U.S. patent application number 14/321179 was filed with the patent office on 2014-10-23 for 3,6-diazabicyclo[3.1.1]heptaines as neuronal nicotinic acetycholine receptor ligands.
The applicant listed for this patent is Targacept, Inc.. Invention is credited to Srinivasa Rao Akireddy, Balwinder Singh Bhatti, Ronald Joseph Heemstra, Srinivasa V. Murthy, Jon-Paul Strachan, Yunde Xiao.
Application Number | 20140315880 14/321179 |
Document ID | / |
Family ID | 43608875 |
Filed Date | 2014-10-23 |
United States Patent
Application |
20140315880 |
Kind Code |
A1 |
Akireddy; Srinivasa Rao ; et
al. |
October 23, 2014 |
3,6-DIAZABICYCLO[3.1.1]HEPTAINES AS NEURONAL NICOTINIC ACETYCHOLINE
RECEPTOR LIGANDS
Abstract
The present invention relates to compounds that bind to and
modulate the activity of neuronal nicotinic acetylcholine
receptors, to processes for preparing these compounds, to
pharmaceutical compositions containing these compounds, and to
methods of using these compounds for treating a wide variety of
conditions and disorders, including those associated with
dysfunction of the central nervous system (CNS).
Inventors: |
Akireddy; Srinivasa Rao;
(Winston-Salem, NC) ; Bhatti; Balwinder Singh;
(Winston-Salem, NC) ; Heemstra; Ronald Joseph;
(Lewisville, NC) ; Murthy; Srinivasa V.;
(Lewisville, NC) ; Strachan; Jon-Paul;
(Burlington, NC) ; Xiao; Yunde; (Clemmons,
NC) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Targacept, Inc. |
Winston-Salem |
NC |
US |
|
|
Family ID: |
43608875 |
Appl. No.: |
14/321179 |
Filed: |
July 1, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13514084 |
Aug 15, 2012 |
8802694 |
|
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PCT/US2010/058836 |
Dec 3, 2010 |
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14321179 |
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61267218 |
Dec 7, 2009 |
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Current U.S.
Class: |
514/210.16 ;
544/349; 546/113; 546/15 |
Current CPC
Class: |
A61P 25/04 20180101;
A61P 25/14 20180101; A61P 25/28 20180101; A61P 25/18 20180101; A61P
25/32 20180101; A61P 21/02 20180101; A61P 9/10 20180101; A61P 25/00
20180101; C07D 471/08 20130101; A61P 25/24 20180101; A61P 43/00
20180101; A61P 25/30 20180101; A61P 25/34 20180101; A61P 25/02
20180101; A61P 25/08 20180101; A61P 25/16 20180101; C07D 487/08
20130101; A61P 25/22 20180101 |
Class at
Publication: |
514/210.16 ;
546/113; 544/349; 546/15 |
International
Class: |
C07D 471/08 20060101
C07D471/08; C07D 487/08 20060101 C07D487/08 |
Claims
1. A compound of Formula I: ##STR00172## wherein: each m is
identical and is 0 or 1; each n is identical and is 0 or 1; when
each m is 0, then each n is 1; when each m is 1, then each n is 0;
R.sup.1 is --C(O)--R.sup.3A, --C(O)O--R.sup.3B, R.sup.2 is H;
R.sup.3A is methyl, propyl, butyl, pentyl, hexyl, alkenyl, alkynyl,
cycloalkyl, cycloalkenyl, cycloalkynyl, aryl, heteroaryl, or
heterocyclic; R.sup.3B is methyl, ethyl, propyl, n-butyl, isobutyl,
sec-butyl, pentyl, hexyl, alkenyl, alkynyl, cycloalkyl,
cycloalkenyl, cycloalkynyl, aryl, heteroaryl, or heterocyclic; each
R.sup.3A and R.sup.3B individually may be optionally substituted
with one or more alkyl, alkenyl, alkynyl, aryl, aryloxy, amino,
amido, heteroaryl, halogen, hydroxyl, alkoxy, cycloalkyl,
cycloalkenyl, cycloalkynyl, heterocyclic, or alkylamido
substituents; or a pharmaceutically acceptable salt thereof.
2. The compound according to claim 1, wherein m is 0.
3. The compound according to claim 1, wherein m is 1.
4. A pharmaceutical composition comprising a compound as claimed in
claim 1, and a pharmaceutically acceptable carrier.
Description
CROSS RELATION TO PRIOR APPLICATIONS
[0001] The present invention is a continuation of U.S. patent
application Ser. No. 13/514,084, filed Aug. 15, 2012, which is a
.sctn.371 application of International Application No.
PCT/US2010/058836, filed Dec. 3, 2010, which claims benefit to U.S.
Provisional Application No. 61/267,218, filed Dec. 7, 2009; each of
which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to compounds that bind to and
modulate the activity of neuronal nicotinic acetylcholine
receptors, to processes for preparing these compounds, to
pharmaceutical compositions containing these compounds, and to
methods of using these compounds for treating a wide variety of
conditions and disorders, including those associated with
dysfunction of the central nervous system (CNS).
BACKGROUND OF THE INVENTION
[0003] The therapeutic potential of compounds that target neuronal
nicotinic receptors (NNRs), also known as nicotinic acetylcholine
receptors (nAChRs), has been the subject of several reviews. See,
for example, Arneric et al., Biochem. Pharmacol. 74: 1092 (2007),
Breining et al., Ann. Rep. Med. Chem. 40: 3 (2005), Hogg and
Bertrand, Curr. Drug Targets: CNS Neurol. Disord. 3: 123 (2004),
Suto and Zacharias, Expert Opin. Ther. Targets 8: 61 (2004), Dani
et al., Bioorg. Med. Chem. Lett. 14: 1837 (2004), Bencherif and
Schmitt, Curr. Drug Targets: CNS Neurol. Disord. 1: 349 (2002),
Yang et al., Acta Pharmacol. Sin. 30(6): 740-751 (2009). Among the
kinds of indications for which NNR ligands have been proposed as
therapies are cognitive disorders, including Alzheimer's disease,
attention deficit disorder, and schizophrenia (Biton et al.,
Neuropsychopharm. 32: 1 (2007), Boess et al., J. Pharmacol. Exp.
Ther. 321: 716 (2007), Hajos et al., J. Pharmacol. Exp. Ther. 312:
1213 (2005), Newhouse et al., Curr. Opin. Pharmacol. 4: 36 (2004),
Levin and Rezvani, Curr. Drug Targets: CNS Neurol. Disord. 1: 423
(2002), Graham et al., Curr. Drug Targets: CNS Neurol. Disord. 1:
387 (2002), Ripoll et al., Curr. Med. Res. Opin. 20(7): 1057
(2004), and McEvoy and Allen, Curr. Drug Targets: CNS Neurol.
Disord. 1: 433 (2002)); pain and inflammation (Decker et al., Curr.
Top. Med. Chem. 4(3): 369 (2004), Vincler, Expert Opin. Invest.
Drugs 14(10): 1191 (2005), Jain, Curr. Opin. Inv. Drugs 5: 76
(2004), Miao et al., Neuroscience 123: 777 (2004)); depression and
anxiety (Shytle et al., Mol. Psychiatry 7: 525 (2002), Damaj et
al., Mol. Pharmacol. 66: 675 (2004), Shytle et al., Depress.
Anxiety 16: 89 (2002)); neurodegeneration (O'Neill et al., Curr.
Drug Targets: CNS Neurol. Disord. 1: 399 (2002), Takata et al., J.
Pharmacol. Exp. Ther. 306: 772 (2003), Marrero et al., J.
Pharmacol. Exp. Ther. 309: 16 (2004)); Parkinson's disease (Bordia
et al., J Pharmacol. Exp. Ther. 327: 239 (2008), Jonnala and
Buccafusco, J. Neurosci. Res. 66: 565 (2001)); addiction (Dwoskin
and Crooks, Biochem. Pharmacol. 63: 89 (2002), Coe et al., Bioorg.
Med. Chem. Lett. 15(22): 4889 (2005)); obesity (Li et al., Curr.
Top. Med. Chem. 3: 899 (2003)); and Tourette's syndrome (Sacco et
al., J. Psychopharmacol. 18(4): 457 (2004), Young et al., Clin.
Ther. 23(4): 532 (2001)).
[0004] There exists a heterogeneous distribution of nAChR subtypes
in both the central and peripheral nervous systems. For instance,
the .alpha.4.beta.2, .alpha.6 containing, .alpha.7, and
.alpha.3.beta.2 subtypes are predominant in vertebrate brain,
whereas the .alpha.3.beta.4 subtype is predominate at the autonomic
ganglia, and the .alpha.1.beta.1.delta..gamma. and
.alpha.1.beta.1.delta..epsilon. subtypes are predominant at the
neuromuscular junction (see Dwoskin et al., Exp. Opin. Ther.
Patents 10: 1561 (2000) and Holliday et al. J. Med. Chem. 40(26),
4169 (1997)). Compounds which selectively target the CNS
predominant subtypes have potential utility in treating various CNS
disorders. However, a limitation of some nicotinic compounds is
that they lack the selectivity required to preferentially target
CNS receptors over receptor located in the muscle and ganglion.
Such drugs are often associated with various undesirable side
effects. Therefore, there is a need to have compounds,
compositions, and methods for preventing or treating various
conditions or disorders where the compounds exhibit a high enough
degree of nAChR subtype specificity to elicit a beneficial effect,
without significantly affecting those receptor subtypes which have
the potential to induce undesirable side effects, including, for
example, appreciable activity at cardiovascular and skeletal muscle
sites.
SUMMARY OF THE INVENTION
[0005] The present invention includes compounds which bind with
high affinity to NNRs of either the .alpha.4.beta.2 subtype, or the
.alpha.6-containing subtype, or both NNR subtypes. The present
invention also relates to pharmaceutically acceptable salts
prepared from these compounds.
[0006] The present invention includes pharmaceutical compositions
comprising a compound of the present invention or a
pharmaceutically acceptable salt thereof. The pharmaceutical
compositions of the present invention can be used for treating or
preventing a wide variety of conditions or disorders, particularly
those disorders mediated by nicotinic acetylcholine receptors.
[0007] The present invention includes a method for treating,
preventing, delaying the onset of, or slowing the progression of
disorders mediated by nicotinic acetylcholine receptors, in mammals
in need of such treatment. The methods involve administering to a
subject a therapeutically effective amount of a compound of the
present invention, including a salt thereof, or a pharmaceutical
composition that includes such compounds.
BRIEF DESCRIPTION OF THE FIGURES
[0008] FIG. 1 illustrates a dose effect curve of Compound A
(3-cyclopropylcarbonyl-3,6-diazabicyclo[3.1.1], as the heptane
di-p-toluoyl-D-tartrate salt) and nicotine on TH positive neurons
after 48 h pretreatment, followed by MPP.sup.+ injury (4 .mu.M, 48
h).
[0009] FIG. 2 illustrates a dose effect curve of Compound A
(3-cyclopropylcarbonyl-3,6-diazabicyclo[3.1.1], as the heptane
di-p-toluoyl-D-tartrate salt) and nicotine on total TH neurite
length after 48 h pretreatment, followed by MPP.sup.+ injury (4
.mu.M, 48 h).
[0010] FIG. 3 illustrates a dose effect curve of Compound B
(3-ethylcarbonyl-3,6-diazabicyclo[3.1.1], as the heptane
di-p-toluoyl-D-tartrate salt) and nicotine on TH positive neurons
after 48 h pretreatment, followed by MPP.sup.+ injury (4 .mu.M, 48
h).
[0011] FIG. 4 illustrates a dose effect curve of Compound B
(3-ethylcarbonyl-3,6-diazabicyclo[3.1.1], as the heptane
di-p-toluoyl-D-tartrate salt) and nicotine on total TH neurite
length after 48 h pretreatment, followed by MPP.sup.+ injury (4
.mu.M, 48 h).
[0012] FIG. 5 illustrates a dose effect curve of BDNF (50 ng/ml)
and nicotine (10 nM) on TH positive neurons after 48 h
pretreatment, followed by MPP.sup.+ injury (4 .mu.M, 48 h).
[0013] FIG. 6 illustrates a dose effect curve of BDNF (50 ng/ml)
and nicotine (10 nM) on total TH neurite length after 48 h
pretreatment, followed by MPP.sup.+ injury (4 .mu.M, 48 h).
DETAILED DESCRIPTION OF THE INVENTION
I. Compounds
[0014] The present invention includes compounds of Formula I:
##STR00001##
wherein: [0015] each m is identical and is 0 or 1; [0016] each n is
identical and is 0 or 1; [0017] when each m is 0, then each n is 1;
[0018] when each m is 1, then each n is 0; [0019] R.sup.1 is [0020]
--C(O)--R.sup.3, [0021] --C(O)O--R.sup.3, [0022] --C(O)NH--R.sup.3,
[0023] --C(O)--(CH.sub.2).sub.q--X--R.sup.3, [0024]
--C(O)O--(CH.sub.2).sub.q--X--R.sup.3, or [0025]
--C(O)NH--(CH.sub.2).sub.q--X--R.sup.3; [0026] q is 1, 2, 3, 4, 5,
or 6; [0027] X is --O--, --S--, --NH--, or --NHC(O)--; [0028]
R.sup.2 is H or alkyl; [0029] R.sup.3 is alkyl, alkenyl, alkynyl,
cycloalkyl, cycloalkenyl, cycloalkynyl, aryl, heteroaryl, or
heterocyclic; [0030] each R.sup.3 individually may be optionally
substituted with one or more alkyl, alkenyl, alkynyl, aryl,
aryloxy, amino, amido, heteroaryl, halogen, hydroxyl, alkoxy,
cycloalkyl, cycloalkenyl, cycloalkynyl, heterocyclic, or alkylamido
substituents; [0031] with the proviso that Formula I does not
include the following compounds: [0032]
3-ethylcarbonyl-3,6-diazabicyclo[3.1.1]heptane, [0033]
6-ethylcarbonyl-3,6-diazabicyclo[3.1.1]heptane, [0034]
6-tert-butoxycarbonyl-3,6-diazabicyclo[3.1.1]heptane; [0035] or a
pharmaceutically acceptable salt thereof.
[0036] The present invention includes compounds of Formula I:
##STR00002##
wherein: [0037] each m is identical and is 0 or 1; [0038] each n is
identical and is 0 or 1; [0039] when each m is 0, then each n is 1;
[0040] when each m is 1, then each n is 0; [0041] R.sup.1 is [0042]
--C(O)--R.sup.3A, [0043] --C(O)O--R.sup.3B, [0044]
--C(O)NH--R.sup.3C, [0045] --C(O)--(CiH.sub.2).sub.q--X--R.sup.3C,
[0046] --C(O)O--(CH.sub.2).sub.q--X--R.sup.3C, or [0047]
--C(O)NH--(CH.sub.2).sub.q--X--R.sup.3C; [0048] q is 1, 2, 3, 4, 5,
or 6; [0049] X is --O--, --S--, --NH--, or --NHC(O)--; [0050]
R.sup.2 is H or alkyl; [0051] when R.sup.2 is H, then R.sup.3A is
methyl, propyl, butyl, pentyl, hexyl, alkenyl, alkynyl, cycloalkyl,
cycloalkenyl, cycloalkynyl, aryl, heteroaryl, or heterocyclic;
[0052] when R.sup.2 is alkyl, then R.sup.3A is methyl, ethyl,
propyl, butyl, pentyl, hexyl, alkenyl, alkynyl, cycloalkyl,
cycloalkenyl, cycloalkynyl, aryl, heteroaryl, or heterocyclic;
[0053] when R.sup.2 is H and each m is 0 and each n is 1, then
R.sup.3B is methyl, ethyl, propyl, n-butyl, isobutyl, sec-butyl,
pentyl, hexyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl,
cycloalkynyl, aryl, heteroaryl, or heterocyclic; [0054] when
R.sup.2 is H and each m is 1 and each n is 0, or when R.sup.2 is
alkyl, then R.sup.3B is methyl, ethyl, propyl, butyl, pentyl,
hexyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, cycloalkynyl,
aryl, heteroaryl, or heterocyclic; [0055] each R.sup.3C
individually is alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl,
cycloalkynyl, aryl, heteroaryl, or heterocyclic; [0056] each
R.sup.3 individually may be optionally substituted with one or more
alkyl, alkenyl, alkynyl, aryl, aryloxy, amino, amido, heteroaryl,
halogen, hydroxyl, alkoxy, cycloalkyl, cycloalkenyl, cycloalkynyl,
heterocyclic, or alkylamido substituents; [0057] or a
pharmaceutically acceptable salt thereof.
[0058] In one embodiment, a compound is selected from the group
consisting of: [0059]
3-methylcarbonyl-3,6-diazabicyclo[3.1.1]heptane; [0060]
3-isopropylcarbonyl-3,6-diazabicyclo[3.1.1]heptane; [0061]
3-cyclopropylcarbonyl-3,6-diazabicyclo[3.1.1]heptane; [0062]
3-propoxycarbonyl-3,6-diazabicyclo[3.1.1]heptane; [0063]
3-isopropoxycarbonyl-3,6-diazabicyclo[3.1.1]heptane: [0064]
3-methoxyethoxycarbonyl-3,6-diazabicyclo[3.1.1]heptane; [0065]
3-(2-fluoroethoxy)carbonyl-3,6-diazabicyclo[3.1.1]heptane; [0066]
3-(2-bromofuran-5-yl)carbonyl-3,6-diazabicyclo[3.1.1]heptane;
[0067]
3-(3-bromofuran-5-yl)carbonyl-3,6-diazabicyclo[3.1.1]heptane;
[0068]
3-(3-chlorofuran-2-yl)carbonyl-3,6-diazabicyclo[3.1.1]heptane;
[0069] 3-(isoxazol-5-yl)carbonyl-3,6-diazabicyclo[3.1.1]heptane;
[0070] 3-(2-methoxyethyl)carbonyl-3,6-diazabicyclo[3.1.1]heptane;
[0071]
3-(2,2,2-trifluoroethyl)carbonyl-3,6-diazabicyclo[3.1.1]heptane;
[0072]
3-(tetrahydrofuran-3-yl)carbonyl-3,6-diazabicyclo[3.1.1]heptane;
[0073]
6-(2-chlorofuran-5-yl)carbonyl-3,6-diazabicyclo[3.1.1]heptane;
[0074]
6-(2-bromorofuran-5-yl)carbonyl-3,6-diazabicyclo[3.1.1]heptane;
[0075] 6-cyclobutylcarbonyl-3,6-diazabicyclo[3.1.1]heptane; [0076]
6-(2-methoxyethyl)carbonyl-3,6-diazabicyclo[3.1.1]heptane; [0077]
cis-3-(2-fluorocycloprop-1-yl)carbonyl-3,6-diazabicyclo[3.1.1]heptane;
[0078]
trans-3-(2-fluorocycloprop-1-yl)carbonyl-3,6-diazabicyclo[3.1.1]he-
ptane; [0079]
cis-6-(2-fluorocycloprop-1-yl)carbonyl-3,6-diazabicyclo[3.1.1]heptane;
and [0080]
trans-6-(2-fluorocycloprop-1-yl)carbonyl-3,6-diazabicyclo[3.1.1]heptane;
[0081] or a pharmaceutically acceptable salt thereof.
[0082] In one embodiment, the present invention is compound,
3-cyclopropylcarbonyl-3,6-diazabicyclo[3.1.1]heptane, Compound A,
or a pharmaceutically acceptable salt thereof.
[0083] One aspect of the present invention includes a
pharmaceutical composition comprising a compound of the present
invention and a pharmaceutically acceptable carrier.
[0084] One aspect of the present invention includes a method for
the treatment or prevention of a disease or condition mediated by
neuronal nicotinic receptors comprising the administration of a
compound of the present invention. In one embodiment, the neuronal
nicotinic receptors are of the .alpha.4.beta.2 subtype. In one
embodiment, the neuronal nicotinic receptors are of the
.alpha.6-containing subtype. In one embodiment, the neuronal
nicotinic receptors are a combination of the .alpha.4.beta.2 and
.alpha.6-containing subtypes.
[0085] One aspect of the present invention includes use of a
compound of the present invention for the preparation of a
medicament for the treatment or prevention of a disease or
condition mediated by neuronal nicotinic receptors comprising the
administration of a compound of the present invention. In one
embodiment, the neuronal nicotinic receptors are of the
.alpha.4.beta.2 subtype. In one embodiment, the neuronal nicotinic
receptors are of the .alpha.6-containing subtype. In one
embodiment, the neuronal nicotinic receptors are a combination of
the .alpha.4.beta.2 and .alpha.6-containing subtypes.
[0086] One aspect of the present invention includes a compound of
the present invention for use as an active therapeutic substance.
One aspect, thus, includes a compound of the present invention for
use in the treatment or prevention of a disease or condition
mediated by neuronal nicotinic receptors comprising the
administration of a compound of the present invention. In one
embodiment, the neuronal nicotinic receptors are of the
.alpha.4.beta.2 subtype. In one embodiment, the neuronal nicotinic
receptors are of the .alpha.6-containing subtype. In one
embodiment, the neuronal nicotinic receptors are a combination of
the .alpha.4.beta.2 and .alpha.6-containing subtypes.
[0087] The scope of the present invention includes all combinations
of aspects and embodiments.
[0088] The following definitions are meant to clarify, but not
limit, the terms defined. If a particular term used herein is not
specifically defined, such term should not be considered
indefinite. Rather, terms are used within their accepted
meanings.
[0089] As used throughout this specification, the preferred number
of atoms, such as carbon atoms, will be represented by, for
example, the phrase "C.sub.x-y alkyl," which refers to an alkyl
group, as herein defined, containing the specified number of carbon
atoms. Similar terminology will apply for other preferred terms and
ranges as well. Thus, for example, C.sub.1-6 alkyl represents a
straight or branched chain hydrocarbon containing one to six carbon
atoms.
[0090] As used herein the term "alkyl" refers to a straight or
branched chain hydrocarbon, which may be optionally substituted,
with multiple degrees of substitution being allowed. Examples of
"alkyl" as used herein include, but are not limited to, methyl,
ethyl, propyl, isopropyl, isobutyl, n-butyl, tert-butyl, isopentyl,
and n-pentyl.
[0091] As used herein, the term "cycloalkyl" refers to a fully
saturated optionally substituted monocyclic, bicyclic, or bridged
hydrocarbon ring, with multiple degrees of substitution being
allowed. Exemplary "cycloalkyl" groups as used herein include, but
are not limited to, cyclopropyl, cyclobutyl, cyclopentyl,
cyclohexyl, and cycloheptyl.
[0092] As used herein, the term "heterocycle" or "heterocyclyl"
refers to an optionally substituted mono- or polycyclic ring
system, optionally containing one or more degrees of unsaturation,
and also containing one or more heteroatoms, which may be
optionally substituted, with multiple degrees of substitution being
allowed. Exemplary heteroatoms include nitrogen, oxygen, or sulfur
atoms, including N-oxides, sulfur oxides, and dioxides. Preferably,
the ring is three to twelve-membered, preferably three- to
eight-membered and is either fully saturated or has one or more
degrees of unsaturation. Such rings may be optionally fused to one
or more of another heterocyclic ring(s) or cycloalkyl ring(s).
Examples of "heterocyclic" groups as used herein include, but are
not limited to, tetrahydrofuran, pyran, tetrahydropyran,
1,4-dioxane, 1,3-dioxane, piperidine, pyrrolidine, morpholine,
tetrahydrothiopyran, and tetrahydrothiophene.
[0093] As used herein, the term "aryl" refers to a single benzene
ring or fused benzene ring system which may be optionally
substituted, with multiple degrees of substitution being allowed.
Examples of "aryl" groups as used include, but are not limited to,
phenyl, 2-naphthyl, 1-naphthyl, anthracene, and phenanthrene.
Preferable aryl rings have five- to ten-members.
[0094] As used herein, a fused benzene ring system encompassed
within the term "aryl" includes fused polycyclic hydrocarbons,
namely where a cyclic hydrocarbon with less than maximum number of
noncumulative double bonds, for example where a saturated
hydrocarbon ring (cycloalkyl, such as a cyclopentyl ring) is fused
with an aromatic ring (aryl, such as a benzene ring) to form, for
example, groups such as indanyl and acenaphthalenyl, and also
includes such groups as, for non-limiting examples,
dihydronaphthalene and tetrahydronaphthalene.
[0095] As used herein, the term "heteroaryl" refers to a monocyclic
five to seven membered aromatic ring, or to a fused bicyclic
aromatic ring system comprising two of such aromatic rings, which
may be optionally substituted, with multiple degrees of
substitution being allowed. Preferably, such rings contain five- to
ten-members. These heteroaryl rings contain one or more nitrogen,
sulfur, and/or oxygen atoms, where N-oxides, sulfur oxides, and
dioxides are permissible heteroatom substitutions. Examples of
"heteroaryl" groups as used herein include, but are not limited to,
furan, thiophene, pyrrole, imidazole, pyrazole, triazole,
tetrazole, thiazole, oxazole, isoxazole, oxadiazole, thiadiazole,
isothiazole, pyridine, pyridazine, pyrazine, pyrimidine, quinoline,
isoquinoline, quinoxaline, benzofuran, benzoxazole, benzothiophene,
indole, indazole, benzimidazole, imidazopyridine, pyrazolopyridine,
and pyrazolopyrimidine.
[0096] As used herein, multiple degrees of substitution includes
substitution with one or more alkyl, halo, haloalkyl, alkoxy,
alkylthio, aryloxy, arylthio, --NR.sup.aR.sup.b,
--C(.dbd.O)NR.sup.aR.sup.b, --NR.sup.aC(.dbd.O)R.sup.b,
--C(.dbd.O)R.sup.a, --C(.dbd.O)OR.sup.a, --OC(.dbd.O)R.sup.a,
--O(CR.sup.aR.sup.b).sub.1-6C(.dbd.O)R.sup.a,
--O(CR.sup.aR.sup.b).sub.dNR.sup.bC(.dbd.O)R.sup.a,
--O(CR.sup.aR.sup.b).sub.1-6NR.sup.bSO.sub.2R.sup.a,
--OC(.dbd.O)NR.sup.aR.sup.b, --NR.sup.aC(.dbd.O)OR.sup.b,
--SO.sub.2R.sup.a, --SO.sub.2NR.sup.aR.sup.b, or
--NR.sup.2SO.sub.2R.sup.3; where each R.sup.a and R.sup.b
individually is hydrogen, alkyl, cycloalkyl, heterocyclyl, aryl, or
arylalkyl, or R.sup.a and R.sup.b can combine with the atoms to
which they are attached to form a 3- to 10-membered ring. Thus, as
one example, Cy may be pyridinyl which may be substituted first by
a halogen, such as F, and second by an alkoxy, such as
--OCH.sub.3.
[0097] As used herein the term "halogen" refers to fluorine,
chlorine, bromine, or iodine.
[0098] As used herein the term "haloalkyl" refers to an alkyl
group, as defined herein, which is substituted with at least one
halogen. Examples of branched or straight chained "haloalkyl"
groups as used herein include, but are not limited to, methyl,
ethyl, propyl, isopropyl, n-butyl, and t-butyl substituted
independently with one or more halogens, for example, fluoro,
chloro, bromo, and iodo. The term "haloalkyl" should be interpreted
to include such substituents as perfluoroalkyl groups such as
--CF.sub.3.
[0099] As used herein the term "alkoxy" refers to a group
--OR.sup.a, where R.sup.a is alkyl as herein defined. Likewise, the
term "alkylthio" refers to a group --SR.sup.a, where R.sup.a is
alkyl as herein defined.
[0100] As used herein the term "aryloxy" refers to a group
--OR.sup.a, where R.sup.a is aryl as herein defined. Likewise, the
term "arylthio" refers to a group --SR.sup.a, where R.sup.a is aryl
as herein defined.
[0101] As used herein "amino" refers to a group --NR.sup.aR.sup.b,
where each of R.sup.a and R.sup.b is hydrogen. Additionally,
"substituted amino" refers to a group --NR.sup.aR.sup.b wherein
each of R.sup.a and R.sup.b individually is alkyl, alkenyl,
alkynyl, cycloalkyl, aryl, heterocylcyl, or heteroaryl. As used
herein, when either R.sup.a or R.sup.b is other than hydrogen, such
a group may be referred to as a "substituted amino" or, for example
if R.sup.a is H and R.sup.b is alkyl, as an "alkylamino."
[0102] As used herein, the term "pharmaceutically acceptable"
refers to carrier(s), diluent(s), excipient(s) or salt forms of the
compounds of the present invention that are compatible with the
other ingredients of the formulation and not deleterious to the
recipient of the pharmaceutical composition.
[0103] As used herein, the term "pharmaceutical composition" refers
to a compound of the present invention optionally admixed with one
or more pharmaceutically acceptable carriers, diluents, or
excipients. Pharmaceutical compositions preferably exhibit a degree
of stability to environmental conditions so as to make them
suitable for manufacturing and commercialization purposes.
[0104] As used herein, the terms "effective amount", "therapeutic
amount", and "effective dose" refer to an amount of the compound of
the present invention sufficient to elicit the desired
pharmacological or therapeutic effects, thus resulting in an
effective treatment of a disorder. Treatment of a disorder may be
manifested by delaying or preventing the onset or progression of
the disorder, as well as the onset or progression of symptoms
associated with the disorder. Treatment of a disorder may also be
manifested by a decrease or elimination of symptoms, reversal of
the progression of the disorder, as well as any other contribution
to the well being of the patient.
[0105] The effective dose can vary, depending upon factors such as
the condition of the patient, the severity of the symptoms of the
disorder, and the manner in which the pharmaceutical composition is
administered. Typically, to be administered in an effective dose,
compounds may be administered in an amount of less than 5 mg/kg of
patient weight. The compounds may be administered in an amount from
less than about 1 mg/kg patient weight to less than about 100
.mu.g/kg of patient weight, and further between about 1 .mu.g/kg to
less than 100 .mu.g/kg of patient weight. The foregoing effective
doses typically represent that amount that may be administered as a
single dose, or as one or more doses that may be administered over
a 24 hours period.
[0106] The compounds of this invention may be made by a variety of
methods, including well-established synthetic methods. Illustrative
general synthetic methods are set out below and then specific
compounds of the invention are prepared in the working
Examples.
[0107] In the examples described below, protecting groups for
sensitive or reactive groups are employed where necessary in
accordance with general principles of synthetic chemistry.
Protecting groups are manipulated according to standard methods of
organic synthesis (T. W. Green and P. G. M. Wuts (1999) Protecting
Groups in Organic Synthesis, 3.sup.rd Edition, John Wiley &
Sons, herein incorporated by reference with regard to protecting
groups). These groups are removed at a convenient stage of the
compound synthesis using methods that are readily apparent to those
skilled in the art. The selection of processes as well as the
reaction conditions and order of their execution shall be
consistent with the preparation of compounds of the present
invention.
[0108] The present invention also provides a method for the
synthesis of compounds useful as intermediates in the preparation
of compounds of the present invention along with methods for their
preparation.
[0109] The compounds can be prepared according to the methods
described below using readily available starting materials and
reagents. In these reactions, variants may be employed which are
themselves known to those of ordinary skill in this art but are not
described in detail here.
[0110] Unless otherwise stated, structures depicted herein are also
meant to include compounds which differ only in the presence of one
or more isotopically enriched atoms. Compounds having the present
structure except for the replacement of a hydrogen atom by a
deuterium or tritium, or the replacement of a carbon atom by a
.sup.13C-- or .sup.14C-enriched carbon are within the scope of the
invention. For example, deuterium has been widely used to examine
the pharmacokinetics and metabolism of biologically active
compounds. Although deuterium behaves similarly to hydrogen from a
chemical perspective, there are significant differences in bond
energies and bond lengths between a deuterium-carbon bond and a
hydrogen-carbon bond. Consequently, replacement of hydrogen by
deuterium in a biologically active compound may result in a
compound that generally retains its biochemical potency and
selectivity but manifests significantly different absorption,
distribution, metabolism, and/or excretion (ADME) properties
compared to its isotope-free counterpart. Thus, deuterium
substitution may result in improved drug efficacy, safety, and/or
tolerability for some biologically active compounds.
[0111] The compounds of the present invention may crystallize in
more than one form, a characteristic known as polymorphism, and
such polymorphic forms ("polymorphs") are within the scope of the
present invention. Polymorphism generally can occur as a response
to changes in temperature, pressure, or both. Polymorphism can also
result from variations in the crystallization process. Polymorphs
can be distinguished by various physical characteristics known in
the art such as x-ray diffraction patterns, solubility, and melting
point.
[0112] Certain of the compounds described herein contain one or
more chiral centers, or may otherwise be capable of existing as
multiple stereoisomers. The scope of the present invention includes
mixtures of stereoisomers as well as purified enantiomers or
enantiomerically/diastereomerically enriched mixtures. Also
included within the scope of the invention are the individual
isomers of the compounds represented by the formulae of the present
invention, as well as any wholly or partially equilibrated mixtures
thereof. The present invention also includes the individual isomers
of the compounds represented by the formulas above as mixtures with
isomers thereof in which one or more chiral centers are
inverted.
[0113] When a compound is desired as a single enantiomer, such may
be obtained by stereospecific synthesis, by resolution of the final
product or any convenient intermediate, or by chiral
chromatographic methods as are known in the art. Resolution of the
final product, an intermediate, or a starting material may be
effected by any suitable method known in the art. See, for example,
Stereochemistry of Organic Compounds (Wiley-Interscience,
1994).
[0114] The present invention includes a salt or solvate of the
compounds herein described, including combinations thereof such as
a solvate of a salt. The compounds of the present invention may
exist in solvated, for example hydrated, as well as unsolvated
forms, and the present invention encompasses all such forms.
[0115] Typically, but not absolutely, the salts of the present
invention are pharmaceutically acceptable salts. Salts encompassed
within the term "pharmaceutically acceptable salts" refer to
non-toxic salts of the compounds of this invention.
[0116] Examples of suitable pharmaceutically acceptable salts
include inorganic acid addition salts such as chloride, bromide,
sulfate, phosphate, and nitrate; organic acid addition salts such
as acetate, galactarate, propionate, succinate, lactate, glycolate,
malate, tartrate, citrate, maleate, fumarate, methanesulfonate,
p-toluenesulfonate, and ascorbate; salts with acidic amino acid
such as aspartate and glutamate; alkali metal salts such as sodium
salt and potassium salt; alkaline earth metal salts such as
magnesium salt and calcium salt; ammonium salt; organic basic salts
such as trimethylamine salt, triethylamine salt, pyridine salt,
picoline salt, dicyclohexylamine salt, and
N,N'-dibenzylethylenediamine salt; and salts with basic amino acid
such as lysine salt and arginine salt. The salts may be in some
cases hydrates or ethanol solvates.
II. General Synthetic Methods
[0117] The compounds of the present invention can be prepared via
the coupling of a mono-protected [3.1.1]heptyl-diazabicycle, namely
one in which one of the two amine functional groups is rendered
un-reactive by suitable derivatization, with a suitably activated
carboxylic acid, chloroformate, or isothionate derivative (Scheme
1).
##STR00003##
[0118] Methods for the preparation of several mono-protected
diazabicycles which can be used to prepare the compounds of the
present invention (specifically, compounds 1 and 2, Scheme 1) are
disclosed in WO 2005/108402 to Pinna, et al. (incorporated by
reference with regard to such synthetic teachings). Those skilled
in the art of organic synthesis will recognize that other suitably
mono-protected diazabicycles (such as compound 5, Scheme 1) can
also be used to prepare compound of the present invention (see, for
example, T. W. Greene and P. G. M. Wuts, Protective Groups in
Organic Synthesis, 3.sup.rd Edition, John Wiley & Sons, New
York (1999).
[0119] One means of making amides of the present invention is to
couple a suitable mono N-protected-3,6-diazabicyclo[3.1.1]heptane
with a suitably functionalized carboxylic acid, followed by removal
of any protecting groups. A wide variety of carboxylic acids are
commercially available. The condensation of an amine and a
carboxylic acid, to produce an amide, typically requires the use of
a suitable activating agent, such as N,N'-dicyclohexylcarbodiimide
(DCC), (benzotriazol-1-yloxy)tris(dimethylamino)phosphonium
hexafluorophosphate (BOP),
(benzotriazol-1-yloxy)tripyrrolidinophosphonium hexafluorophosphate
(PyBOP), O-(benzotriazol-1-yl)-N,N,N',N'-bis(tetramethylene)uronium
hexafluorophosphate (HBPyU),
O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium
hexafluorophosphate (HBTU),
O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium
tetrafluoroborate (TBTU), or
(1-ethyl-3-(3-dimethylaminopropyl)carbodiimide) (EDCI) with
1-hydroxybenzotriazole (HOBt). Other activating agents are well
known to those skilled in the art, for example, see Kiso and
Yajima, Peptides, pp 39-91, Academic Press, San Diego, Calif.
(1995).
[0120] Alternatively, amides of the present invention can be
prepared by coupling a mono-protected diazabicycle with a suitably
functionalized acid chloride, which may be available commercially
or may be prepared by conversion of the suitably functionalized
carboxylic acid. The acid chloride may be prepared by treatment of
the appropriate carboxylic acid with, among other reagents, thionyl
chloride or oxalyl chloride.
[0121] A similar strategy as described above can be used for the
preparation of carbamates and ureas of the present invention.
Briefly, carbamates of the present invention can be prepared by
coupling a suitable functionalized alkyl-, aryl-, or
heteroaryl-chloroformate with a suitable mono
N-protected-3,6-diazabicyclo[3.1.1]heptane, followed by removal of
any protecting groups. Similarly, a suitable mono
N-protected-3,6-diazabicyclo[3.1.1]heptane can be coupled with a
suitable functionalized alkyl-, aryl-, or heteroaryl-isocyanate,
followed by removal of any protecting groups, to prepare ureas of
the present invention.
[0122] As will be appreciated by those skilled in the art, the use
of certain starting materials containing ancillary reactive
functional groups may require additional protection/deprotection
steps to prevent interference with the coupling reaction. Such
protection/deprotection steps are well known in the art (for
example, see T. W. Green and P. G. M. Wuts, Protective Groups in
Organic Synthesis, 3.sup.rd Edition, John Wiley & Sons, New
York (1999)).
[0123] As will be appreciated by those skilled in the art
throughout the present specification, the number and nature of
substituents on rings in the compounds of the present invention
will be selected so as to avoid sterically undesirable
combinations.
[0124] Those skilled in the art of organic synthesis will
appreciate that there exist multiple means of producing compounds
of the present invention, as well as means for producing compounds
of the present invention which are labeled with a radioisotope
appropriate to various uses. For example, coupling of a .sup.11C-
or .sup.18F-labeled acid, chloroformate, or isocyanate with
compound a suitable mono N-protected-3,6-diazabicyclo[3.1.1]heptane
followed by removal of any protecting groups as described above
will produce a compound suitable for use in positron emission
tomography. Likewise, coupling of a .sup.3H- or .sup.14C-labeled
acid, chloroformate, or isocyanate with a suitable mono
N-protected-3,6-diazabicyclo[3.1.1]heptane followed by removal of
any protecting groups as described above will produce an
isotopically modified compound suitable for use in receptor binding
and metabolism studies or as an alternative therapeutic
compound.
III. Pharmaceutical Compositions
[0125] Although it is possible to administer the compound of the
present invention in the form of a bulk active chemical, it is
preferred to administer the compound in the form of a
pharmaceutical composition or formulation. Thus, one aspect the
present invention includes pharmaceutical compositions comprising
one or more compounds of Formula I and/or pharmaceutically
acceptable salts thereof and one or more pharmaceutically
acceptable carriers, diluents, or excipients. Another aspect of the
invention provides a process for the preparation of a
pharmaceutical composition including admixing one or more compounds
of Formula I and/or pharmaceutically acceptable salts thereof with
one or more pharmaceutically acceptable carriers, diluents or
excipients.
[0126] The manner in which the compound of the present invention is
administered can vary. The compound of the present invention is
preferably administered orally. Preferred pharmaceutical
compositions for oral administration include tablets, capsules,
caplets, syrups, solutions, and suspensions. The pharmaceutical
compositions of the present invention may be provided in modified
release dosage forms such as time-release tablet and capsule
formulations.
[0127] The pharmaceutical compositions can also be administered via
injection, namely, intravenously, intramuscularly, subcutaneously,
intraperitoneally, intraarterially, intrathecally, and
intracerebroventricularly. Intravenous administration is a
preferred method of injection. Suitable carriers for injection are
well known to those of skill in the art and include 5% dextrose
solutions, saline, and phosphate buffered saline.
[0128] The formulations may also be administered using other means,
for example, rectal administration. Formulations useful for rectal
administration, such as suppositories, are well known to those of
skill in the art. The compounds can also be administered by
inhalation, for example, in the form of an aerosol; topically, such
as, in lotion form; transdermally, such as, using a transdermal
patch (for example, by using technology that is commercially
available from Novartis and Alza Corporation); by powder injection;
or by buccal, sublingual, or intranasal absorption.
[0129] The term "intranasal delivery" or "nasal delivery" as used
herein means a method for drug absorption through and within the
nose. The term "buccal delivery" as used herein means a method for
presenting the drug for absorption through the buccal, including
inner cheek, tissue. The term "sublingual delivery" means delivery
of the active agent under the tongue. Collectively, these are
transmucosal delivery methods.
[0130] Drugs can be absorbed through mucosal surfaces, such as
those in the nasal passage and in the oral cavity. Drug delivery
via mucosal surfaces can be efficient because they lack the stratum
corneum of the epidermis, a major barrier to absorption across the
skin. Mucosal surfaces are also typically rich in blood supply,
which can rapidly transport drugs systemically while avoiding
significant degradation by first-pass hepatic metabolism.
[0131] There are three routes of absorption for drugs sprayed onto
the olfactory mucosa, including by the olfactory neurons, by the
supporting cells and surrounding capillary bed, and into the
cerebro-spinal fluid. Absorption of drugs through the nasal mucosa
tends to be rapid.
[0132] Like intranasal administration, oral transmucosal absorption
is generally rapid because of the rich vascular supply to the
mucosa and the lack of a stratum corneum in the epidermis. Such
drug transport typically provides a rapid rise in blood
concentrations, and similarly avoids the enterohepatic circulation
and immediate destruction by gastric acid or partial first-pass
effects of gut wall and hepatic metabolism.
[0133] Drugs typically need to have prolonged exposure to an oral
mucosal surface for significant drug absorption to occur. Factors
affecting drug delivery include taste, which can affect contact
time, and drug ionization. Drug absorption is generally greater
from the buccal or oral mucosa than from the tongue and gingiva.
One limitation associated with buccal drug delivery is low flux,
which often results in low drug bioavailability. Low flux may be
somewhat offset by using buccal penetration enhancers, as are known
in the art, to increase the flux of drugs through the mucosa.
[0134] In either of the intranasal or buccal routes, drug
absorption can be delayed or prolonged, or uptake may be almost as
rapid as if an intravenous bolus were administered. Because of the
high permeability of the rich blood supply, the sublingual route
can provide a rapid onset of action.
[0135] The intranasal, buccal, and sublingual routes can be
preferred for use in treating patients who have difficulty in
swallowing tablets, capsules, or other oral solids, or those who
have disease-compromised intestinal absorption.
[0136] Pharmaceutical compositions may be formulated in unit dose
form, or in multiple or subunit doses.
[0137] The administration of the pharmaceutical compositions
described herein can be intermittent, or at a gradual, continuous,
constant or controlled rate. The pharmaceutical compositions may be
administered to a warm-blooded animal, for example, a mammal such
as a mouse, rat, cat, rabbit, dog, pig, cow, or monkey; but
advantageously is administered to a human being. In addition, the
time of day and the number of times per day that the pharmaceutical
composition is administered can vary.
[0138] The compounds of the present invention may be used in the
treatment of a variety of disorders and conditions and, as such,
may be used in combination with a variety of other suitable
therapeutic agents useful in the treatment or prophylaxis of those
disorders or conditions. Thus, one embodiment of the present
invention includes the administration of the compound of the
present invention in combination with other therapeutic compounds.
For example, the compound of the present invention can be used in
combination with other NNR ligands (such as varenicline),
allosteric modulators of NNRs, antioxidants (such as free radical
scavenging agents), antibacterial agents (such as penicillin
antibiotics), antiviral agents (such as nucleoside analogs, like
zidovudine and acyclovir), anticoagulants (such as warfarin),
anti-inflammatory agents (such as NSAIDs), anti-pyretics,
analgesics, anesthetics (such as used in surgery),
acetylcholinesterase inhibitors (such as donepezil and
galantamine), antipsychotics (such as haloperidol, clozapine,
olanzapine, and quetiapine), immuno-suppressants (such as
cyclosporin and methotrexate), neuroprotective agents, steroids
(such as steroid hormones), corticosteroids (such as dexamethasone,
predisone, and hydrocortisone), vitamins, minerals, nutraceuticals,
anti-depressants (such as imipramine, fluoxetine, paroxetine,
escitalopram, sertraline, venlafaxine, and duloxetine), anxiolytics
(such as alprazolam and buspirone), anticonvulsants (such as
phenyloin and gabapentin), vasodilators (such as prazosin and
sildenafil), mood stabilizers (such as valproate and aripiprazole),
anti-cancer drugs (such as anti-proliferatives), antihypertensive
agents (such as atenolol, clonidine, amlopidine, verapamil, and
olmesartan), laxatives, stool softeners, diuretics (such as
furosemide), anti-spasmotics (such as dicyclomine), anti-dyskinetic
agents, and anti-ulcer medications (such as esomeprazole). Such a
combination of pharmaceutically active agents may be administered
together or separately and, when administered separately,
administration may occur simultaneously or sequentially, in any
order. The amounts of the compounds or agents and the relative
timings of administration will be selected in order to achieve the
desired therapeutic effect. The administration in combination of a
compound of the present invention with other treatment agents may
be in combination by administration concomitantly in: (1) a unitary
pharmaceutical composition including both compounds; or (2)
separate pharmaceutical compositions each including one of the
compounds. Alternatively, the combination may be administered
separately in a sequential manner wherein one treatment agent is
administered first and the other second. Such sequential
administration may be close in time or remote in time.
[0139] Another aspect of the present invention includes combination
therapy comprising administering to the subject a therapeutically
or prophylactically effective amount of the compound of the present
invention and one or more other therapy including chemotherapy,
radiation therapy, gene therapy, or immunotherapy.
IV. Methods of Using
[0140] The compounds of the present invention can be used for the
prevention or treatment of various conditions or disorders for
which other types of nicotinic compounds have been proposed or are
shown to be useful as therapeutics, such as CNS disorders,
inflammation, inflammatory response associated with bacterial
and/or viral infection, pain, diabetes, metabolic syndrome,
autoimmune disorders, dermatological conditions, addictions,
obesity or other disorders described in further detail herein. This
compound can also be used as a diagnostic agent in receptor binding
studies (in vitro and in vivo). Such therapeutic and other
teachings are described, for example, in references previously
listed herein, including Williams et al., Drug News Perspec. 7(4):
205 (1994), Arneric et al., CNS Drug Rev. 1(1): 1-26 (1995),
Arneric et al., Exp. Opin. Invest. Drugs 5(1): 79-100 (1996), Yang
et al., Acta Pharmacol. Sin. 30(6): 740-751 (2009), Bencherif et
al., J. Pharmacol. Exp. Ther. 279: 1413 (1996), Lippiello et al.,
J. Pharmacol. Exp. Ther. 279: 1422 (1996), Damaj et al., J.
Pharmacol. Exp. Ther. 291: 390 (1999); Chiari et al.,
Anesthesiology 91: 1447 (1999), Lavand'homme and Eisenbach,
Anesthesiology 91: 1455 (1999), Holladay et al., J. Med. Chem.
40(28): 4169-94 (1997), Bannon et al., Science 279: 77 (1998), PCT
WO 94/08992, PCT WO 96/31475, PCT WO 96/40682, and U.S. Pat. No.
5,583,140 to Bencherif et al., U.S. Pat. No. 5,597,919 to Dull et
al., U.S. Pat. No. 5,604,231 to Smith et al. and U.S. Pat. No.
5,852,041 to Cosford et al.
CNS Disorders
[0141] The compounds and their pharmaceutical compositions are
useful in the treatment or prevention of a variety of CNS
disorders, including neurodegenerative disorders, neuropsychiatric
disorders, neurologic disorders, and addictions. The compounds and
their pharmaceutical compositions can be used to treat or prevent
cognitive deficits and dysfunctions, age-related and otherwise;
attentional disorders and dementias, including those due to
infectious agents or metabolic disturbances; to provide
neuroprotection; to treat convulsions and multiple cerebral
infarcts; to treat mood disorders, compulsions and addictive
behaviors; to provide analgesia; to control inflammation, such as
mediated by cytokines and nuclear factor kappa B; to treat
inflammatory disorders; to provide pain relief; and to treat
infections, as anti-infectious agents for treating bacterial,
fungal, and viral infections. Among the disorders, diseases and
conditions that the compounds and pharmaceutical compositions of
the present invention can be used to treat or prevent are:
age-associated memory impairment (AAMI), mild cognitive impairment
(MCI), age-related cognitive decline (ARCD), pre-senile dementia,
early onset Alzheimer's disease, senile dementia, dementia of the
Alzheimer's type, Alzheimer's disease, cognitive impairment no
dementia (CIND), Lewy body dementia, HIV-dementia, AIDS dementia
complex, vascular dementia, Down syndrome, head trauma, traumatic
brain injury (TBI), dementia pugilistica, Creutzfeld-Jacob Disease
and prion diseases, stroke, central ischemia, peripheral ischemia,
attention deficit disorder, attention deficit hyperactivity
disorder, dyslexia, schizophrenia, schizophreniform disorder,
schizoaffective disorder, cognitive dysfunction in schizophrenia,
cognitive deficits in schizophrenia, Parkinsonism including
Parkinson's disease, postencephalitic parkinsonism,
parkinsonism-dementia of Gaum, frontotemporal dementia Parkinson's
Type (FTDP), Pick's disease, Niemann-Pick's Disease, Huntington's
Disease, Huntington's chorea, dyskinesias, L-dopa induced
dyskinesia, tardive dyskinesia, spastic dystonia, hyperkinesia,
progressive supranuclear palsy, progressive supranuclear paresis,
restless leg syndrome, Creutzfeld-Jakob disease, multiple
sclerosis, amyotrophic lateral sclerosis (ALS), motor neuron
diseases (MND), multiple system atrophy (MSA), corticobasal
degeneration, Guillain-Barre Syndrome (GBS), and chronic
inflammatory demyelinating polyneuropathy (CIDP), epilepsy,
autosomal dominant nocturnal frontal lobe epilepsy, mania, anxiety,
depression, premenstrual dysphoria, panic disorders, bulimia,
anorexia, narcolepsy, excessive daytime sleepiness, bipolar
disorders, generalized anxiety disorder, obsessive compulsive
disorder, rage outbursts, conduct disorder, oppositional defiant
disorder, Tourette's syndrome, autism, drug and alcohol addiction,
tobacco addiction, compulsive overeating and sexual
dysfunction.
[0142] Cognitive impairments or dysfunctions may be associated with
psychiatric disorders or conditions, such as schizophrenia and
other psychotic disorders, including but not limited to psychotic
disorder, schizophreniform disorder, schizoaffective disorder,
delusional disorder, brief psychotic disorder, shared psychotic
disorder, and psychotic disorders due to a general medical
conditions, dementias and other cognitive disorders, including but
not limited to mild cognitive impairment, pre-senile dementia,
Alzheimer's disease, senile dementia, dementia of the Alzheimer's
type, age-related memory impairment, Lewy body dementia, vascular
dementia, AIDS dementia complex, dyslexia, Parkinsonism including
Parkinson's disease, cognitive impairment and dementia of
Parkinson's Disease, cognitive impairment of multiple sclerosis,
cognitive impairment caused by traumatic brain injury, dementias
due to other general medical conditions, anxiety disorders,
including but not limited to panic disorder without agoraphobia,
panic disorder with agoraphobia, agoraphobia without history of
panic disorder, specific phobia, social phobia,
obsessive-compulsive disorder, post-traumatic stress disorder,
acute stress disorder, generalized anxiety disorder and generalized
anxiety disorder due to a general medical condition, mood
disorders, including but not limited to major depressive disorder,
dysthymic disorder, bipolar depression, bipolar mania, bipolar I
disorder, depression associated with manic, depressive or mixed
episodes, bipolar II disorder, cyclothymic disorder, and mood
disorders due to general medical conditions, sleep disorders,
including but not limited to dyssomnia disorders, primary insomnia,
primary hypersomnia, narcolepsy, parasomnia disorders, nightmare
disorder, sleep terror disorder and sleepwalking disorder, mental
retardation, learning disorders, motor skills disorders,
communication disorders, pervasive developmental disorders,
attention-deficit and disruptive behavior disorders, attention
deficit disorder, attention deficit hyperactivity disorder, feeding
and eating disorders of infancy, childhood, or adults, tic
disorders, elimination disorders, substance-related disorders,
including but not limited to substance dependence, substance abuse,
substance intoxication, substance withdrawal, alcohol-related
disorders, amphetamine or amphetamine-like-related disorders,
caffeine-related disorders, cannabis-related disorders,
cocaine-related disorders, hallucinogen-related disorders,
inhalant-related disorders, nicotine-related disorders,
opioid-related disorders, phencyclidine or
phencyclidine-like-related disorders, and sedative-, hypnotic- or
anxiolytic-related disorders, personality disorders, including but
not limited to obsessive-compulsive personality disorder and
impulse-control disorders. Cognitive performance may be assessed
with a validated cognitive scale, such as, for example, the
cognitive subscale of the Alzheimer's Disease Assessment Scale
(ADAS-cog). One measure of the effectiveness of the compounds of
the present invention in improving cognition may include measuring
a patient's degree of change according to such a scale.
[0143] Regarding compulsions and addictive behaviors, the compounds
of the present invention may be used as a therapy for nicotine
addiction and for other brain-reward disorders, such as substance
abuse including alcohol addiction, illicit and prescription drug
addiction, eating disorders, including obesity, and behavioral
addictions, such as gambling, or other similar behavioral
manifestations of addiction.
[0144] The above conditions and disorders are discussed in further
detail, for example, in the American Psychiatric Association:
Diagnostic and Statistical Manual of Mental Disorders, Fourth
Edition, Text Revision, Washington, D.C., American Psychiatric
Association, 2000. This Manual may also be referred to for greater
detail on the symptoms and diagnostic features associated with
substance use, abuse, and dependence.
[0145] Preferably, the treatment or prevention of diseases,
disorders and conditions occurs without appreciable adverse side
effects, including, for example, significant increases in blood
pressure and heart rate, significant negative effects upon the
gastro-intestinal tract, and significant effects upon skeletal
muscle.
[0146] The compounds of the present invention, when employed in
effective amounts, are believed to modulate the activity of the
.alpha.4.beta.2 and/or .alpha.6-containing NNRs without appreciable
interaction with the nicotinic subtypes that characterize the human
ganglia, as demonstrated by a lack of the ability to elicit
nicotinic function in adrenal chromaffin tissue, or skeletal
muscle, further demonstrated by a lack of the ability to elicit
nicotinic function in cell preparations expressing muscle-type
nicotinic receptors. Thus, these compounds are believed capable of
treating or preventing diseases, disorders and conditions without
eliciting significant side effects associated activity at
ganglionic and neuromuscular sites. Thus, administration of the
compounds is believed to provide a therapeutic window in which
treatment of certain diseases, disorders and conditions is
provided, and certain side effects are avoided. That is, an
effective dose of the compound is believed sufficient to provide
the desired effects upon the disease, disorder or condition, but is
believed insufficient, namely is not at a high enough level, to
provide undesirable side effects.
[0147] Thus, the present invention provides the use of a compound
of the present invention, or a pharmaceutically acceptable salt
thereof, for use in therapy, such as a therapy described above.
[0148] In yet another aspect the present invention provides the use
of a compound of the present invention, or a pharmaceutically
acceptable salt thereof, in the manufacture of a medicament for use
in the treatment of a CNS disorder, such as a disorder, disease or
condition described hereinabove.
Inflammation
[0149] The nervous system, primarily through the vagus nerve, is
known to regulate the magnitude of the innate immune response by
inhibiting the release of macrophage tumor necrosis factor (TNF).
This physiological mechanism is known as the "cholinergic
anti-inflammatory pathway" (see, for example, Tracey, "The
Inflammatory Reflex," Nature 420: 853-9 (2002)). Excessive
inflammation and tumor necrosis factor synthesis cause morbidity
and even mortality in a variety of diseases. These diseases
include, but are not limited to, endotoxemia, rheumatoid arthritis,
osteoarthritis, psoriasis, asthma, atherosclerosis, idiopathic
pulmonary fibrosis, and inflammatory bowel disease.
[0150] Inflammatory conditions that can be treated or prevented by
administering the compounds described herein include, but are not
limited to, chronic and acute inflammation, psoriasis, endotoxemia,
gout, acute pseudogout, acute gouty arthritis, arthritis,
rheumatoid arthritis, osteoarthritis, allograft rejection, chronic
transplant rejection, asthma, atherosclerosis,
mononuclear-phagocyte dependent lung injury, idiopathic pulmonary
fibrosis, atopic dermatitis, chronic obstructive pulmonary disease,
adult respiratory distress syndrome, acute chest syndrome in sickle
cell disease, inflammatory bowel disease, irritable bowel syndrome,
Crohn's disease, ulcers, ulcerative colitis, acute cholangitis,
aphthous stomatitis, cachexia, pouchitis, glomerulonephritis, lupus
nephritis, thrombosis, and graft vs. host reaction.
Inflammatory Response Associated with Bacterial and/or Viral
Infection
[0151] Many bacterial and/or viral infections are associated with
side effects brought on by the formation of toxins, and the body's
natural response to the bacteria or virus and/or the toxins. As
discussed above, the body's response to infection often involves
generating a significant amount of TNF and/or other cytokines. The
over-expression of these cytokines can result in significant
injury, such as septic shock (when the bacteria is sepsis),
endotoxic shock, urosepsis, viral pneumonitis and toxic shock
syndrome.
[0152] Cytokine expression is mediated by NNRs, and can be
inhibited by administering agonists or partial agonists of these
receptors. Those compounds described herein that are agonists or
partial agonists of these receptors can therefore be used to
minimize the inflammatory response associated with bacterial
infection, as well as viral and fungal infections. Examples of such
bacterial infections include anthrax, botulism, and sepsis. Some of
these compounds may also have antimicrobial properties.
[0153] These compounds can also be used as adjunct therapy in
combination with existing therapies to manage bacterial, viral and
fungal infections, such as antibiotics, antivirals and antifungals.
Antitoxins can also be used to bind to toxins produced by the
infectious agents and allow the bound toxins to pass through the
body without generating an inflammatory response. Examples of
antitoxins are disclosed, for example, in U.S. Pat. No. 6,310,043
to Bundle et al. Other agents effective against bacterial and other
toxins can be effective and their therapeutic effect can be
complemented by co-administration with the compounds described
herein.
Pain
[0154] The compounds can be administered to treat and/or prevent
pain, including acute, neurologic, inflammatory, neuropathic and
chronic pain. The compounds can be used in conjunction with opiates
to minimize the likelihood of opiate addiction (e.g., morphine
sparing therapy). The analgesic activity of compounds described
herein can be demonstrated in models of persistent inflammatory
pain and of neuropathic pain, performed as described in U.S.
Published Patent Application No. 20010056084 A1 (Allgeier et al.)
(e.g., mechanical hyperalgesia in the complete Freund's adjuvant
rat model of inflammatory pain and mechanical hyperalgesia in the
mouse partial sciatic nerve ligation model of neuropathic
pain).
[0155] The analgesic effect is suitable for treating pain of
various genesis or etiology, in particular in treating inflammatory
pain and associated hyperalgesia, neuropathic pain and associated
hyperalgesia, chronic pain (e.g., severe chronic pain,
post-operative pain and pain associated with various conditions
including cancer, angina, renal or biliary colic, menstruation,
migraine, and gout). Inflammatory pain may be of diverse genesis,
including arthritis and rheumatoid disease, teno-synovitis and
vasculitis. Neuropathic pain includes trigeminal or herpetic
neuralgia, neuropathies such as diabetic neuropathy pain,
causalgia, low back pain and deafferentation syndromes such as
brachial plexus avulsion.
Other Disorders
[0156] In addition to treating CNS disorders, inflammation, and
neovascularization, and pain, the compounds of the present
invention can be also used to prevent or treat certain other
conditions, diseases, and disorders in which NNRs play a role.
Examples include autoimmune disorders such as lupus, disorders
associated with cytokine release, cachexia secondary to infection
(e.g., as occurs in AIDS, AIDS related complex and neoplasia),
obesity, pemphitis, urinary incontinence, overactive bladder,
diarrhea, constipation, retinal diseases, infectious diseases,
myasthenia, Eaton-Lambert syndrome, hypertension, preeclampsia,
osteoporosis, vasoconstriction, vasodilatation, cardiac
arrhythmias, type I diabetes, type II diabetes, bulimia, anorexia
and sexual dysfunction, as well as those indications set forth in
published PCT application WO 98/25619. The compounds of this
invention can also be administered to treat convulsions such as
those that are symptomatic of epilepsy, and to treat conditions
such as syphilis and Creutzfeld-Jakob disease. Lastly, the
compounds of this invention may be used to treat a variety of
dermatological disorders, including but not limited to psoriasis,
dermatitis, acne, pustulosis, vitilago, and the like.
Diagnostic Uses
[0157] The compounds can be used in diagnostic compositions, such
as probes, particularly when they are modified to include
appropriate labels. The probes can be used, for example, to
determine the relative number and/or function of specific
receptors, particularly the .alpha.4.beta.2 and/or
.alpha.6-containing receptor subtypes. For this purpose the
compounds of the present invention most preferably are labeled with
a radioactive isotopic moiety such as .sup.11C, .sup.18F,
.sup.76Br, .sup.123I or .sup.125I.
[0158] The administered compounds can be detected using known
detection methods appropriate for the label used. Examples of
detection methods include position emission topography (PET) and
single-photon emission computed tomography (SPECT). The radiolabels
described above are useful in PET (e.g., .sup.11C, .sup.18F or
.sup.76Br) and SPECT (e.g., .sup.123I) imaging, with half-lives of
about 20.4 minutes for .sup.11C, about 109 minutes for .sup.18F,
about 13 hours for .sup.123I, and about 16 hours for .sup.76Br. A
high specific activity is desired to visualize the selected
receptor subtypes at non-saturating concentrations. The
administered doses typically are below the toxic range and provide
high contrast images. The compounds are expected to be capable of
administration in non-toxic levels. Determination of dose is
carried out in a manner known to one skilled in the art of
radiolabel imaging. See, for example, U.S. Pat. No. 5,969,144 to
London et al.
[0159] The compounds can be administered using known techniques.
See, for example, U.S. Pat. No. 5,969,144 to London et al., as
noted. The compounds can be administered in formulation
compositions that incorporate other ingredients, such as those
types of ingredients that are useful in formulating a diagnostic
composition. Compounds useful in accordance with carrying out the
present invention most preferably are employed in forms of high
purity. See, U.S. Pat. No. 5,853,696 to Elmalch et al.
[0160] After the compounds are administered to a subject (e.g., a
human subject), the presence of that compound within the subject
can be imaged and quantified by appropriate techniques in order to
indicate the presence, quantity, and functionality of selected NNR
subtypes. In addition to humans, the compounds can also be
administered to animals, such as mice, rats, dogs, and monkeys.
SPECT and PET imaging can be carried out using any appropriate
technique and apparatus. See Villemagne et al., In: Arneric et al.
(Eds.) Neuronal Nicotinic Receptors: Pharmacology and Therapeutic
Opportunities, 235-250 (1998) and U.S. Pat. No. 5,853,696 to
Elmalch et al., each herein incorporated by reference, for a
disclosure of representative imaging techniques.
[0161] The radiolabeled compounds bind with high affinity to
selective NNR subtypes (e.g., .alpha.4.beta.2 and/or
.alpha.6-containing) and preferably exhibit negligible non-specific
binding to other nicotinic cholinergic receptor subtypes (e.g.,
those receptor subtypes associated with muscle and ganglia). As
such, the compounds can be used as agents for noninvasive imaging
of nicotinic cholinergic receptor subtypes within the body of a
subject, particularly within the brain for diagnosis associated
with a variety of CNS diseases and disorders.
[0162] In one aspect, the diagnostic compositions can be used in a
method to diagnose disease in a subject, such as a human patient.
The method involves administering to that patient a detectably
labeled compound as described herein, and detecting the binding of
that compound to selected NNR subtypes (e.g., .alpha.4.beta.2
and/or .alpha.6-containing receptor subtypes). Those skilled in the
art of using diagnostic tools, such as PET and SPECT, can use the
radiolabeled compounds described herein to diagnose a wide variety
of conditions and disorders, including conditions and disorders
associated with dysfunction of the central and autonomic nervous
systems. Such disorders include a wide variety of CNS diseases and
disorders, including Alzheimer's disease, Parkinson's disease, and
schizophrenia. These and other representative diseases and
disorders that can be evaluated include those that are set forth in
U.S. Pat. No. 5,952,339 to Bencherif et al.
[0163] In another aspect, the diagnostic compositions can be used
in a method to monitor selective nicotinic receptor subtypes of a
subject, such as a human patient. The method involves administering
a detectably labeled compound as described herein to that patient
and detecting the binding of that compound to selected nicotinic
receptor subtypes namely, the .alpha.4.beta.2 and/or
.alpha.6-containing receptor subtypes.
Receptor Binding
[0164] The compounds of this invention can be used as reference
ligands in binding assays for compounds which bind to NNR subtypes,
particularly the and/or .alpha.6-containing receptor subtypes. For
this purpose the compounds of this invention are preferably labeled
with a radioactive isotopic moiety such as .sup.3H, or .sup.14C.
Examples of such binding assays are described in detail below.
V. Synthetic Examples
Example 1
3-benzyl-3,6-diazabicyclo[3.1.1]heptane (1)
3-benzyl-3,6-diazabicyclo[3.1.1]heptane (1) was prepared according
to the procedure of WO 2005/108402 to Pinna, et al.
Example 2
6-(tert-butoxycarbonyl)-3,6-diazabicyclo[3.1.1]heptane (2)
[0165] 6-(tert-butoxycarbonyl)-3,6-diazabicyclo[3.1.1]heptane (2)
was prepared according to the procedure of WO 2005/108402 to Pinna,
et al
Example 3
3-benzyl-6-(trifluoromethylcarbonyl)-3,6-diazabicyclo[3.1.1]heptane
(3)
[0166] To a solution of 3-benzyl-3,6-diazabicyclo[3.1.1]heptane (1)
(7.5 g, 39.8 mmol), methanol (300 mL), and triethylamine (6.70 mL,
1.2 eq, 47.8 mmol) at 0.degree. C. was added trifluoroacetic
anhydride (6.7 mL, 1.2 eq, 47.80 mmol). The solution was stirred at
ambient temperature for 4 h and the solvent was removed under
vacuum. The solids were filtered off and washed with methylene
chloride. The solvent was removed in vacuo and the residue purified
by column chromatography using a 0-100% ethyl acetate in hexanes
gradient. The appropriate fractions were collected, pooled, and
evaporated to give
3-benzyl-6-(trifluoromethylcarbonyl)-3,6-diazabicyclo[3.1.1]heptane
(3) (7.0 g, 62% yield) as a yellow solid.
Example 4
3-(tert-butoxycarbonyl)-6-(trifluoromethylcarbonyl)-3,6-diazabicyclo[3.1.1-
]heptane (4)
[0167] A solution of
3-benzyl-6-(trifluoromethylcarbonyl)-3,6-diazabicyclo[3.1.1]heptane
(3) (8.3 g, 29.2 mmol), ethanol (60 mL), di-t-butyldicarbonate (6.4
g, 29.2 mmol) and 10% palladium on carbon (3.2 g, 30.1 mmol) in a
Parr reactor was shaken at 60.degree. C. under 3 atm of hydrogen
for 16 h. The solution was cooled, filtered through diatomaceous
earth, and washed with methanol. The solvent was evaporated under
reduced pressure and the remaining residue washed with methylene
chloride and saturated ammonium chloride solution. The organic
layer was passed through a phase separator and purified by column
chromatography eluting with a 0-50% ethyl acetate in hexanes
gradient. The appropriate fractions were collected, pooled, and
evaporated to give
3-(tert-butoxycarbonyl)-6-(trifluoromethylcarbonyl)-3,6-diazabicyclo[3.1.-
1]heptane (4) (8.5 g, 99% yield).
Example 5
3-(tert-butoxycarbonyl)-3,6-diazabicyclo[3.1.1]heptane (5)
[0168] A solution of
3-(tert-butoxycarbonyl)-6-(trifluoromethylcarbonyl)-3,6-diazabicyclo[3.1.-
1]heptane (4) (8.5 g, 28.9 mmol) and potassium carbonate (30.7 g, 2
eq, 57.8 mmol) in methanol (150 mL) was heated at 70.degree. C. for
3 h. The solution was cooled to ambient temperature and the solvent
was removed in vacuo. The crude material was dissolved in a 1:1
solution of methylene chloride:methanol and filtered to give
3-(tert-butoxycarbonyl)-3,6-diazabicyclo[3.1.1]heptane (5) (4.5 g,
79% yield) as an off-white solid.
Example 6
3-(cyclopropylcarbonyl)-3,6-diazabicyclo[3.1.1]heptane (6)
[0169] A solution of
6-(tert-butoxycarbonyl)-3,6-diazabicyclo[3.1.1]heptane (2) (2.50 g,
12.6 mmol), cyclopropanecarboxylic acid (1.2 mL, 1.2 eq, 15 mmol),
triethylamine (3.50 mL, 25.2 mmol), dichloromethane (100 mL) and
O-benzotriazol-1-yl-tetramethyluronium hexafluorophosphate (9.6 g,
2 eq, 25 mmol) was stirred at ambient temperature for 2 h.
Saturated ammonium chloride (50 mL) was added and the reaction
mixture was left to stir for 30 min. The mixture was then passed
through a phase extractor (Isolute from Biotage) and the solvent
was removed in vacuo.
[0170] The crude mixture was dissolved in 20 mL of methylene
chloride. Trifluoroacetic acid (5 mL) was added and the reaction
was stirred for 16 h. The solvent was removed in vacuo and the
residue was dissolved in 1 mL of 1:1 methylene chloride:methanol
and passed through a SCX-2 column (Biotage) (eluting with 3 mL 1:1
methylene chloride:methanol, then 7N methanolic ammonia). The crude
product was purified on a silica gel column eluting with a
chloroform to 90:9:1 Chloroform:methanol:ammonium hydroxide
gradient over 12 column volumes. Appropriate fractions were
collected and solvent was removed in vacuo to yield
3-(cyclopropylcarbonyl)-3,6-diazabicyclo[3.1.1]heptane (6) (750 mg;
36% yield) as a yellow oil.
Example 7
3-(propoxycarbonyl)-3,6-diazabicyclo[3.1.1]heptane (7)
[0171] To a solution of
6-(tert-butoxycarbonyl)-3,6-diazabicyclo[3.1.1]heptane (2) (50 mg,
0.25 mmol) in 5 mL of methylene chloride was added triethylamine
(67 .mu.L, 0.5 mmol) and the solution was cooled to 0.degree. C.
Propyl chloroformate (31 .mu.L, 27.5 mmol) was added and the
solution was stirred for 1 h. The solvent was removed in vacuo and
the residue was washed with 50 mM sodium acetate in methylene
chloride solution. The solution was stirred 10 min and passed
through a phase separator. The solvent was removed in vacuo to give
crude
3-(propoxycarbonyl)-6-(tert-butoxycarbonyl)-3,6-diazabicyclo[3.1.1]heptan-
e.
[0172] The crude mixture was dissolved in 3 mL of methylene
chloride. Trifluoroacetic acid (3 mL) was added and the reaction
was stirred for 2 h. The solvent was removed in vacuo at 40.degree.
C. and the residue was dissolved in 1:1 methylene chloride:methanol
and passed through a SCX-2 column (Biotage) (eluting with 2 mL 1:1
methylene chloride:methanol, then 7N methanolic ammonia). The crude
product was purified on a silica gel column eluting with a
chloroform to 90:9:1 Chloroform:methanol:ammonium hydroxide
gradient. Appropriate fractions were collected and solvent was
removed in vacuo to yield
3-(propoxycarbonyl)-3,6-diazabicyclo[3.1.1]heptane (7) (12 mg, 26%)
as a clear oil.
Example 8
3-(methoxyethoxycarbonyl)-3,6-diazabicyclo[3.1.1]heptane (8)
[0173] To a solution of
6-(tert-butoxycarbonyl)-3,6-diazabicyclo[3.1.1]heptane (2) (50 mg,
0.25 mmol) in 5 mL of methylene chloride was added triethylamine
(67 .mu.L, 0.5 mmol) and the solution was cooled to 0.degree. C.
Methoxyethyl chloroformate (32 .mu.L, 27.5 mmol) was added and the
solution was stirred for 1 h. The solvent was removed in vacuo and
the residue was washed with 50 mM sodium acetate in methylene
chloride solution. The solution was stirred 10 min and passed
through a phase separator. The solvent was removed in vacuo to give
crude
3-(methoxyethoxycarbonyl)-6-(tert-butoxycarbonyl)-3,6-diazabicyclo[3.1.1]-
heptane.
[0174] The crude mixture was dissolved in 3 mL of methylene
chloride. Trifluoroacetic acid (3 mL) was added and the reaction
was stirred for 2 h. The solvent was removed in vacuo at 40.degree.
C. and the residue was dissolved in 1:1 methylene chloride:methanol
and passed through a SCX-2 column (Biotage) (eluting with 2 mL 1:1
methylene chloride:methanol, then 7N methanolic ammonia). The crude
product was purified on a silica gel column eluting with a
chloroform to 90:9:1 Chloroform:methanol:ammonium hydroxide
gradient. Appropriate fractions were collected and solvent was
removed in vacuo to yield
3-(methoxyethoxycarbonyl)-3,6-diazabicyclo[3.1.1]heptane (8) (15
mg, 27%) as a clear oil.
VI. Biological Assays
Example 9
Characterization of Interactions at Nicotinic Acetylcholine
Receptors
Cell Lines
[0175] SH-EP1/human .alpha.4.beta.2 (Eaton et al., 2003),
SH-EP1/human .alpha.4.beta.4 (Gentry et al., 2003),
SH-EP1/.alpha.6.beta.3.beta.4.alpha.5 (Grinevich et al., 2005),
TE671/RD and SH-SY5Y cell lines (obtained from Dr. Ron Lukas,
Barrow Neurological Institute, St. Joseph's Hospital and Medical
Center, Phoenix, Ariz.) were maintained in proliferative growth
phase in Dulbecco's modified Eagle's medium (Gibco/BRL) with 10%
horse serum (Gibco BRL), 5% fetal bovine serum (HyClone, Logan
Utah), 1 mM sodium pyruvate, 4 mM L-glutamine. For maintenance of
stable transfectants, the .alpha.4.beta.2 and .alpha.4.beta.4 cell
media was supplemented with 0.25 mg/mL zeocin and 0.13 mg/mL
hygromycin B. Selection was maintained for the
.alpha.6.beta.3.beta.4.alpha.5 cells with 0.25 mg/mL of zeocin,
0.13 mg/mL of hygromycin B, 0.4 mg/mL of geneticin, and 0.2 mg/mL
of blasticidin. HEK/human .alpha.7/RIC3 cells (obtained from J.
Lindstrom, U. Pennsylvania, Philadelphia, Pa.) were maintained in
proliferative growth phase in Dulbecco's modified Eagle's medium
(Gibco/BRL) with 10% fetal bovine serum (HyClone, Logan Utah), 1 mM
sodium pyruvate, 4 mM L-glutamine, 0.4 mg/mL geneticin; 0.2 mg/ml
hygromycin B.
Receptor Binding Assays
[0176] Preparation of Membranes from Rat Tissues.
[0177] Rat cortices were obtained from Analytical Biological
Services, Incorporated (ABS, Wilmington, Del.). Tissues were
dissected from female Sprague-Dawley rats, frozen and shipped on
dry ice. Tissues were stored at -20.degree. C. until needed for
membrane preparation. Cortices from 10 rats were pooled and
homogenized by Polytron (Kinematica GmbH, Switzerland) in 10
volumes (weight:volume) of ice-cold preparative buffer (KCl, 11 mM;
KH.sub.2PO.sub.4, 6 mM; NaCl 137 mM; Na.sub.2HPO.sub.4 8 mM; HEPES
(free acid), 20 mM; iodoacetamide, 5 mM; EDTA, 1.5 mM; 0.1 mM PMSF
pH 7.4). The resulting homogenate was centrifuged at 40,000 g for
20 minutes at 4.degree. C. and the resulting pellet was resuspended
in 20 volumes of ice-cold water. After 60-minute incubation at
4.degree. C., a new pellet was collected by centrifugation at
40,000 g for 20 minutes at 4.degree. C. The final pellet was
resuspended in preparative buffer and stored at -20.degree. C. On
the day of the assay, tissue was thawed, centrifuged at 40,000 g
for 20 minutes and then resuspended in PBS (Dulbecco's Phosphate
Buffered Saline, Life Technologies, pH 7.4) to a final
concentration of 2-3 mg protein/mL. Protein concentrations were
determined using the Pierce BCA Protein Assay kit (Pierce
Biotechnology, Rockford, Ill.), with bovine serum albumin as the
standard.
Preparation of Membranes from Clonal Cell Lines.
[0178] Cells were harvested in ice-cold PBS, pH 7.4, then
homogenized with a polytron (Brinkmann Instruments, Westbury,
N.Y.). Homongenates were centrifuged at 40,000 g for 20 minutes
(4.degree. C.). The pellet was resuspended in PBS and protein
concentration determined using the Pierce BCA Protein Assay kit
(Pierce Biotechnology, Rockford, Ill.).
Competition Binding to Receptors in Membrane Preparations.
[0179] Binding to nicotinic receptors was assayed on membranes
using standard methods adapted from published procedures (Lippiello
and Fernandes, 1986; Davies et al., 1999). In brief, membranes were
reconstituted from frozen stocks (approximately 0.2 mg protein) and
incubated for 2 h on ice in 150 ml assay buffer (PBS) in the
presence of competitor compound (0.001 nM to 100 mM) and
radioligand. [.sup.3H]-nicotine (L-(-)-[N-methyl-3H]-nicotine, 69.5
Ci/mmol, Perkin-Elmer Life Sciences) was used for human
.alpha.4.beta.2 binding studies. [.sup.3H]-epibatidine (52 Ci/mmol,
Perkin-Elmer Life Sciences) was used for binding studies at the
other receptor subtypes. Incubation was terminated by rapid
filtration on a multimanifold tissue harvester (Brandel,
Gaithersburg, Md.) using GF/B filters presoaked in 0.33%
polyethyleneimine (w/v) to reduce non-specific binding. Filters
were washed 3 times and the radioactivity retained was determined
by liquid scintillation counting.
Binding Data Analysis.
[0180] Binding data were expressed as percent total control
binding. Replicates for each point were averaged and plotted
against the log of drug concentration. The IC.sub.50 (concentration
of the compound that produces 50% inhibition of binding) was
determined by least squares non-linear regression using GraphPad
Prism software (GraphPAD, San Diego, Calif.). K, was calculated
using the Cheng-Prusoff equation (Cheng and Prusoff, 1973).
Example 10
Tabular Spectral and Receptor Binding Data
[0181] The above illustrated amide coupling procedures were used as
a basis to make the compounds shown in Table 1. Reagents and
conditions will be readily apparent to those skilled in the art. In
some cases, compounds were characterized by nuclear magnetic
resonance (NMR) data (included in Table 1). In other cases,
compounds were structurally characterized by LCMS (included in
Table 2).
TABLE-US-00001 TABLE 1 STRUCTURE LCMS (m/z) .sup.1H NMR
##STR00004## 141 .sup.1H NMR (400 MHz, CDCl.sub.3): .delta.
3.81-3.58 (m, 6H), 2.76 (m, 1H), 2.12 (2, 3H), 1.50 (d, J = 8.9 Hz,
1H) ##STR00005## 169 .sup.1H NMR (400 MHz, CDCl.sub.3): .delta.
3.82 (m, 6H), 2.82 (m, 2H), 1.76 (m, 1H), 1.20 (s, 6H) ##STR00006##
167 .sup.1H NMR (400 MHz, CDCl.sub.3): .delta. 3.82 (m, 4H), 3.65
(m, 2H), 2.62 (m, 1H), 1.72 (m, 1H), 1.46 (m, 1H), 1.00 (m, 2H),
0.72 (m, 2H) ##STR00007## 185 .sup.1H NMR (400 MHz, CDCl.sub.3):
.delta. 4.20 (m, 2H), 3.84- 3.62 (m, 6H), 2.70 (m, 1H), 1.65 (m,
2H), 1.50 (m, 1H), 0.98 (d, 3H) ##STR00008## 185 .sup.1H NMR (400
MHz, CDCl.sub.3): .delta. 5.00 (m, 1H), 3.80- 58 (m, 6H), 2.70 (m,
1H), 1.50 (m, 1H), 1.25 (m, 6H) ##STR00009## 273 .sup.1H NMR (400
MHz, CDCl.sub.3): .delta. 7.12 (s, 1H), 6.47 (s, 1H), 4.20-4.12 (m,
2H), 3.97-3.78 (m, 4H), 2.80 (m, 1H), 1.61 (m, 1H) ##STR00010## 260
.sup.1H NMR (400 MHz, CDCl.sub.3): .delta. 7.48 (s, 1H), 6.53 (s,
1H), 4.12-3.82 (m, 4H), 2.84 (m, 1H), 1.61 (d, J = 9.6 Hz, 1H)
##STR00011## 185 .sup.1H NMR (400 MHz, CDCl.sub.3): .delta.
3.80-3.76 (m, 8H), 3.36 (s, 3H), 2.74 (m, 1H), 2.64 (m, 2H), 1.48
(d, J = 9.2 Hz, 1H) ##STR00012## 227 .sup.1H NMR (400 MHz,
CDCl.sub.3): .delta. 7.16 (s, 1H), 6.35 (s, 1H), 4.22 (m, 2H), 4.02
(m, 4H), 2.82 (m ,1H), 1.60 (d, J = 9.0 Hz, 1H) ##STR00013## 273
.sup.1H NMR (400 MHz, CDCl.sub.3): .delta. 7.10 (s, 1H), 6.45 (s,
1H), 4.22 (m, 2H), 3.98-3.78 (m, 4H), 2.80 (m, 1H), 1.58 (d, J =
9.1 Hz, 1H) ##STR00014## 185 .sup.1H NMR (400 MHz, CDCl.sub.3):
.delta. 3.92-3.72 (m, 8H), 2.74 (m, 1H), 3.36 (s, 3H), 2.70-2.62
(m, 2H), 1.52 (d, J = 9.0 Hz, 1H) ##STR00015## 185 .sup.1H NMR (400
MHz, CD.sub.3OD): .delta. 4.85 (m, 1H), 4.55 (m, 2H), 4.40 (m, 2H),
4.02 (m, 2H), 3.12 (m, 1H), 2.52 (m, 1H), 1.98 (m, 1H), 1.60 (m,
1H), 1.38 (m, 1H) ##STR00016## 183 .sup.1H NMR (400 MHz,
CD.sub.3OD): .delta. 4.43 (d, 2H), 4.1 (d, 2H), 4.0 (d, 1H), 3.85
(d, 1H), 2.98 (m, 1H), 2.15-2.40 (m, 3H), 1.86 (d, 1H), 1.0 (d, 6H)
##STR00017## 193 .sup.1H NMR (400 MHz, CD.sub.3OD): .delta. 5.65
(m, 2H), 4.7 (m, 1H), 4.44 (m, 1H), 3.48-3.78 (m, 4H), 3.15 (m,
1H), 2.93 (m, 1H), 2.45-2.75 (m, 4H), 1.83 (d, 1H)
TABLE-US-00002 TABLE 2 STRUCTURE .alpha.6.beta.3.beta.4.alpha.5
K.sub.i Human .alpha.4.beta.2 K.sub.i Rat .alpha.4.beta.2 K.sub.i
LCMS (m/z) ##STR00018## 170 141 ##STR00019## 830 220 23 169
##STR00020## 140 3.0 2.3 167 ##STR00021## 24 185 ##STR00022## 130
185 ##STR00023## 120 201 ##STR00024## 5.9 52 189 ##STR00025## 1800
25 83 273 ##STR00026## 2700 35 80 273 ##STR00027## 2400 7.9 56 260
##STR00028## 150 194 ##STR00029## 72 185 ##STR00030## 1700 11 25
209 ##STR00031## 270 197 ##STR00032## 38 44 227 ##STR00033## 66 260
273 ##STR00034## 14 26 181 ##STR00035## 370 185 ##STR00036## 370
197 ##STR00037## 6300 249 ##STR00038## 69 520 209 ##STR00039## 2900
211 ##STR00040## 3400 212 ##STR00041## 1900 226 ##STR00042## 400
197 ##STR00043## 17000 28 0.18 194 ##STR00044## 11000 19 38 208
##STR00045## 53 60 208 ##STR00046## 34 70 183 ##STR00047## 120 390
207 ##STR00048## 1500 272 ##STR00049## 510 6.1 8.8 203 ##STR00050##
1100 208 ##STR00051## 150 71 207 ##STR00052## 360 220 100 209
##STR00053## 3000 243 ##STR00054## 1400 247 ##STR00055## 1200 265
##STR00056## 9400 229 ##STR00057## 7100 247 ##STR00058## 1600 330
130 211 ##STR00059## 2200 256 ##STR00060## 1300 251 ##STR00061##
2000 211 ##STR00062## 1100 390 197 ##STR00063## 750 197
##STR00064## 3300 225 ##STR00065## 2900 256 ##STR00066## 2000 211
##STR00067## 310 43 27 181 ##STR00068## 37 260 193 ##STR00069## 79
50 171 ##STR00070## 150 240 183 ##STR00071## 430 182 ##STR00072##
60 220 221 ##STR00073## 450 238 ##STR00074## 480 140 710 223
##STR00075## 120 5.0 1.8 181 ##STR00076## 170 77 195 ##STR00077##
3300 271 ##STR00078## 28 6.8 181 ##STR00079## 810 193 ##STR00080##
410 171 ##STR00081## 290 183 ##STR00082## 1700 221 ##STR00083## 970
238 ##STR00084## 11000 223 ##STR00085## 46 34 181 ##STR00086## 420
195 ##STR00087## 14000 1200 271 ##STR00088## 100 50 208
##STR00089## 140 250 208 ##STR00090## 1100 208 ##STR00091## 72 17
194 ##STR00092## 260 169 ##STR00093## 120 59 183 ##STR00094## 1200
207 ##STR00095## 760 209 ##STR00096## 11 34 207 ##STR00097## 440
209 ##STR00098## 600 243 ##STR00099## 1000 247 ##STR00100## 660 265
##STR00101## 2000 229 ##STR00102## 950 247 ##STR00103## 240 211
##STR00104## 750 256 ##STR00105## 360 251 ##STR00106## 2800 225
##STR00107## 420 256 ##STR00108## 320 211 ##STR00109## 64 17 181
##STR00110## 530 5.2 1.1 185 ##STR00111## 120 4.5 0.81 185
##STR00112## 3.7 0.89 185 ##STR00113## 2.2 1.0 185 ##STR00114## 100
2.3 16 318 ##STR00115## 120 11 8.6 265 ##STR00116## 700 330 302
##STR00117## 3400 6500 267 ##STR00118## 21000 1100 301 ##STR00119##
5900 3100 301 ##STR00120## 400 270 200 232 ##STR00121## 210 110 4.0
267 ##STR00122## 38 48 24 301 ##STR00123## 120 90 71 301
##STR00124## 290 12 4.1 169 ##STR00125## 980 74 63 223 ##STR00126##
540 37 25 195 ##STR00127## 440 49 34 195 ##STR00128## 120 5.3 6.7
195 ##STR00129## 470 71 69 223 ##STR00130## 270 44 30 195
##STR00131## 64 4.7 4.4 243 ##STR00132## 50 2.6 1.2 207
##STR00133## 96 26 31 221 ##STR00134## 280 78 30 221 ##STR00135##
220 44 130 209 ##STR00136## 380 23 22 195 ##STR00137## 370 16 19
217 ##STR00138## 22000 1300 233 ##STR00139## 1300 160 210 219
##STR00140## 230 9.9 5.1 169 ##STR00141## 1500 180 72 223
##STR00142## 400 53 15 195 ##STR00143## 360 53 30 195 ##STR00144##
800 75 45 195 ##STR00145## 4400 850 223 ##STR00146## 2400 810 195
##STR00147## 350 30 51 243 ##STR00148## 340 38 32 207 ##STR00149##
610 280 221 ##STR00150## 6400 310 221 ##STR00151## 1100 570 209
##STR00152## 770 49 58 195 ##STR00153## 510 54 16 217 ##STR00154##
900 200 380 219 ##STR00155## 100000 1900 233 ##STR00156## 1300 300
219 ##STR00157## 2600 7.6 100 181 ##STR00158## 1100 22 200 181
##STR00159## 31000 210 181 ##STR00160## 30000 820 181 ##STR00161##
1700 9.2 50 181 ##STR00162## 1800 9.6 180 181 ##STR00163## 150 1.1
0.53 185 ##STR00164## 280 1.8 0.86 185 ##STR00165## 780 4.6 1.6 185
##STR00166## 91 1 0.54 185 ##STR00167## 830 22 4 181 ##STR00168##
58 1.8 0.39 181 ##STR00169## 95 1 0.08 181 ##STR00170## 1700 13 4.8
181 ##STR00171## 120 0.49 0.24 143
[0182] Compounds of Table 2, representative of the present
invention, exhibited inhibition constants (Ki values) at the human
.alpha.4.beta.2 subtype in the ranges of 2 nM to 11,000 nM, with a
number of compound exhibiting Ki<100 nM, indicating high
affinity for the .alpha.4.beta.2 subtype. Ki values at the
.alpha.6.beta.3.beta.4.alpha.5 subtype vary within the range of 38
nM to 100,000 nM, indicating variable affinity for the
.alpha.6.beta.3.beta.4.alpha.5 subtype.
Example 11
Neuroprotective Effect of 48 h Pre-Treatment of Dopaminergic
Neurons with Test Compounds on MPP.sup.+ Injuries (4 .mu.M)
Experimental Protocol
Primary Cultures of Dopaminergic Neurons
[0183] Rat dopaminergic neurons were cultured as described by
Schinelli et al., 1988. Briefly pregnant female rats of 15 days
gestation were killed by cervical dislocation (Rats Wistar;
Janvier) and the fetuses removed from the uterus. The embryonic
midbrains were removed and placed in ice-cold medium of Leibovitz
(L15; Invitrogen) containing 1% of Penicillin-Streptomycin (PS;
Invitrogen) and 1% of bovine serum albumin (BSA; Sigma). Only the
ventral portions of the mesencephalic flexure were used for the
cell preparations as this is the region of the developing brain
rich in dopaminergic neurons. The midbrains were dissociated by
trypsinisation for 20 min at 37.degree. C. (Trypsin EDTA 1.times.;
Invitrogen) diluted in PBS without calcium and magnesium. The
reaction was stopped by the addition of Dulbecco's modified Eagle's
medium (DMEM; Invitrogen) containing DNAase I grade II (0.1 mg/ml;
Roche Diagnostic) and 10% of foetal calf serum (FCS; Invitrogen).
Cells were then mechanically dissociated by 3 passages through a 10
ml pipette. Cells were then centrifuged at 180.times.g for 10 min
at room temperature on a layer of BSA (3.5%) in L15 medium. The
supernatant was discarded and the cells of pellet were re-suspended
in a defined culture medium consisting of Neurobasal (Invitrogen)
supplemented with B27 (2%; Invitrogen), L-glutamine (0.2 mM;
Invitrogen) and 1% of PS solution. Viable cells were counted in a
Neubauer cytometer using the trypan blue exclusion test. The cells
were seeded at a density of 35000 cells/well in 96 well-plates
(wells were pre-coated with poly-L-lysine (greiner)) and were
cultured at 37.degree. C. in a humidified air (95%)/CO2 (5%)
atmosphere. Half of the medium was changed every 2 days with fresh
medium. In these conditions, after 5 days of culture, astrocytes
were present in the culture and release growth factor allowing
neurons differentiation. Five to six percents of the neuronal cell
population were dopaminergic neurons.
Drug Treatments and Dopaminergic Neuron Immunostaining Methods
[0184] Briefly, on day 3 of culture, the medium was removed and
fresh medium with or without test compounds, nicotine (10 nM) or
BDNF (Brain Derived Neurotropic Factor, 50 ng/ml) was added for a
48 h pre-incubation. On day 5 MPP.sup.+ at 4 .mu.M was added (in
presence of test compounds, nicotine or BDNF), 6 wells per
condition were done.
[0185] After 48 h of MPP+ intoxication with or without test
compounds, nicotine (10 nM) or BDNF (50 ng/ml), cells were fixed
(all conditions) by paraformaldehyde 4% solution
[0186] Test compounds (compound A and compound B, as the heptane
di-p-toluoyl-D-tartrate salts) were assayed at seven concentrations
(0.001; 0.01; 0.1; 1; 10; 100 and 1000 nM).
[0187] Nicotine (10 nM) and BDNF (50 ng/ml) were used as reference
test compounds.
[0188] After permeabilization with 0.1% saponin (Sigma), cells were
incubated with mouse monoclonal primary against tyrosine
hydroxylase antibody (TH, Sigma) for dopaminergic neurons
[0189] The total neurite were measured in parallel on same
wells.
[0190] This antibody was revealed with Alexa Fluor 488 goat
anti-mouse IgG (Molecular probe).
Analysis and Method of Quantification
[0191] For each condition, 20 pictures per well were taken in the
same condition using InCell Analyzer.TM. 1000 (GE Healthcare) with
10.times. magnification. The analyses were automatically done using
developer software (GE Healthcare) to measure the total number of
TH positive neurons and the total neurite length. Data were
expressed in percentage of control condition.
[0192] Statistical analyses (using Statview package) were done on
the different conditions using ANOVA test following by Dunnett's
test (when allowed), significance was set for p 0.05.
[0193] The results are illustrated in FIGS. 1-6.
[0194] FIG. 1 shows a dose effect curve of Compound A
(3-cyclopropylcarbonyl-3,6-diazabicyclo[3.1.1], as the heptane
di-p-toluoyl-D-tartrate salt) and nicotine on TH positive neurons
after 48 h pretreatment, followed by MPP.sup.+ injury (4 .mu.M, 48
h).
[0195] FIG. 2 shows a dose effect curve of Compound A
(3-cyclopropylcarbonyl-3,6-diazabicyclo[3.1.1], as the heptane
di-p-toluoyl-D-tartrate salt) and nicotine on total TH neurite
length after 48 h pretreatment, followed by MPP.sup.+ injury (4
.mu.M, 48 h).
[0196] FIG. 3 shows a dose effect curve of Compound B
(3-ethylcarbonyl-3,6-diazabicyclo[3.1.1], as the heptane
di-p-toluoyl-D-tartrate salt) and nicotine on TH positive neurons
after 48 h pretreatment, followed by MPP.sup.+ injury (4 .mu.M, 48
h).
[0197] FIG. 4 shows a dose effect curve of Compound B
(3-ethylcarbonyl-3,6-diazabicyclo[3.1.1], as the heptane
di-p-toluoyl-D-tartrate salt) and nicotine on total TH neurite
length after 48 h pretreatment, followed by MPP.sup.+ injury (4
.mu.M, 48 h).
[0198] FIG. 5 shows a dose effect curve of BDNF (50 ng/ml) and
nicotine (10 nM) on TH positive neurons after 48 h pretreatment,
followed by MPP.sup.+ injury (4 .mu.M, 48 h).
[0199] FIG. 6 shows a dose effect curve of BDNF (50 ng/ml) and
nicotine (10 nM) on total TH neurite length after 48 h
pretreatment, followed by MPP.sup.+ injury (4 .mu.M, 48 h).
[0200] The specific pharmacological responses observed may vary
according to and depending on the particular active compound
selected or whether there are present pharmaceutical carriers, as
well as the type of formulation and mode of administration
employed, and such expected variations or differences in the
results are contemplated in accordance with practice of the present
invention.
[0201] Although specific embodiments of the present invention are
herein illustrated and described in detail, the invention is not
limited thereto. The above detailed descriptions are provided as
exemplary of the present invention and should not be construed as
constituting any limitation of the invention. Modifications will be
obvious to those skilled in the art, and all modifications that do
not depart from the spirit of the invention are intended to be
included with the scope of the appended claims.
* * * * *