CombiFlash (petroleum
ether/ethyl acetate with ethyl acetate from 0% to 3%) to give
7-(trifluoromethyl)thieno[3,2-b]pyridine (140 mg).
[0571] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 8.87 (d, J=4.4 Hz,
1H), 7.90 (d, J=5.6 Hz, 1H), 7.68 (d, J=5.6 Hz, 1H), 7.52 (d, J=4.8
Hz, 1H).
Step 3: 7-(Trifluoromethyl)thieno[3,2-b]pyridine-2-carboxylic
acid
##STR00150##
[0573] A solution of 7-(trifluoromethyl)thieno[3,2-b]pyridine (120
mg, 0.59 mmol) in THF (2 mL) was cooled to -78.degree. C. and
treated dropwise with n-BuLi (2.5 M solution in hexanes, 0.5 ml,
1.25 mmol) and stirred at -78.degree. C. for 30 minutes. The
reaction mixture was bubbled with CO.sub.2 (15 psi) and stirred at
-78.degree. C. for 1 hr. The reaction mixture was quenched with
water (10 mL), and extracted with ethyl acetate (3.times.10 mL).
The combined organic layers were washed with brine (3.times.10 mL),
dried over anhydrous sodium sulfate and concentrated to give
7-(trifluoromethyl)thieno[3,2-b]pyridine-2-carboxylic acid (70
mg).
[0574] LCMS (MH+): m/z=247.9, t.sub.R=0.709 min.
Step 4: benzyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-(trifluoromethyl)thieno
[3,2-b]pyridine-2-carboxamido)propanoate
##STR00151##
[0576] To a solution of
7-(trifluoromethyl)thieno[3,2-b]pyridine-2-carboxylic acid (130 mg,
0.52 mmol) in DMF (5 mL) were added benzyl
(R)-3-amino-2-(((benzyloxy)carbonyl) amino)propanoate (192 mg, 0.52
mmol HCl salt), O-(Benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium
tetrafluoroborate (253 mg, 0.79 mmol) and N,N-diisopropylethylamine
(203 mg, 1.58 mmol). The reaction mixture was stirred at 25.degree.
C. for 16 h. The reaction mixture was quenched with water (10 mL),
and extracted with ethyl acetate (3.times.10 mL). The combined
organic layers were washed with brine (3.times.10 mL), dried over
anhydrous sodium sulfate and concentrated. The residue was further
purified by Preparative HPLC (Method F) to give benzyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-(trifluoromethyl)thieno
[3,2-b]pyridine-2-carboxamido)propanoate (50 mg).
[0577] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 8.91 (d, J=4.8 Hz,
1H), 7.88 (s, 1H), 7.58 (d, J=4.4 Hz, 1H), 7.40-7.28 (m, 10H), 5.93
(d, J=6.8 Hz, 1H), 5.27 (s, 2H), 5.13 (s, 2H), 4.66-4.60 (m, 1H),
4.05-3.92 (m, 1H), 3.88-3.77 (m, 1H).
Step 5:
(R)-2-Amino-3-(7-(trifluoromethyl)thieno[3,2-b]pyridine-2-carboxam-
ido) propanoic acid
##STR00152##
[0579] A solution of benzyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-(trifluoromethyl)thieno
[3,2-b]pyridine-2-carboxamido)propanoate (50 mg, 0.90 mmol) in
HBr/AcOH (2 mL, 33%) was stirred at 50.degree. C. for 16 h. The
solvent was removed. The residue was purified by Preparative HPLC
(Method J) to give (R)-2-amino-3-(7-(trifluoromethyl)thieno
[3,2-b]pyridine-2-carboxamido) propanoic acid (8 mg) as HBr
salt.
[0580] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 9.69 (br, 1H),
9.02 (d, J=3.6 Hz, 1H), 8.63 (br, 4H), 7.93 (d, J=4.0 Hz, 1H),
4.20-4.10 (m, 1H), 3.79-3.77 (m, 2H).
[0581] LCMS (MH+): m/z=334.1, t.sub.R (min, Method BB)=0.36.
[0582] [.alpha.].sup.20D=-10.0 (c=1.0 mg/mL, CH.sub.3OH).
Compound 2s
Methyl
(R)-2-amino-3-(7-(trifluoromethyl)thieno[3,2-b]pyridine-2-carboxami-
do)propanoate
[0583] The overall synthesis scheme for the preparation of methyl
(R)-2-amino-3-(7-(trifluoromethyl)thieno[3,2-b]pyridine-2-carboxamido)pro-
panoate is shown below.
##STR00153##
Step 1: Methyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-(trifluoromethyl)thieno
[3,2-b]pyridine-2-carboxamido)propanoate
##STR00154##
[0585] To a solution of
7-(trifluoromethyl)thieno[3,2-b]pyridine-2-carboxylic acid (1.00 g,
4.05 mmol) in DMF (10 mL) were added methyl
(R)-3-amino-2-(((benzyloxy)carbonyl)amino) propanoate (1.40 g, 4.86
mmol, HCl salt), TBTU (1.95 g, 6.07 mmol) and
N,N-diisopropylethylamine (1.57 g, 12.15 mmol). The reaction
mixture was stirred at 25.degree. C. for 16 h. The reaction mixture
was quenched with water (10 mL), and extracted with ethyl acetate
(3.times.10 mL). The combined organic layers were washed with brine
(3.times.10 mL), dried over anhydrous sodium sulfate and
concentrated. The residue was purified by CombiFlash (petroleum
ether/ethyl acetate with ethyl acetate from 80% to 90%) to give
methyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-(trifluoromethyl)thieno
[3,2-b]pyridine-2-carboxamido)propanoate (500 mg).
Step 2: methyl
(R)-2-amino-3-(7-(trifluoromethyl)thieno[3,2-b]pyridine-2-carboxamido)pro-
panoate
##STR00155##
[0587] A solution of methyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-(trifluoromethyl)thieno
[3,2-b]pyridine-2-carboxamido)propanoate (500 mg, 1.04 mmol) in
HBr/AcOH (10 mL, 33%) was stirred at 15.degree. C. for 16 h. The
solvent was moved. The residue was washed with AcOH (2 mL). The
reaction mixture was filtered, the filtration cake was washed with
AcOH (1 ml) and filtration cake was collected to give methyl
(R)-2-amino-3-(7-(trifluoromethyl)thieno[3,2-b]pyridine-2-carboxamido)pro-
panoate (220 mg) as HBr salt.
[0588] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 9.36 (t, J=6.0
Hz, 1H), 9.04 (d, J=4.8 Hz, 1H), 8.56-8.45 (m, 3H), 8.43 (s, 1H),
7.95 (d, J=4.4 Hz, 1H), 4.29-4.25 (m, 1H), 3.84-3.70 (m, 5H).
[0589] LCMS (MH+): m/z=348.2, t.sub.R (min, Method BB)=0.42.
[0590] [.alpha.].sup.20D=+2.0 (c=1.0 mg/mL, CH.sub.3OH).
Compound 1g
(R)-2-amino-3-(7-isopropoxythieno[3,2-b]pyridine-2-carboxamido)propanoic
acid
[0591] The overall synthesis scheme for the preparation of
(R)-2-amino-3-(7-isopropoxythieno[3,2-b]pyridine-2-carboxamido)propanoic
acid is shown below.
##STR00156##
Step 1: 7-isopropoxythieno[3,2-b]pyridine
##STR00157##
[0593] To propan-2-ol (15 mL) was added Na (339 mg, 15 mmol). The
mixture was stirred at 50.degree. C. for 1 hour and
7-chlorothieno[3,2-b]pyridine (500 mg, 2.95 mmol) was added. The
mixture was stirred at 110-120.degree. C. for another 15 h. The
reaction mixture was concentrated under reduced pressure to remove
solvent to give 7-isopropoxythieno[3,2-b]pyridine (320 mg).
[0594] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 8.51 (d, J=5.6
Hz, 1H), 7.66 (d, J=5.6 Hz, 1H), 7.49 (d, J=5.6 Hz, 1H), 6.70 (d,
J=5.6 Hz, 1H), 4.84-4.81 (m, 1H), 1.37 (d, J=6.0 Hz, 6H).
Step 2: 7-isopropoxythieno[3,2-b]pyridine-2-carboxylic acid
##STR00158##
[0596] To a solution of 7-isopropoxythieno[3,2-b]pyridine (320 mg,
1.7 mmol), in THF (15 mL) was added n-BuLi (2.5 M in hexane, 0.9
mL) at -78.degree. C. The mixture was stirred at -78.degree. C. for
0.5 hour. CO.sub.2 was bubbled into the solution for 0.5 h. The
mixture was stirred at 20-30.degree. C. for another 15 h. The
reaction mixture was concentrated under reduced pressure to remove
solvent. The residue was diluted with water (20 mL) and HCl (2M) to
pH.sup..about.5, filtered, and the filter cake was dried under
reduced pressure to give
7-isopropoxythieno[3,2-b]pyridine-2-carboxylic acid (210 mg).
[0597] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 8.58 (d, J=5.4
Hz, 1H), 8.00 (s, 1H), 7.11 (d, J=5.4 Hz, 1H), 4.93-4.99 (m, 1H),
1.37 (d, J=6.0 Hz, 6H).
Step 3: Preparation of benzyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-isopropoxythieno[3,2-b]pyridine-2-
-carboxamido)propanoate
##STR00159##
[0599] To a solution of
7-isopropoxythieno[3,2-b]pyridine-2-carboxylic acid (200 mg, 0.84
mmol) and benzyl (R)-3-amino-2-(((benzyloxy)carbonyl)amino)
propanoate (304 mg, 0.93 mmol, HCl salt) in DMF (10 mL) was added
O-(Benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium
tetrafluoroborate (406 mg, 1.3 mmol) and N,N-diisopropylethylamine
(545 mg, 4.2 mmol). The mixture was stirred at 20-30.degree. C. for
16 h. The residue was diluted with water (20 mL) and extracted with
ethyl acetate (20 mL.times.2). The combined organic layers were
washed with brine (15 mL), dried over MgSO.sub.4, filtered and
concentrated under reduced pressure. The residue was purified by
flash silica gel chromatography (Eluent of 0.sup..about.90% Ethyl
acetate/Petroleum ether) to give compound benzyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-isopropoxythieno[3,2-b]pyridine-2-
-carboxamido)propanoate (86 mg).
[0600] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 8.56 (d, J=5.2 Hz,
1H), 7.76 (s, 1H), 7.38-7.27 (m, 10H), 7.09 (br, 1H), 6.72 (d,
J=5.6 Hz, 1H), 5.99 (d, J=7.2 Hz, 1H), 5.20 (s, 2H), 5.11 (s, 2H),
4.85-4.85 (m, 1H), 4.65-4.55 (m, 1H), 3.97-3.80 (m, 2H), 1.47 (d,
J=5.6 Hz, 6H).
Step 4:
(R)-2-amino-3-(7-isopropoxythieno[3,2-b]pyridine-2-carboxamido)pro-
panoic acid
##STR00160##
[0602] A solution of benzyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-isopropoxythieno[3,2-b]pyridine-2-
-carboxamido)propanoate (80 mg, 0.15 mmol) in HBr/AcOH (10 mL, 33%)
was stirred at 50.degree. C. for 16 h. The reaction mixture was
concentrated under reduced pressure to remove solvent. The residue
was purified by Preparative-HPLC (Method K) to give
(R)-2-amino-3-(7-isopropoxythieno[3,2-b]pyridine-2-carboxamido)propanoic
acid(26 mg).
[0603] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 9.06 (br, 1H),
8.54 (d, J=5.2 Hz, 1H), 8.10 (s, 1H), 7.57 (br, 2H), 7.08 (d, J=5.2
Hz, 1H), 5.02-4.90 (m, 1H), 3.69-3.65 (m, 1H), 3.55-3.40 (m, 2H),
1.36 (d, J=6.0 Hz, 1H).
[0604] LCMS (MH+): m/z=324.2, t.sub.R (min, Method BB)=0.24.
[0605] [.alpha.].sup.20D=18 (c=1 mg/mL, CH.sub.3OH).
Compound 2t
[0606] Methyl
(R)-2-amino-3-(7-isopropoxythieno[3,2-b]pyridine-2-carboxamido)propanoate
The overall synthesis scheme for the preparation of methyl
(R)-2-amino-3-(7-isopropoxythieno[3,2-b]pyridine-2-carboxamido)propanoate
is shown below.
##STR00161##
Step 1: methyl (R)-2-(((benzyloxy)carbonyl)
amino)-3-(7-isopropoxythieno[3,2-b]pyridine-2-carboxamido)propanoate
##STR00162##
[0608] To a solution of
7-isopropoxythieno[3,2-b]pyridine-2-carboxylic acid (500 mg, 2.11
mmol) and methyl
(R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoate (670 mg, 2.32
mmol, HCl salt) in DMF (20 mL) was added TBTU (1.0 g, 3.17 mmol)
and N,N-diisopropylethylamine (1.36 g, 10.55 mmol). The mixture was
stirred at 20-30.degree. C. for 2 h. The residue was diluted with
water (40 mL) and extracted with ethyl acetate (50 mL.times.2). The
combined organic layers were washed with brine (15 mL), dried over
MgSO.sub.4, filtered and concentrated under reduced pressure. The
residue was purified by flash silica gel chromatography (Eluent of
0100% Ethyl acetate/Petroleum ether) to give methyl
(R)-2-(((benzyloxy)carbonyl)
amino)-3-(7-isopropoxythieno[3,2-b]pyridine-2-carboxamido)propanoate
(510 mg)
[0609] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 8.55 (d, J=5.6 Hz,
1H), 7.88 (s, 1H), 7.43 (br s, 1H), 7.34-7.22 (m, 5H), 6.71 (d,
J=6.4 Hz, 1H), 6.05 (d, J=6.8 Hz, 1H), 5.10 (s, 2H), 4.85-4.79 (m,
1H), 4.60-4.50 (m, 1H), 3.94-3.80 (m, 2H), 3.76 (s, 3H), 1.46 (d,
J=6.0 Hz, 6H).
Step 2: methyl
(R)-2-amino-3-(7-isopropoxythieno[3,2-b]pyridine-2-carboxamido)propanoate
##STR00163##
[0611] A solution of methyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-isopropoxythieno
[3,2-b]pyridine-2-carboxamido)propanoate (260 mg, 0.55 mmol) in
HBr/AcOH (4 mL, 30%) was stirred at 10-20.degree. C. for 16 h. The
reaction mixture was diluted with methyl tert-butyl ether (10 mL)
and filtered, washed with methyl tert-butyl ether (10 mL.times.3)
and dried to give compound methyl
(R)-2-amino-3-(7-isopropoxythieno[3,2-b]pyridine-2-carboxamido)
propanoate (175 mg) as HBr salt.
[0612] .sup.1HNMR (400 MHz, DMSO-d.sub.6) .delta. 9.52 (br, 1H),
8.94 (d, J=6.4 Hz, 1H), 8.52 (br, 3H), 8.35 (s, 1H), 7.56 (d, J=6.4
Hz, 1H), 5.25-5.19 (m, 1H), 4.25-4.20 (m, 1H), 3.85-3.66 (m, 5H),
1.42 (d, J=6.0 Hz, 6H).
[0613] LCMS (MH+): m/z=338.2, t.sub.R (min, Method BB)=0.29.
[0614] [.alpha.].sup.20D=1.3 (c=2 mg/mL, CH3OH).
Compound 1h
(R)-2-amino-3-(7-bromothieno[3,2-b]pyridine-2-carboxamido)propanoic
acid
[0615] The overall synthesis scheme for the preparation of
(R)-2-amino-3-(7-bromothieno[3,2-b]pyridine-2-carboxamido)propanoic
acid is shown below.
##STR00164##
Step 1: 7-bromothieno[3,2-b]pyridine
##STR00165##
[0617] A mixture of thieno[3,2-b]pyridin-7-ol (2 g, 13 mmol) and
POBr.sub.3 (25 g, 8 mmol) was heated at 110.degree. C. for 2 h. The
mixture was cooled and was poured into ice water (100 mL) and then
added 2M NaOH solution to adjust pH to 8. The mixture was extracted
with ethyl acetate (40 mL.times.3). The organic layer was dried
over anhydrous sodium sulfate, filtered and concentrated. The
residue was purified by Combi Flash on silica gel (petroleum ether:
ethyl acetate with ethyl acetate from 0 to 30%) to give
7-bromothieno[3,2-b]pyridine (2.5 g).
[0618] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 8.51 (d, J=4.8 Hz,
1H), 7.82 (d, J=6.0 Hz, 1H), 7.66 (d, J=5.6 Hz, 1H), 7.46 (d, J=5.2
Hz, 1H).
Step 2: Lithium 7-bromothieno[3,2-b]pyridine-2-carboxylate
##STR00166##
[0620] To a solution of diisopropylamine (473 mg, 4.67 mmol) in THF
(20 mL) was added n-BuLi (2.5 M in hexane, 1.87 mL) dropwise at
-70.degree. C. and stirred at -70.degree. C. for 30 min. Then
7-bromothieno[3,2-b]pyridine (1 g, 4.67 mmol) dissolved in THF (5
mL) was added dropwise and stirred at -70.degree. C. for 30 min.
Then gaseous carbon dioxide was bubbled through the reaction
mixture and the mixture was allowed to warm to 25.degree. C. over a
period of 2 h. The mixture was filtered and the filter cake was
washed with THF (10 mL.times.2). The solid was collected and dried
to give lithium 7-bromothieno[3,2-b]pyridine-2-carboxylate (800
mg).
[0621] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 8.47 (d, J=5.2
Hz, 1H), 7.68 (s, 1H), 7.62 (d, J=5.2 Hz, 1H).
Step 3: benzyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-bromothieno[3,2-b]pyridine-2-carb-
oxamido)propanoate
##STR00167##
[0623] To a solution of lithium
7-bromothieno[3,2-b]pyridine-2-carboxylate (200 mg, 0.76 mmol) in
DMF (5 mL) was added
O-(Benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium
tetrafluoroborate (268 mg, 0.83 mmol), N,N-diisopropylethylamine
(196 mg, 1.52 mmol) and benzyl
(R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoate (276 mg, 0.76
mmol, HCl salt). The mixture was stirred at 25.degree. C. for 2 h.
The mixture was diluted with water (15 mL) and extracted with ethyl
acetate (20 mL.times.3). The combined organic layers were washed
with brine (20 mL.times.3), dried over anhydrous sodium sulfate,
filtered and concentrated. The residue was purified by Combi Flash
on silica gel (petroleum ether:ethyl acetate with ethyl acetate
from 0 to 80%) twice to give compound benzyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-bromothieno[3,2-b]pyridine-2-carb-
oxamido)propanoate (190 mg).
[0624] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 8.54 (d, J=4.8 Hz,
1H), 7.88 (s, 1H), 7.51 (d, J=5.2 Hz, 1H), 7.38-7.24 (m, 11H), 6.05
(br d, J=6.8 Hz, 1H), 5.22 (s, 2H), 5.16-5.08 (m, 2H), 4.68-4.57
(m, 1H), 4.00-3.82 (m, 2H).
Step 4:
(R)-2-amino-3-(7-bromothieno[3,2-b]pyridine-2-carboxamido)propanoi-
c acid
##STR00168##
[0626] A mixture of benzyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-bromothieno[3,2-b]pyridine-2-carb-
oxamido)propanoate (100 mg, 0.18 mmol) and 30% HBr in AcOH (3 mL)
was stirred at 25.degree. C. for 16 h. The mixture was
concentrated. The residue was added water (5 mL) and washed with
methyl tert-butyl ether (5 mL.times.2). The aqueous layer was
lyophilized to give
(R)-2-amino-3-(7-bromothieno[3,2-b]pyridine-2-carboxamido)propanoic
acid (75 mg) as HBr salt.
[0627] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 9.28 (t, J=5.6
Hz, 1H), 8.64 (d, J=4.8 Hz, 1H), 8.41 (s, 1H), 8.36 (br d, J=4.0
Hz, 3H), 7.84 (d, J=4.8 Hz, 1H), 4.19-4.12 (m, 1H), 3.88-3.80 (m,
1H), 3.77-3.69 (m, 1H).
[0628] LCMS (MH+): m/z=343.9, t.sub.R (min, Method BB)=0.34.
[0629] [.alpha.].sup.20D=-4.8 (c=3.2 mg/mL, CH.sub.3OH).
Compound 2u
Methyl
(R)-2-amino-3-(7-bromothieno[3,2-b]pyridine-2-carboxamido)propanoat-
e
[0630] The overall synthesis scheme for the preparation of methyl
(R)-2-amino-3-(7-bromothieno[3,2-b]pyridine-2-carboxamido)propanoate
is shown below.
##STR00169##
Step 1: Methyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-bromothieno[3,2-b]pyridine-2-carb-
oxamido)propanoate
##STR00170##
[0632] To a solution of lithium
7-bromothieno[3,2-b]pyridine-2-carboxylate (400 mg, 1.52 mmol) in
DMF (10 mL) was added TBTU (730 mg, 2.27 mmol),
N,N-diisopropylethylamine (392 mg, 3.03 mmol) and methyl
(R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoate (437 mg, 1.52
mmol, HCl salt). The mixture was stirred at 25.degree. C. for 3 h.
The mixture was diluted with water (15 mL) and extracted with ethyl
acetate (20 mL.times.3). The combined organic layers were washed
with brine (20 mL.times.3), dried over anhydrous sodium sulfate,
filtered and concentrated. The residue was purified by Combi Flash
on silica gel (petroleum ether: ethyl acetate with ethyl acetate
from 0 to 80%) three times to give compound methyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-bromothieno[3,2-b]pyridine-2-carb-
oxamido)propanoate (350 mg).
[0633] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 9.12 (br t,
J=5.6 Hz, 1H), 8.63 (d, J=4.8 Hz, 1H), 8.34 (s, 1H), 7.87-7.78 (m,
2H), 7.37-7.23 (m, 5H), 5.09-4.99 (m, 2H), 4.42-4.34 (m, 1H),
3.75-3.58 (m, 5H).
Step 2: methyl
(R)-2-amino-3-(7-bromothieno[3,2-b]pyridine-2-carboxamido)propanoate
##STR00171##
[0635] A mixture of methyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-bromothieno[3,2-b]pyridine-2-carb-
oxamido)propanoate (340 mg, 0.69 mmol) in 30% HBr in AcOH (5 mL)
was stirred at 25.degree. C. for 1 hour. The mixture was
concentrated. The residue was added MeOH (2 mL) and then methyl
tert-butyl ether (6 mL). The mixture was filtered and the solid was
collected and dried to give methyl
(R)-2-amino-3-(7-bromothieno[3,2-b]pyridine-2-carboxamido)propanoa-
te (230 mg) as HBr salt.
[0636] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 9.28 (t, J=5.6
Hz, 1H), 8.64 (d, J=5.2 Hz, 1H), 8.49 (br s, 3H), 8.40 (s, 1H),
7.84 (d, J=4.8 Hz, 1H), 4.31-421 (m, 1H), 3.86-3.71 (m, 5H).
[0637] LCMS (MH+): m/z=358, t.sub.R (min, Method BB)=0.39.
[0638] [.alpha.].sup.20D=2.9 (c=3.5 mg/mL, CH.sub.3OH).
Compound 1i
(R)-2-amino-3-(7-(hydroxymethyl)thieno[3,2-b]pyridine-2-carboxamido)propan-
oic acid
[0639] The overall synthesis scheme for the preparation of
(R)-2-amino-3-(7-(hydroxymethyl)thieno[3,2-b]pyridine-2-carboxamido)propa-
noic acid is shown below.
##STR00172##
Step 1: thieno[3,2-b]pyridine-7-carbonitrile
##STR00173##
[0641] To a solution of 7-chlorothieno[3,2-b]pyridine (5 g, 29.48
mmol) and Zn(CN).sub.2 (3.77 g, 32.1 mmol) in DMF (50 mL) was added
Pd.sub.2(dba).sub.3 (2.70 g, 2.95 mmol), Pd(dppf)Cl.sub.2 (2.16 g,
2.95 mmol) and Zn power(385 mg, 5.90 mmol) under N.sub.2
atmosphere. The mixture was stirred at 120.degree. C. for 2 h. The
mixture was diluted with ethyl acetate (80 mL) and water (50 mL)
and filtered through Celite. The filtrate was extracted with ethyl
acetate (60 mL.times.2). The combined organic layers were washed
with brine (50 mL.times.3) and concentrated. The residue was
purified by Combi Flash on silica gel (petroleum ether:ethyl
acetate with ethyl acetate from 0 to 20%) to give
thieno[3,2-b]pyridine-7-carbonitrile (2.8 g).
[0642] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 8.85 (d, J=4.8 Hz,
1H), 7.94 (d, J=5.6 Hz, 1H), 7.68 (d, J=5.6 Hz, 1H), 7.54 (d, J=4.8
Hz, 1H).
Step 2: methyl thieno[3,2-b]pyridine-7-carboxylate
##STR00174##
[0644] A mixture of thieno[3,2-b]pyridine-7-carbonitrile (2.8 g,
17.5 mmol) and HCl/MeOH (4 M, 50 mL) was stirred at 70.degree. C.
for 16 h. The mixture was concentrated. The residue was added water
(10 mL) and pH adjusted to 8 with aqueous 2N NaOH solution. The
mixture was extracted with ethyl acetate (30 mL.times.3). The
organic layer was dried over anhydrous sodium sulfate, filtered and
concentrated. The residue was purified by Combi Flash on silica gel
(petroleum ether:ethyl acetate with ethyl acetate from 0 to 35%) to
give compound methyl thieno[3,2-b]pyridine-7-carboxylate (2.7
g).
[0645] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 8.84 (d, J=4.8 Hz,
1H), 7.89 (d, J=5.6 Hz, 1H), 7.86 (d, J=4.8 Hz, 1H), 7.63 (d, J=5.6
Hz, 1H), 4.07 (s, 3H).
Step 3: thieno[3,2-b]pyridin-7-ylmethanol
##STR00175##
[0647] To a solution of methyl thieno[3,2-b]pyridine-7-carboxylate
(2.7 g, 14 mmol) in MeOH (30 mL) was added NaBH.sub.4 (793 mg, 21
mmol). The mixture was stirred at 25.degree. C. for 3 h. The
mixture was concentrated. The residue was added water (20 mL) and
extracted with ethyl acetate (20 mL.times.3). The combined organic
layers were dried over anhydrous sodium sulfate, filtered and
concentrated to give thieno[3,2-b]pyridin-7-ylmethanol (2.1 g).
[0648] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 8.62 (d, J=4.4
Hz, 1H), 8.10 (d, J=5.6 Hz, 1H), 7.57 (d, J=6.0 Hz, 1H), 7.32 (d,
J=4.8 Hz, 1H), 5.77 (t, J=5.6 Hz, 1H), 4.82 (d, J=5.6 Hz, 2H). Step
4: lithium 7-(hydroxymethyl)thieno[3,2-b]pyridine-2-carboxylate
##STR00176##
[0649] To a solution of thieno[3,2-b]pyridin-7-ylmethanol (500 mg,
3.03 mmol) in THF (20 mL) was added n-BuLi (2.5 M in hexane, 2.4
mL) dropwise at -70.degree. C. and stirred at -70.degree. C. for 30
min. Then gaseous carbon dioxide (15 psi) was bubbled through the
reaction solution for 30 min and the mixture was allowed to warm to
25.degree. C. over a period of 2 h. The mixture was filtered and
the filter cake was washed with THF (10 mL.times.2). The solid was
collected and dried to give compound lithium
7-(hydroxymethyl)thieno[3,2-b]pyridine-2-carboxylate (700 mg).
Step 5: benzyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-(hydroxymethyl)thieno[3,2-b]pyrid-
ine-2-carboxamido)propanoate
##STR00177##
[0651] To a solution of lithium
7-(hydroxymethyl)thieno[3,2-b]pyridine-2-carboxylate (200 mg,
crude) in DMF (10 mL) was added
O-(Benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium
tetrafluoroborate (448 mg, 1.39 mmol), N,N-diisopropylethylamine
(360 mg, 2.79 mmol) and benzyl
(R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoate (339 mg, 0.93
mmol, HCl salt). The mixture was stirred at 25.degree. C. for 2 h.
The mixture was diluted with water (15 mL) and extracted with ethyl
acetate (20 mL.times.3). The combined organic layers were washed
with brine (20 mL.times.3), dried over anhydrous sodium sulfate,
filtered and concentrated. The residue was purified by Combi Flash
on silica gel (DCM: MeOH with MeOH from 0 to 10%) to give 200 mg
crude product. The crude product was further purified by
preparative-HPLC (Method 0) to give compound benzyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-(hydroxymethyl)thieno[3,2-b]pyrid-
ine-2-carboxamido)propanoate (100 mg).
[0652] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 9.01 (br t,
J=5.6 Hz, 1H), 8.69 (d, J=4.8 Hz, 1H), 8.16 (s, 1H), 7.88 (d, J=8.0
Hz, 1H), 7.39 (d, J=4.8 Hz, 1H), 7.36-7.22 (m, 10H), 5.86 (t, J=5.6
Hz, 1H), 5.15-5.00 (m, 4H), 4.83 (d, J=5.2 Hz, 2H), 4.48-4.37 (m,
1H), 3.76-3.58 (m, 2H).
Step 6:
(R)-2-amino-3-(7-(hydroxymethyl)thieno[3,2-b]pyridine-2-carboxamid-
o)propanoic acid
##STR00178##
[0654] A mixture of benzyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-(hydroxymethyl)thieno[3,2-b]pyrid-
ine-2-carboxamido)propanoate (60 mg, 0.12 mmol) and 12M aq. HCl (12
M, 4 mL) was stirred at 80.degree. C. for 2 h. The residue was
purified by preparative-HPLC (Method Q) to give compound
(R)-2-amino-3-(7-(hydroxymethyl)thieno[3,2-b]pyridine-2-carboxamido)propa-
noic acid (18 mg) as HCl salt.
[0655] .sup.1H NMR (400 MHz, D.sub.2O) .delta. 8.82 (d, J=6.0 Hz,
1H), 8.20 (s, 1H), 7.85 (d, J=6.0 Hz, 1H), 5.22 (s, 2H), 4.18-4.14
(m, 1H), 4.06-3.99 (m, 1H), 3.94-3.86 (m, 1H).
[0656] LCMS (MH+): m/z=296.1, t.sub.R (min, Method BB)=0.26.
[0657] [.alpha.].sup.20D=5.0 (c=1.2 mg/mL, CH.sub.3OH).
Compound 2v
Methyl
(R)-2-amino-3-(7-(hydroxymethyl)thieno[3,2-b]pyridine-2-carboxamido-
) propanoate
[0658] The overall synthesis scheme for the preparation of methyl
(R)-2-amino-3-(7-(hydroxymethyl)thieno[3,2-b]pyridine-2-carboxamido)
propanoate is shown below.
##STR00179##
Step 1: Methyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-(hydroxymethyl)thieno[3,2-b]pyrid-
ine-2-carboxamido)propanoate
##STR00180##
[0660] To a solution of lithium
7-(hydroxymethyl)thieno[3,2-b]pyridine-2-carboxylate (600 mg,
crude) in DMF (15 mL) was added TBTU (1.07 g, 3.35 mmol),
N,N-diisopropylethylamine (1.08 g, 8.37 mmol) and methyl
(R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoate (806 mg, 2.79
mmol, HCl salt). The mixture was stirred at 25.degree. C. for 2 h.
The mixture was diluted with water (20 mL) and extracted with ethyl
acetate (25 mL.times.3). The combined organic layers were washed
with brine (20 mL.times.3), dried over anhydrous sodium sulfate,
filtered and concentrated. The mixture was purified by Combi Flash
on silica gel (DCM: MeOH with MeOH from 0 to 10%) to give 600 mg
crude product. The crude product was further purified by
preparative-HPLC (Method M) to give compound methyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-(hydroxymethyl)thieno[3,2-b]pyrid-
ine-2-carboxamido)propanoate (200 mg).
[0661] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 9.00 (br t,
J=6.0 Hz, 1H), 8.68 (d, J=4.8 Hz, 1H), 8.18 (s, 1H), 7.81 (d, J=8.0
Hz, 1H), 7.39 (d, J=4.8 Hz, 1H), 7.36-7.20 (m, 5H), 5.86 (t, J=5.6
Hz, 1H), 5.11-4.96 (m, 2H), 4.83 (d, J=5.2 Hz, 2H), 4.41-4.31 (m,
1H), 3.72-3.54 (m, 5H).
Step 2: Methyl
(R)-2-amino-3-(7-(hydroxymethyl)thieno[3,2-b]pyridine-2-carboxamido)propa-
noate
##STR00181##
[0663] A mixture of methyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-(hydroxymethyl)thieno[3,2-b]pyrid-
ine-2-carboxamido)propanoate (90 mg, 0.20 mmol) in 12 N HCl (10 mL)
was stirred at 25.degree. C. for 2 h. The mixture was concentrated
in vacuo and lyophilized. The residue was then added HCl/MeOH (4M,
15 mL) and stirred at 25.degree. C. for 2 h. The mixture was
concentrated. The residue was purified by preparative-HPLC (Method
M) to give compound methyl
(R)-2-amino-3-(7-(hydroxymethyl)thieno[3,2-b]pyridine-2-carboxamid-
o)propanoate (25 mg) as HCl salt.
[0664] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 9.50 (br t,
J=6.0 Hz, 1H), 8.79 (d, J=4.8 Hz, 1H), 8.71 (br s, 3H), 8.42 (s,
1H), 7.54 (d, J=4.8 Hz, 1H), 4.92 (s, 2H), 4.30-4.21 (m, 1H).
[0665] LCMS (MH+): m/z=310.1, t.sub.R (min, Method BB)=0.03
min.
[0666] [.alpha.].sup.20D=-1.8 (c=4.5 mg/mL, CH.sub.3OH).
Compound 1J
(R)-2-amino-3-(7-(fluoromethyl)thieno[3,2-b]pyridine-2-carboxamido)propano-
ic acid
[0667] The overall synthesis scheme for the preparation of
(R)-2-amino-3-(7-(fluoromethyl)thieno[3,2-b]pyridine-2-carboxamido)propan-
oic acid is shown below.
##STR00182##
Step 1: benzyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-(fluoromethyl)thieno[3,2-b]pyridi-
ne-2-carboxamido)propanoate
##STR00183##
[0669] To a solution of benzyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-(hydroxymethyl)thieno[3,2-b]pyrid-
ine-2-carboxamido)propanoate (100 mg, 0.19 mmol) in DCM (5 mL) was
added DAST (62 mg, 0.38 mmol). The mixture was stirred at
20.degree. C. for 1 hour. The reaction was quenched with water (1
mL) and concentrated. The residue was added water (10 mL), pH
adjusted to 8 with 2N NaOH solution and extracted with ethyl
acetate (20 mL.times.3). The combined organic layers were
concentrated. The residue was purified by Combi Flash on silica gel
(petroleum ether:ethyl acetate with ethyl acetate from 0 to 100%)
to give compound benzyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-(fluoromethyl)thieno[3,2-b]pyridi-
ne-2-carboxamido)propanoate (25 mg).
[0670] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 8.80 (s, 1H), 8.02
(s, 1H), 7.43-7.30 (m, 12H), 6.11 (br d, J=6.4 Hz, 1H), 5.71 (d,
J=46.4 Hz, 2H), 5.23 (s, 2H), 5.13 (s, 2H), 4.69-4.61 (m, 1H),
4.00-3.96 (m, 2H).
Step 2:
(R)-2-amino-3-(7-(fluoromethyl)thieno[3,2-b]pyridine-2-carboxamido-
)propanoic acid
##STR00184##
[0672] A mixture of benzyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-(fluoromethyl)thieno[3,2-b]pyridi-
ne-2-carboxamido)propanoate (25 mg, 0.05 mmol) and 30% HBr in AcOH
(3 mL) was stirred at 50.degree. C. for 3 h. The mixture was
concentrated. The residue was purified by preparative-HPLC (Method
R) to give compound
(R)-2-amino-3-(7-(fluoromethyl)thieno[3,2-b]pyridine-2-carboxamido)propan-
oic acid (9 mg) as HCl salt.
[0673] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 9.44 (t, J=6.0
Hz, 1H), 8.80 (d, J=4.8 Hz, 1H), 8.54 (br d, J=3.6 Hz, 3H), 8.44
(s, 1H), 7.51 (d, J=4.4 Hz, 1H), 5.87 (d, J=46.0 Hz, 2H), 4.20-4.11
(m, 1H), 3.86-3.80 (m, 2H).
[0674] LCMS (MH+): m/z=298.1, t.sub.R (min, Method BB)=0.26.
Compound 2w
Methyl
(R)-2-amino-3-(7-(fluoromethyl)thieno[3,2-b]pyridine-2-carboxamido)-
propanoate
[0675] The overall synthesis scheme for the preparation of methyl
(R)-2-amino-3-(7-(fluoromethyl)thieno[3,2-b]pyridine-2-carboxamido)propan-
oate is shown below.
##STR00185##
Step 1: Methyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-(fluoromethyl)thieno[3,2-b]pyridi-
ne-2-carboxamido)propanoate
##STR00186##
[0677] To a solution of methyl
(R)-2-amino-3-(7-(hydroxymethyl)thieno[3,2-b]pyridine-2-carboxamido)propa-
noate (100 mg, 0.23 mmol) in DCM (8 mL) was added DAST (73 mg, 0.45
mmol). The mixture was stirred at 20.degree. C. for 1 hour. The
reaction was quenched with water (1 mL) and concentrated. The
residue was added water (10 mL) and pH adjusted to 8 with 2N NaOH
solution and extracted with ethyl acetate (20 mL.times.3). The
combined organic layers were concentrated. The residue was purified
by Combi Flash on silica gel (petroleum ether: ethyl acetate with
ethyl acetate from 0 to 100%) to give compound methyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(7-(fluoromethyl)thieno[3,2-b]pyridi-
ne-2-carboxamido)propanoate (25 mg).
[0678] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 8.79 (d, J=4.8 Hz,
1H), 8.09 (s, 1H), 7.62 (br, 1H), 7.38 (d, J=4.8 Hz, 1H), 7.36-7.27
(m, 5H), 6.20 (br, 1H), 5.70 (d, J=46.4 Hz, 2H), 5.13 (s, 2H),
4.66-4.57 (m, 1H), 3.99-3.85 (m, 2H), 3.82 (s, 3H).
Step 2: methyl
(R)-2-amino-3-(7-(fluoromethyl)thieno[3,2-b]pyridine-2-carboxamido)propan-
oate
##STR00187##
[0680] A mixture of methyl
2-(((benzyloxy)carbonyl)amino)-3-(7-(fluoromethyl)thieno[3,2-b]pyridine-2-
-carboxamido)propanoate (20 mg, 0.045 mmol) in 30% HBr in AcOH (3
mL) was stirred at 20.degree. C. for 1 hour. The mixture was
concentrated. The residue was purified by preparative-HPLC (Method
P) to give compound methyl
(R)-2-amino-3-(7-(fluoromethyl)thieno[3,2-b]pyridine-2-carboxamido-
)propanoate (9 mg, 52% yield) as HCl salt.
[0681] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 9.41 (br, 1H),
8.80 (d, J=4.4 Hz, 1H), 8.66 (br s, 3H), 8.40 (s, 1H), 7.50 (d,
J=4.8 Hz, 1H), 5.86 (d, J=46.4 Hz, 2H), 4.30-4.31 (m, 1H),
3.84-3.77 (m, 2H), 3.74 (s, 3H).
[0682] LCMS (MH+): m/z=312, t.sub.R (min, Method BB)=0.31.
[0683] [.alpha.].sup.20D=2.0 (c=1.0 mg/mL, CH.sub.3OH).
Compound 1k
(R)-2-amino-3-(6-fluoro-7-methylthieno[3,2-b]pyridine-2-carboxamido)propan-
oic acid
[0684] The overall synthesis scheme for the preparation of
(R)-2-amino-3-(6-fluoro-7-methylthieno[3,2-b]pyridine-2-carboxamido)propa-
noic acid is shown below.
##STR00188##
Step 1: 3,5-difluoro-4-iodopicolinonitrile
##STR00189##
[0686] To a solution of diisopropylamine (4.30 g, 42 mmol) in THF
(50 mL) was added n-BuLi (17 mL, 2.5 M in hexane) at -78.degree. C.
and the reaction was stirred at -78.degree. C. for 0.5 h. A
solution of 3,5-difluoropicolinonitrile (5 g, 36 mmol) in THF (50
mL) was added at -78.degree. C. and the reaction mixture stirred at
-78.degree. C. for 0.5 h. I.sub.2 (9.51 g, 37.5 mmol) was added in
portions at -78.degree. C. and the resulting mixture was stirred at
-78.degree. C. for 1 hour. water (50 mL) was added to quench the
reaction. The mixture was extracted with ethyl acetate (100
mL.times.3). The combined organic layers were washed with brine (50
mL.times.2), dried over anhydrous sodium sulfate, filtered and
concentrated. The residue was purified by Combi flash (silica gel,
petroleum ether/ethyl acetate with ethyl acetate from
0.sup..about.30%) to give 3,5-difluoro-4-iodopicolinonitrile (4.5
g).
[0687] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 8.28 (s, 1H).
Step 2: 3,5-difluoro-4-methylpicolinonitrile
##STR00190##
[0689] A mixture of 3,5-difluoro-4-iodopicolinonitrile (2 g, 7.52
mmol), 2,4,6-trimethyl-1,3,5,2,4,6-trioxatriborinane (5.39 g, 42.92
mmol), Pd(dppf)Cl.sub.2.CH.sub.2Cl.sub.2 (1.84 g, 2.26 mmol) and
K.sub.3PO.sub.4 (3.20 g, 15.08 mmol) in dioxane (10 mL) was
degassed and purged with N.sub.2 for 3 times, and then the mixture
was stirred at 120.degree. C. for 10 h under N.sub.2 atmosphere.
Water (10 ml) was added to the reaction and extracted with ethyl
acetate (15 mL.times.3). The combined organic layers were washed
with brine (15 mL.times.2), dried over anhydrous sodium sulfate,
filtered and concentrated. The residue was purified by Combi flash
(silica gel, petroleum ether/ethyl acetate with ethyl acetate from
0.sup..about.20%) to give 900 mg crude product. The crude product
was further purified by preparative HPLC (Method N) to give
3,5-difluoro-4-methylpicolinonitrile (270 mg).
Step 3: 3,5-difluoro-4-methylpicolinaldehyde
##STR00191##
[0691] To a stirred solution of
3,5-difluoro-4-methylpicolinonitrile (270 mg, 1.75 mmol) in THF (10
mL) was added diisobutylaluminium hydride (DIBAL-H) (2.30 mL, 1M in
toluene, 2.30 mmol) at -20.degree. C. and the mixture was stirred
at -20.degree. C. for 1 hour. Water (10 mL) was added to quench the
reaction and 1N HCl was added to adjust the pH to 5-6. The reaction
mixture was extracted with ethyl acetate (15 mL.times.3). The
combined organic layers were washed with brine (20 mL), dried over
anhydrous sodium sulfate, filtered and concentrated to give
3,5-difluoro-4-methylpicolinaldehyde (270 mg).
Step 4: methyl
6-fluoro-7-methylthieno[3,2-b]pyridine-2-carboxylate
##STR00192##
[0693] To a solution of 3,5-difluoro-4-methylpicolinaldehyde (270
mg, crude) in DMF (5 mL) was added slowly TEA (349 mg, 3.45 mmol)
and methyl 2-mercaptoacetate (300 mg, 2.83 mmol) and the mixture
was stirred at 100.degree. C. for 3 h. Water (5 ml) was added and
the mixture was extracted with ethyl acetate (5 mL.times.3). The
combined organic layers were washed with brine (5 mL.times.2),
dried over anhydrous sodium sulfate, filtered and concentrated. The
residue was purified by Combi flash (silica gel, petroleum
ether/ethyl acetate with ethyl acetate from 0.sup..about.50%) to
give the crude compound (200 mg). The crude compound was further
purified by preparative HPLC (Method S) to give methyl
6-fluoro-7-methylthieno[3,2-b]pyridine-2-carboxylate (40 mg).
[0694] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 8.59 (s, 1H), 8.20
(d, J=1.2 Hz, 1H), 3.99 (s, 3H), 2.55 (s, 3H).
Step 5: 6-fluoro-7-methylthieno[3,2-b]pyridine-2-carboxylic
acid
##STR00193##
[0696] To a solution of methyl
6-fluoro-7-methylthieno[3,2-b]pyridine-2-carboxylate (40 mg, 177.59
.mu.mol) in MeOH (4 mL) was added a solution LiOH.H.sub.2O (22 mg,
524.26 .mu.mol) in water (1 mL) and the resulting mixture was
stirred at 30.degree. C. for 2 h. The solvent was removed. Water (2
mL) was added, acidified with sat. KHSO.sub.4 solution to pH
3.sup..about.4 and extracted with ethyl acetate (10 mL.times.5).
The combined organic layers were washed with brine (5 mL), dried
over anhydrous sodium sulfate, filtered and concentrated to give
6-fluoro-7-methylthieno[3,2-b]pyridine-2-carboxylic acid (25
mg).
[0697] LC-MS: t.sub.R=1.267 min, m/z=212.0[M+H].sup.+.
Step 6: benzyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(6-fluoro-7-methylthieno[3,2-b]pyrid-
ine-2-carboxamido)propanoate
##STR00194##
[0699] A mixture of
6-fluoro-7-methylthieno[3,2-b]pyridine-2-carboxylic acid (25 mg,
118 .mu.mop, benzyl
(R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoate (52 mg, 142
.mu.mol, HCl salt),
O-(Benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium
tetrafluoroborate (57 mg, 177 .mu.mol) and
N,N-diisopropylethylamine (31 mg, 241 .mu.mop in DMF (2 mL) was
stirred at 30.degree. C. for 4 h. Water (2 ml) was added to quench
the reaction and the mixture was extracted with ethyl acetate (5
mL.times.3). The combined organic layers were washed with brine (5
mL.times.2), dried over anhydrous sodium sulfate, filtered and
concentrated. The residue was purified by preparative TLC (SiO2,
Ethyl acetate: Petroleum ether=1:1) to give benzyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(6-fluoro-7-methylthieno[3,2-b]pyrid-
ine-2-carboxamido)propanoate (25 mg).
[0700] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 8.53 (s, 1H), 7.78
(s, 1H), 7.40-7.27 (m, 10H), 6.08 (br d, J=5.6 Hz, 1H), 5.30 (s,
1H), 5.21 (s, 2H), 5.11 (s, 2H), 4.69-4.55 (m, 1H), 3.92-3.85 (m,
2H), 2.52 (s, 3H).
Step 7:
(R)-2-amino-3-(6-fluoro-7-methylthieno[3,2-b]pyridine-2-carboxamid-
o)propanoic acid as HBr salt
##STR00195##
[0702] A mixture of benzyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(6-fluoro-7-methylthieno[3,2-b]pyrid-
ine-2-carboxamido)propanoate (25 mg, 48 .mu.mop and 33% HBr in AcOH
(2 mL) was stirred at 50.degree. C. for 16 h. The solvent was
removed. The residue was washed with TBME (5 mL.times.3), the solid
was filtered and the residual solvent removed by lyophilization to
give
(R)-2-amino-3-(6-fluoro-7-methylthieno[3,2-b]pyridine-2-carboxamido)propa-
noic acid (16 mg) as
[0703] HBr salt.
[0704] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 9.18 (t, J=5.6
Hz, 1H), 8.71 (d, J=1.6 Hz, 1H), 8.41-8.26 (m, 3H), 8.26 (s, 1H),
4.21-4.09 (m 1H), 3.86-3.78 (m, 1H), 3.76-3.67 (m, 1H), 2.50 (s,
3H).
[0705] LCMS (MH+): m/z=298, t.sub.R (min, Method BB)=0.34.
[0706] [.alpha.].sup.20D=-16.00 (c=2 mg/mL, MeOH).
Compound 2x
Methyl
(R)-2-amino-3-(6-fluoro-7-methylthieno[3,2-b]pyridine-2-carboxamido-
)propanoate
[0707] The overall synthesis scheme for the preparation of methyl
(R)-2-amino-3-(6-fluoro-7-methylthieno[3,2-b]pyridine-2-carboxamido)propa-
noate is shown below.
##STR00196##
Step 1: methyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(6-fluoro-7-methylthieno[3,2-b]pyrid-
ine-2-carboxamido)propanoate
##STR00197##
[0709] A mixture of
6-fluoro-7-methylthieno[3,2-b]pyridine-2-carboxylic acid (70 mg,
331.42 .mu.mol), methyl
(R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoate (115 mg, 0.4
mmol, HCl salt), TBTU (160 mg, 0.5 mmol) and
N,N-diisopropylethylamine (89 mg, 0.69 mmol) in DMF (5 mL) was
stirred at 30.degree. C. for 16 h. Water (5 ml) was added to quench
the reaction and extracted with ethyl acetate (10 mL.times.3). The
combined organic layers were washed with brine (10 mL.times.2),
dried over anhydrous sodium sulfate, filtered and concentrated. The
residue was purified by preparative TLC (SiO2, Ethyl acetate:
Petroleum ether=1:1) to give methyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(6-fluoro-7-methylthieno[3,2-b]pyrid-
ine-2-carboxamido)propanoate (70 mg).
[0710] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 8.46 (s, 1H), 7.80
(s, 1H), 7.41-7.19 (m, 6H), 6.01-5.85 (m, 1H), 5.05 (s, 2H),
4.59-4.41 (m, 1H), 3.95-3.76 (m, 2H), 3.73 (s, 3H), 2.45 (s,
3H).
Step 2: Methyl
(R)-2-amino-3-(6-fluoro-7-methylthieno[3,2-b]pyridine-2-carboxamido)propa-
noate
##STR00198##
[0712] A mixture of methyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(6-fluoro-7-methylthieno[3,2-b]pyrid-
ine-2-carboxamido)propanoate (70 mg, 0.16 .mu.mol) in 33% HBr in
AcOH (2 mL) was stirred at 30.degree. C. for 1 h. The solvent was
removed. The crude compound was washed with TBME (5 mL.times.3),
filtered and the residual solvent removed by lyophilization to give
methyl
(R)-2-amino-3-(6-fluoro-7-methylthieno[3,2-b]pyridine-2-carboxamido)propa-
noate (50 mg) as HBr salt.
[0713] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 9.21 (t, J=5.6
Hz, 1H), 8.71 (d, J=1.6 Hz, 1H), 8.63-8.37 (br s, 3H), 8.28 (s,
1H), 4.31-4.20 (m, 1H), 3.85-3.71 (m, 5H).
[0714] LCMS (MH+): m/z=312.1, t.sub.R (min, Method BB)=0.38.
[0715] [.alpha.].sup.20D=-2.00 (c=3 mg/mL, MeOH).
Compound 11
(R)-2-amino-3-(6,7-dimethylthieno[3,2-b]pyridine-2-carboxamido)propanoic
acid
[0716] The overall synthesis scheme for the preparation of
(R)-2-amino-3-(6,7-dimethylthieno[3,2-b]pyridine-2-carboxamido)propanoic
acid is shown below.
##STR00199##
Step 1: 2-Chloro-3-fluoro-4-iodo-5-methylpyridine
##STR00200##
[0718] To a solution of diisopropylamine (5.8 mL, 41 mmol) in THF
(50 mL) was added n-BuLi (17.5 mL, 2.5 M in hexane) at -78.degree.
C. and the reaction was stirred at -78.degree. C. for 1 hour. A
solution of 2-chloro-3-fluoro-5-methylpyridine (5.00 g, 34.4 mmol)
in THF (50 mL) was added dropwise at -78.degree. C. and the
reaction mixture stirred at -78.degree. C. for 1 hour. I.sub.2
(9.50 g, 37.4 mmol) was added in portions at -78.degree. C. and the
resulting mixture was stirred at -78.degree. C. for 1 hour.
sat.NH.sub.4Cl (20 mL) was added to quench the reaction, followed
by water (50 mL) at 0.degree. C. and extraction with ethyl acetate
(100 mL.times.3). The combined organic layers were washed with
brine (100 mL.times.2), sat.Na.sub.2S.sub.2O.sub.3 solution (100
mL), dried over anhydrous sodium sulfate, filtered and concentrated
to give 2-chloro-3-fluoro-4-iodo-5-methyl-pyridine (8.2 g).
[0719] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 7.97 (s, 1H), 2.47
(s, 3H).
Step 2: 2-Chloro-3-fluoro-4,5-dimethylpyridine
##STR00201##
[0721] A mixture of 2-chloro-3-fluoro-4-iodo-5-methylpyridine (4.20
g, 15.5 mmol), 2,4,6-trimethyl-1,3,5,2,4,6-trioxatriborinane (4.27
g, 34.0 mmol), K.sub.2CO.sub.3 (4.28 g, 30.9 mmol) and
pd(dtbpf)Cl.sub.2 (1.01 g, 1.55 mmol) in dioxane (10 mL) was
degassed by purging with N2, and then the mixture was stirred at
80.degree. C. under N.sub.2 for 16 h. Then additional
2,4,6-trimethyl-1,3,5,2,4,6-trioxatriborinane (4.27 g, 34.0 mmol)
was added, and the resulting mixture was stirred at 80.degree. C.
for another 16 h. Water (20 ml) was added to quench the reaction
followed by extraction with ethyl acetate (20 mL.times.3). The
combined organic layers were washed with brine (20 mL.times.2),
dried over anhydrous sodium sulfate, filtered and concentrated. The
residue was purified by Combi flash (silica gel, petroleum
ether/ethyl acetate with ethyl acetate from 0.sup..about.10%) to
give 2-chloro-3-fluoro-4,5-dimethylpyridine (1.2 g).
[0722] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 7.95 (s, 1H),
2.22-2.27 (m, 6H).
Step 3: 3-Fluoro-4,5-dimethyl-2-vinylpyridine
##STR00202##
[0724] A mixture of 2-chloro-3-fluoro-4,5-dimethylpyridine (1.70 g,
10.7 mmol), 4,4,5,5-tetramethyl-2-vinyl-1,3,2-dioxaborolane (2.46
g, 15.9 mmol), Pd(dppf)Cl.sub.2 (780 mg, 1.07 mmol) and
K.sub.2CO.sub.3 (2.94 g, 21.3 mmol) in a mixture of dioxane (80 mL)
and water (8 mL) was degassed by purging with N2, and then the
mixture was stirred at 80.degree. C. for 16 h under N.sub.2
atmosphere. Water (50 ml) was added and the mixture was extracted
with ethyl acetate (50 mL.times.3). The combined organic layers
were washed with brine (50 mL.times.2), dried over
Na.sub.2SO.sub.4, filtered and concentrated. The residue was
purified by Combi flash (silica gel, petroleum ether/ethyl acetate
with ethyl acetate from 0.sup..about.30%) to give
3-fluoro-4,5-dimethyl-2-vinylpyridine (1.0 g).
[0725] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 8.10 (s, 1H),
7.04-6.82 (m, 1H), 6.31 (dd, J=2.0 Hz, 17.6 Hz, 1H), 5.48 (dd,
J=2.0 Hz, 11.2 Hz, 1H), 2.4 (s, 3H), 2.18 (d, J=2.0 Hz, 3H).
Step 4: 3-Fluoro-4,5-dimethylpicolinaldehyde
##STR00203##
[0727] Ozone (15 psi) was bubbled through a solution of
3-fluoro-4,5-dimethyl-2-vinylpyridine (1.00 g, 6.61 mmol) in DCM
(200 mL) at -70.degree. C. for 15 min. Then PPh.sub.3 (2.08 g, 7.94
mmol) was added at -70.degree. C., the mixture was stirred at
25.degree. C. for 2 h. The mixture was concentrated in vacuo, and
the resulting residue was purified by Combi Flash on silica gel
(petroleum ether:ethyl acetate with ethyl acetate from 0 to 50%) to
give 3-fluoro-4,5-dimethylpicolinaldehyde (600 mg).
[0728] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 10.16 (s, 1H),
8.37 (s, 1H), 2.39 (s, 3H), 2.30 (s, 3H).
Step 5: Methyl 6,7-dimethylthieno[3,2-b]pyridine-2-carboxylate
##STR00204##
[0730] To a solution of 3-fluoro-4,5-dimethylpicolinaldehyde (550
mg, 3.59 mmol) in DMF (10 mL) was added TEA (1 mL, 7.18 mmol) and
the mixture was stirred at 25.degree. C. for 30 min, then methyl
2-sulfanylacetate (460 mg, 4.33 mmol) was added slowly. The mixture
was stirred at 100.degree. C. for 3 h. Water (10 ml) was added to
quench the reaction and the mixture was extracted with ethyl
acetate (10 mL.times.3). The combined organic layers were washed
with brine (10 mL.times.2), dried over Na.sub.2SO.sub.4, filtered
and concentrated to give methyl
6,7-dimethylthieno[3,2-b]pyridine-2-carboxylate (800 mg), which was
used without any further purification.
[0731] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 8.53 (s, 1H), 8.18
(s, 1H), 3.97 (s, 3H), 2.52 (s, 3H), 2.43 (s, 3H).
Step 6: 6,7-Dimethylthieno[3,2-b]pyridine-2-carboxylic acid
##STR00205##
[0733] To a solution of methyl
6,7-dimethylthieno[3,2-b]pyridine-2-carboxylate (400 mg, crude) in
MeOH (8 mL) was added a solution of LiOH.H.sub.2O (160 mg, 3.81
mmol) in water (2 mL) and the resulting mixture was stirred at
25.degree. C. for 1 hour. The mixture was concentrated, and water
(5 mL) was added, followed by extraction with ethyl acetate (5
mL.times.2). The aqueous layer was acidified with sat.KHSO.sub.4
solution to pH 3. The solid was filtered and dried to give
6,7-dimethylthieno[3,2-b]pyridine-2-carboxylic acid (140 mg).
.sup.1H NMR (400 MHz, DMSO-d.sub.6) 13.60 (brs, 1H), 8.55 (s, 1H),
8.05 (s, 1H), 2.50 (s, 3H), 2.39 (s, 3H).
Step 7: benzyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(6,7-dimethylthieno[3,2-b]pyridine-2-
-carboxamido)propanoate
##STR00206##
[0735] A mixture of 6,7-dimethylthieno[3,2-b]pyridine-2-carboxylic
acid (70 mg, 338 .mu.mol), benzyl
(R)-3-amino-2-(((benzyloxy)carbonyl)amino)propanoate (148 mg, 406
.mu.mol, HCl salt),
0-(Benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium
tetrafluoroborate (163 mg, 508 .mu.mol) and
N,N-diisopropylethylamine (88.0 mg, 677 .mu.mol) in DMF (5 mL) was
stirred at 25.degree. C. for 16 h. Water (5 mL) was added to quench
the reaction and the mixture was extracted with ethyl acetate (5
mL.times.3). The combined organic layers were washed with brine (5
mL.times.2), dried over Na.sub.2SO.sub.4, filtered and
concentrated. The residue was purified by preparative TLC (SiO2,
Ethyl acetate: Petroleum ether=2:1) to give benzyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(6,7-dimethylthieno[3,2-b]pyridine-2-
-carboxamido)propanoate (100 mg).
[0736] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 8.50 (s, 1H), 7.77
(s, 1H), 7.42-7.28 (m, 10H), 7.08 (br s, 1H), 6.01 (d, J=6.4 Hz,
1H), 5.22 (s, 2H), 5.12 (s, 2H), 4.63 (d, J=3.6 Hz, 1H), 4.00-3.81
(m, 2H), 2.51 (s, 3H), 2.42 (s, 3H).
Step 8:
(R)-2-amino-3-(6,7-dimethylthieno[3,2-b]pyridine-2-carboxamido)pro-
panoic acid
##STR00207##
[0738] A mixture of benzyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(6,7-dimethylthieno[3,2-b]pyridine-2-
-carboxamido)propanoate (100 mg, 193 .mu.mol) and 33% HBr in AcOH
(5 mL) was stirred at 50.degree. C. for 16 h. The mixture was
concentrated. The solid was suspended in AcOH (5 mL), filtered, and
washed with additional AcOH (1 mL.times.2). The solvent was removed
by lyophilization to give (R)-2-amino-3-(6,7-di
methylthieno[3,2-b]pyridine-2-carboxamido)propanoic acid (77 mg) as
HBr salt.
[0739] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta.9.27 (t, J=5.2
Hz, 1H), 8.69 (s, 1H), 8.29-8.41 (m, 3H), 8.27 (s, 1H), 4.11-4.22
(m, 1H), 3.72-3.84 (m, 2H), 2.58 (s, 3H), 2.44 (s, 3H).
[0740] LCMS (MH+): m/z=294.2, t.sub.R (min, Method BB)=0.24.
[0741] [.alpha.].sup.20D=-3.00 (c=6 mg/mL, MeOH).
Compound 2y
Methyl
(R)-2-amino-3-(6,7-dimethylthieno[3,2-b]pyridine-2-carboxamido)prop-
anoate
[0742] The overall synthesis scheme for the preparation of methyl
(R)-2-amino-3-(6,7-dimethylthieno[3,2-b]pyridine-2-carboxamido)propanoate
is shown below.
##STR00208##
Step 1: (R)-methyl
2-(((benzyloxy)carbonyl)amino)-3-(6,7-dimethylthieno[3,2-b]pyridine-2-car-
boxamido)propanoate
##STR00209##
[0744] A mixture of 6,7-dimethylthieno[3,2-b]pyridine-2-carboxylic
acid (70 mg, 337 .mu.mol), (R)-methyl
3-amino-2-(((benzyloxy)carbonyl)amino)propanoate (117 mg, 0.40
mmol, HCl salt), TBTU (163 mg, 0.51 mmol) and
N,N-diisopropylethylamine (88 mg, 0.68 mmol) in DMF (5 mL) was
stirred at 25.degree. C. for 16 h. Water (5 mL) was added to quench
the reaction and the mixture was extracted with ethyl acetate (5
mL.times.3). The combined organic layers were washed with brine (5
mL.times.2), dried over Na.sub.2SO.sub.4, filtered and
concentrated. The residue was purified by preparative TLC (SiO2,
Ethyl acetate: Petroleum ether=2:1) to give methyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(6,7-dimethylthieno[3,2-b]pyridine-2-
-carboxamido)propanoate (100 mg).
[0745] .sup.1H NMR (400 MHz, CDCl.sub.3) .delta. 8.50 (s, 1H), 7.86
(s, 1H), 7.40-7.27 (m, 6H), 6.00 (d, J=6.4 Hz, 1H), 5.13 (s, 2H),
4.60 (m, 1H), 4.02-3.81 (m, 5H), 2.51 (s, 3H), 2.42 (s, 3H).
Step 2: methyl
(R)-2-amino-3-(6,7-dimethylthieno[3,2-b]pyridine-2-carboxamido)propanoate
##STR00210##
[0747] A mixture of methyl
(R)-2-(((benzyloxy)carbonyl)amino)-3-(6,7-dimethylthieno[3,2-b]pyridine-2-
-carboxamido)propanoate (100 mg, 0.23 mmol) in 33% HBr in AcOH (5
mL) was stirred at 25.degree. C. for 2 h. The solvent was removed.
The solid was suspended in AcOH (5 mL), filtered, washed with AcOH
(1 mL.times.2) and lyophilized to give methyl
(R)-2-amino-3-(6,7-dimethylthieno[3,2-b]pyridine-2-carboxamido)propanoate
(65 mg) as HBr salt.
[0748] .sup.1H NMR (400 MHz, DMSO-d.sub.6) .delta. 9.33 (t, J=5.6
Hz, 1H), 8.72 (s, 1H), 8.59-8.40 (br s, 3H), 8.29 (s, 1H),
4.42-4.17 (m, 1H), 3.80-3.73 (m, 5H), 2.60 (s, 3H), 2.45 (s,
3H).
[0749] LCMS (MH+): m/z=308.1, t.sub.R (min, Method BB)=0.30
min.
[0750] [.alpha.].sup.20D=-2.00 (c=5 mg/mL, MeOH).
[0751] e. In Vitro and In Vivo Characterization of Compounds of the
Invention
Example 1a: Affinity Data and Permeability Data of Parent Compounds
of Prodrugs of Formula I
[0752] Scintillation Proximity Assay (SPA):
[0753] To determine the affinity of the compounds of the present
invention a SPA is used. The assay is run in a 384-plate format
(OptiPlate-384) where each well contains a mix of 5 .mu.L of test
compound, 5 .mu.L NR1s1s2 (ligand binding domains of the NMDA
receptor, MW 35.6 kDa, 0.075 ug/well final), 5 .mu.L
[3H]-MDL-105,519 (radiolabelled, high affinity N-methyl-D-aspartate
(NMDA) glutamate receptor antagonist at the glycine site obtained
from Sigma Aldrich, final concentration 5 nM, Kd=1.3 nM), 5 .mu.L
streptavidin coated imaging beads (Perkin Elmer cat. No.: RPNQ0273,
8 ug/well). The assay buffer contains 100 mM HEPES-NaOH, 150 mM
NaCl, 1 mM EDTA, 10% glycerol at pH 7.4 in ultra-pure water.
Non-specific binding is defined by inclusion of 10 .mu.M L-689,560
(highly potent NMDA antagonist) and total binding by 1% DMSO.
Following 30 minutes incubation in the dark (shaker,
Multi-microplate Genie), the SPA beads are allowed to settle for 3
h after which the signal is read on a Viewlux instrument (Perkin
Elmer). Normalized data are used to calculate IC50 and Ki
values.
[0754] MDR1-MDCKII Permeability Assay Papp(AB)
[0755] MDR1-MDCKII cells (obtained from Piet Borst at the
Netherlands Cancer Institute) were seeded onto polyethylene
membranes (PET) in 96-well BD insert systems at 2.5.times.105
cells/mL until to 4-7 days for confluent cell monolayer
formation.
[0756] Experimental Procedure:
[0757] Test compounds were diluted with the transport buffer (HBSS
with 10 mM HEPES, added 1% BSA, pH 7.4) from DMSO stock solution to
a concentration of 0.5 .mu.M (DMSO: 0.4%) and applied to the apical
or basolateral side of the cell monolayer. Permeation of the test
compounds from A to B direction or B to A direction was determined
in triplicate over a 60-minute incubation at 37.degree. C. and 5%
CO.sub.2 with a relative humidity of 95%. In addition, the efflux
ratio of each compound was also determined. Test and reference
compounds were quantified by LC/MS/MS analysis based on the peak
area ratio of analyte/IS.
[0758] Reference compounds: Fenoterol (conc: 2 .mu.M) was used as
low permeability marker and Propranolol (conc: 2 .mu.M) was used as
high permeability marker in A to B Permeability, furthermore was
bi-directional permeability of a P-glycoprotein substrate (digoxin)
included.
[0759] Data Analysis:
[0760] The apparent permeability coefficient Papp (cm/s) was
calculated using the equation:
Papp=(dCr/dt).times.Vr/(A.times.C0) (1)
[0761] Where dCr/dt is the cumulative concentration of compound in
the receiver chamber as a function of time (.mu.M/s); Vr is the
solution volume in the receiver chamber (0.05 mL on the apical
side; 0.25 mL on the basolateral side); A is the surface area for
the transport, i.e. 0.0804 cm.sup.2 for the area of the monolayer;
C0 is the initial concentration in the donor chamber (.mu.M).
[0762] The efflux was calculated using the equation:
Efflux ratio=Papp(BA)/Papp(AB) (2)
[0763] The mass balance (Recovery) was calculated. The mass balance
is defined as: the sum of the compound recovered from the acceptor
chamber and the compound remaining in the donor chamber at the end
of the experiment, divided by the initial donor amount. The mass
balance should be as high as possible. Criterion: Recovery <50%
is insufficient.
[0764] To evaluate the integrity of the cell monolayer, Lucifer
Yellow permeability was measured in one direction (A to B). The
percentage of Lucifer Yellow was calculated in control wells as an
estimation of the overall cell membrane integrity. The wells are
considered fully acceptable if % Lucifer Yellow is less than
2%.
TABLE-US-00003 TABLE 3a Permeability data and Ki data of parent
compounds of the invention SPA Ki Permeability Papp (AB) Compound
(nM) (values given are .times.10.sup.-6 cm/s) 1a 170 BLOQ 1b 140
BLOQ 1c 96 BLOQ 1d 860 BLOQ 1e 690 BLOQ 1f 360 1.03 1g 220 BLOQ 1h
63 NT 1i 3900 NT 1j 180 NT 1k 260 NT 1l 490 0.47 BLOQ = Below Level
of Quantification NT = Not tested
[0765] Table 3a shows that compounds of formula V have affinity to
the glycine site of the NMDA receptor.
Example 1b: Permeability Data of Prodrug Compounds of the
Invention
[0766] The experiments for the prodrugs were the same as for the
parent compounds exemplified in Table 3a. The results are listed in
table 3b. Results shows that prodrugs of the parent compounds have
an improved permeability compared to the respective parent
compounds.
TABLE-US-00004 TABLE 3b Permeability of prodrug compounds of the
invention. Permeability Papp (AB) Example (values given are
.times.10.sup.-6 cm/s) 2a 8.36 2b 9.25 2c 14.75 2d 15.19 2e 10.32
2f 18.44 2g 7.11 2h 6.11 2i 8.19 2j 11.94 2k 4.77 2l 6.50 2m 8.68
2n 5.86 2o NT 2p 0.81 2q 1.97 2r 5.54 2s 12.34 2t 4.81 2u NT 2v
1.16 2w 4.19 2x 15.50 2y 7.08
Example 2: In Vivo Exposure Data
[0767] In Vivo Procedure:
[0768] Brain disposition of test compound was evaluated in male
Sprague Dawley rats (standard body weight range). Briefly, discrete
(nominal dose: 2 mg/kg, 2 ml/kg) or cassetted (nominal dose: 1
mg/kg/compound, 2 ml/kg) test compounds were administered by
intravenous bolus injection (formulated in 10%
hydroxypropyl-.beta.-cyclodextrin or 10-20% Captisol, pH=3).
[0769] Sample Collection:
[0770] Serial blood samples were collected from a lateral tail vein
at designated time points (n=3 per time point) then rats were put
under deep isofluorane induced anaesthesia prior to removal of
brains (n=3 per time point). Blood samples were stabilized against
further metabolism ex vivo by addition of an esterase inhibitor
(100 .mu.M diisopropyl fluorophosphate). Similarly, esterase
inhibitor (100-125 .mu.M) was included in the brain homogenate
buffer.
[0771] Blood was collected into K3-EDTA-coated tubes and the
samples are gently turned upside-down to ensure a homogenous
sample. The tubes were centrifuged at 3300.times.g for 10 min. at
max 4.degree. C. and plasma samples were transferred to Micronic
tubes. Brain samples were dissected once the animal had been
sacrificed, slightly "dipped" on filter paper to remove blood
overflow on the outside, and transferred into Covaris AFA tubes.
Plasma and brain samples were stored at -80.degree. C. until
analysis.
[0772] Sample Preparation:
[0773] Seven calibration standards and three QC samples were
prepared in plasma and brain homogenate, respectively, in the
concentration range 10-10000 ng/mL. Blank samples (control matrix
with internal standard) were prepared and treated in the same way
as calibration standards. Prior to analysis, the brain samples were
homogenized with milliQ water 1:4 (w/v) using a Covaris
focused-ultrasonicator. Study samples with expected concentration
above upper limit of quantification were diluted with blank
matrix.
[0774] Brain homogenate and plasma from study samples, calibration
standards, quality controls and blank samples were subsequently
treated with the same extraction procedure, i.e. protein
precipitation by adding 150 .mu.L acetonitrile with internal
standard (Tolbutamide) to 25 .mu.L of sample. Samples were
centrifuged and the supernatant from each sample was diluted 1:1
with water to lower the content of organic solvent.
[0775] LC-MS/MS:
[0776] Samples were analyzed using an AB Sciex API4000 triple
quadrupole (TQ) mass spectrometer operated in positive and negative
electrospray ionization and MS/MS mode (multiple reaction
monitoring, MRM). The mass spectrometer was coupled to a Waters
Acquity UPLC equipped with a Waters Acquity UPLC HSS C18 SB (1.7
.mu.m, 30 mm.times.2.1 mm) analytical column. Chromatographic
separation was achieved by a 3-minute gradient starting with 98%
mobile phase A (0.1% Formic Acid in water) and 2% mobile phase B
(0.1% Formic Acid in Acetonitrile) increasing to 95% mobile phase
B. Flow rate was 0.6 mL/min and the column temperature was
40.degree. C. MRM transitions (m/z) were as follows:
380.fwdarw.248, 350.fwdarw.263, Tolbutamide: 269.fwdarw.106 (neg)
and 271.fwdarw.155 (pos). Quantification was performed by linear
regression, 1/x2 weighting.
[0777] Concentrations of prodrug and drug in plasma and brain were
quantified against matrix matched calibration standards. The blood
brain deposition data is shown in the table below.
TABLE-US-00005 TABLE 4 in vivo exposure data of corresponding
parent compound after administration a prodrug of the invention in
male Sprague Dawley rats Total Plasma Total Brain Com- Com-
concentration concentration pound pound Dose (ng/mL) 30 min (ng/mL)
30 min dosed quantified mg/kg post dose post dose 2a 1a 2 303 4.9
2b 1b 1 421 29.8 1c 1c 2 270 8.4 2c 1c 2 176 176 2d 1c 2 568 67 2f
1c 2 500 BLOQ 2m 1c 2 156 7.3 2u 1h 2 186 BLOQ BLOQ = Below Level
of Quantification
Example 3--Maximal Electro Shock Threshold
[0778] Naive rats were acclimatised to the procedure room in their
home cages, with food and water available ad libitum. All rats were
weighed at the beginning of the study and randomly assigned to
treatment groups. The individual treatment groups were dosed with
either 10% hydroxypropyl-.beta.-cyclodextrin (vehicle) or compound
2c (3, 10, or 30 mg/g), The dosing of the animals were performed by
subcutaneous injection 30 min before test according to treatment
groups. Rats were individually assessed for the production of a
tonic hind limb extensor seizure using a Hugo Sachs Electronik
stimulator, which delivered an adjustable constant current (1-300
mA) of 0.3 seconds duration via corneal electrodes. The stimulus
intensity was varied, from a typical baseline of 25 mA, by an `up
and down` method of shock titration. Thus, the first rat within a
treatment group was given a shock at the expected or estimated
seizure threshold (CC.sub.50) current, that is, the current
producing tonic hind limb extensor seizure in 50% of animals. For
subsequent animals, the stimulus intensity was lowered or raised in
log 0.06:10{circumflex over ( )}(1+x*0.06) mA intervals if the
preceding rat did or did not show tonic hind limb extension,
respectively. This procedure continued for all rats within a
treatment group. Data generated from treatment groups of n=12-16
were used to calculate the CC.sub.50 values according to the method
of Kimball et al. (Kimball A, Burnett W, Doherty D. Chemical
protection against ionizing radiation. I. Sampling methods for
screening compounds in radiation protection studies with mice.
Radiat Res. 1957; 7(1):1-12). Significant differences between
drug-treated animals and vehicle were assessed according to
Litchfield and Wilcoxon (Litchfield J, Wilcoxon F. A simplified
method for evaluating dose-effect experiments. J Pharmacol Exp
Ther. 1949; 96(1): 99-113).
[0779] As shown in FIG. 1, administration of compound 2c dosed at
3, 10 and 30 mg/kg subcutaneously showed dose dependent effects on
the maximal electro shock threshold.
Example 4-Forced Swim Test
[0780] Adult male Wistar Kyoto rats from Envigo (former Harlan;
Blackthorn, UK). Animals are maintained under controlled conditions
(21.+-.1.degree. C., 37.+-.1%, 12/12 h light/dark cycles, lights on
at 8 a.m.) with food and water available ad libitum. In all studies
WKY rats were randomly allocated to a maximum of 5 treatment groups
(n=20 per group). WKY rats received either a single administration
of either saline (vehicle), ketamine (5 mg/kg) or compound 2c (3,
10, or 30 mg/kg) according to treatment group. The dosing of the
animals were performed by subcutaneous injection 24 h before test
g. The WKY rats were individually placed into a glass cylinder (50
cm height, 20 cm diameter) containing 30 cm of water at
25.+-.1.degree. C. for a 5 min test phase. The test session
recorded (using a video camera placed above the cylinder for
subsequent behavioural analysis) the time of immobility (s).
One-way analysis of variance (ANOVA) was used to detect statistical
significance in the FST data. The Fisher least significant
difference (LSD) test was used for post hoc analyses. Probability
values of P<0.05 were considered as statistically significant.
Statistical analyses were performed using SPSS.
[0781] As shown in FIG. 2, administration of compound 2c dosed at
3, 10 and 30 mg/kg subcutaneously showed significant effects in
time of immobility at the 30 mg/kg dose.
Example 5--Resting State Electroencephalography (rsEEG) in Rats
[0782] Surgical Procedure
[0783] On the day of surgery, rats (270-300g) were anesthetized
with a 0.25 ml/100g subcutaneous (SC) injection of 1:1
hypnorm/Dormicum and mounted in a stereotaxic frame (David Kopf
Instruments, Tujunga, CA, USA) with blunt ear bars. Marcain (0.2 ml
SC) was injected under the scalp, and gel (Neutral Opthta Eye Gel)
put on the eyes to prevent the mucous membrane drying out. Holes
were burred in the skull to allow for placement of two depth
electrodes (E363-series; PlasticsOne, Roanoke, Va., USA) in left
and right pre/infralimbic PFC (AP: 3.0 mm from the bregma suture,
Medial-Lateral (ML): +/-0.7 mm from the sagittal suture and DV: 3.0
mm from the dura) and thalamus (AP: -2.8 mm from the bregma suture,
ML: +0.7 mm from the sagittal suture and DV: 4.4 mm from the dura)
and three screw electrodes at vertex (AP: -2 mm from the bregma
suture, ML: +2.0 mm from the sagittal suture), a reference
electrode (AP: +8.0 mm and ML: -2.0 mm), and a ground electrode
(AP: -5 mm, ML: +5 mm). During surgeries, nails were cut to prevent
rats from scratching wounds following surgery. After completion of
surgeries, rats were placed under warming lamps until recovery of
consciousness (maximum 4 hrs). Water soaked food pellets were
placed in the home cage, so the rat easily and quickly could start
feeding. Extra muesli was supplied to aid the recovery. Rats were
treated with Norodyl and Noromox for 5 days in total and closely
observed during a 10-14-day post-surgery recovery period. Animal
bodyweights were recorded daily. No rats lost more than 10% of
their pre-surgery bodyweight. Sutures were removed after 7-10 days.
At the end of experiments electrical lesions were performed in all
recording electrodes and brains were cut for visual microscopy
inspection of electrode placement. The differences between depth-
and screw-electrode impedances were handled by investigating
relative power changes and common-mode noise sources were reduced
from recording in shielded boxes and excluding power estimates
around 50, 100, and 150 Hz from analyses.
[0784] Electrophysiological Recordings
[0785] Rats were handled daily and habituated to recording box the
week before recording sessions. Recordings were performed during
the dark phase of the light/dark cycle. At 8 AM, rats (400-500 g)
were individually transferred to an acrylic chamber (30 cm wide 45
cm deep 55 cm high) placed within an electrically shielded
sound-proof box (90 cm wide 55 cm deep 65 cm high) and were
tethered to a six-pin wire suspended from a rotating swivel,
allowing free movement within the recording box. Rats were
habituated for 2-h followed by 45 minutes of baseline recording,
where after rats were injected subcutaneously with 10%
hydroxypropyl-.beta.-cyclodextrin (vehicle), 10 mg/kg ketamine in
saline, or 20 mg/kg compound 2c in 10% HP.beta.CD and left in the
box for two more h. Rats only went through recording sessions once
a week with at least six days between recordings to allow for
wash-out of compounds. The analog LFP/ECoG signals were amplified
and band-pass filtered at 0.01-300 Hz (Precision Model 440;
Brownlee, Palo Alto, Calif., USA) and converted to a digital signal
at a sampling rate of 1 kHz (CED Power 1401, Power 1 (625 kHz, 16
bit) and CED Expansion ADC16; CED, Cambridge, England). An analog
50 Hz notch filter (Precision Model 440, Brownlee) was applied to
the LFP/ECoG signals of the first dataset but was not applied in
the following pharmaco-EEG experiments. Video recordings were
processed in EthoVision producing the mobility signal, which was
subsequently collected in Spike2 along with the LFP/ECoG signals
with a delay used subsequently to synchronize the signals.
[0786] Data Analysis
[0787] The development of the locomotive state-detection algorithm
and the state-specific pharmaco-EEG analyses were carried out in
MATLAB R2017a (The MathWorks, Inc., Natick, Mass., USA) using
functions from the sigTOOL toolbox. Significant differences between
drug-treated animals and vehicle were assessed according to
Turkey's honest significant difference.
[0788] As shown in FIGS. 3A-3D, administration of compound 2c dosed
at 20 mg/kg subcutaneously showed significant effects in high
frequency oscillation in resting state Electroencephalography and
showing similarities to that observed with ketamine.
Example 6--Microdialysis Studies in Rats
[0789] Male Sprague-Dawley rats, initially weighing 275-300 g, were
used. The animals were housed under a 12-hr light/dark cycle under
controlled conditions for regular in-door temperature
(21.+-.2.degree. C.) and humidity (55.+-.5%) with food and tap
water available ad libitum.
[0790] Rats were anaesthetised with hypnorm/dormicum (2 ml/kg) and
intracerebral guide cannulas (CMA/12) were stereotaxically
implanted into the brain, aiming to position the dialysis probe tip
in the ventral hippocampus (co-ordinates: 5.6 mm posterior to
bregma, lateral -4.8 mm, 7.0 mm ventral to dura. Anchor screws and
acrylic cement were used for fixation of the guide cannulas. The
body temperature of the animals was monitored by rectal probe and
maintained at 37.degree. C. The rats were allowed to recover from
surgery for 2 days, housed singly in cages.
[0791] On the day of the experiment a microdialysis probe (CMA/12,
0.5 mm diameter, 3 mm length) was inserted through the guide
cannula. The probe was connected via a dual channel swivel to a
microinjection pump. Perfusion of the microdialysis probe with
filtered Ringer solution (145 mm NaCl, 3 mM KCl, 1 mM MgCl2, 1.2 mM
CaCl.sub.2)) was begun shortly before insertion of the probe into
the brain and continued for the duration of the experiment at a
constant flow rate of 1 .mu.l/min. After 180 min of stabilisation,
the experiments were initiated. Dialysates were collected every 20
min into polystyrene microvials containing trifluoroacetic acid
(final concentration 0.25%) at 4.degree. C. After the experiments
the animals were sacrificed and the brains removed and the probe
placement was verified.
[0792] In vitro recovery of the probes was determined by using
stock solutions of compound 2c and compound 1c at 1000 ng/ml. The
experiments were performed at room temperature. For each compound
three microdialysis probes (CMA/3) were inserted into tubes
containing stock solutions. Perfusion of the microdialysis probe
with filtered Ringer solution was begun shortly before insertion of
the probe into the stock solutions and continued for the duration
of the experiment at a constant flow rate of 1 .mu.l/min. After 60
min of stabilisation 3 consecutive 20-min samples were sampled by
each probe.
[0793] As shown in FIG. 4, considerable extracellular levels of
compound 1c in the rat ventral hippocampus after systemic
administration of compound 2c dosed at 30 mg/kg subcutaneously were
observed.
* * * * *