Duplantier, Allen Jacob (Pfizer Global Research and Development, Eastern Point Road Groton, CT, 06340, US)
Zhang, Lei (Pfizer Global Reseach and Development, Eastern Point Road Groton, CT, 06340, US)
O'donnell, Christopher John (Pfizer Global Research and Develpment, Eastern Point Road Groton, CT, 06340, US)
Rogers, Bruce Nelsen (Pfizer Global Research and Development, Eastern Point Road Groton, CT, 06340, US)
Vincent, Lawrence Albert (Pfizer Global Research and Development, Eastern Point Road Groton, CT, 06340, US)
Sviridov, Sergey I. (Pfizer Global Research and Development, European Pharma Patent Department Ramsgate Roa, Sandwich Kent CT13 9NJ, GB)
Belyankin, Andrei V. (Pfizer Global Research and Development, European Pharma Patent Department Ramsgate Roa, Sandwich Kent CT13 9NJ, GB)
Duplantier, Allen Jacob (Pfizer Global Research and Development, Eastern Point Road Groton, CT, 06340, US)
Zhang, Lei (Pfizer Global Reseach and Development, Eastern Point Road Groton, CT, 06340, US)
O'donnell, Christopher John (Pfizer Global Research and Develpment, Eastern Point Road Groton, CT, 06340, US)
Rogers, Bruce Nelsen (Pfizer Global Research and Development, Eastern Point Road Groton, CT, 06340, US)
Vincent, Lawrence Albert (Pfizer Global Research and Development, Eastern Point Road Groton, CT, 06340, US)
Sviridov, Sergey I. (Pfizer Global Research and Development, European Pharma Patent Department Ramsgate Roa, Sandwich Kent CT13 9NJ, GB)
| 1. | A compound of the formula Ia or Ib Ia Ib wherein B = N or CR2; E = N or CR5; with the proviso that if B = N, E = CR5 and with the proviso that if E = N, then B = CR2; each of R2 and R5 is independently selected from H, F, Cl, Br, cyano, CF3, (C1 C8)alkyl, and (C3C8)cycloalkyl; each of R3 and R4 is selected from the group consisting of F, Cl, Br, I, nitro, cyano, CF3, NR6R7, NR6C(=O)R7, NR6S(=O)2R7, OR6, OC(=O)R6, OC(=O)NR6R7, C(=O)ORS, C(=O)R6, C(OH)R6R7 C(=O)NR6R7, SR6, S(=O)R6, S(=O)2R6, S(=O)2NR6R7, and R6; each R6 and R7 is independently selected from H, (CrC8)alkyl, (C2C8)alkenyl, (C2 C8)alkynyl, (C3C8)cycloalkyl, (C4C8)cycloalkenyl, 38 membered heterocycloalkyl, (C5 CnJbicycloalkyl, (C7C1 ^bicycloalkenyl, 511 membered heterobicycloalkyl, 511 membered heterobicycloalkenyl, (C8C11) aryl, and 512 membered heteroaryl; wherein each R6 and R7 is optionally substituted with one or more substituents, independently selected from F, Cl, Br, I, nitro, cyano, CF3, NR9R10, NR9C(=O)R10, NR9C(=O)OR10, NR9Sf=O)2R10, OR9, OC(=O)R9, OC(=O)NR9R10, OC(=O)SRa, C(=O)ORa, C(=O)Ra, C(=O)NRSR1 , SRa S(=O)R9, S(=O)2R9, S(=O)2NR9R10and R9; or R6 and R7 taken together with the nitrogen of NR6R7 form a 38 membered heterocycloalkyl; each R9 and R10 is independently selected from H, (CrC8)alkyl, (C2C8)alkenyl, (C2C8)alkynyl, (C3C8)cycloalkyl, (C4C8)cycloalkenyl, 38 membered heterocycloalkyl, {CsC^bicycloalkyl, (CzC^Jbicycloalkenyl, 511 membered heterobicycloalkyl, (511 membered) heterobicycloalkenyl, (C6C11) aryl or 512 membered heteroaryl; wherein each R9 and R10 is optionally substituted with one or more substituents independently selected from F, Cl, Br, I, nitro, cyano, CF3, NR12R13, NR12C(=O)R13, NR12C(=O)OR13, NR12S(=O)2R13, OR12, OC(=O)R12, OC(=O)NR12R13, OC(=O)SR12, C(=O)OR12, C(=O)R12, C(=O)NR12R13, SR12, S(=O)R12, S(=O)2R12, S(=O)2NR12R13 and R12; or R9 and R10 taken together with the nitrogen of NR9R10 form a 38 membered heterocycloalkyl; and each R12 and R13 is independently selected from H, (CiC8)alkyl, (C2C8)alkenyl, (C2C8)alkynyl, (C3C8)cycloalkyl, (C4C8)cycloalkenyl, 38 membered heterocycloalkyl, (C5Cn)bicycloalkyl, (C7C1 ^bicycloalkenyl, 511 membered heterobicycloalkyl, 511 membered heterobicycloalkenyl, (C6Cn) aryl and (512 membered) heteroaryl; or enantiomeric, diastereomeric, or tautomeric isomers thereof or pharmaceutically acceptable salts thereof. |
| 2. | The compound of claim 1 , wherein the compound is a compound of the formula Ib in claim 1. |
| 3. | The compound of claim 2, wherein B = N and E = CR5. |
| 4. | The compound of claim 2, wherein B = N1 E = CH. |
| 5. | The compound of claim 2, wherein B = CR2, E = N. |
| 6. | The compound of claim 2, wherein B = CH, E=N. |
| 7. | A compound selected from the group consisting of: (/?)() 2(1 ,4diazabicyclo[3.2.1]oct4yl)[1 ,3]oxozolo[4,5b]pyridine, (R)()6chloro 2(1,4diazabicyclo[3.2.1]oct4yl)[1 ,3]oxozolo[5,4b]pyridine, (R)()6bromo2(1 A diazabicycloβ^.iJocMytøi.SfaxozolotS^blpyridine, (R)() 2(1,4diazabicyclo[3.2.1]oct4 yl)5methyl[1 ,3]oxazolo[4,5b]pyridine, (R)()6chloro2(1 ,4diazabicyclo[3.2.1]oct4 yl)[1 ,3]oxazolo[4,5b]pyridine, (R)()6bromo2(1,4diazabicyclo[3.2.1]oct4 yl)[1 ,3]oxazolo[4,5b]pyridine, (R)()2(1 ,4diazabicyclo[3.2.1]oct4yl)6 phenyl[1 ,3]oxazolo[4,5b]pyridine, (R)()2(1 ,4diazabicyclo[3.2.1]oct4yl)6(2fluoro6 methoxyphenyl)[1 ,3]oxazolo[4,5b] pyridine, (R)()2(1 ,4diazabicyclo[3.2.1]oct4yl)6(2 fluoro6methoxyphenyl)[1,3]oxazolo[5,4b] pyridine, (R)()2(1 ,4diazabicyclo[3.2.1]oct4yl) 6(2fluoro6methy!phenyl)[1,3]oxazolo [4,5b]pyridine, (R) ()2(1,4diazabicyclo[3.2.1]oct 4yl)6(2fluoro6methylphenyl)[1 ,3]oxazolo [5.4b]pyridine, (R)()2(1 ,4 diazabicyclo[3.2.1]oct4yl)[1,3]oxazolo[4,5b]pyridine6carbonitrile, (R)()2(1 ,4 diazabicyclo[3.2.1]oct4yl)6methyl[1 ,3]oxazolo[4,5b]pyridine, (R)()2(1 ,4 diazabicycloIS^.IJoct^yOeethylli.Sloxazoloμ.δblpyridine, (R)()6Chloro2(1,4diaza bicycloIS^.IJocMyOSmethyloxazolo^.δbJpyridine, (RJH^fi ^diazabicyclop^.ilocM yl)5methyloxazolo[4,5b]pyridine6carbonitrile, (R)()6bromo2( 1 ,4 diazabicyclo[3.2.1]oct4yl)5methyl[1 ,3}oxazolo[4,5b]pyridine, (R)()2(1 ,4 diazabicyclo[3.2.1]oct4yl)6phenoxy[1 ,3]oxazolo[5,4b]pyridine, and (R)()2(1 ,4 diazabicyclop^.ilocMyOS.edimethylti .Sloxazolo^.δblpyridine or a pharmaceutically acceptable salt, hydrate, or solvate thereof or optical isomer or stereoisomer thereof. |
| 8. | A compound selected from the group consisting of: (S)(+)2(1 ,4diazabicyclo[3.2.1 ]oct4yl)[1 ,3]oxozolo[5,4b]pyridine, (S)(+)6chloro 2(1 ,4diazabicyclo[3.2.1]oct4yl)[1 ,3]oxozolo[5,4b]pyridine, (S)(+)6bromo2(1 ,4 diazabicyclo[3.2.1]oct4yl)[1 ,3]oxozolo[5,4b]pyridine, (S)(+)6chloro2(1 ,4 diazabicyclo[3.2.1]oct4yl)[1 ,3]oxozolo[5,4b]pyridine, and (S)(+)6bromo2(1 ,4 diazabicyclo[3.2.1]oct4yl)[1 ,3]oxazolo[4,5b]pyridine or a pharmaceutically acceptable salt, hydrate, or solvate thereof or optical isomer or stereoisomer thereof. |
| 9. | A pharmaceutical composition comprising a compound according to claim 1, or a pharmaceutically acceptable thereof, and a pharmaceutically acceptable carrier. |
| 10. | A pharmaceutical composition for treating a disorder or condition selected from cognitive and attention deficit symptoms of Alzheimer's, neurodegeneration associated with diseases such as Alzheimer's disease, presenile dementia (mild cognitive impairment), senile dementia, schizophrenia or psychosis including the cognitive deficits associated therewith, attention deficit disorder, attention deficit hyperactivity disorder (ADHD), mood and affective disorders, amyotrophic lateral sclerosis, borderline personality disorder, traumatic brain injury, behavioral and cognitive problems associated with brain tumors, AIDS dementia complex, dementia associated with Down's syndrome, dementia associated with Lewy Bodies, Huntington's disease, depression, general anxiety disorder, agerelated macular degeneration, Parkinson's disease, tardive dyskinesia, Pick's disease, post traumatic stress disorder, dysregulation of food intake including bulemia and anorexia nervosa, withdrawal symptoms associated with smoking cessation and dependent drug cessation, Tourette's syndrome, glaucoma, neurodegeneration associated with glaucoma, symptoms associated with pain, pain and inflammation, TNFα related conditions, rheumatoid arthritis, rheumatoid spondylitis, muscle degeneration, osteoporosis, osteoarthritis, psoriasis, contact dermatitis, bone resorption diseases, atherosclerosis, Paget's disease, uveititis, gouty arthritis, inflammatory bowel disease, adult respiratory distress syndrome (ARDS), Crohn's disease, rhinitis, ulcerative colitis, anaphylaxis, asthma, Reiter's syndrome, tissue rejection of a graft, ischemia reperfusion injury, stroke, multiple sclerosis, cerebral malaria, sepsis, septic shock, toxic shock syndrome, fever and myalgias due to infection, HIV1, HIV2, and HIV3, cytomegalovirus (CMV), influenza, adenovirus, a herpes virus (including HSV1, HSV2), a herpes zoster, cancer (multiple myeloma, acute and chronic myelogenous leukemia, or cancerassociated cachexia), diabetes (pancreatic beta cell destruction, or type I and type Il diabetes), wound healing (healing burns, and wounds in general including from surgery), bone fracture healing, ischemic heart disease, tinnitus, or stable angina pectoris in a mammal, comprising an amount of a compound according to claim 1 , or a pharmaceutically acceptable salt thereof, that is effective in treating such disorder or condition and a pharmaceutically acceptable carrier. |
| 11. | A method for treating a disease or condition in a mammal in need of treatment, wherein the mammal receives symptomatic relief from activation of an α7 nicotinic acetylcholine receptor, comprising administering to a mammal in need of such treatment a compound of the formula I, or a pharmaceutically acceptable salt thereof. |
| 12. | The method of claim 11, wherein the disease or condition is selected from cognitive and attention deficit symptoms of Alzheimer's, neurodegeneration associated with diseases such as Alzheimer's disease, presenile dementia (mild cognitive impairment), senile dementia, Schizophrenia, psychosis and related cognitive deficits associated therewith, attention deficit disorder, attention deficit hyperactivity disorder, mood and affective disorders, amyotrophic lateral sclerosis, borderline personality disorder, traumatic brain injury, behavioral and cognitive problems associated with brain tumors, AIDS dementia complex, dementia associated with Down's syndrome, dementia associated with Lewy Bodies, Huntington's disease, depression, general anxiety disorder, agerelated macular degeneration, Parkinson's disease, tardive dyskinesia, Pick's disease, post traumatic stress disorder, dysregulation of food intake including bulemia and anorexia nervosa, withdrawal symptoms associated with smoking cessation and dependent drug cessation, Gilles de Ia Tourette's Syndrome, glaucoma, neurodegeneration associated with glaucoma, or symptoms associated with pain. |
| 13. | A pharmaceutical composition comprising a compound of claim 1, or a pharmaceutically acceptable salt thereof, and an antipsychotic drug or pharmaceutically acceptable salt thereof. |
| 14. | A method of treating a mammal suffering from schizophrenia or psychosis, comprising administering a compound of claim 1, or a pharmaceutically acceptable salt thereof, in an amount that is effective in treating schizophrenia, and an antipsychotic drug or pharmaceutically acceptable salt thereof. |
| 15. | The method of claim 12, wherein the disease or condition is selected from cognitive deficits associated with schizophrenia, cognitive and attention deficit symptoms of Alzheimer's Disease, and neurodegeneration associated with Alzheimer's Disease. |
Background of the Invention
The present invention relates to α7 nicotinic receptor agonists and to a method for treating disorders of the Central Nervous System (CNS) and other disorders in a mammal, including a human, by administering to the mammal an ct7 nicotinic receptor agonist. It also relates to pharmaceutical compositions containing a pharmaceutically acceptable carrier and a
CNS-penetrant α7 nicotinic receptor agonist.
Nicotinic acetylcholine receptors (nAChRs) play a large role in central nervous system (CNS) activity and in different tissue throughout the body. They are known to be involved in functions, including, but not limited to, cognition, learning, mood, emotion, and neuroprotection. There are several types of nicotinic acetylcholine receptors, and each one appears to have a different role. Some nicotinic receptors regulate CNS function, including, but not limited to, attention, learning and memory; some regulate pain, inflammation, cancer, and diabetes by controlling tumor necrosis factor alpha (TNF-α). Nicotine affects all such receptors, and has a variety of activities. Unfortunately, not all of the activities are desirable. In fact, undesirable properties of nicotine include its addictive nature and the low ratio between efficacy and safety.
Schizophrenia is a complex multifactorial illness caused by genetic and non- genetic risk factors that produce a wide variety of symptoms. Historically, the disease has been characterized by positive and negative symptoms. The positive symptoms include delusions and hallucinations and the negative symptoms include apathy, withdrawal, lack of motivation and pleasure. More recently, deficits in affect, attention, cognition and information processing have been recognized as key pathologies in this complex disorder. No single biological element has emerged as a dominant pathogenic factor in this disease. Indeed, it is likely that schizophrenia is a syndrome that is produced by the combination of many low penetrance risk factors. Pharmacological studies established that dopamine receptor antagonists are efficacious in treating the overt psychotic features (positive symptoms) of schizophrenia such as hallucinations and delusions. Clozapine, an "atypical" antipsychotic drug, is novel because it is effective in treating not only the positive symptoms, but also negative, and to some extent the cognitive symptoms of this disease. Clozapine's utility as a drug is greatly limited because continued use leads to an increased risk of agranulocytosis and seizure. No other antipsychotic drug is effective in treating the cognitive symptoms of schizophrenia. This is significant because the restoration of cognitive functioning is the best predictor of a successful clinical and functional outcome of schizophrenic patients (Green, M. F., Am J. Psychiatry, 153:321- 30, 1996).
By extension, it is clear that better drugs are needed to treat the cognitive disorders of schizophrenia in order to restore a better state of mental health to patients with this disorder.
One aspect of the cognitive deficit of schizophrenia can be measured by using the auditory event-related potential (P50) test of sensory gating. In this test, electroencepholographic (EEG) recordings of neuronal activity of the hippocampus are used to measure the subject's response to a series of auditory "clicks" (Adler, L.E. et. al., Biol. Psychiatry, 46:8-18, 1999). Normal individuals respond to the first click with greater degree than to the second click. In general, schizophrenics and schizotypal patients respond to both clicks nearly the same (Cullum, CM. et. al., Schizophr. Res., 10:131-41 ,1993). These data reflect a schizophrenic's inability to "filter" or ignore unimportant information. The sensory transiently gating deficit appears to be one of the key pathological features of this disease (Cadenhead, K.S. et. al., Am. J. Psychiatry, 157:55-9, 2000). Multiple studies show that nicotine normalizes the sensory deficit of schizophrenia (Adler, L.E. et. al., Am. J. Psychiatry, 150:1856-61, 1993). Pharmacological studies indicate that nicotine's effect on sensory gating is via the <x7 nAChR (Adler, L.E. et. al., Schizophr. Bull., 24:189-202, 1998). Indeed, the biochemical data indicate that schizophrenics have 50% fewer of α7 nAChR receptors in the hippocampus, thus giving a rationale to partial loss of α7 nAChR functionality (Freedman, R. et. al., Biol. Psychiatry, 38:22-33, 1995). Interestingly, genetic data indicate that a polymorphism in the promoter region of the α7 nAChR gene is strongly associated with the sensory gating deficit in schizophrenia (Freedman, R. et. al., Proc. Nat'l Acad. Sci. USA, 94(2):587-92, 1997; Myles- Worsley, M. et. al., Am. J. Med. Genet, 88(5):544-50, 1999). To date, no mutation in the coding region of the α7 nAChR has been identified. Thus, schizophrenics express the same α7 nAChR as non-schizophrenics. Selective α7 nAChR agonists may be found using a functional assay on FLIPR (see WO 00/73431). FLlPR is designed to read the fluorescent signal from each well of a 96 or 384 well plate as fast as twice a second for up to 30 minutes. This assay may be used to accurately measure the functional pharmacology of α7 nAChR. To conduct such an assay, one uses cell lines that express functional forms of the cc7 nAChR using the α7/5-HT 3 channel as the drug target and cell lines that express functional 5HT 3 R. In both cases, the ligand-gated ion channel was expressed in SH-EP1 cells. Both ion channels can produce robust signal in the FLIPR assay.
Bray, C, et al., "Mice Deficient in CHRNA7, a Subunit of the Nicotinic Acetylcholine Receptor, Produce Sperm with Impaired Motility", Biol. Reprod. June 8, 2005, report genetic evidence that sperm nicotinic acetylcholine receptors are important for maintenance of normal sperm motility.
Metz, Christine N., et al., 6 Nature Immunol. No 8, 756-757, 2005, and de Jonge, Wouter J., 6 Nature Immunol. No. 8., 844-851, 2005, report that acetylcholine released by stimulation of the vagus nerve binds to alpha 7 nAChRs expressed by macrophages to suppress proinflammatory cytokine production. The authors indicate that the anti- inflammatory pathway can be manipulated with cholinaergic agonists such as nicotine,
providing possible therapeutic approaches for treating postoperative ileus or controlling host inflammatory responses during sepsis. cc7 nicotinic receptor agonists are also described in U.S. Patent Nos. 6,809,094, and 6,881 ,734, both of which are incorporated by reference herein in their entirety.
Pharmaceutical compositions comprising an <χ7 nicotinic receptor agonist and an antipsychotic drug are described in US Published App. 2003/045540, which is incorporated by reference herein in its entirety.
The compositions of the present invention that contain an cc7 nicotinic receptor agonist are useful for the treatment of cognitive deficits or impairments in schizophrenia and in Alzheimer's Disease.
Summary of the Invention
This invention relates to a compound of the formula Ia or Ib
Ia Ib wherein
B = N or CR 2 ; E = N or CR 5 ; with the proviso that if B = N, E = CR 5 and with the proviso that if E = N, then B =
CR^ each of R 2 and R 5 is independently selected from H, F, Cl, Br, cyano, CF 3 , (C 1 - C 8 )alkyl, and (C 3 -C 8 )cycloalkyl; each of R 3 and R 4 is selected from the group consisting of F, Cl, Br, I, nitro, cyano, CF 3 , -NR 6 R 7 , -NR 6 C(=O)R 7 , -NR 6 S(=O) 2 R 7 , -OR 6 , -OC(=O)R 6 , -OC(=O)NR 6 R 7 , -C(=O)OR 6 , - C(=O)R 6 , C(OH)R 6 R 7 , -C(=O)NR 6 R 7 , -SR 6 , -S(=O)R 6 , -S(=O) 2 R 6 , -S(=O) 2 NR 6 R 7 , and R 6 ; each R 6 and R 7 is independently selected from H, (C 1 -C 8 )SIkVl, (C 2 -C 8 )alkenyl, (C 2 - C 8 )alkynyl, (C 3 -C 8 )cycloalkyl, (C 4 -C 8 )cycloalkenyl, 3-8 membered heterocycloalkyl, (C 5 - C^Jbicycloalkyl, (C 7 -C 1 ^bicycloalkenyl, 5-11 membered heterobicycloalkyl, 5-11 membered heterobicycloalkenyl, (C 6 -Ci 1 ) aryl, and 5-12 membered heteroaryl; wherein each R 6 and R 7 is optionally substituted with one or more substituents, independently selected from F, Cl, Br, I, nitro, cyano, CF 3 , -NR 9 R 10 , -NR 9 C(=O)R 10 , -NR 9 C(=O)OR 10 , -NR 9 S(=O) 2 R 10 , -OR 9 , -
OC(=O)R a , -OC(=O)NR a R lu , -OC(=O)SR a , -C(=O)OR a , -C(=O)R a , -C(=O)NR ,9 a D R1 π 0 u , -SR a
S(=O)R M , -S(=O) 2 R a , -S(=O) 2 NR a R lu and R a ;
-A-
or R 6 and R 7 taken together with the nitrogen of NR 6 R 7 form a 3-8 membered heterocycloalkyl; each R 9 and R 10 is independently selected from H 1 (CτC B )alkyl, (C 2 -C 8 )alkenyl,
(C 2 -C 8 )alkynyl, (C 3 -Ca)cycloalkyl, (C 4 -C 8 )cycloalkenyl, 3-8 membered heterocycloalkyl, (Cs-CnJbicycloalkyl, (C 7 -Cii)bicycloalkenyl, 5-11 membered heterobicycloalkyl, (5-11
\ g membered) heterobicycloalkenyl, (C 6 -C 1 - I ) aryl or 5-12 membered heteroaryl; wherein each R and R 10 is optionally substituted with one or more substituents independently selected from F, Cl, Br, I 1 nitro, cyano, CF 3 , -NR 12 R 13 , -NR 12 C(=O)R 13 , -NR 12 C(=O)OR 13 , -NR 12 S(=O) 2 R 13 , - OR 12 , -OC(=O)R 12 , -OC(=O)NR 12 R 13 , -OC(=O)SR 12 , -C(=O)OR 12 , -C(=O)R 12 , -C(=O)NR 12 R 13 , -SR 12 , -S(=O)R 12 , -S(=O) 2 R 12 , -S(=O) 2 NR 12 R 13 and R 12 ; or R 9 and R 10 taken together with the nitrogen of NR 9 R 10 form a 3-8 membered heterocycloalkyl; and each R 12 and R 13 is independently selected from H, (C r C 8 )alkyl, (C 2 -C 8 )alkenyl, (C 2 -C 8 )alkynyl, (C 3 -C 8 )cycloalkyl, (C 4 -C 8 )cycloalkenyl, 3-8 membered heterocycloalkyl, (C 5 -Ci 1 )bicycloalkyl, (Cy-CnJbicycloalkenyl, 5-11 membered heterobicycloalkyl, 5-11 membered heterobicycloalkenyl, (C 6 -C 11 ) aryl and (5-12 membered) heteroaryl; or enantiomeric, diastereomeric, or tautomeric isomers thereof or pharmaceutically acceptable salts thereof.
More specific embodiments of this invention relate to compounds of the formula Ib. More specific embodiments of this invention relate to compounds of the formula Ib wherein B = N, E = CR 5 .
More specific embodiments of this invention relate to compounds of the formula Ib wherein B = N, E = CH.
More specific embodiments of this invention relate to compounds of the formula Ib wherein B = CR 2 , E = N.
More specific embodiments of this invention relate to compounds of the formula Ib wherein B = CH, E=N.
More specific embodiments of this invention relate to compounds of the formula 1 b wherein E = N 1 B = CH, R 4 = H and R 3 is selected from the group consisting of H 1 F, Cl, Br, cyano, CF 3 , (Ci-C 8 )alkyl, and (C 3 -C 8 )cycloalkyl.
More specific embodiments of this invention relate to compounds of the formula 1 b wherein E = N, B = CH, R 4 = H and R 3 is selected from the group consisting of (C 6 -C 11 ) aryl and 5-12 membered heteroaryl.
More specific embodiments of this invention relate to compounds of the formula 1b wherein E = N 1 B = CH, R 4 = H and R 3 is selected from the group consisting of (Ci-C 8 )alkoxy and (C 6 -C 1 - I ) aryloxy.
More specific embodiments of this invention relate to compounds of the formula 1b wherein E = N, B = CH, R 4 = H and R 3 is selected from the group consisting Of -NR 6 R 7 , -SR 6 , - S(=O)R 6 , -SO 2 R 6 , -C(O)R 6 , C(=O)OR 6 , and -C(OH)R 6 R 7 .
More specific embodiments of this invention relate to compounds of the formula 1b wherein E = N, B = CH, R 4 = (C 1 -C 8 )SIkVl, and R 3 is selected from the group consisting of H, F, Cl, Br, cyano, CF 3 , (C 1 -C 8 )SIkYl, and (C 3 -C 8 )cycloalkyl.
More specific embodiments of this invention relate to compounds of the formula 1 b wherein E = N 1 B = CH, R 4 = (C 1 -C 8 )SIkYl, and R 3 is selected from the group consisting of (C 6 - Ci 1 ) aryl and 5-12 membered heteroaryl. More specific embodiments of this invention relate to compounds of the formula 1b wherein E = N 1 B = CH, R 4 = (C r C 8 )alkyl, and R 3 is selected from the group consisting of (C 1 - C 8 )alkoxy and (C 6 -C 11 ) aryloxy.
More specific embodiments of this invention relate to compounds of the formula 1 b wherein E = N, B = CH, R 4 = (C 1 -C 8 JaIkYl, and R 3 is selected from the group consisting of -NR 6 R 7 , -SR 6 , -S(=O)R 6 , -SO 2 R 6 , -C(O)R 6 , C(=O)OR 6 , and -C(OH)R 6 R 7 .
More specific embodiments of this invention relate to compounds of the formula 1 b wherein E = N, B = CH, R 4 = (C 6 -C 11 ) aryl or 5-12 membered heteroaryl, and R 3 is selected from the group consisting of H, F, Cl, Br, cyano, CF 3 , (C 1 -C 8 )SIkYl, and (C 3 -C 8 )cycloalkyl.
More specific embodiments of this invention relate to compounds of the formula 1b wherein E = N, B = CH, R 4 = (C 6 -C 11 ) aryl or 5-12 membered heteroaryl, and R 3 is selected from the group consisting of (C 1 -C 8 JaIkOXy and (C 6 -C 1 - I ) aryloxy.
More specific embodiments of this invention relate to compounds of the formula 1b wherein E = N, B = CH, R 4 = (C 6 -C 11 ) aryl or 5-12 membered heteroaryl, and R 3 is selected from the group consisting of -NR 6 R 7 , -SR 6 , -S(=O)R 6 , -SO 2 R 6 , -C(O)R 6 , C(=O)OR 6 , - C(OH)R 6 R 7 .
More specific embodiments of this invention relate to compounds of the formula 1 b wherein B = N, E = CH, R 4 = H and R 3 is selected from the group consisting of H, F, Cl, Br, cyano, CF 3 , (C r C 8 )alkyl, and (C 3 -C 8 )cycloalkyl.
More specific embodiments of this invention relate to compounds of the formula 1 b wherein B = N, E = CH, R 4 = H and R 3 is selected from the group consisting of (C 6 -C 11 ) aryl and 5-12 membered heteroaryl.
More specific embodiments of this invention relate to compounds of the formula 1 b wherein B = N 1 E = CH, R 4 = H and R 3 is selected from the group consisting of (C 1 -C 8 JaIkOXy and (C 6 -C 11 ) aryloxy. More specific embodiments of this invention relate to compounds of the formula 1b wherein B = N 1 E = CH, R 4 = H and R 3 is selected from the group consisting Of -NR 6 R 7 , -SR 6 , - S(=O)R 6 , -SO 2 R 6 , -C(O)R 6 , C(=O)OR 6 , and -C(OH)R 6 R 7 .
More specific embodiments of this invention relate to compounds of the formula 1b wherein B = N, E = CH, R 4 = (C r C 8 )alkyl, and R 3 is selected from the group consisting of H, F, Cl, Br, cyano, CF 3 , (CrC 8 )alkyl, and (C 3 -C 8 )cycloalkyl.
More specific embodiments of this invention relate to compounds of the formula 1b wherein B = N, E = CH, R 4 = (C 1 -C 8 JaIkYl, and R 3 is selected from the group consisting of (C 6 - Ci 1 ) aryl and 5-12 membered heteroaryl.
More specific embodiments of this invention relate to compounds of the formula 1b wherein B = N 1 E = CH, R 4 = (CrC 8 )alkyl, and R 3 is selected from the group consisting of (C 1 - C 8 )alkoxy and (C 6 -C 11 ) aryloxy. More specific embodiments of this invention relate to compounds of the formula 1b wherein B = N, E = CH, R 4 = (C r C 8 )alkyl, and R 3 is selected from the group consisting of -NR 6 R 7 , -SR 6 , -S(=O)R 6 , -SO 2 R 6 , -C(O)R 6 , C(=O)OR 6 , and -C(OH)R 6 R 7 .
More specific embodiments of this invention relate to compounds of the formula 1b wherein B = N, E = CH, R 4 = (C 6 -C 1I ) aryl or 5-12 membered heteroaryl, and R 3 is selected from the group consisting of H, F, Cl, Br, cyano, CF 3 , (C-i-C^alkyl, and (C 3 -C 8 )cycloalkyl.
More specific embodiments of this invention relate to compounds of the formula 1 b wherein B = N, E = CH, R 4 = (C 6 -C 1 - I ) aryl or 5-12 membered heteroaryl, and R 3 is selected from the group consisting of (CrC 8 )alkoxy and (C 6 -C 11 ) aryloxy.
More specific embodiments of this invention relate to compounds of the formula 1b wherein B = N, E = CH, R 4 = (C 6 -C 11 ) aryl or 5-12 membered heteroaryl, and R 3 is selected from the group consisting of -NR 6 R 7 , -SR 6 , -S(=O)R 6 , -SO 2 R 6 , -C(O)R 6 , C(=O)OR 6 , - C(OH)R 6 R 7 .
The term "alkyl", as used herein, unless otherwise indicated, includes saturated monovalent hydrocarbon radicals having straight or branched moieties. Examples of alkyl groups include, but are not limited to, methyl, ethyl, propyl, isopropyl, and f-butyl.
The term "alkoxy", as used herein, unless otherwise indicated, includes an O-alkyl radical, wherein "alkyl" is defined herein.
The term "alkenyl", as used herein, unless otherwise indicated, includes alkyl moieties having at least one carbon-carbon double bond wherein alkyl is as defined above. Examples of alkenyl include, but are not limited to, ethenyl and propenyl.
The term "alkynyl", as used herein, unless otherwise indicated, includes alkyl moieties having at least one carbon-carbon triple bond wherein alkyl is as defined above. Examples of alkynyl groups include, but are not limited to, ethynyl and 2-propynyl.
The term "alkylene", as used herein, unless otherwise indicated, includes saturated divalent hydrocarbon radicals having straight or branched moieties. Examples of alkyl groups include, but are not limited to, -CH 2 -, -CH 2 -CH 2 -, -CH 2 -CH 2 -CH 2 -, -CH(CH 3 )-CH 2 -, and -CH 2 - C(CH 3 ),-.
The term "cycloalkyl", as used herein, unless otherwise indicated, includes non- aromatic saturated cyclic alkyl moieties wherein alkyl is as defined above. Examples of cycloalkyl include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cycloheptyl. "Bicycloalkyl" groups are non-aromatic saturated carbocyclic groups consisting of two rings. Examples of bicycloalkyl groups include, but are not limited to, bicyclo-[2.2.2]-octyl and norbornyl. The term "cycloalkenyl" and "bicycloalkenyl" refer to non- aromatic carbocyclic cycloalkyl and bicycloalkyl moieties as defined above, except comprising of one or more carbon-carbon double bonds connecting carbon ring members (an "endocyclic" double bond) and/or one or more carbon-carbon double bonds connecting a carbon ring member and an adjacent non-ring carbon (an "exocyclic" double bond). Examples of cycloalkenyl groups include, but are not limited to, cyclopentenyl and cyclohexenyl. A non-limiting example of a bicycloalkenyl group is norborenyl. Cycloalkyl, cycloalkenyl, bicycloalkyl, and bicycloalkenyl groups also include groups similar to those described above for each of these respective categories, but which are substituted with one or more oxo moieties. Examples of such groups with oxo moieties include, but are not limited to oxocyclopentyl, oxocyclobutyl, oxocyclopentenyl, and norcamphoryl.
The term "aryl", as used herein, unless otherwise indicated, includes an organic radical derivedifrom an aromatic hydrocarbon by removal of one hydrogen atom. Examples of aryl groups include, but are not limited to phenyl and naphthyl. The term "aryloxy", as used herein, unless otherwise indicated, includes an O-aryl radical, wherein "aryl" is defined herein.
The terms "heterocyclic" and "heterocycloalkyl", as used herein, refer to non-aromatic cyclic groups containing one or more heteroatoms, preferably from one to four heteroatoms, each selected from O, S and N. "Heterobicycloalkyl" groups are non-aromatic two-ringed cyclic groups, wherein at least one of the rings contains a heteroatom (O, S, or N). The heterocyclic groups of this invention can also include ring systems substituted with one or more oxo moieties. Examples of non-aromatic heterocyclic groups include, but are not limited to, aziridinyl, azetidinyl, pyrrolidinyl, piperidinyl, azepinyl, piperazinyl, 1 ,2,3,6-tetrahydropyridinyl, oxiranyl, oxetanyl, tetrahydrofuranyl, tetrahydropyranyl, tetrahydrothienyl, tetrahydrothiopyranyl, piperidino, morpholino, thiomorpholino, thioxanyl, pyrrolinyl, indolinyl, 2H-pyranyl, 4H-pyranyl, dioxanyl, 1 ,3-dioxolanyl, pyrazolinyl, dihydropyranyl, dihydrothienyl, dihydrofuranyl, pyrazolidinyl, imidazolinyl, imidazolidinyl, 3-azabicyclo[3.1.0]hexanyl, 3-azabicyclo[4.1.0]heptanyl, 3H-indolyl, quinuclidinyl and quinolizinyl.
The term "heteroaryl", as used herein, refers to aromatic groups containing one or more heteroatoms (O, S, or N). A multicyclic group containing one or more heteroatoms wherein at least one ring of the group is aromatic is a "heteroaryl" group. The heteroaryl groups of this invention can also include ring systems substituted with one or more oxo moieties. Examples
of heteroaryl groups include, but are not limited to, pyridinyl, pyridazinyl, imidazolyl, pyrimidinyl, pyrazolyl, triazolyl, pyrazinyl, quinolyl, isoquinolyl, tetrazolyl, furyl, thienyl, isoxazolyl, thiazolyl, oxazolyl, isothiazolyl, pyrrolyl, quinolinyl, isoquinolinyl, indolyl, benzimidazolyl, benzofuranyl, cinnolinyl, indazolyl, indolizinyl, phthalazinyl, pyridazinyl, triazinyl, isoindolyl, purinyl, oxadiazolyl, thiazolyl, thiadiazolyl, furazanyl, benzofurazanyl, benzothiophenyl, benzotriazolyl, benzothiazolyl, benzoxazolyl, quinazolinyl, quinoxalinyl, naphthyridinyl, dihydroquinolyl, tetrahydroquinolyl, dihydroisoquinolyl, tetrahydroisoquinolyl, benzofuryl, furopyridinyl, pyrolopyrimidinyl, and azaindolyl.
The foregoing heteroaryl, heterocyclic and heterocycloalkyl groups may be C-attached or N-attached (where such is possible). For instance, a group derived from pyrrole may be pyrrol-1-yl (N-attached) or pyrrol-3-yl (C-attached).
Examples of specific compounds of this invention are the following compounds and their pharmaceutically acceptable salts, hydrates, solvates and optical and other stereoisomers: (R)-(-)- 2-(1,4-diazabicyclo[3.2.1]oct-4-yl)[1,3]oxozolo[4,5-b]pyridi ne, (R)-(-)-6-chloro-
2-(1 ,4-diazabicyclo[3.2.1]oct-4-yl)[1 ,3]oxozolo[5,4-b]pyridine, (R)-(-)-6-bromo-2-(1 ,4- diazabicyclo[3.2.1]oct-4-yl)[1,3]oxozolo[5,4-b]pyridine, (R)-(-) 2-(1,4-diazabicyclo[3.2.1]oct-4- yl)-5-methyl[1 ,3]oxazolo[4,5-b]pyridine, ' (R)-(-)-6-chloro-2-(1 ,4-diazabicyclo[3.2.1]oct-4- yl)[1 ,3]oxazolo[4,5-b]pyridine, (R)-(-)-6-bromo-2-(1 ,4-diazabicyclo[3.2.1]oct-4- yl)[1 ,3]oxazolo[4,5-b]pyridine, (R)-(-)-2-(1 ,4-diazabicyclo[3.2.1 ]oct-4-yl)-6- phenyl[1 ,3]oxazolo[4,5-b]pyridine, (R)-(-)-2-(1 ^-diazabicycloβ^.iloct^-ylJ-θ-^-fluoro-θ- methoxyphenyl)[1 ,3]oxazolo[4,5-b] pyridine, (R)-(-)-2-(1 ,4-diazabicyclo[3.2.1]oct-4-yl)-6-(2- fluoro-6-methoxyphenyl)[1 ,3]oxazolo[5,4-b] pyridine, (R)-(-)-2-(1 ,4-diazabicyclo[3.2.1]oct-4-yl)- 6-(2-fluoro-6-methylphenyl)t1 ,3]oxazolo [4,5-b]pyridine, (R)- (-)-2-(1 ,4-diazabicyclo[3.2.1]oct- 4-yl)-6-(2-fluoro-6-methylphenyl)[1,3]oxazolo [5.4-b]pyridine, (R)-(-)-2-(1,4- diazabicyclo[3.2.1]oct-4-yl)[1 ,3]oxazolo[4,5-b]pyridine-6-carbonitrile, (R)-(-)-2-(1 ,4- diazabicyclo[3.2.1]oct-4-yl)-6-methyl[1 ,3]oxazolo[4,5-b]pyridine, (R)-(-)-2-(1 ,4- diazabicycloβ^.iloct^-yO-e-ethyiπ.Sloxazoloμ.δ-btøyridi ne, (R)-(-)-6-Chloro-2-(1,4-diaza- bicyclo[3.2.1]oct-4-yl)-5-methyl-oxazolo[4,5-b]pyridine, (R)-(-)-2-(1 ,4-diaza-bicyclo[3.2.1]oct-4- yl)-5-methyl-oxazolo[4,5-b]pyridine-6-carbonitrile, (R)-(-)-6-bromo-2-(1 ,4- diazabicyclo[3.2.1]oct-4-yl)-5-methyl[1 ,3}-oxazolo[4,5-b]pyridine, (R)-(-)-2-(1 ,4- diazabicyclop^.ilocM-yO-θ-phenoxyti.Sloxazolofδ^-blpyridin e, and (R)-(-)-2-(1 ,4- diazabicyclop^.iloct^-ylJ-δ.θ-dimethyiπ .Sj-oxazolorAδ-bJpyridine.
Examples of specific compounds of this invention also include the following compounds and their pharmaceutically acceptable salts, hydrates, solvates and optical and other stereoisomers:
(S)-(+)-2-(1 ,4-diazabicyclo[3.2.1]oct-4-yl)[1 ,3]oxozolo[5,4-b]pyridine, (S)-(+)-6-chloro-
2-(1 ,4-diazabicyclo[3.2.1]oct-4-yl)[1 ,3]oxozolo[5,4-b]pyridine, (S)-(+)-6-bromo-2-(1 ,4- diazabicyclo[3.2.1]oct-4-yl)[1 ,3]oxozolo[5,4-b]pyridine, (S)-(+)-6-chloro-2-(1 ,4- diazabicyclo[3.2.1]oct-4-yl)[1 ,3]oxo2olo[5,4-b]pyridine, (S)-(+)-6-bromo-2-(1 ,4- diazabicyclo[3.2.1]oct-4-yl)[1 ,3]oxa2olo[4,5-b]pyridine,
Unless otherwise indicated, the term "one or more substituents", as used herein, refers to from one to the maximum number of substituents possible based on the number of available bonding sites.
The term "treatment", as used herein, refers to reversing, alleviating, inhibiting the progress of, or preventing the disorder or condition to which such term applies, or one or more symptoms of such condition or disorder. The term "treatment", as used herein, refers to the act of treating, as "treating" is defined immediately above.
Compounds of formula Ia or Ib may contain chiral centers and therefore may exist in different enantiomeric and diastereomeric forms. Individual isomers can be obtained by known methods, such as resolution, stereoselective reaction, or chromatographic separation in the preparation of the final product or its intermediate. This invention relates to all optical isomers and all stereoisomers of compounds of the formula Ia or Ib , both as racemic mixtures and as individual enantiomers and diastereoismers of such compounds, and mixtures thereof, and to all pharmaceutical compositions and methods of treatment defined above that contain or employ them, respectively.
In so far as the compounds of formula Ia or Ib of this invention are basic compounds, they are all capable of forming a wide variety of different salts with various inorganic and organic acids. Although such salts must be pharmaceutically acceptable for administration to animals, it is often desirable in practice to initially isolate the base compound from the reaction mixture as a pharmaceutically unacceptable salt and then simply convert to the free base compound by treatment with an alkaline reagent and thereafter convert the free base to a pharmaceutically acceptable acid addition salt. The acid addition salts of the base compounds of this invention are readily prepared by treating the base compound with a substantially equivalent amount of the chosen mineral or organic acid in an aqueous solvent or in a suitable organic solvent, such as methanol or ethanol. Upon careful evaporation of the solvent, the desired solid salt is readily obtained. The acids which are used to prepare the pharmaceutically acceptable acid addition salts of the aforementioned base compounds of this invention are those which form non-toxic acid addition salts, Le 1 , salts containing pharmaceutically acceptable anions, such as the chloride, bromide, iodide, nitrate, sulfate or bisulfate, phosphate or acid phosphate, acetate, lactate, citrate or acid citrate, tartrate or bi- tartrate, succinate, maleate, fumarate, gluconate, saccharate, benzoate, methanesulfonate,
ethanesulfonate, benzenesulfonate, p-toluenesulfonate and pamoate (i.e.. 1 ,1'-methylene- bis-(2-hydroxy-3-naphthoate))salts.
The present invention also includes isotopically labelled compounds, which are identical to those recited in formula Ia or Ib , but for the fact that one or more atoms are replaced by an atom having an atomic mass or mass number different from the atomic mass or mass number usually found in nature. Examples of isotopes that can be incorporated into compounds of the present invention include isotopes of hydrogen, carbon, nitrogen, oxygen, phosphorous, sulfur, fluorine and chlorine, such as 2 H, 3 H, 13 C, 11 C, 14 C, 15 N, 18 0, 17 0, 31 P, 32 P, 35 S, 18 F, and 38 CI, respectively. Compounds of the present invention, prodrugs thereof, and pharmaceutically acceptable salts of said compounds or of said prodrugs which contain the aforementioned isotopes and/or other isotopes of other atoms are within the scope of this invention. Certain isotopically labelled compounds of the present invention, for example those into which radioactive isotopes such as 3 H and 14 C are incorporated, are useful in drug and/or substrate tissue distribution assays. Tritiated, Le 11 3 H, and carbon-14, Le 1 , 14 C, isotopes are particularly preferred for their ease of preparation and detectability. Further, substitution with heavier isotopes such as deuterium, Le., 2 H, can afford certain therapeutic advantages resulting from greater metabolic stability, for example increased in vivo half-life or reduced dosage requirements and, hence, may be preferred in some circumstances. Isotopically labelled compounds of formula Ia or Ib of this invention and prodrugs thereof can generally be prepared by carrying out the procedures disclosed in the Schemes and/or in the Examples and Preparations below, by substituting a readily available isotopically labelled reagent for a non-isotopically labelled reagent.
The present invention also relates to a pharmaceutical composition comprising a compound of the formula Ia or Ib , or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier.
The present invention also relates to a pharmaceutical composition for the treatment of schizophrenia in a mammal, including a human, comprising an amount of a compound of the formula Ia or Ib , or a pharmaceutically acceptable salt thereof, that is effective in treating schizophrenia and a pharmaceutically acceptable carrier. The present invention also relates to a method for treating schizophrenia in a mammal, including a human, comprising administering to said mammal an amount of a compound of the formula Ia or Ib , or a pharmaceutically acceptable salt thereof, that is effective in treating schizophrenia.
The present invention also relates to a pharmaceutical composition for the treatment of schizophrenia in a mammal, including a human, comprising an <x7 nicotinic receptor agonizing amount of a compound according to formula Ia or Ib and a pharmaceutically acceptable carrier.
The present invention also relates to a method for treating schizophrenia in a mammal, including a human, comprising administering to said mammal an α7 nicotinic receptor agonizing amount of a compound of the of formula Ia or Ib , or a pharmaceutically acceptable salt thereof.
This invention provides a method of treating a disorder or condition comprising as a symptom a deficiency in attention and/or cognition in a mammal, including a human, which method comprises administering to said mammal an amount of a compound of Formula Ia or
Ib, or a pharmaceutically acceptable salt thereof effective in treating said disorder or condition.
The phrase "deficiency in attention and/or cognition" as used herein in "disorder comprising as a symptom a deficiency in attention and/or cognition" refers to a subnormal functioning in one or more cognitive aspects such as memory, intellect, or learning and logic ability, in a particular individual relative to other individuals within the same general age population. "Deficiency in attention and/or cognition" also refers to a reduction in any particular individual's functioning in one or more cognitive aspects. This invention further provides a method of treating a neurodegenerative disorder or condition in a mammal, including a human, which method comprises administering to said mammal an amount of a compound of Formula Ia or Ib, or a pharmaceutically acceptable salt thereof effective in treating said disorder or condition.
As used herein, and unless otherwise indicated, a "neurodegenerative disorder or condition" refers to a disorder or condition that is caused by the dysfunction and/or death of neurons in the central nervous system. The treatment of these disorders and conditions can be facilitated by administration of an agent which prevents the dysfunction or death of neurons at risk in these disorders or conditions and/or enhances the function of damaged or healthy neurons in such a way as to compensate for the loss of function caused by the dysfunction or death of at-risk neurons.
A neurodegenerative disorder that can be treated according to the present invention includes, but is not limited to, Alzheimer's Disease.
The compounds of Formula Ia or Ib are useful to treat, or are useful to make a medicament to treat, a condition in a mammal that may be treated by administration of an α7 nicotinic acetylcholine receptor agonist. The compounds of Formula Ia or Ib are useful to treat, or are useful to make a medicament to treat, a mammal where the mammal receives symptomatic relief from activation of an α7 nicotinic acetylcholine receptor agonist.
For example, the present invention also relates to a pharmaceutical composition for treating a disorder or condition selected from cognitive and attention deficit symptoms of Alzheimer's, neurodegeneration associated with diseases such as Alzheimer's disease, pre¬ senile dementia (mild cognitive impairment), senile dementia, schizophrenia or psychosis including the cognitive deficits associated therewith, attention deficit disorder, attention deficit
hyperactivity disorder (ADHD), mood and affective disorders, amyotrophic lateral sclerosis, borderline personality disorder, traumatic brain injury, behavioral and cognitive problems associated with brain tumors, AIDS dementia complex, dementia associated with Down's syndrome, dementia associated with Lewy Bodies, Huntington's disease, depression, general anxiety disorder, age-related macular degeneration, Parkinson's disease, tardive dyskinesia, Pick's disease, post traumatic stress disorder, dysregulation of food intake including bulemia and anorexia nervosa, withdrawal symptoms associated with smoking cessation and dependent drug cessation, Tourette's syndrome, glaucoma, neurodegeneration associated with glaucoma, symptoms associated with pain, pain and inflammation, TNF-α related conditions, rheumatoid arthritis, rheumatoid spondylitis, muscle degeneration, osteoporosis, osteoarthritis, psoriasis, contact dermatitis, bone resorption diseases, atherosclerosis, Paget's disease, uveititis, gouty arthritis, inflammatory bowel disease, adult respiratory distress syndrome (ARDS), Crohn's disease, rhinitis, ulcerative colitis, anaphylaxis, asthma, Reiter's syndrome, tissue rejection of a graft, ischemia reperfusion injury, stroke, multiple sclerosis, cerebral malaria, sepsis, septic shock, toxic shock syndrome, fever and myalgias due to infection, HIV-1, HIV-2, and HIV-3, cytomegalovirus (CMV), influenza, adenovirus, a herpes virus (including HSV-1, HSV-2), a herpes zoster, cancer (multiple myeloma, acute and chronic myelogenous leukemia, or cancer-associated cachexia), diabetes (pancreatic beta cell destruction, or type I and type Il diabetes), wound healing (healing burns, and wounds in general including from surgery), bone fracture healing, ischemic heart disease, tinnitus, or stable angina pectoris in a mammal, comprising an amount of a compound of the formula I, or a pharmaceutically acceptable salt thereof, that is effective in treating such disorder or condition and a pharmaceutically acceptable carrier. A condition that is preferred for treatment is attention deficit disorder, attention deficit hyperactivity disorder, mood and affective disorders, amyotrophic lateral sclerosis, borderline personality disorder, traumatic brain injury, behavioral and cognitive problems associated with brain tumors, AIDS dementia complex, dementia associated with Down's syndrome, dementia associated with Lewy Bodies, Huntington's disease, depression, general anxiety disorder, age-related macular degeneration, Parkinson's disease, tardive dyskinesia, Pick's disease, post traumatic stress disorder, dysregulation of food intake including bulemia and anorexia nervosa, withdrawal symptoms associated with smoking cessation and dependent drug cessation, Gilles de Ia Tourette's Syndrome, glaucoma, neurodegeneration associated with glaucoma, or symptoms associated with pain.
The present invention also relates to a pharmaceutical composition for treating male infertility.
The present invention also relates to a pharmaceutical composition for treating inflammation, for example, postoperative ileus.
The present invention also relates to a method for treating a disorder or condition listed, comprising administering to a mammal in need of such treatment an amount of a compound of the formula Ia or Ib, or a pharmaceutically acceptable salt thereof, that is effective in treating such disorder or condition. The present invention also relates to a pharmaceutical composition, which may be a composition for treating a disorder or condition listed in the previous paragraphs, comprising an α7 nicotinic receptor agonizing amount of a compound of the formula Ia or Ib, or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier.
The present invention also relates to a method for treating a disorder or condition listed in the previous paragraphs, comprising administering to a mammal in need of such treatment an α7 nicotinic receptor agonizing amount of a compound of the formula Ia or Ib, or a pharmaceutically acceptable salt thereof.
The present invention also relates to a method for treating a disease or condition in a mammal in need thereof, wherein the mammal receives symptomatic relief from activation of an α7 nicotinic acetylcholine receptor, comprising administering to a mammal in need of such treatment a compound of the formula Ia or Ib, or a pharmaceutically acceptable salt thereof. The disease or condition may be, for example, cognitive and attention deficit symptoms of Alzheimer's, neurodegeneration associated with diseases such as Alzheimer's disease, pre¬ senile dementia (mild cognitive impairment), or senile dementia. The disease or condition may also be, for example, schizophrenia or psychosis and related cognitive deficits associated therewith. The disease or condition may also be, for example, attention deficit disorder, attention deficit hyperactivity disorder, mood and affective disorders, amyotrophic lateral sclerosis, borderline personality disorder, traumatic brain injury, behavioral and cognitive problems associated with brain tumors, AIDS dementia complex, dementia associated with Down's syndrome, dementia associated with Lewy Bodies, Huntington's disease, depression, general anxiety disorder, age-related macular degeneration, Parkinson's disease, tardive dyskinesia, Pick's disease, post traumatic stress disorder, dysregulation of food intake including bulemia and anorexia nervosa, withdrawal symptoms associated with smoking cessation and dependent drug cessation, Gilles de Ia Tourette's Syndrome, glaucoma, neurodegeneration associated with glaucoma, or symptoms associated with pain.
The present invention also relates to a method for treating male infertility in a mammal in need thereof comprising administering to the mammal a compound of Formula Ia or Ib, or a pharmaceutically acceptable salt thereof.
The present invention also relates to a method for treating inflammation such as postoperative ileus, in a mammal in need thereof comprising administering to the mammal a compound of Formula Ia or Ib, or a pharmaceutically acceptable salt thereof.
The present invention also relates to a pharmaceutical composition comprising a compound of the formula Ia or Ib 1 or a pharmaceutically acceptable salt thereof, and an antipsychotic drug or pharmaceutically acceptable salt thereof.
The present invention also relates to a method of treating a mammal suffering from schizophrenia or psychosis, comprising administering a compound of formula Ia or Ib, or a pharmaceutically acceptable salt thereof, in an amount that is effective in treating schizophrenia, and an antipsychotic drug or pharmaceutically acceptable salt thereof. The compound of formula Ia or Ib and the antipsychotic drug may be administered together or separately. The compound of formula Ia or Ib and the antipsychotic drug may be administered simultaneously or at separate intervals. When administered simultaneously the compound of formula Ia or Ib and the antipsychotic drug may be incorporated into a single pharmaceutical composition. Alternatively, two separate compositions, i.e., one containing a compound of formula Ia or Ib and the other containing an antipsychotic drug, may be administered simultaneously.
The antipsychotic drug may be, for example, Chlorpromazine, Fluphenazine, Haloperidol, Loxapine, Mesoridazine, Molindone, Perphenazine, Pimozide, Thioridazine, Thiothixene, or Trifluoperazine. These drugs all have an affinity for the dopamine 2 receptor. The antipsychotic drug may also be, for example, Asenapine, Ziprasidone, Olanzapine, Clozapine, Risperidone, Sertindole, Quetiapine, Aripiprazole or Amisulpride.
Certain combinations of this invention include at least two active components: an atypical antipsychotic, a prodrug thereof, a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable salt of said prodrug, and a compound of Formula Ia or Ib, or a pharmaceutically acceptable salt thereof. The combinations of this invention also include a pharmaceutically acceptable vehicle, carrier or diluent.
The combinations may result in synergistic action allowing a lower dose of the atypical antipsychotic to be administered while achieving at least the same psychotropic effect as achieved with a standard dose of the atypical antipsychotic. The dosage of the atypical antipsychotic may be reduced by about 25-90%, for example, about 40-80% and typically about 50-70%. The reduction in amount of antipsychotic required will be dependent on the amount of the compound of Formula Ia or Ib given. The selection of the dosage of each therapeutic agent is that which can provide relief to the patient as measured by a reduction or amelioration of symptoms associated with the disorder or condition of the patient. As is well known, the dosage of each component depends on several factors such as the potency of the selected specific compound, the mode of administration, the age and weight of the patient, the severity of the condition to be treated, and the like. Determining a dose is within the skill of the ordinary artisan. To the extent necessary for completeness, the synthesis of the components of the compositions and dosages are as described in the listed patents above or the Physicians' Desk Reference, 57th
ed., Thompson, 2003 which are expressly incorporated herein by reference. Desirably, when ziprasidone is selected as the active agent, the daily dose contains from about 5 mg to about 460 mg. More preferably, each dose of the first component contains about 20 mg to about 320 mg of the ziprasidone, and even more preferably, each dose contains from about 20 mg to about 160 mg of ziprasidone. Pediatric dosages may be less such as for example in the range of about 0.5 mg to about 40 mg daily. This dosage form permits the full daily dosage to be administered in one or two oral doses, for example.
General outlines of the dosages for the atypical antipsychotics, and some preferred dosages, are provided herein. This list is not intended to be complete but is merely a guideline for any of the desired combinations of the present invention.
Olanzapine: from about 0.25 to about 100 mg, once/day; preferably, from about 1 to about 30 mg, once/day; and most preferably about 1 to about 25 mg once/day;
Clozapine: from about 12.5 to about 900 mg daily; preferably, from about 150 to about 450 mg daily; Risperidone: from about 0.25 to about 16 mg daily; preferably, from about 2-8 mg daily;
Sertindole: from about 0.0001 to about 1.0 mg/kg daily;
Quetiapine: from about 1.0 to about 40 mg/kg given once daily or in divided doses;
Asenapine: from about 0.005 to about 60 mg total per day, given as a single dose or in divided doses;
Paliperidone: from about 0.01 mg/kg to about 4 mg/kg body weight, more preferably from about 0.04 to about 2 mg/kg body weight;
Bifeprunox.
The presently preferred atypical antipsychotic used according to the invention is ziprasidone. Ziprasidone (5-[2-[4-(1 ^-benzisothiazol-S-ylJpiperazin-i-yllethyll-δ-chloroindolin -
2-one) is a benzisothiazolyl piperazine atypical antipsychotic with in vitro activity as a 5-HTi A receptor agonist and an inhibitor of serotonin and norepinephrine reuptake (U.S. Patent No.
4,831,031). The postsynaptic 5-HT 1A receptor has been implicated in both depressive and anxiety disorders (NM Barnes, T Sharp, 38 Neuropharmacology 1083-152,1999). Oral bioavailability of ziprasidone taken with food is approximately 60%, half-life is approximately
6-7 hours, and protein binding is extensive.
Ziprasidone is efficacious for the treatment of patients with schizophrenia and schizomood disorders, refractory schizophrenia, cognitive impairment in schizophrenia, affective and anxiety symptoms associated with schizoaffective disorder and bipolar disorder. The drug is considered a safe and efficacious atypical antipsychotic (Charles Caley &
Chandra Cooper, 36 Ann. Phartnacother.. 839-51 ; (2002).
The present invention is useful in treating mental disorders and conditions, the treatment of which is facilitated by the administration of ziprasidone. Thus, the present invention has application where ziprasidone use is indicated as, e.g., in U.S. Patent Nos.
6,245,766; 6,245,765; 6,387,904; 5,312,925; 4,831,031; and European EP 0901789 published March 17, 1999, all of which are incorporated herein by reference.
Other atypical antipsychotics which can be used include, but are not limited to: Olanzapine, 2-methyl-4-(4-methyl-1-piperazinyl)-10H-thieno[2,3-b][1,5]be nzodiazepine.
Olanizapine is a known compound and is described in U.S. Patent No. 5,229,382 as being useful for the treatment of schizophrenia, schizophreniform disorder, acute mania, mild anxiety states, and psychosis. U.S. Patent No. 5,229,382 is herein incorporated herein by reference in its entirety;
Clozapine, 8-chloro-11-(4-methyl-1-piperazinyl)-5H-dibenzo[b,e][1 ,4]diazepine.
Clozapine is described in U.S. Patent No. 3,539,573, which is herein incorporated by reference in its entirety. Clinical efficacy in the treatment of schizophrenia is described (Hanes, et al., Psychopharmacol. Bull., 24, 62 (1988));
Risperidone, 3-[2-[4-(6-fluoro-1 ,2-benzisoxazol-3-yl)piperidino]ethyl]-2-methyl-6,7,8,9 - tetrahydro-4H-pyrido-[1 ,2-a]pyrimidin-4-one. Risperidone and its use in the treatment of psychotic diseases are described in U.S. Patent No. 4,804,663, which is herein incorporated by reference in its entirety; Sertindole, 1-[2-[4-[5-chloro-1-(4-fluorophenyl)-1 H-indol-3-yl]-1- piperidinyl]ethyl]imidazolidin-2-one. Sertindole is described in U.S. Patent No. 4,710,500. Its use in the treatment of schizophrenia is described in U.S. Patent Nos. 5,112,838 and 5,238,945. U.S. Patent Nos. 4,710,500; 5,112,838; and 5,238,945 are herein incorporated by reference in their entireties; Quetiapine, 5-[2-(4-dibenzo[b,f][1,4]thiazepin-11-yl -1-piperazinyl)ethoxy]ethanol.
Quetiapine and its activity in assays which demonstrate utility in the treatment of schizophrenia are described in U.S. Patent No. 4,879,288, which is herein incorporated by reference in its entirety. Quetiapine is typically administered as its (E)-2-butenedioate (2:1) salt. Aripiprazole, 7-{4-[4-(2,3-dichlorophenyl)-1-piperazinyl]-butoxy}-3- ,4-dihydro carbostyril or 7-{4-[4-(2,3-dichlorophenyl)-1-piperazinyl]-butoxy}-3,4-dihy dro -2(1 H)- quinolinone. Aripiprazole is an atypical antipsychotic agent used for the treatment of schizophrenia and described in U.S. Patent No. 4,734,416 and U.S. Patent No. 5,006,528, which are herein incorporated by reference in their entireties. Amisulpride, which is described in U.S. Patent No. 4,401,822. U.S. Patent No.
4,401 ,822 is incorporated herein in its entirety.
Asenapinβ, frans-5-chloro-2-methyl-2,3,3a,12b-tetrahydro-1 H- dibenz[2,3:6,7]oxepino[4,5-c]pyrrole. Preparation and use of asenapine is described in U.S. Patent Nos. 4,145,434 and 5,763,476, the entire contents of which are incorporated herein by reference. Paliperidone, ' 3-[2-[4-(6-fluoro-1 ,2-benzisoxazol-3-yl)-1-piperidinyl]ethyl]-6,7,8 ,9- tetrahydro-9-hydroxy-2-methyl-4H-pyrido[1,2-a]pyrimidin-4-on e. Preparation and use of paliparidone is described, for example, in U.S. Patent Nos. 6,320,048; 5,158,952; and 5,254,556, the entire contents of which are incorporated herein by reference.
Bifeprunox, 2-[4-[4-(5-fluoro-1 H-indol-3-yl)-3,6-dihydro-1 (2H)-pyridinyl]butyl] -1 H- isoindole-1,3(2H)-dione. Preparation and use of bifeprunox is described in U.S. Patent 6,225,312, which is incorporated in its entirety herein.
A preferred combination is ziprasidone with a compound of Formula Ia or Ib, or a pharmaceutically acceptable salt thereof of the present invention.
Detailed Description of the Invention The compounds of the formulas Ia and Ib may be prepared by the methods described below, together with synthetic methods known in the art of organic chemistry, or modifications and derivatizations that are familiar to those of ordinary skill in the art. In the schemes and discussion that follow, B, E, R 1 , R 3 , R 4 , R 6 , and R 7 unless otherwise indicated, are defined as above in the definition of compounds of formulas Ia and Ib. Exemplary methods include, but are not limited to, those described below.
The reactions described below may be performed in solvents that are appropriate to the reagents and materials employed and that are suitable for use in the reactions described. In the description of the synthetic methods described below, it is also to be understood that all reaction conditions, whether actual or proposed, including choice of solvent, reaction temperature, reaction duration time, reaction pressure, and other reaction conditions (such as anhydrous conditions, under argon, under nitrogen, etc.), and work up procedures, may be those conditions that are standard for that reaction, as would be readily recognized by one of skill in the art. Alternate methods that are known in the literature may also be used.
As used herein, the expression "inert reaction solvent" refers to a solvent system in which the components do not interact with starting materials, reagents, or intermediates of products in a manner which adversely affects the yield of the desired product.
During any of the following synthetic sequences it may be necessary and/or desirable to protect sensitive or reactive groups on any of the molecules concerned. This may be achieved by means of conventional protecting groups, such as those described in T. W. Greene and P. G. M. Wuts, Protective Groups in Organic Synthesis, John Wiley & Sons,
1999.
SCHEME 1
-Saryl, -SO 2 alkyl, -SO 2 aryl
A compound of the formula Ia or Ib (referred to as formula I in Scheme 1) may be prepared, for example, as illustrated in Scheme 1. Referring to Scheme 1, the amine of formula Il is reacted with a compound of the formula III wherein L is a leaving group (e.g., choride, bromide, methyl sulfide, alkyl sulfide, aryl sulfide, alkyl sulfoxide, or aryl sulfoxide) in the presence or absence of base (e.g., triethylamine, diisopropylamine, pyridine, 2,6-lutidine, sodium or potassium hydroxide, sodium or potassium or cesium carbonate, sodium or potassium tert-butoxide, diisopropylethylamine, or 1,8-diazabicyclo[5.4.0]undec-7-ene) in the presence or absence of an inert reaction solvent such as water, methanol, ethanol, isopropanol, acetonitrile, methylene chloride, chloroform, 1 ,2-dichloroethane, tetrahydrofuran, diethylether, dioxane, 1,2-dimethoxyethane, benzene, toluene, dimethylformamide, or dimethylsulfoxide. This reaction is typically carried out at a temperature from about -10°C to about 15O 0 C. In one set of preferred conditions, when L is methylsulfide and the reaction is carried out in the absence of solvent at a temperature from about 70 0 C to about 120 0 C. In a second set of preferred conditions, when L is chloride and the reaction is carried out in the presence of triethylamine, diisopropylethylamine, or sodium terf-butoxide in a solvent selected from chloroform, methylene chloride and toluene at a temperature from about O 0 C to about 5O 0 C. Compounds of the formula Il can be prepared using methods analogous to those reported in the literature, as described in Rubstov, M.V.; Mikhlina, E.E.; Vorob'eva, V. Ya.; Yanina, A. Zh. Obshch. Khim. (1964), V34, 2222-2226, and in WO 2004/024729, which is incorporated by reference herein in its entirety. Compounds of formula III can also be prepared by methods analogous to those reported in the literature, see: Lok, R.; Leone, R.E.; Williams, A.J. J. Org. Chem. (1996), 61, 3289-3297; Yamato, M.; Takeuchi, Y.; Hashigaki, K.; Hirota, T. Chem. Pharm. Bull. (1983), 31, 733-736; Chu-Moyer, M.Y.; Berger, R. J. Org. Chem. (1995), 60, 5721-5725; Sato, Y.; Yamada, M.; Yoshida, S.; Soneda, T.; Ishikawa, M.;
Nizato, T.; Suzuki, K.; Konno, F. J. Med. Chβm. (1998), 41, 3015-3021 and Van Allan, J. A.; Deacon, B. D. Organic Syntheses; Wiley: New York (1963); Collect. Vol. IV, pp 569-70.
SCHEME 2
xπi M - B(OR) 2 , SnR j , SiR 3 , Li, Mg R = H, alkyl, or joined as cycloalkyl
Scheme 2 illustrates an alternative preparation of compounds of the formula Ia or Ib (referred to as formula I in Scheme 2). Referring to Scheme 2, treatment of a compound of the formula Xl with a halogenating reagent such as but not limited to Cl 2 , Br 2 , I 2 , N- bromosuccinimide, N-chlorosuccinimide, or N-iodosuccinimide in an inert reaction solvent such as water, acetic acid, methanol, ethanol, tetrhydrofuran, carbon tetrachloride, chloroform, acetonitrile or mixtures thereof in the presence or absence of a base such as potassium acetate, sodium acetate, cesium acetate, sodium carbonate, lithium carbonate, potassium carbonate, cesium carbonate, cesium fluoride n-butyllithium, lithium diisopropyl amide at -78°C to 100 0 C; preferable Br 2 in water and acetic acid with sodium acetate at 25°C to 100 0 C produces a compound of formula XIII where Z is Br. Alternatively, a compound of formula XIII where Z = OTf can be prepared by reaction of a compound of formula XII with trifluoroacetic anyhydride, N-phenyltrifluoromethanesulfonimide, or 2-[N 1 N- bis(trifluoromethylsulfonyl)amino]-5-chloropyridine in the presence of a base such as but not limited to triethylamine, diethylisopropylamine, lithium diisopropyl amide, potassium diisopropyl amide, lithium hexamethyldisilazide, potassium hexamethyldisilazide, pyridine, lutidine, collidine, sodium or potassium hydroxide, sodium or potassium or cesium carbonate, sodium or potassium tert-butoxide, sodium or potassium hydrogen carbonate, sodium or potassium acetate in an inert reaction solvent such as ether, tetrahydrofuran, 1,2- dimethoxyethane, dioxanes, methylene chloride, chloroform, benzene, toluene at -78°C to 100°C; preferable N-phenyltrifluoromethanesulfonimide, lithium diisopropyl amide in THF at - 78 0 C to 25 0 C.
Referring to Scheme 2, a compound of the formula I can be prepared from a compound of formula XIII wherein Z is chloro, bromo, iodo or triflate (OTf) by first reacting it with bis(pinacolato)diboron and a palladium catalyst such as palladium (0) tetrakis(triphenylphosphine), palladium (II) acetate, allyl palladium chloride dimer, tris(dibenzylideneacetone)dipalladium (0), tris(dibenzylidene-acetone)dipalladium (0) chloroform adduct, palladium (II) chloride or dichloro[1,1'- bis(diphenylphosphino)ferrocene]palladium (II) dichloromethane adduct, preferably dichloro[1 ,1'-bis(diphenylphosphino)-ferrocene]palladium (II) dichloromethane adduct, in the presence or absence of a phosphine ligand such as 1 ,1'-bis(diphenylphosphino)ferrocene, triphenylphosphine, tri-o-tolylphosphine, tri-tert-butylphosphine, 1 ,2- bis(diphenylphosphino)ethane, 1,3-bis(diphenylphosphino)-propane, BINAP, 2-biphenyl dicyclohexylphosphine, 2-biphenyl-di-tert-butylphosphine, 2-(N,N-dimethylamino)-2'-di-tert- butylphosphino-biphenyl or 2-(N,N-dimethylamino)-2'-dicyc!ohexylphosphinobiphenyl, preferably 1 ,1'-bis(diphenylphosphino)ferrocene, and in the presence or absence of a base such as potassium acetate, sodium acetate, cesium acetate, sodium carbonate, lithium carbonate, potassium carbonate, cesium carbonate or cesium fluoride, preferably potassium
acetate, to yield a compound of the formula XIV wherein the Z group has been replaced with M, wherein M = borane pinacol ester. Generally, this reaction is carried out in a reaction inert solvent such as 1,4-dioxane, acetonitrile, methyl sulfoxide, tetrahydrofuran, ethanol, methanol, 2-propanol, toluene, preferably methyl sulfoxide, at a temperature from about from O 0 C to about 200 0 C, preferably from about 8O 0 C to about 120 0 C.
Other methods of converting a compound of the formula XIII with the Z group mentioned above into a compound of the formula XIV wherein the Z group is replaced with M, wherein M is boronic acid, boronic acid ester or trialkylstannane, are known in the art. For instance, treatment of a compound of the formula XIII, wherein Z is Br or I, with an alkyl lithium reagent such as, but not limited to n-butyl lithium, sec butyl lithium or tert-butyl lithium, in a solvent such as diethyl ether, tetrahydrofuran, 1,2-dimethoxyethane, hexane, toluene, dioxane or a similar reaction inert solvent, at a temperature from about -100 0 C to about 25 0 C affords the corresponding compound of the formula XIV wherein Z is Li. Treatment of a solution of this material with a suitable boronic ester such as trimethoxyborane, triethoxyborane or triisopropylborane, followed by a standard aqueous work-up with acid will afford the corresponding compound of the formula XIV wherein M is boronic acid.
Alternatively, treating a mixture of a compound of the formula XIII wherein Z is Br or I and a boronic ester with an alkyl lithium reagent, as described above, followed by a standard aqueous work-up with acid will afford the corresponding compound of formula XIV wherein M is boronic acid. Alternatively, treating a compound of the formula XIII wherein Z is Br or I with an alkyl lithium reagent such as, but not limited to n-butyl lithium, sec butyl lithium or tert-butyl lithium, in a solvent such as diethyl ether, tetrahydrofuran, dimethoxyethane, hexane, toluene, dioxane or a similar reaction inert solvent, at a temperature from about -100 0 C to about 25 0 C will afford the corresponding compound of the formula XIV wherein M is Li. Treatment of a solution of this material with a suitable trialkylstannyl halide such as, but not limited to trimethylstannyl chloride or bromide or tributylstannyl chloride or bromide, followed by a standard aqueous work-up will afford the corresponding compound of the formula XIV wherein M is trimethyl- or tributylstannane.
Referring to Scheme 2, treatment of a compound of the formula XIV wherein M is a boronic acid, boronic ester, or trialkylstannane group, with an aryl or heteroaryl chloride, aryl or heteroaryl bromide, aryl or heteroaryl iodide, or aryl or heteroaryl triflate of the formula R 3 Z, preferably an aryl or heteroaryl bromide, with a palladium catalyst such as palladium (0) tetrakis(triphenylphosphine), palladium (II) acetate, allyl palladium chloride dimer, tris(dibenzylideneacetone)dipalladium (0), tris(dibenzylideneacetone)dipalladium (0) chloroform adduct, palladium (II) chloride or dichloro[1,1'-bis(diphenylphosphino)ferrocene]palladium (II) dichloromethane adduct, preferably dichloro[1,1'-bis(diphenylphosphino)-ferrocene]palladium (II) dichloromethane
adduct, in the presence or absence of a phosphine ligand such as 1,1'-bis(diphenylphosphino)ferrocene, triphenylphosphine, tri-o-tolylphosphine, tri-tert-butylphosphine, 1 ,2-bis(diphenylphosphino)ethane, 1 ,3-bis(diphenylphosphino)- propane, BINAP, 2-biphenyl dicyclohexylphosphine, 2-biphenyl-di-tert-butylphosphine, 2-(N,N-dimethylamino)-2'-di-tert-butylphosphino-biphenyl or
2-(N,N-dimethylamino)-2'-dicyclohexylphosphinobiphenyl, preferably
1,1'-bis(diphenylphosphino)ferrocene, and in the presence or absence of a base such as potassium phosphate, potassium acetate, sodium acetate, cesium acetate, sodium carbonate, lithium carbonate, potassium carbonate, cesium fluoride or cesium carbonate, preferably potassium phosphate, affords a compound of formula I. This reaction is typically carried out in a reaction inert solvent such as 1,4-dioxane, acetonitrile, methyl sulfoxide, tetrahydrofuran, ethanol, methanol, 2-propanol, or toluene, preferably 1,4-dioxane, in the presence or absence of from about 1%-about 10% water, preferably about 5% water, at a temperature from about 0 0 C to about 200 0 C, preferably from about 6O 0 C to about 100 0 C. Referring to Scheme 2, alternatively, a compound of the formula XIII can be reacted with a compound of the formula R 3 M, wherein M is a boronic acid, boronic acid ester, borane pinacol ester or trialkylstannane group, in the presence of a palladium catalyst such as palladium (0) tetrakis(triphenylphosphine), palladium (II) acetate, allyl palladium chloride dimer, tris(dibenzylideneacetone)dipalladium (0), tris(dibenzylideneacetone)dipalladium (0) chloroform adduct, palladium (II) chloride or dichloro[1 ,1 '- bis(diphenylphosphino)ferrocene]palladium (II) dichloromethane adduct, preferably palladium (II) acetate, in the presence or absence of a phosphine ligand such as 1 ,1 '- bis(diphenylphosphino)ferrocene, triphenylphosphine, tri-o-tolylphosphine, tri-tert- butylphosphine, 1 ,2-bis(diphenylphosphino)ethane, 1 ,3-bis(diphenylphosphino)-propane, BINAP, 2-biphenyl dicyclohexylphosphine, 2-biphenyl-di-tert-butylphosphine, 2-(N 1 N- dimethylamino)-2'-di-tert-butylphosphino-biphenyl or 2-(N,N-dimethylamino)-2'- dicyclohexylphosphinobiphenyl, preferably 2-(N,N-dimethylamino)-2'- dicyclohexylphosphinobiphenyl, and in the presence or absence of a base such as potassium phosphate, potassium acetate, sodium acetate, cesium acetate, sodium carbonate, lithium carbonate, potassium carbonate, cesium fluoride or cesium carbonate, preferably cesium fluoride, affords a compound of formula I. This reaction is typically carried out in a reaction inert solvent such as 1,4-dioxane, 1 ,2-dimethoxyethane, acetonitrile, methyl sulfoxide, tetrahydrofuran, ethanol, methanol, 2-propanol, or toluene, preferably 1,2-dimethoxyethane, in the presence or absence of from about 1% to about 10% triethylamine, preferably about 1% triethylamine, at a temperature from about 0 0 C to about 200 0 C, preferably from about 60°C to about 100°C.
It will be readily understood by one skilled in the art that a scheme analogous to Scheme 2 can be envisioned wherein R 4 is introduced after R 3 by analogous procedures to those described above.
The amine 1,4-diaza-bicyclo[3.2.1]octane (formula II) can be prepared as illustrated in Scheme 3. Referring to Scheme 3, the preparation of compound Ilia is known in the literature [Saunders, et al. J. Chem. Soc, Chem. Commun. 1988, 1618-9]. Oxime IVa can be prepared from compound MIa by reaction with hydroxyl amine in a polar solvent such as methanol and / or water. Compound IVa can be converted to a lactam of the formula Va by reaction with an acid such as sulfuric acid; this reaction is well known to those skilled in the art as a Beckmann rearrangement. Compound Va can then be reacted with a reducing agent such as lithium aluminum hydride in an aprotic solvent such as tetrahydrofuran or ethyl ether to give 1 ,4-diaza-bicyclo[3.2.1]octane (formula II). The reactions presented in Scheme 3 are known to those skilled in the art and are described in J. March, Advanced Organic Chemistry, 3 rd edition, John Wiley & Sons, New York, 1985. Single enantiomers of Il [(+) Il or (-) II] can be prepared as illustrated in Scheme 4.
Referring to Scheme 4, the preparation of racemic mixtures of compounds of the formula Via, where R is ether a methyl or an ethyl group, is known in the literature (Dutta, P. L. and Foye, W. O. J. Pharm. Sci. 1990; 79 (5), 447-452). Treatment of a compound of the formula (+/-) Via with either benzyl bromide or benzyl chloride in a solvent such as ethanol, tetrahydrofuran, ethyl ether or dimethylformamide in the presence or absence of a base such as triethylamine or pyridine provides a racemic mixture of compounds of the formula (+/-) Vila. This reaction is typically carried out at a temperature of about -1O 0 C to about 100 0 C. One preferred set of conditions is benzyl bromide in ethanol in the absence of base at room temperature over a period of 15 hours. Single enantiomers of Vila [(+) Vila or (-) Vila] can be obtained by high pressure liquid chromatography using a chiral column. A preferred set of conditions for separating the enantiomers of Vila is to use a Chiralcel OD column and elute with an 85/15 mixture of heptane and isopropyl alcohol at a flow rate of about 275 ml/min. Referring to Scheme 4, the single enantiomers of compound Vila are reacted with a hydride- transfer reagent such as lithium aluminum hydride in an aprotic solvent such as tetrahydrofuran or ethyl ether at a temperature of about -1O 0 C to about 70 0 C to give the corresponding single enantiomer of the formula Villa. A preferred condition is lithium aluminum hydride in tetrahydrofuran at 7O 0 C for 3 hours. The single enantiomers of Villa are converted to the corresponding single enantiomers of IXa by a reaction known to those skilled in the art as a Mitsunobu Reaction. Under the typical conditions of the Mitsunobu Reaction, the single enantiomers of Villa are reacted with either diethyl azodicarboxylate or diisopropyl azodicarboxylate and triphenylphosphine in an aprotic solvent such a tetrahydrofuran or ethyl ether at a temperature from about -2O 0 C to about 7O 0 C. A preferred set of conditions is
diethyl azodicarboxylate and triphenylphosphine in tetrahydrofuran at O 0 C to 2O 0 C for 1 hour. Single enantiomers of IXa are converted to the corresponding single enantiomers of Il by removal of the benzyl protecting group using various methods known to those skilled in the art as described in T. W. Greene and P. G. M. Wuts, Protective Groups in Organic Synthesis, John Wiley & Sons, 1999. One preferred method is palladium catalyzed hydrogenation. A set of preferred conditions for the conversion of a single enantiomer of IXa to its corresponding single enantiomer of Il is to shake vigorously a mixture of a compound of the formula IXa and catalytic 5% palladium on carbon, in ethanol and concentrated hydrochloric acid under hydrogen at 50 psi at room temperature over a period of 20 hours. Single enantiomers of compounds II, Via, Vila, Villa and IXa can be obtained by resolution. A method for preparing either (+) Villa or (-) Villa is illustrated in Scheme 5. The preparation of (+) Xa and (-) Xa is known in the literature [Humphrey, J. M.; Bridges/ R. J.; Hart, J. A. and Chamberlin, A. R. J. Org. Chem. 1994, 59 (9), 2467-2472]. Referring to Scheme 5, compounds (+) Villa and (-)Vllla are prepared from either (+)Xa or (-)Xa by subsequent reactions with chloroacetyl chloride, sodium azide, triphenylphosphine, water and lithium aluminum hydride.
The first reaction of Scheme 5 is performed in a mixture of water and an organic solvent such as ether, benzene, toluene or THF in the presence of a base such as sodium bicarbonate, sodium carbonate, or triethylamine at a temperature from about O 0 C to about 100 0 C for a time period from about 15 min to about 16 h. One preferred set of conditions is a mixture of aqueous sodium bicarbonate and ether at room temperature for 1 h. The second reaction of Scheme 5 is performed in a mixture of water and an organic solvent such as DMSO, DMF or THF at a temperature from about O 0 C to about 100 0 C for a time period from about 10 min to about 16 h. One preferred set of conditions is a mixture of water and DMSO at 7O 0 C for 10 min. The third reaction of Scheme 5 is performed in an organic solvent such as ether, THF, toluene, dioxane or DMF at a temperature from about O 0 C to about 100 0 C for a time period from about 1h to about 48 h. One preferred set of conditions is ether at room temperature for 20 h. The fourth reaction of Scheme 5 is performed in water or a mixture of water and an organic solvent such THF, dioxane, DMSO or DMF at a temperature from about 25 0 C to about 15O 0 C for a time period from about 15 min to about 16 h. One preferred set of conditions is a mixture of water and THF at 100 0 C for 2 h. The fifth reaction of Scheme 5 is analogous to the reduction of Vila to Villa as illustrated in scheme 4. This reaction utilizes a hydride-transfer reagent such as lithium aluminum hydride in an aprotic solvent such as tetrahydrofuran or ethyl ether at a temperature of about -10 0 C to about 7O 0 C to give the corresponding single enantiomer of the formula Villa. A preferred set of conditions is lithium aluminum hydride in tetrahydrofuran at 7O 0 C for 3 hours.
SCHEME 3
reduction Ilia IVa Va
SCHEME 4
(+) Vila (-) Vila
reduction
Mitsunobu Reaction
reduction i
(+) Il or (-) 11
SCHEME 5
SCHEME 6
XXVI
Compounds of the formula I can be prepared as illustrated in Scheme 6. Referring to Scheme 6, compounds of the formula XXIII can be obtained, for example, by nitration of a compound of formula XXII. Nitration conditions are known to those skilled in the art (for example, see J. March, Advanced Organic Chemistry, 3 rd edition, John Wiley & Sons, New yourk, 1985). Compounds of the formula XXIV can be obtained from compounds of the formula XXIII under reducing conditions such as, but not limited to zinc, tin or iron and acid, catalytic hydrogenation, transfer hydrogenolysis or sodium hydrosulfite in an inert reaction solvent such as water, methanol, ethanol, isopropanol. One preferred set of conditions is catalytic hydrogenation using palladium on carbon as a catalyst in ethanol at ambient temperature and 50 psi of hydrogen. The compound of formula XXIV can then be treated with a compound of formula XXV, wherein F and G are defined as R 6 and R 7 above, and a reducing agent such as, but not limited to sodium triacetoxyborohydride, sodium borohydride,
sodium cyanoborohydride, lithium aluminum hydride, catalytic hydrogenation or transfer hydrogenolysis in the presence or absence of an acid such as but not limited to acetic acid, hydrochloric acid, trifluoroacetic acid, sulfuric acid, phosphoric acid or nitric acid in an inert reaction solvent such as chloroform, dichloromethane, 1 ,2-dichloroethane, acetonitrile, toluene, benzene, ethanol, methanol or water at 0°C to 100 0 C to afford a compound of formula XXVI, with a preferred condition being sodium triacetoxyborohydride in 1,2- dichloroethane at 25°C to 90 0 C.
Also referring to Scheme 6, a compound of formula XXIV can be reacted with a compound of formula R 6 L in which R 6 is as defined above, except that R 6 may not be hydrogen, and L is a leaving group (e.g., Cl, Br, I, OSO 2 alkyl, OSO 2 aryl) in the presence or absence of base (e. g., sodium or potassium hydroxide, sodium or potassium or cesium carbonate, sodium or potassium terf-butoxide, sodium or potassium hydrogen carbonate, sodium or potassium acetate) in the presence or absence of an inert reaction solvent such as water, methanol, ethanol, isopropanol, acetonitrile, methylene chloride, chloroform, 1 ,2- dichloroethane, tetrahydrofuran, diethylether, dioxane, 1 ,2-dimethoxyethane, benzene, toluene, dimethylformamide, or dimethylsulfoxide at a temperature from about -1O 0 C to about 150 0 C to produce a compound of formula XXVI. The preferred conditions are L = Br, in ethanol at 25 0 C to 78°C.
Also referring to Scheme 6, a compound of formula XXIV can undergo a transformation to replace a diazonium group derived from an aryl amine with a fluoride to yield a compound of formula XXVII. The most commonly used procedure for diazotization of an aryl amine involves sodium nitrite in aqueous hydrochloric acid or sulfuric acid. Fluoro- containing counter ions may be then introduced into the reaction mixture to convert the diazonium ion to a fluoride. Commonly used counter-ions include, but not limited to BF 4 ' , PF 6 ' , AsF 6 ' and SbF 6 " . Hydrogen fluoride may also be used as a fluoride source. For a review of this transformation, see: H. Zollinger, Diazo Chemistry I, VCH, Weinheim, 1994 (Chapter 10).
SCHEME 7
HO B R3 / °-rrV R3 Base , /°t B γ R3
X=halogen, OTf, OMs III
XViIi xix L= -SMe, -Salkyl
Referring to Scheme 7, a compound of formula III is prepared from a compound of formula XVIII. As illustrated in Scheme 7, a compound of Formula XVIII is treated with carbon disulfide in the presence of potassium hydroxide (for analogous procedure in literature, see: Katz, L; Cohen, M. S. J. Org. Chem. 1954, 19, 758-766; Supin, G. S. et al.; J. Gen. Chem.
USSR (EN) 1975, 45, 363-367; Sugimoto, H, Makino, I.; Hirai, K. J. Org. Chem. 1988, 53, 2263-2267) or with ethyl potassium xanthate (Van Allan, J. A.; Deacon, B. D. Organic Syntheses; Wiley; New York, 1963; Collect. Vol. IV, pp 569-570; Chu-Moyer, M. Y.; Berger, R. J. Org. Chem. 1995, 60, 5721-5725) in an inert solvent such as but not limited to water, methanol, ethanol or isopropanol at 50 0 C to 100 0 C to yield a compound of Formula XIX. Alternatively, a compound of Formula XIX is prepared by treating a compound of formula XVIII with thiophosgene (Zinner, H. et al.; Chem. Ber. 1960, 93, 2035-2040; Kimura, F.; Haga, T.; Sakashita, N.; Maeda, K.; Hayashi, H.; Seki, T.; Yoshida, T. Jpn. Patent 59 10,590; 1984; Chem. Abstr. 1984, 101, 38448; Chu-Moyer, M. Y.; Berger, R. J. Org. Chem. 1995, 60, 5721- 5725) in a inert reaction solvent such as but not limited to tetrahydrofuran (THF), 1 ,4-dioxane, ethyl ether or dimethoxyethane (DME) at a reaction temperature ranging from 0 0 C to 30 0 C. The compound of formula XIX is then converted to a compound of formula III upon treatment with alkyl-X wherein X is a good leaving group such as halogen, mesylate or triflate in the presence of a base (suitable bases include but not limited to sodium or potassium or cesium carbonate, sodium or potassium tert-butoxide, sodium or potassium acetate, where sodium or potassium carbonate is preferred). The reaction is carried out in an inert solvent such as tetrahydrofuran (THF), 1,4-dioxane, ethyl ether or dimethoxyethane (DME) at ambient temperature.
SCHEME 8
XX XXI
XV(a)
Hydrogenation
XVIII(a)
Compounds of formula XVIII (a) are either commercially available, or prepared as illustrated in Scheme 8.
Referring to Scheme 8, the synthesis is initiated from a compound of formula XX wherein X is Cl or Br. Both compounds of formula XX can be conveniently prepared from commercial sources using nitration, chlorination or bromination procedures that are described in the literature. Compound XX is then converted to the corresponding benzyl ether XXI according to the procedures described in T. W. Greene and P. G. M Wuts, Protective Groups in Organic Synthesis, John Wiley & Sons, 1999, where the procedure using benzyl bromide and sodium hydride in dimethylformamide (DMF) is preferred.
Referring to Scheme 8, a compound of the Formula XV(a), wherein R 4 is alkyl, alkenyl, C 6 -C 11 aryl or 5-12 membered heteroaryl group, is prepared using benzyl ether XXI and a reagent of formula R 4 -M, wherein M is defined as a boronic acid, boronic ester, trialkylstanane, magnesium halogen, or zinc, with a palladium catalyst such as but not limited to palladium(O) tetrakis(triphenylphosphine), palladium(ll) acetate, tris(dibensylideneacetone)dipalladium(0), dichloro[1 ,1 '-
bis(diphenylphosphino)ferrocene]palladium (II) dichloromethane adduct, in the presence of a phosphine ligand such as but not limited to triphenylphosphine, tri-o-tolylphosphine, tri-tert- butylphosphine, 1 , 1 '-bis(diphenylphsophino)ferrocene, 1 ,2-bis(diphenylphsophino)ethane, 1,3-bis(diphenylphsphino)-propane, 2,2'-bis(diphenylphosphino)-1 ,1'-binaphthyl (BINAP), in the presence or absence of a base such as but not limited to potassium or sodium acetate, sodium or potassium or cesium carbonate, potassium phosphate, cesium fluoride and sodium tert-butoxide. This reaction is typically carried out in an inert solvent such as 1,4-dioxane, ethyl ether, tetrahydrofuran (THF), benzene, toluene, DMF, DMSO in the presence or absence of 1 %-10% water at a temperature from 0 0 C to 200 0 C. Referring to Scheme 8, compounds of Formula XV(b) are prepared using benzyl ether XXI and a terminal alkyne, a reaction known in the art as Sonogashira Coupling reaction. The reaction is typically carried out with a palladium catalyst such as palladium (0) tetrakis(triphenylphosphine), palladium (II) acetate, allyl palladium chloride dimer, tris(dibenzylideneacetone)dipalladium (0), tris(dibenzylidene-acetone)dipalladium (0) chloroform adduct, palladium (II) chloride or dichloro[1,1'- bis(diphenylphosphino)ferrocene]palladium (II) dichloromethane adduct, in the presence or absence of a copper salt such as CuI, in the presence of a large excess base such as, but not limited to, triethylamine, diisopropylethylamine, diisopropylamine as solvent, or a mixed solvent of a base and a suitable solvent such as 1,4-dioxane, benzene, toluene at a temperature from O 0 C to 200 0 C.
Referring to Scheme 8, a compound of the Formula XV(c) is prepared by treating benzyl ether XXI with an amine of Formula NHR 6 R 7 using the conditions well-described in the literature (Wagaw, S.; Buchwald, S. L. J. Org. Chem. 1996, 61, 7240; Driver, M. S.; Hartwig, J. F. J. Am. Chem. Soc. 1996, 118, 7217). The reaction is typically carried out with a palladium catalyst such as palladium(ll) acetate, tris(dibensylideneacetone)dipalladium(0), dichloro-[1,1'-bis(diphenylphosphino)ferrocene] palladium (II) dichloromethane adduct, in the presence of a phosphine ligand such as BINAP, 1,3-bis(diphenylphsphino)-propane, or 1,1'- bis(diphenylphsophino)ferrocene, in the presence of a base such as sodium tert-butoxide in a suitable solvent such as toluene at a temperature from 6O 0 C to 110 0 C. Referring to Scheme 8, compounds of Formula XV(a)-(c) are then converted to the compounds of Formula XVIII(a) upon hydrogenation, which removes benzyl protecting group, reduces the nitro group to amino group and, in the case that any of the substituents are alkenyl or alkynyl, converts the unsaturated bond to the corresponding alkyl group. A wide variety of hydrogenation conditions well known in the art are applicable for this transformation. 10% palladium/carbon under a pressure of hydrogen (45 PSI) in an inert solvent such as methanol, ethanol or ethylacetate is preferred.
SCHEME 9
= H
(B=CH, E = N, R 3 = H, R 4 = OR 6 )
Alternatively, compound of formula I can also be synthesized as illustrated in Scheme 9. Starting from a compound of formula XXVIII 1 reduction of the nitro group with a reducing reagent such as, but not limited to, zinc, iron, SnCI 2 , sodium hydrosulfite in an inert reaction solvent such as water, methanol, ethanol, isopropanol to yield a compound of formula XVI, which is then converted to a compound of formula XVII following the procedures detailed in Schemes 1 and 7. Referring to Scheme 9, a compound of formula I can be generated by treating a compound of formula XVII with a reagent of formula R 4 -M, wherein M is defined as a boronic acid, boronic ester, trialkylstanane, magnesium halogen, or zinc, with a palladium catalyst such as but not limited to palladium(O) tetrakis(triphenylphosphine), palladium(ll) acetate, tris(dibensylideneacetone)dipalladium(0), dichloro[1 ,1 '- bis(diphenylphosphino)ferrocene]palladium (II) dichloromethane adduct, in the presence of a phosphine ligand such as but not limited to triphenylphosphine, tri-o-tolylphosphine, tri-tert- butylphosphine, 1 , 1 '-bis(diphenylphsophino)ferrocene, 1 ,2-bis(diphenylphsophino)ethane, 1,3-bis(diphenylphsphino)-propane, 2,2'-bis(diphenylphosphino)-1,1'-binaphthyl (BINAP), in the presence or absence of a base such as but not limited to potassium or sodium acetate, sodium or potassium or cesium carbonate, potassium phosphate, cesium fluoride and sodium tert-butoxide. This reaction is typically carried out in an inert solvent such as 1,4-dioxane,
ethyl ether, tetrahydrofuran (THF), benzene, toluene, DMF, DMSO in the presence or absence of 1%-10% water at a temperature from 0 0 C to 200 0 C.
Referring to Scheme 9, a compound of formula I, wherein R 4 = OR 6 , is prepared by treating a compound of fromula XVII, wherein X is chloro or bromo, with an alcohol of the formula R 6 OH, wherein R 6 is defined as in the general description. The reaction is usually carried out in the presence of a copper salt such as, but not limited to, copper(l) chloride (CuCI), copper(ll) triflate and copper(l) iodide (CuI), in the presence or absence of a ligand such as, but not limited to, 2,2,6,6-tetramethylheptane-3,5-dione (TMHD), 1,10- phenanthroline, 8-hydroxyquinoline, 2-aminopyridine and pentane-2,4-dione (acac), and in the presence or absence of a base such as cesium carbonate, potassium phosphate, potassium acetate, sodium acetate, cesium acetate, sodium carbonate, lithium carbonate, potassium carbonate, preferably cesium carbonate, using the reacting alcohol as solvent or in an inert solvent such as, but not limited to, benzene, toluene, xylene, N,N-dimethylformamide (DMF), dimethylsulfoxide (DMSO) and N-methylpyrrolidinone (NMP) at a temperature from about O 0 C to about 200 0 C. Alternatively, I can be prepared by heating XVIII with the sodium salt of the alcohol R 6 OH with the corresponding alcohol as solvent.
Referring to Scheme 9, a compound of formula I is prepared by treating a compound of formula XVII, wherein X is chloro or bromo, with amine NHR 6 R 7 . The reaction is carried out in the presence or absence of a palladium catalyst such as palladium(ll) acetate, tris(dibensylideneacetone)dipalladium(0), dichloro-[1 ,1 '-bis(diphenylphosphino)ferrocene] palladium (II) dichloromethane adduct, in the presence or absence of a phosphine ligand such as BINAP, 1,3-bis(diphenylphsphino)-propane, or 1 ,1'-bis(diphenylphsophino)ferrocene, in the presence of a strong base such as sodium tert-butoxide in a suitable solvent such as toluene at a temperature from 6O 0 C to 11O 0 C. Isolation and purification of the products can be accomplished by standard procedures that are known to a chemist of ordinary skill.
In each of the reactions discussed above, or illustrated in Schemes 1-9, above, pressure is not critical unless otherwise indicated. Pressures from about 0.5 atmospheres to about 5 atmospheres are generally acceptable, with ambient pressure, Le 1 , about 1 atmosphere, being preferred as a matter of convenience.
The compounds of the formula Ia or Ib and their pharmaceutically acceptable salts (hereafter "the active compounds") can be administered via either the oral, transdermal (e.g.. through the use of a patch), intranasal, sublingual, rectal, parenteral or topical routes. Transdermal and oral administration are preferred. These compounds are, most desirably, administered in dosages ranging from about 0.25 mg up to about 1500 mg per day, preferably from about 0.25 to about 300 mg per day in single or divided doses, although variations will necessarily occur depending upon the weight and condition of the subject being treated and the
particular route of administration chosen. However, a dosage level that is in the range of about 0.01 tng to about 10 mg per kg of body weight per day is most desirably employed. Variations may nevertheless occur depending upon the weight and condition of the persons being treated and their individual responses to said medicament, as well as on the type of pharmaceutical formulation chosen and the time period and interval during which such administration is carried out. In some instances, dosage levels below the lower limit of the aforesaid range may be more than adequate, while in other cases still larger doses may be employed without causing any harmful side effects, provided that such larger doses are first divided into several small doses for administration throughout the day. The active compounds can be administered alone or in combination with pharmaceutically acceptable carriers or diluents by any of the several routes previously indicated. More particularly, the active compounds can be administered in a wide variety of different dosage forms, ejj.. they may be combined with various pharmaceutically acceptable inert carriers in the form of tablets, capsules, transdermal patches, lozenges, troches, hard candies, powders, sprays, creams, salves, suppositories, jellies, gels, pastes, lotions, ointments, aqueous suspensions, injectable solutions, elixirs, syrups, and the like. Such carriers include solid diluents or fillers, sterile aqueous media and various non-toxic organic solvents. In addition, oral pharmaceutical compositions can be suitably sweetened and/or flavored. In general, the active compounds are present in such dosage forms at concentration levels ranging from about 5.0% to about 70% by weight.
For oral administration, tablets containing various excipients such as microcrystalline cellulose, sodium citrate, calcium carbonate, dicalcium phosphate and glycine may be employed along with various disintegrants such as starch (preferably corn, potato or tapioca starch), alginic acid and certain complex silicates, together with granulation binders like polyvinylpyrrolidone, sucrose, gelatin and acacia. Additionally, lubricating agents such as magnesium stearate, sodium lauryl sulfate and talc can be used for tabletting purposes. Solid compositions of a similar type may also be employed as fillers in gelatin capsules; preferred materials in this connection also include lactose or milk sugar, as well as high molecular weight polyethylene glycols. When aqueous suspensions and/or elixirs are desired for oral administration the active ingredient may be combined with various sweetening or flavoring agents, coloring matter and, if so desired, emulsifying and/or suspending agents, together with such diluents as water, ethanol, propylene glycol, glycerin and various combinations thereof.
For parenteral administration, a solution of an active compound in either sesame or peanut oil or in aqueous propylene glycol can be employed. The aqueous solutions should be suitably buffered (preferably pH greater than 8), if necessary, and the liquid diluent first rendered isotonic. These aqueous solutions are suitable for intravenous injection purposes. The oily
solutions are suitable for intraarticular, intramuscular and subcutaneous injection purposes. The preparation of all these solutions under sterile conditions is readily accomplished by standard pharmaceutical techniques well known to those skilled in the art.
It is also possible to administer the active compounds topically and this can be done by way of creams, a patch, jellies, gels, pastes, ointments and the like, in accordance with standard pharmaceutical practice.
The compounds of the invention may show advantageous potency as measured by functional activation of the α7/5-HT 3 chimeric receptor, or high selectivity over other ion channels, such as 5-HT 3 or the IKr channel, or a combination thereof. In one embodiment of the invention, such advantageous properties may be present in the (*) enantiomer and not in the (+) enantiomer of the compounds of the invention, or may be present to a greater extent in the (- ) enantiomer relative to the (+) enantiomer of the compounds of the invention. The high selectivity over the IKr channel is an exemplary advantage of the compounds of the invention.
The effectiveness of the active compounds in suppressing nicotine binding to specific receptor sites can be determined by the following procedure, which is a modification of the methods of Lippiello, P. M. and Fernandes, K. G. (in "The Binding of L-f H]Nicotine To A Single Class of High-Affinity Sites in Rat Brain Membranes", Molecular Pharm., 29, 448-54, (1986)) and Anderson, D. J. and Arneric, S. P. (in "Nicotinic Receptor Binding of 3 H-Cystisine, 3 H-Nicotine and 3 H-Methylcarmbamylcholine In Rat Brain", European J. Pharm., 253, 261-67 (1994)). Male Sprague-Dawley rats (200-300 g) from Charles River were housed in groups in hanging stainless steel wire cages and were maintained on a 12 hour light/dark cycle (7 a.m.- 7 p.m. light period). They received standard Purina Rat Chow and water ad libitum. The rats were killed by decapitation. Brains were removed immediately following decapitation. Membranes were prepared from brain tissue according to the methods of Lippiello and Fernandez (Molec. Pharmacol., 29, 448-454, (1986)) with some modifications. Whole brains were removed, rinsed with ice-cold buffer, and homogenized at 0° in 10 volumes of buffer (w/v) using a Brinkmann Polytron™ (Brinkmann Instruments Inc., Westbury, NY), setting 6, for 30 seconds. The buffer consisted of 50 mM Tris HCI at a pH of 7.5 at room temperature. The homogenate was sedimented by centrifugation (10 minutes; 50,000 x g; 0° to 4 0 C). The supernatant was poured off and the membranes were gently resuspended with the Polytron and centrifuged again (10 minutes; 50,000 x g; 0 0 C to 4°C). After the second centrifugation, the membranes were resuspended in assay buffer at a concentration of 1.0g/100mL The composition of the standard assay buffer was 50 mM Tris HCI, 120 mM NaCI, 5 mM KCI, 2 mM MgCI 2 , 2 mM CaCI 2 and had a pH of 7.4 at room temperature. Routine assays were performed in borosilicate glass test tubes. The assay mixture typically consisted of 0.9 mg of membrane protein in a final incubation volume of 1.0 mL Three sets of tubes were prepared wherein the tubes in each set contained 50μL of vehicle,
blank, or test compound solution, respectively. To each tube was added 200μL of [ 3 H]- nicotine in assay buffer followed by 750μL of the membrane suspension. The final concentration of nicotine in each tube was 0.9 nM. The final concentration of cytisine in the blank was 1μM. The vehicle consisted of deionized water containing 30μL of 1 N acetic acid per 50 mL of water. The test compounds and cytisine were dissolved in vehicle. Assays were initiated by vortexing after addition of the membrane suspension to the tube. The samples were incubated at 0° to 4° C in an iced shaking water bath. Incubations were terminated by rapid filtration under vacuum through Whatman GF/B™ glass fiber filters (Brandel Biomedical Research & Development Laboratories, Inc., Gaithersburg, MD) using a Brandel™ multi- manifold tissue harvester (Brandel Biomedical Research & Development Laboratories, Inc., Gaithersburg, MD). Following the initial filtration of the assay mixture, filters were washed two times with ice-cold assay buffer (5 ml each). The filters were then placed in counting vials and mixed vigorously with 20 ml of Ready Safe™ (Beckman, Fullerton, CA) before quantification of radioactivity. Samples were counted in a LKB Wallac Rackbeta™ liquid scintillation counter (Wallac Inc., Gaithersburg, MD) at 40-50% efficiency. All determinations were in triplicate.
Calculations: Specific binding (C) to the membrane is the difference between total binding in the samples containing vehicle only and membrane (A) and non-specific binding in the samples containing the membrane and cytisine (B), i.e., Specific binding = (C) = (A) - (B).
Specific binding in the presence of the test compound (E) is the difference between the total binding in the presence of the test compound (D) and non-specific binding (B), i.e., (E) = (D) - (B).
% Inhibition = (1-((E)/(C)) times 100. The compounds of the invention that were tested in the above assay preferably exhibit IC 50 values of less than 10μM. f 125 n-Bunqarotoxin binding to oc7 nicotinic receptors in GHACI cells: Membrane preparations were made for nicotinic receptors expressed in GH 4 CI cell line. Briefly, one gram of cells by wet weight were homogenized with a polytron in 25 mis of buffer containing 20 mM Hepes, 118 mM NaCI, 4.5 mM KCI, 2.5 mM CaCI 2 , 1.2 mM MgSO 4 , pH 7.5. The homogenate was centrifuged at 40,000 x g for 10 min at 4 0 C, the resulting pellet was homogenized and centrifuged again as described above. The final pellet was resuspended in 20 mis of the same buffer. Radioligand binding was carried out with [ 125 I] alpha-bungarotoxin from New England Nuclear, specific activity about 16 uCi/ ug, used at 0.4 nM final concentration in a 96 well microtiter plate. The plates were incubated at 37 0 C for 2 hours with 25 μl drugs or vehicle for total binding, 100 μl [ 125 I] Bungarotoxin and 125 μl tissue preparation. Nonspecific binding was determined in the presence of methyllycaconitine at 1
μM final concentration. The reaction was terminated by filtration using 0.5% Polyethylene imine treated Whatman GF/B™ glass fiberfilters (Brandel Biomedical Research & Development Laboratories, Inc., Gaithersburg, MD) on a Skatron cell harvester (Molecular Devices Corporation, Sunnyvale, CA) with ice-cold buffer, filters were dried overnight, and counted on a Beta plate counter using Betaplate Scint. (Wallac Inc., Gaithersburg, MD). Data are expressed as IC50's (concentration that inhibits 50% of the specific binding) or as an apparent Ki, IC50/1+[L]/KD. [L] = ligand concentration, KD = affinity constant for [ 125 I] ligand determined in separate experiment.
The compounds of the invention that were tested in the above assay preferably exhibit IC 50 values of less than 10μM. f 125 n-Bunqarotoxin binding to alphal nicotinic receptors in Torpedo electroplax membranes:
Frozen Torpedo electroplax membranes (100 μl) were resuspended in 213 mis of buffer containing 20 mM Hepes, 118 mM NaCI, 4.5 mM KCI, 2.5 mM CaCI 2 , 1.2 mM MgSO 4 , pH 7.5 with 2 mg/ml BSA. Radioligand binding was carried out with [ 125 I] alpha-bungarotoxin from New England Nuclear, specific activity about 16 uCi/ ug, used at 0.4 nM final concentration in a 96 well microtiter plate. The plates were incubated at 37 0 C for 3 hours with 25 μl drugs or vehicle for total binding, 100 μl [ 125 I] Bungarotoxin and 125 μl tissue preparation. Nonspecific binding was determined in the presence of alpha-bungarotoxin at 1 μM final concentration. The reaction was terminated by filtration using 0.5% Polyethylene imine treated GF/B filters on a Brandel cell harvester with ice-cold buffer, filters were dried overnight, and counted on a Beta plate counter using Betaplate Scint. Data are expressed as IC50's (concentration that inhibits 50% of the specific binding) or as an apparent Ki, IC50/1+[L]/KD. [L] = ligand concentration, KD = affinity constant for [ 125 I] ligand determined in separate experiment. The compounds of the invention that were tested in the above assay preferably exhibit IC 50 values of greater than 10 nM, more preferably greater than 100 nM. 5-HTr, Receptor Binding in NG-108 Cells Using 3H-LY278584: NG-108 cells endogenously express 5-HT 3 receptors. Cells are grown in DMEM containing 10% fetal bovine serum supplemented with L-glutamine (1:100). Cells are grown to confluence and harvested by removing the media, rinsing the flasks with phosphate buffered saline (PBS) and then allowed to sit for a 2-3 minutes with PBS containing 5 mM EDTA. Cells are dislodged and poured into a centrifuge tube. Flasks are rinsed with PBS and added to centrifuge tube. The cells are centrifuged for ten minutes at 40,000 x g (20,000 rpm in Sorvall SS34 rotor(Kendro Laboratory Products, Newtown, CT)). The supernatant is discarded (into chlorox) and at this point the remaining pellet is weighed and can be stored frozen (-80 degrees C) until used in the binding assay. Pellets (fresh or frozen - 250 mgs per 96 well plate) are homogenized in 50 mM Tris HCI buffer containing 2 mM MgCI 2 (pH 7.4)
using a Polytron homogenizer (setting 15,000 rpm) for ten seconds. The homogenate is centrifuged for ten minutes at 40,000 x g. The supernatant is discarded and the pellet resuspended with the Polytron in fresh ice-cold 50 mM Tris HCl containing 2 rnM MgCI 2 (pH 7.4) buffer and centrifuged again. The final pellet is resuspended in assay buffer (50 mM Tris HCI buffer (pH 7.4 at 37 0 C degrees) containing 154 mM NaCI,) for a final tissue concentration of 12.5 mg per mL buffer (1.25 X final concentration). Incubations were initiated by the addition of tissue homogenate to 96 well polypropylene plates containing test compounds that have been diluted in 10% DMSO/50 mM Tris buffer and radioligand (1 nM final concentration of 3H-LY278584). Nonspecific binding was determined using a saturating concentration of a known potent 5-HT 3 antagonist (10 μM ICS-205930). After an hour incubation at 37 0 C in a water bath, the incubation is ended by rapid filtration under vacuum through a fire-treated Whatman GF/B glass fiber filter (presoaked in 0.5% Polyethylene imine for two hours and dried) using a 96 well Skatron Harvester (3 sec pre-wet; 20 seconds wash; 15 seconds dry). Filters are dried overnight and then placed into Wallac sample bags with 10 mLs BetaScint. Radioactivity is quantified by liquid scintillation counting using a BetaPlate counter (Wallac, Gaithersburg, MD). The percent inhibition of specific binding is calculated for each concentration of test compound. An IC50 value (the concentration which inhibits 50% of the specific binding) is determined by linear regression of the concentration-response data (log concentration vs. logit percent values). Ki values are calculated according to Cheng & Prusoff - Ki = IC50/(1 + (L/Kd)), where L is the concentration of the radioligand used in the experiment and the Kd value is the dissociation constant for the radioligand determined in separate saturation experiments.
The compounds of the invention that were tested in the above assay preferably exhibit IC 50 values of greater than 10 nM, more preferably greater than 100 nM. Cell-based Assay for Measuring the EC50 of α7 nAChR Agonists
Construction and expression of the α7-5HT3 receptor:
The cDNA encoding the N-terminal 201 amino acids from the human α7 nAChR that contain the ligand binding domain of the ion channel was fused to the cDNA encoding the pore forming region of the mouse 5HT 3 receptor as described by Eisele JL, et al., "Chimaeric nicotinic-serotonergic receptor combines distinct ligand binding and channel specificities," Nature (1993), Dec. 2;366(6454):479-83, and modified by Groppi, et al., WO 00/73431. The chimeric α7-5HT 3 ion channel was inserted into pGS175 and pGS179 which contain the resistance genes for G-418 and hygromycin B, respectively. Both plasmids were simultaneously transfected into SH-EP1 cells and cell lines were selected that were resistant to both G-418 and hyrgromycin B. Cell lines expressing the chimeric ion channel were identified by their ability to bind fluorescent α-bungarotoxin on their cell surface. The cells with the highest amount of fluorescent α-bungarotoxin binding were isolated using a
Fluorescent Activated Cell Sorter (FACS). Cell lines that stably expressed the chimeric cc7- 5HT 3 were identified by measuring fluorescent α-bungarotoxin binding after growing the cells in minimal essential medium containing nonessential amino acids supplemented with 10% fetal bovine serum, L-glutanπine, 100 units/ml penicillin/streptomycin, 250 ng/mg fungizone, 400 μg/ml hygromycin B, and 400 μg/ml G-418 at 37° C with 6% CO 2 in a standard mammalian cell incubator for at least 4 weeks in continuous culture.
Assay of the activity of the chimeric α7-5HT 5 receptor
To assay the activity of the oc7-5HT 3 ion channel, cells expressing the channel were plated into each well of either a 96 or 384 well dish (Corning #3614) and grown to confluence prior to assay. On the day of the assay, the cells were loaded with a 1:1 mixture of 2 mM Calcium Green 1, AM (Molecular Probes) dissolved in anhydrous DMSO and 20% pluronic F- 127 (Molecular Probes). This solution was added directly to the growth media of each well to achieve a final concentration 2 μM. The cells were incubated with the dye for 60 min at 37° C and is washed with a modified version of Earle's balanced salt solution (MMEBSS) as described in WO 00/73431. The ion conditions of the MMEBSS was adjusted to maximize the flux of calcium ion through the chimeric α7-5HT 3 ion channel as described in WO 00/73431. The activity of compounds on the chimeric α7-5HT 3 ion channel was analyzed on FLIPR. The instrument was set up with an excitation wavelength of 488 nanometers using 500 milliwatts of power. Fluorescent emission was measured above 525 nanometers with an appropriate F-stop to maintain a maximal signal to noise ratio. Agonist activity of each compound was measured by directly adding the compound to cells expressing the chimeric oc7-5HT 3 ion channel and measuring the resulting increase in intracellular calcium that is caused by the agonist-induced activation of the chimeric ion channel. The assay is quantitative such that concentration-dependent increase in intracelluar calcium is measured as concentration-dependent change in Calcium Green fluorescence. The effective concentration needed for a compound to cause a 50% maximal increase in intracellular calcium is termed the EC 50 .
The compounds of the invention that were tested in the above assay preferably exhibit IC 50 values of less than 10μM, more preferably less than 1 μM. The following experimental examples illustrate but do not limit the present invention.
In the examples, commercial reagents were used without further purification. Purification by chromatography was done on prepacked silica columns from Biotage (Dyax Corp, Biotage Division, Charlottesville, VA). Melting points (mp) were obtained using a Mettler Toledo FP62 melting point apparatus (Mettler-Toledo, Inc., Worthington, OH) with a temperature ramp rate of 10°C/min and are uncorrected. Proton nuclear magnetic resonance ( 1 H NMR) spectra were recorded in deuterated solvents on a Varian INOVA400 (400 MHz) spectrometer (Varian NMR Systems, Palo Alto, CA). Chemical shifts are reported in parts per million (ppm, δ)
relative to Me 4 Si (δ 0.00). Carbon-13 nuclear magnetic resonance ( 13 C NMR) spectra were recorded on a Varian INOVA400 (100 MHz). Chemical shifts are reported in ppm (δ) relative to the central line of the 1:1:1 triplet of deuterochloroform (δ 77.00), the center line of deuteromethanol (δ 49.0) or deuterodimethylsulfoxide (δ 39.7). The number of carbon resonances reported may not match the actual number of carbons in some molecules due to magnetically and chemically equivalent carbons and may exceed the number of actual carbons due to conformational isomers. Mass spectra (MS) were obtained using a Waters ZMD mass spectrometer using flow injection atmospheric pressure chemical ionization (APCI) (Waters Corporation, Milford, Mass). Gas chromatography with mass detection (GCMS) were obtained using a Hewlett Packard HP 6890 series GC system with a HP 5973 mass selective detector and a HP-1 (crossϋnked methyl siloxane) column (Agilent Technologies, Wilmington, DE). LC-MS spectra were recorded on a Water ZQ 1525μ Mass Spectrometry with Electrospray (ESI+) and a Binary HPLC Pump at 25°C using gradient elution. Solvent A is 98% water, 2% acetonitrile with 0.01% formic acid, Solvent B is 100% acetonitrile with 0.005% formic acid. A linear gradient over 3.55 min was used starting at 95%A, 5%B and ending at 0%A, 100%B with a flow rate of 1 mL/min.
EXAMPLES
Intermediate 1
5-Methyl-2-(methylthio)f1,31oxazolor4,5-blpyridine K 2 CO 3 was added to a stirred mixture of 5-methyl[1,3]oxazolo[4,5-b]pyridine-2-thiol (17.7 g, 0.106 mol) and DMF (250 mL) under argon. Then methyl iodide (5.61 mL, 0.09 mol) was added dropwise. The mixture was stirred at room temperature for 2 h and evaporated. Water (200 mL) and chloroform (200 mL) were added to the residue, and the mixture was shaken. The organic layer was separated, and the aqueous layer was extracted with chloroform (3 x 200 mL). The combined organic layers were dried over Na 2 SO 4 and evaporated. The residue was purified by chromatography on silica gel (200 g, 63-100 μm, hexane→hexane/ethyl acetate 7:3) to furnish 5-methyl-2-(methylthio)[1,3]oxazolo[4,5- b]pyridine (10 g, 55%) as white crystals. 1 H-NMR-data (DMSO-d6): 7.93 (1H), 7.18 (1H), 2.78 (3H), 2.54 (3H). LCMS retention time = 2.7 min, m/z 181.1 (M+H) + 5-Methviri.31oxazolor4.5-bipyridine-2-thiol
KOH (14 g, 0.25 mol) was added to a stirred mixture of 2-amino-6-methylpyridin-3-ol (15.5 g, 0.125 mol) in absolute EtOH (500 mL) under an argon atmosphere. Carbon disulfide (16 mL, 0.25 mol) was added and the reaction mixture was heated to reflux in argon for 16 h. The reaction mixture was evaporated to dryness, water (250 mL) was added followed by acetic acid (20 mL) until the pH was ~5. The formed precipitate was separated by filtration, washed with water, and dried to afford 17.7 g (85%) of 5-methyl[1,3]oxazolo[4,5-b]pyridine-2- thiol as a yellow crystalline solid. 1 H-NMR-data (DMSO-d6): 7.70 (1H), 7.07 (1H), 2.46 (3H).
2-amino-6-methylpyridin-3-ol
A mixture of 3-hydroxy-6-methyl-2-nitropyridine (20 g, 0.129 mol) and 10% Pd/C (4 g) was stirred vigorously in a flow of hydrogen for 20 h. The catalyst was filtered off, washed with methanol, and the filtrate was evaporated to dryness to provide 15.5 g (97%) of a brown crystalline solid. 1 H-NMR-data (DMSO-d6): 9.0 (1H), 6.72 (1H) 1 6.21 (1H), 5.29 (2H), 2.15 (3H).
Intermediate 2
(RH .Φ-Diaza-bicvclore^.iloctane dihvdrochloride
A mixture of (5R)-4-benzyl-1 ,4-diazabicyclo[3.2.1]octane hydrochloride (800 mg, 2.9 mmol) and 5% Pd/C (100 mg) in MeOH (10 mL) was stirred in a flow of hydrogen for 24 h.
The catalyst was filtered off and washed with methanol. The filtrate was evaporated to dryness. The residual crystals were washed with isopropanol to afford (5S)-1,4- diazabicyclo[3.2.1]octane dihydrochloride (320 mg, 60%) as highly hygroscopic crystals. MS m/z 113.1 (M + H) + . 1 H-NMR (CD 3 OD): 4.36 (1 H), 3.9 - 3.6 (1 H), 3.47 - 3.72 (7H), 2.37 - 2.61 (2H).
(5R)-4-Benzyl-1 ,4-diazabicvclo[3.2.πoctane hydrochloride
Triphenylphosphine (2.36 g, 9 mmol) was added to a stirred solution of 2-[(2R)-1- benzylpiperazin-2-yl]ethanol (1.3 g, 5.9 mmol) in THF (90 mL) under argon. The mixture was cooled to 0 0 C, and a solution of DIAD (1.67 mL, 7.8 mmol) in THF (5 mL) was added dropwise under vigorous stirring for 15 min. The mixture was stirred for 12 h at room temperature and evaporated. The residue was dissolved in ether (50 mL). Water (25 mL) and
5 N H 2 SO 4 (0.9 mL) were added. The mixture was shaken, and the organic layer was separated. Then 10 N NaOH was added to the aqueous layer to attain pH -11-12, and the solution was extracted with ether (3 x 25 mL). The combined ethereal layers were dried with Na 2 SO 4 , evaporated to dryness, and co-evaporated with dioxane. The residue was dissolved in ether (10 mL) under heating, and 4 M HCI in dioxane (4 mL) was added under stirring. The formed precipitate was separated by filtration, washed with ether, and dried to give 820 mg of light-yellow highly hygroscopic crystals. MS m/z (M + H) + 203.1. 1 H-NMR (DMSO-d6) for free amine: 7.19 - 7.33 (5H), 3.37 (1H), 3.30 (1 H), 3.03 (1H), 2.60 - 2.80 (4H), 2.44 (1H), 2.29 - 2.36 (2H), 2.20 (1 H), 1.90 - 1.98 (1 H), 1.29 - 1.39 (1 H).
2-r(2R)-1-Benzylpiperazin-2-vπethanol
A solution of methyl [(2R)-1-benzyl-3,6-dioxopiperazin-2-yl]acetate (3.6 g, 0.013 mol) in absolute THF (30 mL) was added dropwise to a stirred suspension of LiAIH 4 (2.4 g, 0.063 mol) in THF (20 mL) under argon. The mixture was heated at reflux for 3 h and cooled to room temperature. Then 10 N NaOH (2.5 mL) and water were added with stirring until a solid residue (~2 mL) formed. The mixture was filtered and the filtrate was evaporated to dryness and co-evaporated with CCI 4 . The residue was purified by chromatography (25 g of silica gel,
CHCIa-→CHCIs/MeOH 7:3) to afford 1.3 g of a yellow oil. MS m/z 221.1 (M + H) + . 1 H-NMR (DMSO-d6): 7.18 - 7.34 (5H), 3.92 (1H), 3.42 - 3.53 (2H), 3.21 (1H), 2.94 (1H), 2.75 - 2.81 (1H), 2.65 - 2.70 (1H), 2.47 - 2.65 (3H), 2.14 (1H), 1.62 - 1.85 (2H).
Methyl r(2R)-1-benzyl-3,6-dioxopiperazin-2-vπacetate Dimethyl N-benzyl-D-aspartate hydrochloride (5 g, 0.017 mol) was added to a suspension of NaHCO 3 (11 g, 0.13 mol) in a mixture of water (30 mL) and ether (30 mL) under vigorous stirring. The reaction mixture was stirred for 10 min until the gas evolution ceased. Then chloroacetyl chloride (2.76 mL, 0.034 mol) was added dropwise under vigorous stirring. After 1 h, the layers were separated, and the aqueous one was extracted with ether (2 * 50 mL). The combined organic layers were washed with brine, dried over sodium sulfate and filtered. Dioxane was added and the mixture was concentrated under reduced pressure. A suspension of NaN 3 (3.4 g, 0.052 mol) in a mixture of DMSO (40 mL) and water (4 mL) was added to the residue under vigorous stirring. The mixture was heated to 70 °C for 10 min and then cooled rapidly with a ice-water bath. Water (100 mL) and ether (100 mL) were added, and the layers were separated. The aqueous layer was extracted with ether (2 x 100 mL). The combined ethereal layers were washed with water and brine, and dried over sodium sulfate. Then triphenylphosphine (6.7 g, 0.0255 mol) was added to the obtained solution, and the mixture was stirred for 20 h at room temperature. The mixture was evaporated to dryness, and THF (30 mL) and water (3 mL) were added. The resulting mixture was heated at reflux for 2 h, concentrated under reduced pressure, dioxane was added and the solution was concentrated once more. The residue was purified by chromatography (200 g of silica gel, CCI 4 →CHCI 3 -→CHCI 3 /Me0H 9:1) to furnish 4.0 g of a light-yellow solid. MS m/z (M + H) + 277.1. 1 H-NMR (DMSO-d6): 8.25 (d, 1H), 7.21 - 7.3 (m, 5H), 4.85 (d, 1H), 4.29 (d, 1H), 4.10 (d, 1H), 4.00 (dd, 1H), 3.80 (dd, 1H), 3.53 (s, 3H), 2.90 (dd, 1H), 2.84 (dd, 1H). Dimethyl N-Benzyl-D-aspartate hydrochloride
Method A:
Dimethyl-D-aspartate (10 g, 0.05 mol), triethylamine (7 mL, 0.05 mol), and NaB(OAc) 3 H (15.9 g, 0.075 mol) were mixed in absolute dichloromethane (100 mL). Benzaldehyde (5.6 mL, 0.055 mol) was added dropwise under vigorous stirring for 30 min. The mixture was stirred for 20 h at room temperature. A saturated solution of K 2 CO 3 (50 mL) and water (50 mL) were added. The layers were separated, and the aqueous one was extracted with dichloromethane (3 x 100 mL). The combined organic layers were washed with a saturated solution of K 2 CO 3 , dried with Na 2 SO 4 , evaporated, and coevaporated with dioxane. The residue was dissolved in ether (150 mL), and 4 M HCI in dioxane (13 mL) was added. The resulting precipitate was separated by filtration, washed with ether, and dried to afford 13.3 g of a white solid. 1 H-NMR-data (DMSO-d6): 10.3 (s, 1H), 9.95 (s, 1H), 7.55-7.6
and 7.41-7.47 (m, 5H), 4.32 (dd, 1H), 4.23 (s, 2H), 3.75 (s, 3H), 3.65 (s, 3H), 3.24 (dd, 1H), 3.07 (dd, 1H).
Method B:
Dimethyl-D-aspartate (3.2 g, 16.3 mmol), and triethylamine (3.4 mL, 25 mmol) were mixed in absolute THF (30 mL). Benzyl bromide (1.93 ml, 16.3 mol) was added and the mixture was stirred for 20 h at 65 - 70° C. The mixture was concentrated under reduced pressure, and was partitioned between a mixture of water (50 mL), ether (50 mL) and saturated aqueous potassium carbonate (50 mL). The layers were separated, and the aqueous layer was extracted with ether (50 mL). The combined organic layers were washed with brine, dried over sodium sulfate, and concentrated under reduced pressure. The residue was dissolved in ether (150 mL), and 4 M HCI in dioxane (6 mL) was added. The resulting precipitate was separated by filtration, washed with ether, and dried to afford the title compound (2.8g, 48%) as white crystals. 1 H-NMR-data (DMSO-d6): 10.3 (s, 1H), 9.95 (s, 1 H),
7.55-7.6 and 7.41-7.47 (m, 5H), 4.32 (dd, 1 H), 4.23 (s, 2H), 3.75 (s, 3H), 3.65 (s, 3H), 3.24 (dd, 1H), 3.07 (dd, 1H).
Intermediate 3
(1-Benzyl-3-oxo-piperazin-2-yl)-acetic acid ethyl ester
To (3-oxo-piperazin-2-yl)-acetic acid ethyl ester (100 grams, 0.54 mol) in 500 mL of anhydrous ethanol was added 70.5 mL (0.59 mol) of benzyl bromide. The mixture was stirred at 25 0 C for 3 days. The mixture was then treated with 16 mL (90 mmol) of (J-Pr) 2 NEt and 6 mL (50 mmol) of benzyl bromide and stirred at 45 0 C for three more hours. The solvent was evaporated at reduced pressure and the residue partitioned between 1N HCI and ethyl acetate. The aqueous phase was washed with ethyl acetate twice, and then it was cooled with ice, made basic with 2 N aqueous sodium hydroxide and was extracted three times with ethyl acetate. The combined organic phases were washed with brine, dried over MgSO 4 and concentrated under reduced pressure. The residual oil crystallized upon treatment with 300 mL of diethyl ether. The precepitate was collected by filtration and washed with ether. Drying in a stream of air gave 66 grams (44%) of an off-white solid. H-NMR (DMSO-d6) δ 7.4 - 7.2
(m, 5H), 6.4 - 6.6 (bs, 1H), 4.3 - 4.1 (m, 2H), 3.97 (d, 1H), 3.50 (t, 1H), 3.41 (d, 1H), 3.4 - 3.3 (m, 2H), 3.1 - 2.8 (m, 3H), 2.1 - 1.9 (m, 1H), 1.25 (t, 3H). MS (APCl) 277.4 (M+H).
Intermediate 4 3-amino-5-chloropyridin-2-ol
To a 500 mL round bottom flask charged with 5-chloro-2-hydroxy-3-nitro pyridine (4.9 g, 28.7 mmol), Fe (7.2 g, 129.7 mmol) and CaCI 2 (2.86 g, 25.8 mmol) was added 4:1 EtOHiH 2 O (50 mL) and the mixture was heated at reflux for 2h. After cooling to room temperature the mixture was filtered through a celite pad and washed with ethanol/water.
The dark filtrate was evaporated and dried in vacuum for 2h to afford 3-amino-5-chloropyridin- 2-ol. LCMS: m/e 145 (M+1).
Intermediate 5
2-Fluoro-6-methylDhenylboronic acid A 500 mL 3-neck round bottom flask, equipped with a magnetic stirring bar, thermometer, and nitrogen gas inlet, was charged with 2-bromo-1-fluoro-3-methylbenzene (6.95 g, 36.80 mmol), B(O 1 Pr) 3 (10.38 g, 12.7 mmol), and 60 mL of anhydrous ether under nitrogen. The mixture was cooled to -70 0 C with a dry ice/acetone bath, then a solution of 1 BuLi (1.7 M in pentane, 47.6 mL, 80.96 mmol) was added dropwise keeping internal temperature below -50 0 C. The mixture was warmed to -5 0 C and stirred for 30 min., then 35 mL of 5M HCI was added and stirred at room temperature for an additional 30 min. The mixture was extracted with MTBE (3x70 mL), the extract was washed with brine (2x50 mL), and evaporated under reduced pressure keeping the temperature below 20 0 C. The resulting residue was dissolved in a mixture of 100 mL of aqueous 2M NaOH and 50 mL of ether. The mixture was washed with ether (3x50 mL), and the aqueous layer was carefully acidified with cone. HCI to pH 1 in an ice bath. The resulting precipitate was collected by vacuum filtration, washed with cold water (2x10 mL), and dried under vacuum at room temperature to give 2- fluoro-6-methylphenylboronic acid (1.63 g) as a tan solid. M. P 110-112 0 C; 1 H NMR (300 MHz, DMSO-d 6 ): δ 8.40 (2H), 7.21 (1H), 6.96 (1H), 6.87 (1H), 2.30 (3H). 2-Bromo-1 -fluoro-3-methylbenzene
A 200 mL round bottom flask, equipped with a magnetic stirring bar, was charged with 2-bromo-3-methylaniline (12.2 g, 65.58 mmol), 113 mL of water, and 17.5 mL of cone. HCI. The mixture was briefly heated to dissolve the solids, then cooled to -10 0 C. To the resulting suspension a solution of NaNO 2 (5.06 g, 73.38 mmol) in 13 mL of water was added dropwise at -5 to -10 0 C. Then 16.8 mL of 60% HPF 6 in water (122.23 mmol) was added, and the resulting suspension was stirred for 30 min. The precipitate was collected by vacuum filtration, washed with ice-cold water (2x30 mL), then with an ice-cold MeOH/ether (16mL/64mL) mixture and dried under vacuum at room temperature for 20 h to give 20.46 g (91%) of diazonium salt. The dry salt was thermally decomposed in 5 g batches in a small (25 mL) vacuum distillation apparatus under vacuum (2 mm Hg), at 165-175 0 C, with receiving flask cooled with a dry ice/acetone mixture. The collected fractions were combined to give 7.85 g of 2-bromo-1 -fluoro-3-methylbenzene as a colorless oil. 1 H NMR (300 MHz, CDCI 3 ): δ 7.16 (1H), 6.92-7.04 (2H), 2.43 (3H).
2-Bromo-3-methylaniline A 500 mL 3-neck RB flask, equipped with a magnetic stirring bar, reflux condenser and addition funnel, was charged with 2-bromo-1-methyl-3-nitrobenzene (15.0 g, 69.4 mmol), and 90 mL of EtOH. The mixture was cooled to 10 0 C with an ice bath, and a solution of SnCI 2
(64.2 g, 339 mmol) in 130 ml_ of cone. HCI was added dropwise over 1 h keeping the temperature between 15 and 18 °C. The resulting suspension was stirred at room temperature for 1 h, then heated to 60 0 C for 15 min, and cooled to 0 0 C with an ice bath. The mixture was carefully basified with 10 M NaOH to pH 14 keeping temperature below 30 0 C. Then the mixture was diluted with 300 mL of water and extracted with ether (5 x 200 mL). The ether extract was dried over Na 2 SO 4 and evaporated to give 17 g of 2-bromo-3- methylaniline as a colorless oil. LCMS m/z (M+H) + 186.0. 1 H NMR (300 MHz, DMSO-d 6 ): δ 6.93 (1H), 6.63 (1H), 6.96 (1 H), 5.23 (2H), 2.26 (3H).
Intermediate 6 θ-Cvano^-fluorophenylboronic acid
A 500 mL 3-neck, round bottom flask, equipped with a magnetic stirring bar, addition funnel, and nitrogen gas inlet, was charged with 3-fluorobenzonitrile (10.0 g, 82.56 mmol), triisopropyl borate (28.5 mL, 23.3 g, 123.84 mmol), and 100 mL of anhydrous THF. The mixture was cooled to -50 0 C under nitrogen and a solution of LDA in THF/hexane (86.7 mmol, freshly prepared from 8.77 g of diisopropylamine in 20 mL of THF and 54.2 mL of a 1.6 M solution of n-BuLi in hexane) was added dropwise over a period of 1 h. The mixture was warmed to -5 0 C and stirred for 30 min. Then 70 mL of 5 N HCI aq and 50 mL of MTBE was added and stirred for 30 min at room temperature. The mixture was extracted with MTBE (4x100 mL), the MTBE extract was washed with brine (2x100 mL), evaporated under reduced pressure keeping the temperature below 20 0 C, and dried under vacuum at room temperature to give 12.16 g (89 %) of δ-cyano^-fluorophenylboronic acid as a white solid. LCMS m/z (M+H) + : 165.8. 1 H NMR (300 MHz, DMSO-d 6 ): δ 8.92 (2H), 7.65 (1H), 7.57 (1H), 7.49 (1H).
EXAMPLE 1 (RU-) 2-(1.4-Diazabicvclor3.2.1loct-4-viπi .31oxazolor4.5-b1pyridine A 8 mL screw cap vial with a screwtop cap, equipped with a magnetic stirring bar, was charged with 2-(methylthio)[1,3]oxazolo[4,5-b]pyridine (120 mg, 0.723 mmol), (+)-1,4- diazabicyclo[3.2.1]octane dihydrochloride (134 mg, 0.723 mmol), NaHCO 3 (134 mg, 1.59 mmol), and 1 mL of isopropanol. The vial was closed and the mixture was stirred at 85 0 C. (Note: the pressure was released by opening and closing back the vial during first hour of the reaction). After 20 h, the mixture was evaporated under vacuum, the resulting residue was suspended in dichloromethatne (2 mL), the insoluble material was removed by filtration, and the filtrate was purified by column chromatography (silica gel, dichlormethane 94%, MeOH 5 %, NH 4 OH aq . 1%) to give 98 mg (59 %) of (-)-2-(1,4-diazabicyclo[3.2.1]oct-4- yl)[1 ,3]oxazolo[4,5-b]pyridine as a tan hygroscopic solid. LCMS (M+H): 231.3. 1 H NMR (300 MHz, CDCI 3 ): δ 8.23 (1H), 7.42 (1H), 6.91 (1H), 4.90 (1H), 3.94 (1H), 3.42 (1H), 3.06-3.21 (4H), 2.88 (1H), 2.71 (1H), 1.08-2.19 (2H). The product was dissolved in 2 mL of MeOH, then 1 mL of 2M HCI in ether was added. The mixture was evaporated and dried under vacuum for
24 h to give 124 mg of (-) 2-(1,4-diazabicyclo[3.2.1]oct-4-yl)[1,3]oxazolo[4,5-b]pyridi ne dihydrochloride. M. P. >250 0 C dec. [α] D = -71.947 (c=0.524, MeOH). LCMS m/z (M+H): 231.3.
2-(Mβthv)thio)ri,31oxazolor4,5-biPyridine A 250 mL RB flask, equipped with a magnetic stirring bar and nitrogen gas inlet, was charged with [1,3]oxazolo[4,5-b]pyridine-2(3H)-thione (5.00 g, 32.9 mmol), potassium carbonate (4.54 g, 32.8 mmol), and 80 mL of anhydrous DMF. Then iodomethane (2.45 mL, 5.57 g, 39.3 mmol) was added dropwise to the stirring reaction mixture under nitrogen. The mixture was stirring for 2 h, then diluted with 300 mL of water, and extracted with EtOAc (4x150 mL). The combined organic extract was washed with water (3x100 mL), then with brine (100 mL), dried over Na 2 SO 4 and evaporated to give 4.53 g (83 %) of 2- (methylthio)[1,3]oxazolo[4,5-b]pyridine as a tan solid. LCMS m/z (M+H): 167.1. 1 H NMR (300 MHz, DMSO-d 6 ): δ 8.44 (1H), 8.08 (1H), 7.35 (1H), 2.81 (3H). π,31Oxazolof4.5-blpyridine-2(3H)-thione A 500 mL RB flask, equipped with a magnetic stirring bar, reflux condenser, and nitrogen gas inlet, was charged with 2-amino-3-hydroxypyridine (10.0 g, 90.8 mmol), 220 mL of anhydrous EtOH, and potassium ethyl xanthate (29.1 g, 182 mmol). The mixture was heated under reflux under nitrogen for a period of 18 h. Then the mixture was cooled to room temperature, the solvent was evaporated under vacuum, and the residue was dissolved in 250 mL of water. The aqueous solution was acidified with AcOH to pH 5, and the resulting precipitate was collected by vacuum filtration, washed with water (3x60 mL), and dried under vacuum to give 13.1 g (95 %) of [1,3]oxazolo[4,5-b]pyridine-2(3H)-thione as a tan solid. LCMS m/z (M+H): 153.2. 1 H NMR (300 MHz, DMSO-d 6 ): δ 14.52 (1H), 8.23 (1 H), 7.88 (1H), 7.35 (1H). EXAMPLE 2
(SVt+^-dΛ-DiazabicvclorS.Σ.IlocM-vDπ.SioxazolorδΛ-bi pyridine A 20 mL vial was charged with (-)-1,4-diazabicyclo[3.2.1]octane dihydrochloride (134 mg, 0.72 mmol), 2-(methylthio)[1 ,3]oxozolo[5,4-b]pyridine (132 mg, 0.79 mmol), NaHCO 3 (168 mg, 2 mmol, 4 equiv.) and i-PrOH (5 mL). The vial was tightly capped with a screw cap and was heated at 85-90 0 C for 24 h. The solvent was evaporated under vacuum and the residue was directly charged onto a silica gel column. Elution of the column with 9:1 methylene chloride:MeOH containing 1 mL/L NH 4 OH gave 40 mg of a sticky solid. LC-MS (231, M+1). The solid was dissolved in 2 mL of MeOH, and then 1 mL of 2M HCI in ether was added. After stirring the mixture for 10 min the solvent was removed and 4 mL of methylene chloride was added. The resulting suspension was shaken for 5 min and then the solvent was removed under reduced pressure. The residue was dried under vacuum to give the hydrochloride salt
of (+)-2-(1,4diazabicyclo[3.2.1]oct-4-yl)[1,3]oxazolo[5,4-b]pyr idine as a white solid. LCMS: m/e 231.4 (m+1). [α] D : +65.711 (C = 0.202 g/mL, MeOH).
2-(Methylthio)F1.3loxozoloF5,4-blpyridine
A 100 mL round bottom flask charged with [1 ,3]oxazolo[5,4-b]pyridine-2(1H)-thione (1.62 g, 10.6 mmol), K 2 CO 3 (1.61 g, 11.6 mmol) and DMF (30 mL) was stirred for 10 minutes at room temperature. Then MeI (1.81 g, 12.78 mmol, 0.79 mL) was added in one portion.
The reaction mixture was stirred under N 2 for 3h at room temperature. Water (20 mL) was added and the mixture was extracted with EtOAc (3 x 50 mL). The combined organics were washed with water (2 x 100 mL), brine (100 mL) and then dried over Na 2 SO 4 . Evaporation of the solvent gave 2-(methylthio)[1,3]oxozolo[5,4-b]pyridine (1.54 g). LC/MS: 167, (M+1). 1 H
NMR (300 MHz, CDCI 3 ): δ 2.76 (3H), 7.20 (1H), 7.80 (1H), 8.51 (1H).
A 250 mL round bottom flask was charged with 3-aminopyridin-2-ol (1.5 g, 13.6 mmol) and anhydrous THF (50 mL). Thiophosgene (1.86 g, 16.3 mmol) was slowly added. The resulting suspension was stirred for 1h before neutralizing to pH 5 with 2N NaOH. The solvent was removed under reduced pressure and then water (20 mL) was added. The resulting solid was filtered and washed thoroughly with water and dried under vacuum to afford a brown solid (2 g, 84%). 1 H NMR (300 MHz, CDCI 3 ): δ 6.29 (1H), 7.35 (2H).
3-Aminopyridin-2-ol To a 500 mL round bottom flask charged with 2-hydroxy-3-nitro pyridine (2 g, 14.2 mmol) was added 2:1 EtOH:MeOH (120 mL). The mixture was stirred for 10 minutes while flushing with N 2 gas. 10% Pd/C (200 mg) was added as a suspension in ethyl acetate (5 mL) and the heterogeneous reaction mixture was stirred under H 2 gas for 16 h. The mixture was purged with nitrogen and filtered. The filtrate was evaporated and dried to give 3- aminopyridn-2-ol as a pink solid (1.31 g, 84%). Mp: 124-125 0 C. LC/MS m/z 111 (M+1).
EXAMPLES 3 - 7 The following examples were prepared according to the method of example 2:
EXAMPLE 8
(SH+) 6-Chloro-2-(1.4-diazabicvclor3.2.noct-4-yl)f1 ,31oxazolof4.5-bipyridine dihydrochloride A 8 mL screw cap vial with a screwtop cap, equipped with a magnetic stirring bar, was charged with (S)-(+)-2-(1 ,4-diazabicyclo[3.2.1]oct-4-yl)[1,3]oxazolo[4,5-b]pyridine (100 mg, 0.43 mmol), N-chlorosuccinimide (58 mg, 0.43 mmol), and 2 mL of chloroform. The vial was closed and the mixture was stirred at 75 0 C for 16h. Then another 51 mg (0.38 mmol) of N-chlorosuccinimide was added and stirred at 75 0 C for 16h. Then the mixture was cooled to room temperatrue, filtered, and evaporated. The residue was purified by column chromatography (silica gel, dichloromethane 94%, MeOH 5 %, NH 4 OH aq . 1%) to give 43 mg of (S)-(+) 6-chloro-2-(1,4-diazabicyclo[3.2.1]oct-4-yl)[1,3]oxazolo[4,5 -b]pyridine as a tan hygroscopic solid. The product was dissolved in 1 mL of MeOH, then 0.163 mL of 2M HCI in ether was added. After standing overnight the resulting precipitate was collected by filtration, and dried under vacuum to give 23.0 mg of (SM+) 6-chloro-2-(1,4-diazabicyclo[3.2.1]oct-4- yl)[1 ,3]oxazolo[4,5-b]pyridine dihydrochloride. MP. >250 0 C dec. [α] D = +58.696 (c=0.361, MeOH), LCMS m/z (M+H) 264.8.
EXAMPLE 9
(R)-(-) 6-Chloro-2-(1,4-diazabicvclor3.2.noct-4-yl)ri.31oxazolor4.5- blpyridine dihvdrochloride (R)-(-) 6-Chloro-2-(1 ,4-diazabicyclo[3.2.1]oct-4-yl)[1 ,3]oxazolo[4,5-b]pyridine dihydrochloride was prepared according to the example 8 starting from (R)-(-) 2-(1,4- diazabicyclop^.ilocM-yOπ.SloxazolorAδ-blpyridine. m.p. >250 0 C dec. [α] D = -67.460 (c=0.252, MeOH), LCMS m/z (M+H) + 264.8.
EXAMPLE 10 (SH+) 6-bromo-2-(1 ,4-diazabicvclor3.2.πoct-4-yl)π ,31oxazolor4,5-b1pyridine dihvdrochloride A 20 mL screw cap vial with a septum cap, equipped with a magnetic stirring bar, was charged with (S)-(+)-2-(1,4-diazabicyclo[3.2.1]oct-4-yl)[1,3]oxazolo[4,5- b]pyridine (200 mg, 0.87 mmol), sodium acetate (855 mg, 10.4 mmol), and 8 mL of 50% AcOH aq . The vial was
closed and the mixture was stirred at room temperature until everything was dissolved. Then bromine (49 uL, 153 mg, 0.955 mmol) was added dropwise and the mixture was stirred for 15 min. Then another drop of bromine was added. After stirring 10 min one more drop of bromine was added. After 10 min the mixture was cooled with an ice-bath and basified with 12 N NaOH to pH 14. Then the mixture was extracted with EtOAc (9x3 mL), the extract was dried over Na 2 SO 4 and evaporated to give 186 mg (69 %) of (S)-(+) 6-bromo-2-(1 ,4- diazabicycloβ.Z.ilocM-yOπ.Sloxazolo^.S-blpyridine as a tan hygroscopic solid; m.p. 122- 124 0 C. LCMS (M+H): 309.0. 1 H NMR (300 MHz, CDCI 3 ): δ 8.29 (1H), 7.55 (1H), 4.84 (1H), 3.90 (1H), 3.41 (1H), 4.05-3.18 (4H), 2.85 (1H), 2.67 (1H), 1.99-2.15 (2H). The product (86 mg) was dissolved in 1 mL of MeOH and 0.30 mL of 2M HCI in ether was added. After standing overnight a precipitate formed and was collected by filtration and dried under vacuum to give 72.5 mg of (S)-(+) 6-bromo-2-(1,4-diazabicyclo[3.2.1]oct-4-yl)[1,3]oxazolo[4,5- b]pyridine dihydrochloride as a yellow solid, m.p. >250 0 C dec. [α] D = +66.875 (c=0.160, MeOH), LCMS (M+H) m/z 309.0. EXAMPLE 11
(RH-)6-bromo-2-(1,4-diazabicvclof3.2.1loct-4-yl)f1,31oxaz olor4,5-blpyridine dihydrochloride
(R)-(-)6-bromo-2-(1 ,4-diazabicyclo[3.2.1]oct-4-yl)[1 ,3]oxazolo[4,5-b]pyridine dihydrochloride was prepared according to the procedure of example 10 starting from (R)-{-)- 2-(1,4-diazabicyclo[3.2.1]oct-4-yl)[1,3]oxazolo[4,5-b]pyridi ne. Yellow solid; m.p. >250 0 C dec. [α] D = -61.446 (c=0.166, MeOH), LCMS (M+H) m/z 308.9.
EXAMPLE 12
(RH-) 2-(1 ,4-diazabicvclor3.2.noct-4-yl)-6-phenylf1.31oxazolor4,5-bipy ridine dihvdrochloride An 8 mL screw cap vial, equipped with a magnetic stirring bar, was charged with (R)- (-)-6-bromo-2-(1,4-diazabicyclo[3.2.1]oct-4-yl)[1,3]oxazolo[ 4,5-b]pyridine (100 mg, 0.324 mmol), sodium bicarbonate (57 mg, 0.680 mmol), Pd(PPh 3 J 4 (19 mg, 0.0162 mmol), 1 mL of water, and 2 mL of tetrahydrofuran. The vial was closed and the mixture was stirred at 80 0 C for 16 h. Then the mixture was extracted with ethyl acetate (5x3 mL), the organic extract was dried over Na 2 SO 4 , evaporated, and the residue was purified by column chromatography (silica gel, dichloromethane 94%, MeOH 5 %, NH 4 OH aq . 1%) to give 51 mg of (R)-(-)-2-(1 ,4- diazabicyclo[3.2.1]oct-4-yl)-6-phenyl[1,3] oxazolo[4,5-b]pyridine as a white hygroscopic solid. The solid was dissolved in 1 mL of MeOH, then 0.60 mL of 2M HCI in ether was added. After standing for 16h the resulting precipitate was collected by filtration, and dried under vacuum to give 49 mg of (R)-(-) ^-(i^-diazabicycloβ^.ilocM-yiy-β-phenyiπ.Sloxazoloμ.δ-b lpyridine dihydrochloride as a white solid; m.p. 250-255 0 C dec. [α] D = -72.892 (c=0.166, MeOH), LCMS (M+H) m/z 307.3.
EXAMPLE 13
(RV(-)-2-(1,4-diazabicvclor3.2.1loct-4-yl)-6-(2-fluoro-6- methoxyphenyl)n ,31oxazolo[4.5-bl pyridine dihvdrochloride
An 8 mL screw cap vial, equipped with a magnetic stirring bar, was charged with (R)- (-) 6-bromo-2-(1,4-diazabicyclo[3.2.1]oct-4-yl)[1,3]oxazolo[4,5- b]pyridine (50 mg, 0.16 mmol),
2-fluoro-6-methoxyhenylboronic acid (27 mg, 0.16 mmol), CsF (76 mg, 0.50 mmol), Pd(PPh 3 ) 4
(7 mg, 0.006 mmol), 0.2 mL of water, and 0.5 mL of tetrahydrofuran. The vial was flushed with nitrogen, closed with a screwtop cap, and the mixture was stirred at 150 0 C for 10 min. Then the solvents were removed under reduced pressure, and the resulting residue was extracted with 3 mL of dichloromethane/methanol (4:1) mixture. The extract was evaporated, and the residue was purified by column chromatography (silica gel, dichloromethane 94%, methanol 5
%, NH 4 OH aq . 1%) to give 56.0 mg of (R)-(-)-2-(1,4-diazabicyclo[3.2.1]oct-4-yl)-6-(2-fluoro-6- methoxyphenyl)[1 ,3]oxazolo [4,5-b]pyridine as a viscous hygroscopic solid. The residue was dissolved in 1 mL of MeOH, then 1.0 mL of 2M HCI in ether was added. The mixture was evaporated and dried under vacuum for 24 h to give 50.6 mg of (R)-(-)-2-(1 ,4- diazabicyclo[3.2.1]oct-4-yl)-6-(2-fluoro-6-methoxyphenyl) [1 ,3]oxazolo[4,5-b]pyridine dihydro- chloride as pale yellow solid; m.p. 203-206 0 C dec, [α] D = -63.33 (c = 0.120, MeOH), LCMS
(M+H) m/z 355.1.
EXAMPLES 14- 16 The following examples were prepared according to the method of Example 13:
EXAMPLE 17
(f?M-)-2-(1 ,4-diazabicvclo[3.2.noct-4-yl)ri ,31oxazolor4,5-blpyridine-6-carbonitrile dihvdrochloride An 8 mL screw cap vial, equipped with a magnetic stirring bar, was charged with (R)-
(-)- 6-bromo-2-(1,4-diazabicyclo[3.2.1]oct-4-yl)t1,3]oxazolo[4,5- b]pyridine (50 mg, 0.16 mmol), Zn(CN) 2 (12 mg, 0.10 mmol), Pd 2 (dba) 3 (4.0 mg, 0.004 mmol), DPPF (6.0 mg, 0.011 mmol), and 1 mL of dimethylformamide (wet, containing 1 % of H 2 O, 10 uL). The vial was flushed with nitrogen, closed with a screwtop cap, and the mixture was stirred at 120 0 C for 16 h. Then the mixture was evaporated under vacuum, and the resulting residue was extracted with 5 mL of a dichloromethane/methanol (4:1) mixture. The extract was concentrated under reduced pressure, and the residue was purified by column chromatography (silica gel, DCM 94%, MeOH 5 %, NH 4 OH aq . 1%) to give 23.1 mg of (R)-(-)2-(1,4-diazabicyclo[3.2.1]oct-4- yl)[1 ,3]oxazolo[4,5-b]pyridine-6-carbonitrile as a tan solid; m.p. 213-215 0 C. The product was dissolved in 1 mL of MeOH 1 then 0.3 mL of 2M HCI in ether was added. The mixture was concentrated and dried under vacuum to give 28 mg of (R)-(-)- 2-(1,4-diazabicyclo[3.2.1]oct- 4-yl)[1,3]oxazolo[4,5-b]pyridine-6-carbonitrile dihydrochloride as tan solid, [α] D = -61.91 (c = 0.126, MeOH), LCMS (M+H) m/z 256.4.
EXAMPLE 18 (R)-(-)-2-(1.4-diazabicvclor3.2.noct-4-yl)-6-methviri,31oxaz olor4.5-blpyridine dihvdrochloride
An 8 mL screw cap vial, equipped with a magnetic stirring bar, was charged under nitrogen with (R)-(-)- 6-bromo-2-(1,4-diazabicyclo[3.2.1]oct-4-yl)[1,3]oxazolo[4,5- b]pyridine
(50 mg, 0.16 mmol), Pd(dppf) 2 CI 2 -CH 2 Cl 2 (2.6 mg, 0.0032 mmol), 0.7 mL of anhydrous dioxane, and ZnMe 2 (165 uL of 2M solution in toluene, 0.330 mmol). The vial was flushed with nitrogen, closed with a screwtop cap, and the mixture was stirred at 150 0 C for 10 min. Then the mixture was diluted with 3 mL of MeOH, filtered through celite, and the celite cake was washed with 3 mL of MeOH. The clear solution was evaporated and the residue was purified by column chromatography (silica gel, dichloromethane 94%, methanol 5 %, NH4OH (aq.) 1%) to give 24.3 mg of (-) 2-(1,4-diazabicyclo[3.2.1]oct-4-yl)-6-methyl[1,3]oxazolo[4,5 - b]pyridine as a brownish solid. The product was dissolved in 0.5 mL of methanol, then 0.5 mL of 2M HCI in ether was added, and the mixture was cooled to O 0 C. The resulting precipitate was collected by filtration and dried under vacuum to give 29 mg of (R)-(-) -2-(1,4- diazabicycloβ^.iloct^-yO-e-methylli.Sloxazoloμ.S-blpyridin e dihydrochloride as a tan solid. [OC] D = -59.500 (c = 0.200, MeOH), LCMS (M+H) m/z 245.1.
EXAMPLE 19
(RV(- ' >-2-(1,4-cliazabicvclor3.2.1loct-4-yl)-6-ethviri,31 oxazolor4,5-blpyridinβ dihvdrochloride
(^-(-^-(i^-diazabicyclotS^.ijoct^-yO-δ-ethylti.Sloxazolo μ.S-blpyridine dihydrochloride was prepared according to example 18 using diethylzinc in place of dimethylzinc. Tan solid, [α] D = -62.366 (c = 0.186, MeOH), LCMS (M+H) m/z 259.3.
EXAMPLE 20 (R)-(-)-6-bromo-2-(1.4-diazabicvclor3.2.1loct-4-yl)-5-methyl f1.3)-oxazolor4.5-b1pyridine dihvdrochloride
(R)-(-)-6-bromo-2-(1,4-diazabicyclo[3.2.1]oct-4-yl)-5-met hyl[1 ,3}-oxazolo[4,5- bjpyridine dihydrochloride was prepared according to the procedure of example 10 starting from (R)-(-)-2-(1 ^-diazabicycloβ^.iloct^-yO-δ-methylti ,3}-oxazolo[4,5-b]pyridine. White powder; [α] D = -54.545 (c=0.264, MeOH), LCMS (M+) m/z 323.2.
EXAMPLE 21
(RH-V2-(1.4-diazabicvclof3.2.1loct-4-yl)-5-methviπ.3)-ox azolof4.5-blpyridine-6-carbonitrile dihvdrochloride
(R)-(-)-2-(1,4-diazabicyclo[3.2.1]oct-4-yl)-5-methyl[1,3} -oxazolo[4,5-b]pyridine-6- carbonitrile dihydrochloride was prepared according to the procedure of example 17 starting from (RJ-^J-e-bromo^-ti^-diazabicyclop^.ilocM-ylJ-S-methylli.SVox azolo^.δ-blpyridine. White powder. LCMS: m/e 270.2 (M+H); [α] D = -56.075 (c = 0.214, MeOH). EXAMPLE 22
(R)-(-)-6-chloro-2-(1.4-diazabicvcloF3.2.1loct-4-yl)-5-me thviπ.3loxazolo[4.5-bipyridine dihvdrochloride
(R)-(-)-6-chloro-2-(1,4-diazabicyclo[3.2.1]oct-4-yl)-5-me thyl[1,3]oxazolo[4,5-b]pyridine dihydrochloride was prepared according to the procedure of example 8 starting from (R)-(-)-2- (1,4-diazabicydo[3.2.1]oct-4-yl)-5-methyl[1,3]oxazolo[4,5-b] pyridine. White solid. [α] D = - 72.115 (c=0.104, MeOH), LCMS m/z 279.3 (M+H).
EXAMPLE 23
(R^M-Σ-d Λ-diazabicvclofS.Σ.nocM-vD-e-phenoxyπ .SloxazolorSΛ-bipyridine
An 8 mL screw cap vial, equipped with a magnetic stirring bar, was charged with Cs 2 CO 3 (104 mg, 0.32 mmol), phenol (30.2 mg, 0.32 mmol) and 1-methyl-2-pyrrolidinone (2 mL). The mixture was degassed using N 2 and then (R)-(-)-6-bromo-2-(1 ,4- diazabicycloβ^.ilocM-ylHI.SloxozoloβAblpyridine (50 mg, 0.16 mmol), 2,2,6,6-tetramethyl hexane dione (TMHD) (5.8 mg, 0.032 mmol) and CuBr (4.57 mg, 0.032 mmol) was added sequentially. The vial was degassed with nitrogen, closed with a screwtop cap, and the mixture was stirred at 120 0 C for 24h. The solvent was evaporated and the crude mixture was purified by a silica gel column chromatography eluting with 5-10 % MeOH/CH 2 CI 2 to give the
title compound as a light brown oil which slowly solidified to light yellow crystals (29 mg, 57 %). LCMS: m/e 323.4 (M+1); [α] D = -44.00 (c = 0.584 g/100 mL, MeOH).
EXAMPLE 24 fm-(-)-2-(1.4-dia2abicvclof3.2.noct-4-vn-5,6-dimethyiri,3}-o xa2olor4.5-b1pyridine dihvdrochloride
(^-(-^-(i ^-diazabicyclofa^.ilocM-yO-S.e-dimethyin.S^oxazolo^.S-blpyri dine dihydrochloride was prepared according to the procedure of example 18 starting from (R)-(-)- 6-bromo-2-(1 ,4-diazabicyclo[3.2.1]oct-4-yl)-5-methyl[1 ,3}-oxazolo[4,5-b]pyridine. White powder. LCMS: m/e (M+H); [α] D = -47.881 (c= 0.236, MeOH).