U.S. patent application number 09/811888 was filed with the patent office on 2001-11-29 for neuroprotective substituted piperidine compounds with activity as nmda nr2b subtype selective antagonists.
Invention is credited to Alanine, Alexander, Buettelmann, Bernd, Jaeschke, Georg, Neidhart, Marie-Paule H., Pinard, Emmanuel, Wyler, Rene.
Application Number | 20010047014 09/811888 |
Document ID | / |
Family ID | 8168543 |
Filed Date | 2001-11-29 |
United States Patent
Application |
20010047014 |
Kind Code |
A1 |
Alanine, Alexander ; et
al. |
November 29, 2001 |
Neuroprotective substituted piperidine compounds with activity as
NMDA NR2B subtype selective antagonists
Abstract
The invention relates to a compound of the formula 1 its R,R-,
S,S-enantiomers and racemic mixtures thereof and to their
pharmaceutically acceptable acid addition salts. The compound of
formula I and its R,R- and S,S-enantiomers may be used as
medicaments for the treatment of diseases, wherein the therapeutic
indications include acute forms of neurodegeneration caused by
stroke or brain trauma; chronic forms of neurodegeneration such as
Alzheimer's disease, Parkinson's disease, Huntington's disease or
ALS (amyotrophic lateral sclerosis); neurodegeneration associated
with bacterial or viral infections, and, diseases such as
schizophrenia, anxiety, depression and chronic/acute pain.
Inventors: |
Alanine, Alexander;
(Schlierbach, FR) ; Buettelmann, Bernd;
(Schopfheim, DE) ; Neidhart, Marie-Paule H.;
(Hagenthal le Bas, FR) ; Jaeschke, Georg; (Basle,
CH) ; Pinard, Emmanuel; (Linsdorf, FR) ;
Wyler, Rene; (Zuerich, CH) |
Correspondence
Address: |
HOFFMANN-LA ROCHE INC.
PATENT LAW DEPARTMENT
340 KINGSLAND STREET
NUTLEY
NJ
07110
|
Family ID: |
8168543 |
Appl. No.: |
09/811888 |
Filed: |
March 19, 2001 |
Current U.S.
Class: |
514/327 ;
546/216 |
Current CPC
Class: |
A61P 25/18 20180101;
A61P 25/22 20180101; A61P 25/06 20180101; A61P 25/16 20180101; C07D
211/48 20130101; A61P 21/04 20180101; A61P 25/28 20180101; A61P
29/00 20180101; A61P 25/24 20180101; A61P 25/14 20180101 |
Class at
Publication: |
514/327 ;
546/216 |
International
Class: |
C07D 211/40; A61K
031/445 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 25, 2000 |
EP |
00108769.1 |
Claims
1. A compound with the structure of formula I 8its R,R- and
S,S-enantiomers and their pharmaceutically acceptable acid addition
salts.
2. A compound of formula I in accordance with claim 1, selected
from the group consisting of (3R, 4R)
4-benzyl-1-[2-(4-hydroxy-phenoxy)-ethyl]-pip- eridine-3,4-diol,
(3S, 4S) 4-benzyl-1-[2-(4-hydroxy-phenoxy)-ethyl]-piperi-
dine-3,4-diol and racemic mixtures thereof.
3. A compound of formula I in accordance with claim 2, which is (3
R,4R)-4-benzyl-1-[2-(4-hydroxy-phenoxy)-ethyl]
-piperidine-3,4-diol.
4. A compound of formula I in accordance with claim 2, which is
(3S,4S)-4-benzyl-1-[2-(4-hydroxy-phenoxy)-ethyl]-piperidine-3,4-diol.
5. A medicament containing one or more compounds according to claim
2 and pharmaceutically inert excipients.
6. A medicament in accordance with claim 5 useful for the treatment
of diseases including disease states caused by overactivation of
respective NMDA receptor subtypes including acute forms of
neurodegeneration caused by stroke or brain trauma; chronic forms
of neurodegeneration such as Alzheimer's disease, Parkinson's
disease, Huntington's disease or ALS (amyotrophic lateral
sclerosis); neurodegeneration associated with bacterial or viral
infections, and, diseases such as schizophrenia, anxiety,
depression and chronic/acute pain.
7. A process for preparing a compound of formula I as defined in
claim 1, which process comprises reacting a compound of formula
9with a compound of formula 10and deprotecting the hydroxy group to
give compounds of formulae 11
8. The method of claim 7 further comprising reacting the compounds
obtained with pharmaceutically acceptable inorganic and organic
acids thereby forming addition salts.
9. The method of claim 8 wherein said pharmaceutically acceptable
acids are selected from the group consisting of hydrochloric acid,
nitric acid, sulfuric acid, lactic acid, phosphoric acid, citric
acid, formic acid, fumaric acid, maleic acid, acetic acid, succinic
acid, tartaric acid, methane-sulfonic acid, and p-toluenesulfonic
acid.
10. A method of treatment of a disease state caused by malfunction
of the NMDA receptor subtypes comprising administering to a patient
in need of such treatment, an effective amount of a composition for
treating said disease state, said composition containing an
effective amount of a compound that functions as a NDMA receptor
subtype specific blocker in a pharmaceutically acceptable carrier,
said compound having the structure of formula I 12
11. The method of treatment of claim 10 wherein the disease state
being treated consists of acute forms of neurodegeneration caused
by stroke or brain trauma; chronic forms of neurodegeneration such
as Alzheimer's disease, Parkinson's disease, Huntington's disease
or ALS (amyotrophic lateral sclerosis); neurodegeneration
associated with bacterial or viral infections, and, diseases such
as schizophrenia, anxiety, depression and chronic/acute pain.
Description
FIELD OF INVENTION
[0001] The present invention is generally related to substituted
piperidine compounds and more particularly to compounds with
activity as NMDA receptor subtype selective blockers that have low
activity as blockers of hERG potassium channels.
[0002] The present invention relates to the compound of formula
2
[0003] to its R,R- and S,S-enantiomers and to their
pharmaceutically acceptable acid addition salts.
[0004] The compounds of the present invention are NMDA
(N-methyl-D-aspartate)-receptor-subtype selective blockers, which
have a key function in modulating neuronal activity and plasticity
which makes them key players in mediating processes underlying
development of CNS including learning and memory formation and
function.
[0005] Under pathological conditions of acute and chronic forms of
neurodegeneration overactivation of NMDA receptors is a key event
for triggering neuronal cell death. NMDA receptors are composed of
members from two subunit families, namely NR-1 (8 different splice
variants) and NR-2 (A to D) originating from different genes.
Members from the two sub-unit families show a distinct distribution
in different brain areas. Heteromeric combinations of NR-1 members
with different NR-2 sub-units result in NMDA receptors, displaying
different pharmacological properties. Possible therapeutic
indications for NMDA receptor subtype specific blockers include
acute forms of neurodegeneration caused, e.g., by stroke or brain
trauma; chronic forms of neurodegeneration such as Alzheimer's
disease, Parkinson's disease, Huntington's disease or ALS
(amyotrophic lateral sclerosis); neurodegeneration associated with
bacterial or viral infections, diseases such as schizophrenia,
anxiety and depression and acute/chronic pain.
[0006] Objects of the present invention are novel compounds of
formula I, its R,R- and S,S-enantiomers, racemic mixtures of these
enantiomers and pharmaceutically acceptable salts of these novel
compounds; their use in the treatment or prophylaxis of diseases
caused by overactivation of respective NMDA receptor subtypes,
which include acute forms of neurodegeneration caused, e.g., by
stroke or brain trauma; chronic forms of neurodegeneration such as
Alzheimer's disease, Parkinson's disease, Huntington's disease or
ALS (amyotrophic lateral sclerosis); neurodegeneration associated
with bacterial or viral infections, and diseases such as
schizophrenia, anxiety, depression and acute/chronic pain; the use
of these compounds for manufacture of corresponding medicaments;
processes for the manufacture of these novel compounds; and
medicaments containing the compounds of the invention.
[0007] The term "pharmaceutically acceptable acid addition salts"
embraces salts with inorganic and organic acids, such as
hydrochloric acid, nitric acid, sulfuric acid, lactic acid,
phosphoric acid, citric acid, formic acid, fumaric acid, maleic
acid, acetic acid, succinic acid, tartaric acid, methane-sulfonic
acid, p-toluenesulfonic acid and the like.
[0008] 4-Hydroxy-piperidin derivatives are described, for example
in EP 824 098, in which the piperidine ring is substituted by one
hydroxy group in 4-position. These compounds are described to
possess activities on the NMDA receptor and are useful in the
treatment of acute forms of neurodegeneration caused, for example,
by stroke and brain trauma, and chronic forms of neurodegeneration
such as Alzheimer's disease, Parkinson's disease, ALS (amyotrophic
lateral sclerosis), neurodegeneration associated with bacterial or
viral infections and acute/chronic pain.
[0009] It is known from EP 824 098 that these compounds are good
NMDA receptor subtype specific blockers with a high affinity for
NR2B subunit containing receptors and low affinity for NR2A subunit
containing receptors.
[0010] Activity versus .alpha..sub.1-adrenergic receptors is also
low and the compounds are active in vivo against audiogenic
seizures in mice in the low mg/kg range. Importantly, these
compounds were neuroprotective in an animal stroke model, namely, a
permanent occlusion of the middle cerebral artery. However, in
vitro and in vivo cardiotoxicity studies showed that these
compounds had the propensity to prolong cardiac action potential
duration in vitro and consequently the `QT`-interval in vivo and
thus, had a potential liability to produce cardiac arrhythmias. The
ability of such compounds to prolong the cardiac action potential
was identified as being due to an action at the hERG type potassium
channel, which is important for action potential repolarisation in
humans and other species, and most compounds known to prolong the
QT-interval in man are active at blocking this channel. Thus, the
compounds of the prior art block heterologously recombinant human
ERG potassium channels.
[0011] It has now surprisingly been found that the following
preferred compounds of formula I (3R,4R) and
(3S,4S)-4-benzyl-[2-(4-hydroxy-phenoxy-
)-ethyl]-piperidine-3,4-diol,
(3R,4R)-4-benzyl-1-[2-(4-hydroxy-phenoxy)-et-
hyl]-piperidine-3,4-diol and
(3S,4S)-4-benzyl-1-[2-(4-hydroxy-phenoxy)-eth-
yl]-piperidine-3,4-diolare NMDA NR2B subtype selective antagonists.
These preferred compounds of the invention share the highly
specific subtype selective blocking properties of compounds of the
prior art, for example of
1-[2-(4-hydroxy-phenoxy)-ethyl]-4-(4-methyl-benzyl)-piperidin-4-ol
(EP 824 098), and are neuroprotectants in vivo, unlike the
compounds of EP 824098, the preferred compounds of the invention
are significantly less active as blockers of the hERG potassium
channels and, thus, are much less likely to have pro-arrhythmic
activity in man.
[0012] In the following table the high selectivity of compounds of
the present invention is demonstrated.
1 Selectivity profile of NMDA NR2B subtype selective antagonists
Inhibition of Inhibition of Inhibition of [3H]-Ro 25- [3H]-Prazosin
hERG K+ current 6981 binding binding IC.sub.50 (.mu.M) (effect
Compound IC.sub.50 (.mu.M).sup.a IC.sub.50 (.mu.M).sup.b (%) at 10
.mu.M.sup.c) EP 824098 0.010 3.5 0.69 .mu.M 1-[2-(4-hydroxy-
phenoxy)-ethyl]-4- (4-methyl-benzyl)- piperidin-4-ol I (racemate)
0.045 27 >10 .mu.M (45%), I-1 (R,R) 0.038 25 >10 .mu.M (44%)
I-2 (S,S) 0.039 30 >10 .mu.M (40%) .sup.aInhibition of [3H]-Ro
25-6981 binding indicates affinity for NMDA NR2B subunit containing
receptors. .sup.bInhibition of [3H]-Prazosin binding indicates
affinity for .alpha..sub.1-adrenergic receptors. .sup.cIndicates
potency for blockade of recombinant human ERG potassium channels
expressed in a mammalian cell line (chinese hamster ovary cells,
CHO).
[0013] The novel compounds of formula I and their pharmaceutically
acceptable salts can be prepared by methods known in the art, for
example by a process described below, which process comprises
[0014] reacting a compound of formula 3
[0015] with a compound of formula 4
[0016] and deprotecting the hydroxy group to give compounds of
formulae 5
[0017] and, preferably, converting the compounds obtained into a
pharmaceutically acceptable acid addition salts.
[0018] In accordance with the described process variant,
4-benzyl-3,4-dihydroxy-piperidine,
(3R,4R)-4-benzyl-3,4-dihydroxy-piperid- ine or
(3S,4S)-4-benzyl-3,4-dihydroxy-piperidine is treated with
1-benzyloxy-4-(2-chloro-ethoxy)-benzene in the presence of
K.sub.2CO.sub.3. The reaction is carried out at about
80-100.degree. C. The O-protecting group is then cleaved off in
conventional manner, for example by hydrogenating in the presence
of Pd/C.
[0019] The acid addition salts of the compounds of formula I are
especially well suited for a pharmaceutical use.
[0020] The following schemes 1 and 2 describe the preparation of
the compound of formula I and its desired enantiomeric forms. The
starting materials of formulae III and
1-benzyloxy-4-(2-chloro-ethoxy)-benzene are known compounds or can
be prepared by methods known in the art.
[0021] In schemes 1 and 2 the following abbreviations have been
used:
2 Z--Cl benzylchloroformate MCPBA meta-chloroperbenzoic acid DMAP
dimethylaminopyridine Pd/C palladium on carbon catalyst DMF
dimethylformamide Bn benzyl
[0022] 6
[0023] wherein "hal" may be chloro or bromo. 7
[0024] The detailed description of the above mentioned processes is
described in Examples 1-17.
[0025] As mentioned earlier, the compounds of formula I and their
pharmaceutically acceptable addition salts possess valuable
pharmacodynamic properties. They are NMDA-receptor subtype
selective blockers, which have a key function in modulating
neuronal activity and plasticity which makes them key players in
mediating processes underlying development of CNS as well as
learning and memory formation.
[0026] The compounds were investigated in accordance with the test
given hereinafter.
Method 1
3H-Ro 25-6981 Binding(Ro 25-6981 is
[R-(R*,S*)]-.alpha.-(4-Hydroxy-phenyl)-
-.beta.-methyl-4-(phenyl-methyl)-1-piperidine propanol)
[0027] Male Fullinsdorf albino rats weighing between 150-200 g were
used. Membranes were prepared by homogenization of the whole brain
minus cerebellum and medulla oblongata with a Polytron (10,000 rpm,
30 seconds), in 25 volumes of a cold Tris-HCl 50 mM, EDTA 10 mM, pH
7.1 buffer. The homogenate was centrifuged at 48,000 g for 10
minutes at 4.degree. C. The pellet was resuspended using the
Polytron in the same volume of buffer and the homogenate was
incubated at 37.degree. C. for 10 minutes. After centrifugation the
pellet was homogenized in the same buffer and frozen at -80.degree.
C. for at least 16 hours but not more than 10 days. For the binding
assay the homogenate was thawed at 37.degree. C., centrifuged and
the pellet was washed three times as above in a Tris-HCl 5 mM, pH
7.4 cold buffer. The final pellet was resuspended in the same
buffer and used at a final concentration of 200 .mu.g of
protein/ml.
[0028] [3H]-Ro 25-6981 binding experiments were performed using a
Tris-HCl 50 mM, pH 7.4 buffer. For displacement experiments 5 nM of
3H-Ro 25-6981 were used and non specific binding was measured using
10 .mu.M of tetrahydroisoquinoline and usually it accounts for 10%
of the total. The incubation time was 2 hours at 4.degree. C. and
the assay was stopped by filtration on Whatman GF/B glass fiber
filters (Unifilter-96, Packard, Zurich, Switzerland). The filters
were washed 5 times with cold buffer. The radioactivity on the
filter was counted on a Packard Top-count microplate scintillation
counter after addition of 40 mL of microscint 40 (Canberra Packard
S.A., Zurich, Switzerland).
[0029] The effects of compounds were measured using a minimum of 8
concentrations and repeated at least once. The pooled normalized
values were analyzed using a non-linear regression calculation
program which provide IC.sub.50 with their relative upper and lower
95% confidence limits (RS1, BBN, USA).
Method 2
3H-Prazosin Binding
[0030] Male Fullinsdorf albino rats weighing between 150-200 g were
used. Membranes were prepared by homogenization of the whole brain
minus cerebellum and medulla oblongata with a Plytron (10,000 rpm,
30 seconds), in 25 volumes of a cold Tris-HCl 50 mM, EDTA 10 mM, pH
7.1 buffer. The homogenate was centrifuged at 48,000 g for 10
minutes at 4.degree. C. The pellet was resuspended using the
Polytron in the same volume of buffer and the homogenate was
incubated at 37.degree. C. for 10 minutes. After centrifugation the
pellet was homogenized in the same buffer and frozen at -80.degree.
C. for at least 16 hours but not more than 10 days. For the binding
assay the homogenate was thawed at 37.degree. C., centrifuged and
the pellet was washed three times as above in a Tris-HCl 5 mM, pH
7.4 cold buffer. The final pellet was resuspended in the same
buffer and used at a final concentration of 200 mg of
protein/ml.
[0031] 3H-Prazosin binding experiments were performed using a
Tris-HCl 50 mM, pH 7.4 buffer. For displacement experiments 0.2 nM
of 3H-Prazosine were used and non specific binding was measured
using 100 mM of Chlorpromazine. The incubation time was 30 minutes
at room temperature and the assay was stopped by filtration on
Whatman GF/B glass fiber filters (Unifilter-96, Canberra Packard
S.A., Zurich, Switzerland). The filters were washed 5 times with
cold buffer. The radioactivity on the filter was counted on a
Packard Top-count microplate scintillation counter after addition
of 40 ml of microscint 40 (Canberra Packard S.A., Zurich,
Switzerland). The effects of compounds were measured using a
minimum of 8 concentrations and repeated at least once. The pooled
normalized values were analyzed using a non-linear regression
calculation program which provide IC.sub.50 with their relative
upper and lower 95% confidence limits (RS1, BBN, USA).
[0032] The thus-determined activity of compounds in accordance with
the invention is in the range of 0.039-0.045 (in .mu.M), as
described in the table above.
Method 3
Methods for Studying the Inhibition of the hERG K.sup.+ Channel
[0033] CHO cells were stably transfected by a pcDNA3-hERG
expression vector containing a SV40-neo cassette for selection.
Cells were thinly plated into 35 mm dishes and used for the
electrophysiological experiment 1/2-3 d later.
[0034] During the experiment the cells were continuously superfused
with an extracellular saline containing (in mM): NaCl 150, KCl 10,
MgCl.sub.2 1, CaCl.sub.2 3, HEPES 10 (pH=7.3 by addition of NaOH).
A 10-mM stock solution of the test compound was made from pure
DMSO. Test solution were made by at least 1000-fold dilution of the
stock solution into the extracellular saline. The glass
micropipettes for whole-cell patch-clamp recording were filled with
a containing (in mM): KCl 110, BAPTA 10, HEPES 10, MgCl.sub.2 4.5,
Na.sub.2ATP 4, Na.sub.2-phosphocreatine 20, creatine kinase 200
.mu.g/ml (pH=7.3 by addition of KOH).
[0035] The whole-cell configuration of the patch-clamp technique
was used for the experiments. Cells were clamped to -80 mV holding
potential and repetitively (0.1 Hz) stimulated by a voltage pulse
pattern consisting of a 1-s conditioning depolarisation to 20 mV
immediately followed by a hyperpolarisation of 50 ms duration to
-120 mV. The membrane current was recorded for at least 3 min (18
stimuli) before compound application (control), and then for
another two 3-min intervals in presence of two different
concentrations of the compound. The current amplitudes (I.sub.test)
at the end of each compound application interval were divided by
the mean current amplitude (I.sub.control) during the initial
control period to calculate the percentage effect of the
compound:
effect (%)=(1-I.sub.test/I.sub.control).multidot.100.
[0036] Compound concentrations were chosen in decade steps (usually
1 and 10 .mu.M) around the expected 50% inhibitory concentration
(IC.sub.50). If after the first experiment the IC.sub.50 turned out
to lie outside the range between the two chosen concentrations the
concentrations were changed to bracket the IC.sub.50 in the
following experiments. The compound was tested on at least three
cells. Its IC.sub.50 was then estimated from the population of all
percent-effect values by non-linear regression using the function
effect=100/(1-IC.sub.50/concentration).sup.- Hill). Concentrations
higher than 10 .mu.M were not tested. If 10 .mu.M of the compound
turned out to produce less than 50% effect, IC50 was labelled as
">10 .mu.M" and the compound was characterised by the average
effect seen at 10 .mu.M.
[0037] The compounds of formula I and their salts, as herein
described, together with pharmaceutically inert excipients are
preferably incorporated into standard pharmaceutical dosage forms,
for example, for oral or parenteral application with the usual
pharmaceutical adjuvant materials, for example, organic or
inorganic inert carrier materials, such as, water, gelatin,
lactose, starch, magnesium stearate, talc, vegetable oils, gums,
polyalkylene-glycols and the like. Examples of pharmaceutical
preparations in solid form are tablets, suppositories, capsules, or
in liquid form are solutions, suspensions or emulsions.
Pharmaceutical adjuvant materials include preservatives,
stabilizers, wetting or emulsifying agents, salts to change the
osmotic pressure or to act as buffers. The pharmaceutical
preparations can also contain other therapeutically active
substances.
[0038] The daily dose of compounds of formula I to be administered
varies with the particular compound employed, the chosen route of
administration and the recipient. Representative of a method for
administering the compounds of formula I is by the oral and
parenteral type administration route. An oral formulation of a
compound of formula I is preferably administered to an adult at a
dose in the range of 1 mg to 1000 mg per day. A parenteral
formulation of a compound of formula I is preferably administered
to an adult at a dose in the range of from 5 to 500 mg per day.
[0039] The invention is further illustrated in the following
examples.
EXAMPLE 1
4-Benzyl-4-hydroxy-piperidine-1-carboxylic Acid Benzyl Ester
[0040] To a solution of 5.0 g (26.2 mmol) of
4-hydroxybenzylpiperidine in 50 ml CH.sub.2Cl.sub.2 were added
under argon 5.5 ml (39.3 mmol) of Et.sub.3N and 3.7 ml (26.2 mmol)
of benzylchloroformate at 0.degree. C. After stirring the reaction
mixture for 3 hours at r.t. 100 ml 1N HCl were added and the
aqueous phase was extracted twice with CH.sub.2Cl.sub.2 and the
combined organic layers were washed with 50 ml water, dried over
MgSO.sub.4 and the solvent was removed under reduced pressure to
give the crude product. Purification by chromatography over silica
gel (hexane/ethyl acetate 4:1 to 2:1) yielded 3.9 g
4-benzyl-4-hydroxy-piperidine-1-carboxylic acid benzyl ester (11.9
mmol, 48%) as a yellow oil.
[0041] MS:m/e=326(M+1)
EXAMPLE 2
4-Benzyl-3,6-dihydro-2H-pyridine-1-carboxylic acid benzyl ester
[0042] To a solution of 40.0 g (123 mmol) of
4-benzyl-4-hydroxy-piperidine- -1-carboxylic acid benzyl ester in
250 ml CH.sub.2Cl.sub.2 were added 39.6 ml (492 mmol) pyridine and
at 0.degree. C. 17.8 ml (246 mmol) of SOCl.sub.2. The reaction
mixture was stirred for 30 min. at 0.degree. C. and then 250 ml of
aqueous (2N) HCl were added. The aqueous phase was extracted twice
with CH.sub.2Cl.sub.2 and the combined organic layers were washed
with water, dried over MgSO.sub.4 and the solvent was removed under
reduced pressure to give 36.3 g (118 mmol, 96%) of
4-benzyl-3,6-dihydro-2H-pyridine-1-carboxylic acid benzyl ester as
an orange oil.
[0043] MS:m/e=308(M+1)
EXAMPLE 3
(1R,6S) and
(1S,6R)-6-Benzyl-7-oxa-3-aza-bicyclo[4.1.0]heptane-3-carboxyli- c
Acid Benzyl Ester
[0044] To a solution of 36.0 g (117 mmol) of
4-benzyl-3,6-dihydro-2H-pyrid- ine-1-carboxylic acid benzyl ester
in 250 ml CH.sub.2Cl.sub.2 were added 40.9 g (166 mmol, .about.70%)
MCPBA. The reaction mixture was stirred for 2 hours and a 1N
NaOH-solution was added. The aqueous phase was extracted twice with
CH.sub.2Cl.sub.2 and the combined organic layers were washed with 1
N NaOH, dried over MgSO.sub.4 and the solvent was removed under
reduced pressure to give 37.6 g (116 mmol, 99%) of (1R,6S) and
(1S,6R)-6-benzyl-7-oxa-3-aza-bicyclo[4.1.0]heptane-3-carboxylic
acid benzyl ester as an oil.
[0045] MS:m/e=324(M+1)
EXAMPLE 4
(3R,4R) and (3S,4S)-4-Benzyl-3,4-dihydroxy-piperidine-1-carboxylic
Acid Benzyl Ester
[0046] To a solution of 37.6 g (116 mmol) of (1R,6S) and
(1S,6R)-6-benzyl-7-oxa-3-aza-bicyclo[4.1.0]heptane-3-carboxylic
acid benzyl ester in 170 ml THF were added 37 ml H.sub.2SO.sub.4
(10%). The reaction mixture was stirred for 16 hours and then
concentrated under reduced pressure. The residue was dissolved in
ethyl acetate and extracted with sat. NaHCO.sub.3. The aqueous
phase was extracted twice with ethyl acetate and the combined
organic layers were washed with sat. NaHCO.sub.3, dried over
MgSO.sub.4 and the solvent was removed under reduced pressure to
give 40.8 g (100%, purity .about.95%) of crude (3R,4R) and
(3S,4S)-4-benzyl-3,4-dihydroxy-piperidine-1-carboxylic acid benzyl
ester.
[0047] MS:m/e=342(M+1)
EXAMPLE 5
(4R, 4R),
4-Benzyl-4-hydroxy-3-((2S)-trifluoroacetyl-cyclopentanecarbonylo-
xy)-piperidine-1-carboxylic Acid Benzyl Ester
[0048] To a solution of 43.0 g (126 mmol) (3R,4R) and
(3S,4S)-4-benzyl-3,4-dihydroxy-piperidine-1-carboxylic acid benzyl
ester and 23.1 g (189 mmol) DMAP in 600 ml CH.sub.2Cl.sub.2 were
added dropwise under argon 500 ml (340 mmol, 0.70 N)
(S)-N-trifluoroacetyl-prolinechlori- de. The reaction mixture was
stirred for 16 hours at r.t. and then sat. NaHCO.sub.3 solution was
added. The aqueous phase was extracted three times with
CH.sub.2Cl.sub.2 and the combined organic layers were washed with
sat. NaHCO.sub.3 and 1N HCl, dried over MgSO.sub.4 and the solvent
was removed under reduced pressure to give the crude product.
Purification by chromatography on silica gel (hexane:ethyl acetate
4:1 to 1:1) and crystallization from diethylether yielded 17.9 g
(33 mmol, 27%) (3R,4R),
4-benzyl-4-hydroxy-3-(2S)-trifluoroacetyl-cyclopentanecarbonylox-
y)-piperidine-1-carboxylic acid benzyl ester.
[0049] MS:m/e=535(M+1), (c=1.11, CH.sub.2Cl.sub.2).
EXAMPLE 6
(3S,4S),
4-Benzyl-4-hydroxy-3-((2S)-trifluoroacetyl-cyclopentanecarbonylox-
y)-piperidine-1-carboxylic acid benzyl ester
[0050] To a solution of 43.0 g (126 mmol) (3R,4R) and
(3S,4S)-4-benzyl-3,4-dihydroxy-piperidine-1-carboxylic acid benzyl
ester and 23.1 g (189 mmol) DMAP in 600 ml CH.sub.2Cl.sub.2 were
added under argon 500 ml (340 mmol, 0.70 N)
(S)-N-trifluoroacetyl-prolinechloride dropwise. The reaction
mixture was stirred for 16 hours at r.t. and then sat. NaHCO.sub.3
solution was added. The aqueous phase was extracted three times
with CH.sub.2Cl.sub.2 and the combined organic layers were washed
with sat. NaHCO.sub.3 and 1N HCl, dried over MgSO.sub.4 and the
solvent was removed under reduced pressure to give the crude
product. Purification by chromatography on silica gel (hexane:ethyl
acetate 4:1 to 1:1) and crystallization from diethylether yielded
14.3 g (27 mmol, 21%)
(3S,4S)-4-benzyl-4-hydroxy-3-((2s)-trifluoroacetyl-cyclopentanecarbonylox-
y)-piperidine-1-carboxylic acid benzyl ester.
[0051] MS:m/e=535(M+1), (c=1.11, CH.sub.2Cl.sub.2).
EXAMPLE 7
(3R,4R)-4-Benzyl-3,4-dihydroxy-piperidine-1-carboxylic acid benzyl
ester
[0052] To a solution of 17.9 g (33.5 mmol) (3R), (4R),
4-benzyl-4-hydroxy-3-((2S)-trifluoroacetyl-cyclopentanecarbonyloxy)-piper-
idine-1-carboxylic acid benzyl ester in 500 ml EtOH were added 250
ml (250 mmol) of 1 N NaOH. The reaction mixture was stirred for 16
hours and water was then added. The aqueous phase was extracted
three times with CH.sub.2Cl.sub.2 and the combined organic layers
were washed with water, dried over MgSO.sub.4 and the solvent was
removed under reduced pressure to give 11.2 g (32.8 mmol, 98%) (3R,
4R)-4-benzyl-3,4-dihydroxy-piperidin- e-1-carboxylic acid benzyl
ester as an oil.
[0053] MS:m/e=342.3(M+1), [.alpha.].sub.D.sup.20=-36.75(c=1.02,
CH.sub.2Cl.sub.2).
EXAMPLE 8
(3S,4S)-4-Benzyl-3,4-dihydroxy-piperidine-1-carboxylic acid benzyl
ester
[0054] To a solution of 14.3 g (27 mmol)
(3S,4S)-4-benzyl-4-hydroxy-3-((2S-
)-trifluoroacetyl-cyclopentanecarbonyloxy)-piperidine-1-carboxylic
acid benzyl ester in 500 ml EtOH were added 250 ml (250 mmol) 1 N
NaOH. The reaction mixture was stirred for 16 hours and water was
added. The aqueous phase was extracted three times with
CH.sub.2Cl.sub.2 and the combined organic layers were washed with
water, dried over MgSO.sub.4 and the solvent was removed under
reduced pressure to give 8.4 g (25 mmol, 92%)
(3S,4S)-4-benzyl-3,4-dihydroxy-piperidine-1-carboxylic acid benzyl
ester as an oil.
[0055] MS:m/e=342.3(M+1), [.alpha.].sub.D.sup.20=35.30(c=1.02,
CH.sub.2Cl.sub.2).
EXAMPLE 9
(3R,4R) and (3S,4S)-4-Benzyl-3,4-dihydroxy-piperidine
[0056] (3R,4R) and
(3S,4S)-4-Benzyl-3,4-dihydroxy-piperidine-1-carboxylic acid benzyl
ester 1.46 g (4.3 mmol) was dissolved in 30 ml EtOH and
hydrogenated in the presence of 400 mg Pd/C (10%) under atmospheric
pressure of H.sub.2 at r.t. After 16 hours the reaction was
complete and the catalyst was filtered off and the solvent was
removed under reduced pressure to give 796 mg (3.8 mmol, 89%)
(3R,4R) and (3S,4S)-4-benzyl-3,4-dihydroxy-piperidine as an
oil.
[0057] MS:m/e=207.1(M).
EXAMPLE 10
(3R,4R)-4-Benzyl-3,4-dihydroxy-piperidine
[0058] (3R,4R)-4-benzyl-3,4-dihydroxy-piperidine-1-carboxylic acid
benzyl ester 11.0 g (32 mmol) was dissolved in 250 ml EtOH and
hydrogenated in the presence of 1.1 g Pd/C (10%) under atmospheric
pressure of H.sub.2 at r.t. After 16 hours the reaction was
complete and the catalyst was filtered off and the solvent was
removed under reduced pressure to give 6.6 g (32 mmol, 100%)
(3R,4R)-4-benzyl-3,4-dihydroxy-piperidine as an oil.
[0059] MS:m/e=207.1(M), [.alpha.].sub.D.sup.20=-42.3(c=1.00,
ethanol).
EXAMPLE 11
(3S), (4S)-4-Benzyl-3,4-dihydroxy-piperidine
[0060] (3S,4S)-4-Benzyl-3,4-dihydroxy-piperidine-1-carboxylic acid
benzyl ester 8.2 g (24 mmol) was dissolved in 250 ml EtOH and
hydrogenated in the presence of 1.1 g Pd/C, (10%)under atmospheric
pressure at r.t. After 16 hours the reaction was complete and the
catalyst was filtered off and the solvent was removed under reduced
pressure to give 5.5 g (quant., .about.95% purity)
(3S,4S)-4-Benzyl-3,4-dihydroxy-piperidine as an oil.
[0061] MS:m/e=207.1(M), [.alpha.].sub.D .sup.20=+42.57 (c=1.05,
ethanol).
EXAMPLE 12
(3R,4R) and
(3S,4S)-4-Benzyl-1-[2-(4-benzyloxy-phenoxy)-ethyl]-piperidine--
3,4-diol
[0062] To a solution of 0.2 g (1.0 mmol) (3R,4R) and
(3S,4S)-4-benzyl-3,4-dihydroxy-piperidine in 10 ml DMF were added
297 mg (1.0 mmol) 1-benzyloxy-4-(2-chloro-ethoxy)-benzene and 0.2 g
(1.5 mmol) K.sub.2CO.sub.3 and the reaction mixture was heated to
90.degree. C. for 16 hours. After the addition of water, the
aqueous phase was extracted three times with ethyl acetate and the
combined organic layers were washed with water, dried over
MgSO.sub.4 and the solvent was removed under reduced pressure to
give 551 mg (100%, .about.80% purity) (3R,4R) and
(3S,4S)-4-benzyl-1-[2-(4-benzyloxy-phenoxy)-ethyl]-piperidine-3,4-dio-
l as a solid.
[0063] MS:m/e=434.5(M+1).
EXAMPLE 13
(3R,4R)-4-Benzyl-1-[2-(4-benzyloxy-phenoxy)-ethyl]-piperidine-3,4-diol
[0064] To a solution of 5.0 g (24 mmol)
(3R,4R)-4-benzyl-3,4-dihydroxy-pip- eridine in 150 ml DMF were
added 7.4 g (24 mmol) 1-benzyloxy-4-(2-chloro-e- thoxy)-benzene and
5.0 g (36 mmol) K.sub.2CO.sub.3 and the reaction mixture was heated
to 90.degree. C. for 72 hours. After the addition of water the
aqueous phase was extracted three times with ethyl acetate and the
combined organic layers were washed with water, dried over
MgSO.sub.4 and the solvent was removed under reduced pressure to
give 10.5 g (24 mmol, 100%)
(3R,4R)-4-benzyl-1-[2-(4-benzyloxy-phenoxy)-ethyl]-piperidine-
-3,4-diol as a solid.
[0065] MS:m/e=434.5(M+1), [.alpha.].sub.D.sup.20=-27.5 (c=0.95,
CH.sub.2Cl.sub.2).
EXAMPLE 14
(3S,4S)-4-Benzyl-1-[2-(4-benzyloxy-phenoxy)-ethyl]-piperidine-3,4-diol
[0066] To a solution of 5.0 g (24 mmol)
(3S,4S)-4-benzyl-3,4-dihydroxy-pip- eridine in 150 ml DMF were
added 7.4 g (24 mmol) 1-benzyloxy-4-(2-chloro-e- thoxy)-benzene and
5.0 g (36 mmol) K.sub.2CO.sub.3 and the reaction mixture was heated
to 90.degree. C. for 72 hours. After the addition of water the
aqueous phase was extracted three times with ethyl acetate and the
combined organic layers were washed with water, dried over
MgSO.sub.4 and the solvent was removed under reduced pressure to
give 10.9 g (quant., .about.95% purity)
(3S,4S)-4-benzyl-1-[2-(4-benzyloxy-phenoxy)-e-
thyl]-piperidine-3,4-diol as a solid.
[0067] MS:m/e=434.5(M+1), [.alpha.].sub.D.sup.20=+26.2(c=1.04,
CH.sub.2Cl.sub.2).
EXAMPLE 15
(3R,4R) and
(3S,4S)-4-Benzyl-1-[2-(4-hydroxy-phenoxy)-ethyl]-piperidine-3,-
4-diol
[0068] (3R,4R) and (3
S,4S)-4-benzyl-1-[2-(4-benzyloxy-phenoxy)-ethyl]-pip-
eridine-3,4-diol 550 mg (1.3 mmol) was dissolved in 10 ml EtOH and
hydrogenated in the presence of 100 mg Pd/C (10%) under atmospheric
pressure at 50.degree. C. After 4 hours the reaction was complete
and the catalyst was filtered off and the solvent was removed under
reduced pressure to give the crude product. Purification by
chromatography (CH.sub.2Cl.sub.2/MeOH 9:1) yielded 249 mg (0.73
mmol, 56%) (3R,4R) and
(3S,4S)-4-benzyl-1-[2-(4-hydroxy-phenoxy)-ethyl]-piperidine-3,4-diol
as a solid.
[0069] MS:m/e=344.4(M+1).
EXAMPLE 16
(3R,4R)-4-Benzyl-1-[2-(4-hydroxy-phenoxy)-ethyl]-piperidine-3,4-diol
[0070]
(3R,4R)-4-benzyl-1-[2-(4-benzyloxy-phenoxy)-ethyl]-piperidine-3,4-d-
iol 10.3 g (24 mmol) was dissolved in 300 ml EtOH and hydrogenated
in the presence of 1.1 g Pd/C (10%) under atmospheric pressure at
50.degree. C. After 4 hours the reaction was complete and the
catalyst was filtered off and the solvent was removed under reduced
pressure to give the crude product. Purification by chromatography
(CH.sub.2Cl.sub.2/MeOH 10:1) and crystallization from ethyl acetate
and hexane yielded then 4.6 g (10.6 mmol, 45%)
(3R,4R)-4-benzyl-1-[2-(4-hydroxy-phenoxy)-ethyl]-piperidine-3,-
4-diol as a solid.
[0071] MS:m/e=344.4(M+1), [.alpha.].sub.D.sup.20=-36.2(c=1.03,
CH.sub.2Cl.sub.2).
EXAMPLE 17
(3S,4S)-4-Benzyl-1-[2-(4-hydroxy-phenoxy)-ethyl]-piperidine-3,4-diol
[0072]
(3S,4S)-4-Benzyl-1-[2-(4-benzyloxy-phenoxy)-ethyl]-piperidine-3,4-d-
iol 10.3 g (24 mmol) was dissolved in 300 ml EtOH and hydrogenated
in the presence of 1.1 g Pd/C (10%) under atmospheric pressure at
50.degree. C. After 4 hours the reaction was complete and the
catalyst was filtered off and the solvent was removed under reduced
pressure to give the crude product. Purification by chromatography
(CH.sub.2Cl.sub.2/MeOH 10:1) and crystallization from ethyl acetate
and hexane yielded then 5.7 g (16.6 mmol, 69%)
(3S,4S)-4-benzyl-1-[2-(4-hydroxy-phenoxy)-ethyl]-piperidine-3,-
4-diol as a solid.
[0073] MS:m/e=344.3(M+1), [.alpha.].sub.D.sup.20=+37.1(c1.04,
CH.sub.2Cl.sub.2).
3 Tablet Formulation (Wet Granulation) Ingredients mg/tablet 1.
Active compound 5 25 100 500 2. Lactose Anhydrous DTG 125 105 30
150 3. Sta-Rx 1500 6 6 6 30 4. Microcrystalline Cellulose 30 30 30
150 5. Magnesium Stearate 1 1 1 1 TOTAL 167 167 167 831
Manufacturing Procedure: 1. Mix Items 1, 2, 3 and 4 and granulate
with purified water. 2. Dry the granulation at 50.degree. C. 3.
Pass the granulation through suitable milling equipment. 4. Add
Item 5 and mix for three minutes; compress on a suitable press.
[0074]
4 Capsule Formulation Ingredients mg/capsule 1. Active compound 5
25 100 500 2. Hydrous Lactose 159 123 148 -- 3. Corn Starch 25 35
40 70 4. Talc 10 15 10 25 5. Magnesium Stearate 1 2 2 5 TOTAL 200
200 300 600 Manufacturing Procedure; 1. Mix Items 1, 2, and 3 in a
suitable mixer for 30 minutes. 2. Add Items 4 and 5 and mix for 3
minutes. 3. Fill into a suitable capsule.
* * * * *