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Title:
TETRAZOLE-SUBSTITUTED ARYL AMIDE DERIVATIVES AND USES THEREOF
Document Type and Number:
WIPO Patent Application WO/2009/043780
Kind Code:
A1
Abstract:
Compounds of the formula (I) wherein R1, R2, Ar1, Ar2, and n are as defined herein. Also provided are pharmaceutical compositions, methods of using, and methods of preparing the subject compounds.

Inventors:
DU BOIS DAISY JOE (US)
ELWORTHY TODD RICHARD (US)
MAAG HANS (US)
SAHDEO SUNIL (US)
Application Number:
PCT/EP2008/062800
Publication Date:
April 09, 2009
Filing Date:
September 24, 2008
Export Citation:
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Assignee:
HOFFMANN LA ROCHE (CH)
DU BOIS DAISY JOE (US)
ELWORTHY TODD RICHARD (US)
MAAG HANS (US)
SAHDEO SUNIL (US)
International Classes:
A61K31/4439; C07D257/04; A61P25/28; C07D401/10; C07D403/10; C07D405/12; C07D409/10
Domestic Patent References:
WO2008000645A12008-01-03
WO2004029050A12004-04-08
WO2004029050A12004-04-08
Other References:
MEYER ET AL.: "Neuroprotective effects of 2,4-dimethoxybenzylidene anabaseine (DMXB) and tetrahydroaninoacridine (THA) in neocortices of nucleus basalis lesioned rats", BRAIN RESEARCH, vol. 786, 1998, pages 252 - 254, XP002516745
TIMMERMANN ET AL.: "An allosteric modulator of the alpha 7 nicotinic acetylcholine receptor possessing cognition-enhancing properties in vivo", JOURNAL OF PHARMACOLOGY AND EXPERIMENTAL THERAPEUTICS, AMERICAN SOCIETY FOR PHARMACOLOGY AND EXPERIMENTAL THERAPEUTICS, US, vol. 323, no. 1, 1 October 2007 (2007-10-01), pages 294 - 307, XP009102709, ISSN: 0022-3565
REZVANI ET AL.: "Effect of R3487/MEM3454, a novel nicotinic ?7 receptor partial agonist and 5-HT3 antagonist on sustained attention in rats", PROGRESS IN NEURO-PSYCHOPHARMACOLOGY AND BIOLOGICAL PSYCHIATRY, vol. 33, no. 2, 2009, pages 269 - 275, XP002516746
Attorney, Agent or Firm:
WASNER, Marita (Basel, CH)
Download PDF:
Claims:

CLAIMS

1. A compound of formula I :

or a pharmaceutically acceptable salt thereof, wherein: n is from 1 to 3;

Ar 1 and Ar 2 each independently is optionally substituted aryl or optionally substituted heteroaryl;

R 1 is hydrogen or Ci_ 6 alkyl;

R 2 is hydrogen, or R 2 may form an alkylene bridge with Ar 2 ; provided that when Ar 1 is 4-methyl-phenyl, 5-methyl-pyridinyl or 5-chloro- pyridinyl, then n is 2 or 3; and provided that when n is 2, R 2 and R 3 are hydrogen and Ar 1 is phenyl or 2- methoxy-phenyl, then Ar 2 is not 4-methoxy-phenyl or 3,4-dimethoxy-phenyl.

2. The compound of claim 1, wherein

Ar 1 and Ar 2 are each independently phenyl, pyridinyl, pyrimidinyl, pyrrolidinyl or thienyl, each independently optionally substituted one, two or three times, preferably once or twice, with a group or groups independently selected from halo, alkyl, haloalkyl, alkoxy, cyano, amino, amino sulfonyl, alkoxycarbonyl, alkylcarbonyl, alkylsulfanyl, alkylsulfonyl, hydroxy, hydroxyalkyl, or alkylenedioxy.

3. The compound of claim 1 or 2, wherein Ar is phenyl, optionally substituted one, two or three times, preferably once or twice, with a group or groups independently selected from Ci_ 6 alkyl-carbonyl, halo, cyano, Ci_ βalkoxy, Ci_ 6 alkoxy-carbonyl, Ci_ 6 alkyl, hydroxy , hydroxy-Ci_ 6 alkyl, Ci_ 6 alkyl-sulfanyl, or C i_ 6 alkyl- sulfonyl, or

pyridinyl, optionally substituted one, two or three times, preferably once or twice, with a group or groups independently selected from Ci_ 6 alkoxy, Ci_ 6 alkyl-sulfonyl, or halo-Ci_ 6 alkyl, or pyridinyl, optionally substituted with Ci_ 6 alkoxy, or pyrrolyl, optionally substituted with Ci_ 6 alkyl, or thienyl, optionally substituted with Ci_ 6 alkoxycarbonyl.

4. The compound of any of claims 1 to 3, wherein Ar 1 is 2-methoxy-phenyl that is optionally substituted once at the 3-, A-, 5- or 6- position with fluoro, chloro, methyl or methoxy, or is pyridin-2-yl or pyridin-3-yl optionally substituted with methoxy or trifluoromethyl.

5. The compound of any of claims 1 to 4, wherein Ar 2 is phenyl, optionally substituted one, two or three times, preferably once or twice, with a group or groups independently selected from Ci_6alkoxy, C^alkyl, Ci _ βalkylsulfonyl, amino, amino sulfonyl, alkylenedioxy and halo, or pyridinyl.

6. The compound of any one of claims 1 to 5, wherein n is 2.

7. The compound of any one of claims 1 to 6, wherein R 1 is hydrogen.

8. The compound of any one of claims 1 to 7, wherein R 2 is hydrogen.

9. The compound of claim 1, wherein said compound is selected from: 2'-Methoxy-5-tetrazol- 1 -yl-biphenyl-3-carboxylic acid phenethyl-amide; 2'-Methoxy-5-tetrazol- 1 -yl-biphenyl-3-carboxylic acid [2-(4-methoxy-phenyl)- ethyl]-amide; 2'-Methoxy-5-tetrazol-l -yl-biphenyl-3-carboxylic acid [2-(3-methoxy-phenyl)- ethyl]-amide;

2'-Methoxy-5-tetrazol- 1 -yl-biphenyl-3-carboxylic acid [2-(4-sulfamoyl-phenyl)- ethyl]-amide;

2'-Methoxy-5-tetrazol- 1 -yl-biphenyl-3-carboxylic acid [2-(4-chloro-phenyl)- ethyl]-amide;

2'-Methoxy-5-tetrazol-l -yl-biphenyl-3-carboxylic acid [2-(3,4-dichloro-phenyl)- ethyl]-amide; 2'-Methoxy-5-tetrazol-l -yl-biphenyl-3-carboxylic acid [2-(3-bromo-4-methoxy- phenyl)-ethyl]-amide;

2'-Methoxy-5-tetrazol- 1 -yl-biphenyl-3-carboxylic acid [2-(2-fluoro-phenyl)- ethyl]-amide;

2'-Methoxy-5-tetrazol-l -yl-biphenyl-3-carboxylic acid [2-(3,4-difluoro-phenyl)- ethyl]-amide;

2'-Methoxy-5-tetrazol- 1 -yl-biphenyl-3-carboxylic acid (2-/?-tolyl-ethyl)-amide;

2'-Methoxy-5-tetrazol- 1 -yl-biphenyl-3-carboxylic acid (2-o-tolyl-ethyl)-amide;

2'-Methoxy-5-tetrazol-l -yl-biphenyl-3-carboxylic acid (2-benzo[l,3]dioxol-5-yl- ethyl)-amide; 2'-Methoxy-5-tetrazol-l -yl-biphenyl-3-carboxylic acid (2-m-tolyl-ethyl)-amide;

4'-Methoxy-5-tetrazol-l -yl-biphenyl-3-carboxylic acid [2-(3,4-dimethoxy- phenyl)-ethyl]-amide;

4'-Chloro-5-tetrazol-l -yl-biphenyl-3-carboxylic acid [2-(3,4-dimethoxy-phenyl)- ethyl]-amide; 4'-Methyl-5-tetrazol-l -yl-biphenyl-3-carboxylic acid [2-(3,4-dimethoxy-phenyl)- ethyl]-amide;

2'-Methyl-5-tetrazol-l -yl-biphenyl-3-carboxylic acid [2-(3,4-dimethoxy-phenyl)- ethyl]-amide;

2'-Chloro-5-tetrazol-l -yl-biphenyl-3-carboxylic acid [2-(3,4-dimethoxy-phenyl)- ethyl]-amide;

2'-Fluoro-5-tetrazol-l -yl-biphenyl-3-carboxylic acid [2-(3,4-dimethoxy-phenyl)- ethyl]-amide;

2'-Ethoxy-5-tetrazol-l -yl-biphenyl-3-carboxylic acid [2-(3,4-dimethoxy-phenyl)- ethyl]-amide; 2'-Acetyl-5-tetrazol-l -yl-biphenyl-3-carboxylic acid [2-(3,4-dimethoxy-phenyl)- ethyl]-amide;

2',4'-Dimethoxy-5-tetrazol-l -yl-biphenyl-3-carboxylic acid [2-(3,4-dimethoxy- phenyl)-ethyl]-amide;

2',5'-Dimethoxy-5-tetrazol-l-yl-biphenyl-3-carboxylic acid [2-(3,4-dimethoxy- phenyl)-ethyl]-amide;

5'-Fluoro-2'-methoxy-5-tetrazol- 1 -yl-biphenyl-3-carboxylic acid [2-(3,4- dimethoxy-phenyl)-ethyl]-amide; 5'-Chloro-2'-methoxy-5-tetrazol-l -yl-biphenyl-3-carboxylic acid [2-(3,4- dimethoxy-phenyl)-ethyl]-amide;

2',5'-Dichloro-5-tetrazol-l-yl-biphenyl-3-carboxylic acid [2-(3,4-dimethoxy- phenyl)-ethyl]-amide;

2'-Hydroxymethyl-5-tetrazol-l -yl-biphenyl-3-carboxylic acid [2-(3,4-dimethoxy- phenyl)-ethyl]-amide;

2',3'-Dichloro-5-tetrazol-l -yl-biphenyl-3-carboxylic acid [2-(3,4-dimethoxy- phenyl)-ethyl]-amide;

2'-Methylsulfanyl-5-tetrazol-l -yl-biphenyl-3-carboxylic acid [2-(3,4-dimethoxy- phenyl)-ethyl]-amide; 2',3'-Difluoro-5-tetrazol-l-yl-biphenyl-3-carboxylic acid [2-(3,4-dimethoxy- phenyl)-ethyl]-amide;

2',4'-Dichloro-5-tetrazol-l -yl-biphenyl-3-carboxylic acid [2-(3,4-dimethoxy- phenyl)-ethyl]-amide;

2'-Hydroxy-5-tetrazol-l -yl-biphenyl-3-carboxylic acid [2-(3,4-dimethoxy- phenyl)-ethyl]-amide;

5'-[2-(3,4-Dimethoxy-phenyl)-ethylcarbamoyl]-2-nitro-3'-tetrazol-l-yl-biphenyl- 4-carboxylic acid ethyl ester;

2'-Ethyl-5-tetrazol-l -yl-biphenyl-3-carboxylic acid [2-(3,4-dimethoxy-phenyl)- ethyl]-amide; 2'-Cyano-5-tetrazol-l -yl-biphenyl-3-carboxylic acid [2-(3,4-dimethoxy-phenyl)- ethyl]-amide;

2',3'-Dimethoxy-5-tetrazol-l -yl-biphenyl-3-carboxylic acid [2-(3,4-dimethoxy- phenyl)-ethyl]-amide;

4'-Methoxy-2'-methyl-5-tetrazol- 1 -yl-biphenyl-3-carboxylic acid [2-(3,4- dimethoxy-phenyl)-ethyl]-amide;

2'-Methoxy-5-tetrazol- 1 -yl-biphenyl-3-carboxylic acid [2-(4-dimethylamino- phenyl)-ethyl]-amide;

2'-Methoxy-5-tetrazol- 1 -yl-biphenyl-3-carboxylic acid [2-(4-methanesulfonyl- phenyl)-ethyl]-amide;

4'-Methylsulfanyl-5-tetrazol- 1 -yl-biphenyl-3-carboxylic acid [2-(2-fluoro- phenyl)-ethyl]-amide; 2'-Methoxy-5-tetrazol-l -yl-biphenyl-3-carboxylic acid [3-(3,4-dimethoxy- phenyl)-propyl]-amide;

2'-Methoxy-5-tetrazol-l -yl-biphenyl-3-carboxylic acid 3,4-dimethoxy- benzylamide;

2'-Methoxy-5-tetrazol- 1 -yl-biphenyl-3-carboxylic acid (2-pyridin-3-yl-ethyl)- amide;

2'-Methoxy-5-tetrazol- 1 -yl-biphenyl-3-carboxylic acid (2-pyridin-4-yl-ethyl)- amide;

2'-Methoxy-5-tetrazol- 1 -yl-biphenyl-3-carboxylic acid (2-pyridin-2-yl-ethyl)- amide; N-[2-(2-Fluoro-phenyl)-ethyl]-3-(3-methoxy-pyridin-2-yl)-5-tetrazol- 1 -yl- benzamide;

N- [2-(2-Fluoro-phenyl)-ethyl] -3 -tetrazol- 1 -yl-5 -(5 -trifluoromethyl-pyridin-2-yl)- benzamide;

N-[2-(3,4-Dimethoxy-phenyl)-ethyl]-3-(2-methoxy-pyridin-3-yl)-5-tetrazol-l-yl- benzamide;

2'-Methoxy-5-tetrazol-l -yl-biphenyl-3-carboxylic acid (7-methoxy-l,2,3,4- tetrahydro-naphthalen- 1 -ylmethyl)-amide;

3-(3-Methoxy-pyridin-2-yl)-N-(7-methoxy-l,2,3,4-tetrahydro-naphthalen-l- ylmethyl)-5-tetrazol- 1 -yl-benzamide; N-[2-(2-Fluoro-phenyl)-ethyl]-3-(5-methanesulfonyl-pyridin-2-yl)-5-tetrazol- 1 - yl-benzamide;

N- [2-(2-Fluoro-phenyl)-ethyl] -3 -(2-methoxy-pyrimidin-5 -yl)-5 -tetrazol- 1 -yl- benzamide;

3 -( 1 -Ethyl- 1 H-pyrro 1-3 -yl)-N- [2-(2-fluoro-phenyl)-ethyl] -5 -tetrazol- 1 -yl- benzamide; and

5- {3-[2-(2-Fluoro-phenyl)-ethylcarbamoyl]-5-tetrazol- 1 -yl-phenyl} -thiophene-2- carboxylic acid tert-butyl ester.

10. A process for preparing the compound of claim 1, wherein a compound of formula (1)

is reacted with an amine of formula (2)

to give a compound of formula I wherein Ar 1 , Ar 2 , R 1 , R 2 and n are as defined in claim 1. 11. A pharmaceutical composition containing at least one compound of formula I according to any one of claims 1 to 9. 12. The compound of any one of claims 1 to 9, for the treatment of diseases related to the alpha 7 nAHhR receptor.

13. The compound according to claim 12, for the use as cognitive enhancer or for the treatment of Alzheimer's disease.

14. The use of a compound of formula I according to any one of claims 1 to 9 for the preparation of a medicament useful as cognitive enhancer or for the preparation of a medicament for the treatment of Alzheimer's disease. 15. The invention as hereinbefore described.

Description:

TETRAZOLE-SUBSTITUTED ARYL AMIDE DERIVATIVES AND USES

THEREOF

This invention relates to nicotinic acetylcholine receptors (nAChR), and particularly to positive allosteric modulators for the alpha 7 nAChR subtype, and methods of making and using such compounds.

Present invention provides compounds of formula I:

or a pharmaceutically acceptable salt thereof, wherein: n is from 1 to 3; Ar 1 and Ar 2 each independently is optionally substituted aryl or optionally substituted heteroaryl;

R 1 is hydrogen or Ci_ 6 alkyl;

R 2 is hydrogen, or R 2 may form an alkylene bridge with Ar 2 ; provided that when Ar 1 is 4-methyl-phenyl, 5-methyl-pyridinyl or 5-chloro- pyridinyl, then n is 2 or 3; and provided that when n is 2, R 2 and R 3 are hydrogen and Ar 1 is phenyl or 2- methoxy-phenyl, then Ar 2 is not 4-methoxy-phenyl or 3,4-dimethoxy-phenyl.

The invention also provides pharmaceutical compositions, methods of using, and methods of preparing the aforementioned compounds.

Nicotinic acetylcholine receptors (nAChR) are members of the ligand-gated ion channel family. When activated, the conductance of ions across the nicotinic ion channels increases. Nicotinic alpha 7 receptor (alpha 7 nAChR) forms a homopentameric channel in vitro that is highly permeable to calcium cations. Each alpha 7 nAChR has four transmembrane domains, known as Ml, M2, M3, and M4. The M2 domain has been suggested to form the wall lining the channel. Sequence alignment shows that the alpha 7 nAChR is highly conserved during evolution. The M2 domain that lines the channel is identical in protein sequence from chick to human. Alpha 7 nAChR is described by, Revah et al. (1991), Nature, 353, 846-849; Galzi et al. (1992), Nature 359, 500-505; Fucile et al. (2000), PNAS 97(7), 3643-3648; Briggs et al. (1999), Eur. J. Pharmacol. 366 (2-3), 301-308; and Gopalakrishnan et al. (1995), Eur. J. Pharmacol. 290(3), 237- 246.

The alpha 7 nAChR channel is expressed in various brain regions and is believed to be involved in many important biological processes in the central nervous system (CNS), including learning, memory and attention (Levin et al., Psychopharmacology (1998), 138, 217-230). Alpha 7 nAChR are localized on both presynaptic and postsynaptic terminals and have been suggested to be involved in modulating synaptic transmission. Agonists of alpha 7 nAChR have been shown to improve attention and cognition in Alzheimer's and attention deficit disorder conditions (Wilens et al., Am. J. Psychiatry (1999), 156(12), 1931-1937).

The analgesic effects of nicotine have long been known. Agonists of the alpha 7 nAChR receptor have been shown to modulate production of pro-inflammatory cytokines, including interleukins (ILs), tumor necrosis factor (TNF) alpha, and high-mobility group box (HMGB-I), and to inhibit inflammatory signalling in the CNS (de Jonge et al., Br. J. Pharmacol. (2007), 1-15). The alpha 7 nAChR receptor has a role in modulating CNS pain transmission, and alpha 7 nAChR agonists have shown an antinociceptive effect in an acute pain model (Damaj et al., Neuropharmacol. (2000) 39, 2785-2791. Since acetylcholine (ACh) is an endogenous agonist of alpha 7 nAChR, agonists that act at the same site as ACh can stimulate and possibly block receptor activity through desensitization and competitive blockade processes (Forman et al., BiophysicalJ. (1988), 54(1), 149-158) and lead to prolonged receptor inactivation (Buisson et al., J. Neurosci. (2001), 21(6), 1819-1829). Desensitization limits the duration that the ion channel remains activated during agonist application. Thus the enhancement of Alpha 7 nAChR

activity provided by such agonists will also increase competition with ACh, and therefore limit the usefulness of agonists as drugs.

Positive allosteric modulators of the nicotinic alpha 7 receptor channel enhance the activity of ACh and other nicotinic alpha 7 receptor agonists. Positive allosteric modulators activate alpha 7 nAChR when sufficient ACh is present in the central nervous system. Positive allosteric modulators of alpha 7 nAChRs thus are useful for treatment of CNS, pain and inflammatory diseases or conditions, to regulate CNS functions such as cognition, learning, mood, emotion and attention, and control production of proinflammatory cytokines associated with pain and inflammatory conditions. There is accordingly a need for new positive allosteric modulators of the the nicotinic alpha 7 receptor channel.

Definitions

"Agonist" refers to a compound that enhances the activity of another compound or receptor site.

"Alkyl" means the monovalent linear or branched saturated hydrocarbon moiety, consisting solely of carbon and hydrogen atoms, having from one to twelve carbon atoms.

"Lower alkyl" refers to an alkyl group of one to six carbon atoms, i.e. Ci-Cβalkyl.

Examples of alkyl groups include, but are not limited to, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, octyl, dodecyl, and the like.

Examples for "branched alkyl" are isopropyl, isobutyl, tert-butyl, and the like. Preferred alkyl is lower alkyl as defined herein.

"Alkylene" means a linear saturated divalent hydrocarbon radical of one to six carbon atoms or a branched saturated divalent hydrocarbon radical of three to six carbon atoms, e.g., methylene, ethylene, 2,2-dimethylethylene, propylene, 2-methylpropylene, butylene, pentylene, and the like.

"Alkoxy" means a moiety of the formula -OR, wherein R is an alkyl moiety as defined herein. Examples of alkoxy moieties include, but are not limited to, methoxy, ethoxy, isopropoxy, tert-butoxy and the like. "Alkoxyalkyl" means a moiety of the formula -R'-R", where R' is alkylene and R" is alkoxy as defined herein. Exemplary alkoxyalkyl groups include, by way of example, 2- methoxyethyl, 3-methoxypropyl, l-methyl-2-methoxyethyl, l-(2-methoxyethyl)-3- methoxypropyl, and l-(2-methoxyethyl)-3-methoxypropyl.

"Alkylcarbonyl" means a moiety of the formula -C(O)-R, where R is alkyl as defined herein.

"Alkoxycarbonyl" means a moiety of formula -C(O)-R wherein R is alkoxy as defined herein. "Alkylsulfanyl" means a moiety of the formula -S-R wherein R is alkyl as defined herein. "Alkylsulfonyl" means a moiety of the formula -SO 2 -R' where R' is alkyl as defined herein.

"Alkylenedioxy" means a group of the formula wherein n is 1

(methylenedioxy) or 2 (alkylenedioxy). When an alkylenedioxy is a substituent on an aryl group such as phenyl, the alkylenedioxy occupies two adjacent ring atoms. For example, phenyl substituted with methylenedioxy is benzo[l,3]dioxole, and phenyl substituted with ethylenedioxy is 2,3-dihydro-benzo[l,4]dioxine.

"Amino" means a moiety of the formula -NRR' where R and R' each independently is hydrogen or alkyl as defined herein. "Amino sulfonyl" means a moiety of the formula -SO 2 -R' where R' is amino as defined herein. "Antagonist" refers to a compound that diminishes or prevents the action of another compound or receptor site.

"Aryl" means a monovalent cyclic aromatic hydrocarbon moiety consisting of a mono-, bi- or tricyclic aromatic ring. The aryl group can be optionally substituted as defined herein. Preferred aryl include optionally substituted phenyl and optionally substituted naphthyl. A preferred aryl is optionally substituted phenyl.

"Heteroaryl" means a monocyclic, bicyclic or tricyclic radical of 5 to 12 ring atoms having at least one aromatic ring containing one, two, or three ring heteroatoms selected from N, O, or S, the remaining ring atoms being C, with the understanding that the attachment point of the heteroaryl radical will be on an aromatic ring. The heteroaryl ring may be optionally substituted as defined herein. Examples of heteroaryl moieties include, but are not limited to, imidazolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, oxadiazolyl, thiadiazolyl, pyrazinyl, thienyl (i.e. thiophenyl), furanyl, pyranyl, pyridinyl, pyrrolyl, pyrazolyl, pyrimidyl, quinolinyl, isoquinolinyl, benzofuryl (i.e. benzo furanyl), benzo thiophenyl, benzothiopyranyl, benzimidazolyl, benzo xazo IyI, benzooxadiazolyl, benzo thiazolyl, benzo thiadiazolyl, benzopyranyl, indolyl, isoindolyl, triazolyl, triazinyl,

quinoxalinyl, purinyl, quinazolinyl, quinolizinyl, naphthyridinyl, pteridinyl, carbazolyl, azepinyl, diazepinyl, acridinyl and the like, each of which may be optionally substituted. Preferred heteroaryl include indolyl, pyridinyl, pyrimidinyl, thienyl, furanyl, pyrrolyl, imidazolyl and pyrazolyl, each of which may be optionally substituted. Particularly preferred heteroaryl are pyridinyl, pyrimidinyl, thienyl (i.e. thiophenyl), and pyrrolyl, each optionally substituted as described herein.

"Haloalkyl" means alkyl as defined herein in which one or more hydrogen has been replaced with same or different halogen. Exemplary haloalkyls include -CH 2 Cl, -CH 2 CF 3 , -CH 2 CCl 3 , perfiuoroalkyl (e.g., -CF 3 ), and the like. "Hydro xyalkyl" refers to a subset of heteroalkyl and refers in particular to an alkyl moiety as defined herein that is substituted with one or more, preferably one, two or three hydroxy groups, provided that the same carbon atom does not carry more than one hydroxy group. Representative examples include, but are not limited to, hydroxymethyl, 2-hydroxyethyl, 2-hydroxypropyl, 3-hydroxypropyl, 1 -(hydro xymethyl)-2-methylpropyl, 2-hydroxybutyl, 3-hydroxybutyl, 4-hydroxybutyl, 2,3-dihydroxypropyl, 2-hydroxy-l- hydroxymethylethyl, 2,3-dihydroxybutyl, 3,4-dihydroxybutyl and 2-(hydroxymethyl)- 3-hydroxypropyl.

"Optionally substituted", when used in association with "aryl", and "heteroaryl" , means an aryl, or heteroaryl which is optionally substituted independently with one to three substituents, preferably one or two substituents selected from alkyl, eye Io alkyl, alkoxy, halo, haloalkyl, haloalkoxy, cyano, nitro, amino, hydroxyalkyl, alkoxyalkyl, alkylsulfonyl, alkylsulfonamido, benzyloxy, cycloalkylalkyl, cycloalkoxy, cycloalkylalkoxy, alkylsulfonyloxy. Certain preferred optional substituents for "aryl" or "heteroaryl" include alkyl, halo, haloalkyl, alkoxy, cyano, amino, aminosulfonyl, alkylsulfonyl, alkylsulfanyl, alkoxycarbonyl, alkylcarbonyl, hydroxy, hydroxyalkyl, and alkylenedioxy. More preferred substituents are methyl, ethyl, fluoro, chloro, trifluoromethyl, methoxy, ethoxy, amino, aminosulfonyl, methanesulfonyl, methylsulfanyl, acetyl, (i.e. -C(O)Me), hydroxymethyl, hydroxy, -C(O)OEt, C(O)O-tert- butyl, and cyano. "Modulator" means a molecule that interacts with a target. The interactions include, but are not limited to, agonist, antagonist, and the like, as defined herein. "Optional" or "optionally" means that the subsequently described event or circumstance may but need not occur, and that the description includes instances where the event or

circumstance occurs and instances in which it does not. "Optionally substituted" hence means unsubstituted or substituted with one or more of the substituents as described herein.

"Disease" and "Disease state" means any disease, condition, symptom, disorder or indication.

"Inert organic solvent" or "inert solvent" means the solvent is inert under the conditions of the reaction being described in conjunction therewith, including for example, benzene, toluene, acetonitrile, tetrahydrofuran, N,N-dimethylformamide, chloroform, methylene chloride or dichloromethane, dichloroethane, diethyl ether, ethyl acetate, acetone, methyl ethyl ketone, methanol, ethanol, propanol, isopropanol, tert-butanol, dioxane, pyridine, and the like. Unless specified to the contrary, the solvents used in the reactions of the present invention are inert solvents.

"Pharmaceutically acceptable" means that which is useful in preparing a pharmaceutical composition that is generally safe, non-toxic, and neither biologically nor otherwise undesirable and includes that which is acceptable for veterinary as well as human pharmaceutical use.

"Pharmaceutically acceptable salts" of a compound means salts that are pharmaceutically acceptable, as defined herein, and that possess the desired pharmacological activity of the parent compound. Such salts include: acid addition salts formed with inorganic acids such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid, and the like; or formed with organic acids such as acetic acid, benzenesulfonic acid, benzoic, camphorsulfonic acid, citric acid, ethanesulfonic acid, fumaric acid, glucoheptonic acid, gluconic acid, glutamic acid, glycolic acid, hydro xynaphtoic acid, 2-hydroxyethanesulfonic acid, lactic acid, maleic acid, malic acid, malonic acid, mandelic acid, methanesulfonic acid, muconic acid, 2-naphthalenesulfonic acid, propionic acid, salicylic acid, succinic acid, tartaric acid, p- toluenesulfonic acid, trimethylacetic acid, and the like; or salts formed when an acidic proton present in the parent compound either is replaced by a metal ion, e.g., an alkali metal ion, an alkaline earth ion, or an aluminum ion; or coordinates with an organic or inorganic base. Acceptable organic bases include diethanolamine, ethanolamine, N-methylglucamine, triethanolamine, tromethamine, and the like. Acceptable inorganic bases include aluminum hydroxide, calcium hydroxide, potassium hydroxide, sodium carbonate and sodium hydroxide.

The preferred pharmaceutically acceptable salts are the salts formed from acetic acid, hydrochloric acid, sulphuric acid, methanesulfonic acid, maleic acid, phosphoric acid, tartaric acid, citric acid, sodium, potassium, calcium, zinc, and magnesium. It should be understood that all references to pharmaceutically acceptable salts include solvent addition forms (solvates) or crystal forms (polymorphs) as defined herein, of the same acid addition salt.

"Cognition" means any mental process associated with acquiring and retaining knowledge. A "cognition disorder" means any disturbance to the mental process or processes related to thinking, reasoning, judgment ad memory. Cognition disorders may result from or other wise be associated with Parkinson's disease, Huntington's disease, anxiety, depression, manic depression, psychosis, epilepsy, obsessive compulsive disorders, mood disorders, migraine, Alzheimer's disease, sleep disorders, feeding disorders such as anorexia, bulimia, and obesity, panic attacks, akathisia, attention deficit hyperactivity disorder (ADHD), attention deficit disorder (ADD), withdrawal from drug abuse such as cocaine, ethanol, nicotine and benzodiazepines, schizophrenia, and also disorders associated with spinal trauma and/or head injury such as hydrocephalus. The terms "those defined above" and "those defined herein" when referring to a variable incorporates by reference the broad definition of the variable as well as preferred, more preferred and most preferred definitions, if any.

Nomenclature and Structures

In general, the nomenclature used in this Application is based on AUTONOM™ v.4.0, a Beilstein Institute computerized system for the generation of IUPAC systematic nomenclature. Chemical structures shown herein were prepared using ISIS ® version 2.2. Any open valency appearing on a carbon, oxygen, sulfur or nitrogen atom in the structures herein indicates the presence of a hydrogen atom. Whenever a chiral carbon is present in a chemical structure, it is intended that all stereoisomers associated with that chiral carbon are encompassed by the structure. All patents and publications identified herein are incorporated herein by reference in their entirety.

Compounds of the Invention

The invention provides compounds of formula I:

or a pharmaceutically acceptable salt thereof, wherein: n is from 1 to 3;

Ar 1 and Ar 2 each independently is optionally substituted aryl or optionally substituted heteroaryl;

R 1 is hydrogen or Ci_ 6 alkyl; R 2 is hydrogen, or R 2 may form an alkylene bridge with Ar 2 ; provided that when Ar 1 is 4-methyl-phenyl, 5-methyl-pyridinyl or 5-chloro- pyridinyl, then n is 2 or 3; and provided that when n is 2, R 2 and R 3 are hydrogen and Ar 1 is phenyl or 2- methoxy-phenyl, then Ar 2 is not 4-methoxy-phenyl or 3,4-dimethoxy-phenyl. In certain embodiments of formula I, n is 1. In certain embodiments of formula I, n is 2. In certain embodiments of formula I, n is 3. In certain embodiments of formula I, R 1 is hydrogen. In certain embodiments of formula I, R 2 is hydrogen. In certain embodiments of formula I, Ar 1 and Ar 2 are each independently phenyl, pyridinyl, pyrimidinyl, pyrrolidinyl or thienyl, each independently optionally substituted one, two or three times, preferably once or twice, with a group or groups independently selected from halo, alkyl, haloalkyl, alkoxy, cyano, amino, aminosulfonyl, alkoxycarbonyl, alkylcarbonyl, alkylsulfanyl, alkylsulfonyl, hydroxy, hydroxyalkyl, or alkylenedioxy.

In certain embodiments of formula I, Ar 1 is phenyl, optionally substituted one, two or three times, preferably once or twice, with a group or groups independently selected from Ci_ 6 alkyl-carbonyl, halo, cyano, Ci_

6 alkoxy, Ci_ 6 alkoxy-carbonyl, C^alkyl, hydroxy , hydroxy-Ci_ 6 alkyl, Ci_ 6 alkyl-sulfanyl, or Ci_ 6 alkyl-sulfonyl, or pyridinyl, optionally substituted one, two or three times, preferably once or twice, with a group or groups independently selected from Ci_ 6 alkoxy, Ci_ 6 alkyl-sulfonyl, or halo-Ci_ 6 alkyl, or pyridinyl, optionally substituted with Ci_ 6 alkoxy, or pyrrolyl, optionally substituted with C^alkyl, or thienyl, optionally substituted with Ci_ 6 alkoxycarbonyl. In certain embodiments of formula I, Ar 1 is optionally substituted aryl. In certain embodiments of formula I, Ar 1 is optionally substituted phenyl.

In certain embodiments of formula I, Ar 1 is phenyl optionally substituted one, two or three times, preferably once or twice, with a group or groups independently selected from halo, Ci_ 6 alkyl, Ci_ 6 alkoxy, halo-Ci_ 6 alkyl, Ci_ 6 alkyl-carbonyl, Ci_ 6 alkoxy-carbonyl, Ci_ 6 alkyl-sulfonyl, Ci_ 6 alkyl-sulfanyl, amino, hydroxy-Ci_ 6 alkyl, hydroxy, alkylenedioxy and cyano.

In certain embodiments of formula I, Ar 1 is phenyl optionally substituted once or twice with a group or groups independently selected from fluoro, chloro, methyl, ethyl, methoxy, ethoxy, acetyl, methanesulfonyl, methanesulfanyl, hydroxymethyl, hydroxy, ethoxycarbonyl and cyano. In certain embodiments of formula I, Ar 1 is phenyl, 2-methoxy-phenyl, 3-methoxy- phenyl, 4-methoxy-phenyl, 2-chloro-phenyl, 3-chloro-phenyl, 4-chloro-phenyl, 2-methyl- phenyl, 3-methyl-phenyl, 4-methyl-phenyl, 2-fluoro-phenyl, 3-fluoro-phenyl, 4-fluoro- phenyl, 2-ethoxy-phenyl, 2-acetyl-phenyl, 2,3-dimethoxy-phenyl, 2,4-dimethoxy-phenyl, 2,5-dimethoxy-phenyl, 3,4-dimethoxy-phenyl, 3,5-dimethoxy-phenyl, 3,6-dimethoxy- phenyl, 2,3-dichloro-phenyl, 2,4-dichloro-phenyl, 2,5-dichloro-phenyl, 3,4-dichloro- phenyl, 3,5-dichloro-phenyl, 3,6-dichloro-phenyl, 2,3-difluoro-phenyl, 2,4-difluoro- phenyl, 2,5-difluoro-phenyl, 3,4-difluoro-phenyl, 3,5-difluoro-phenyl, 3,6-difluoro- phenyl, 2,3-dimethyl-phenyl, 2,4-dimethyl-phenyl, 2,5-dimethyl-phenyl, 3,4-dimethyl- phenyl, 3,5-dimethyl-phenyl, 3,6-dimethyl-phenyl, 3-chloro-2-methoxy-phenyl, 4- chloro-2-methoxy-phenyl, 5-chloro-2-methoxy-phenyl, 6-chloro-2-methoxy-phenyl, 2- chloro-3-methoxy-phenyl, 4-chloro-3-methoxy-phenyl, 5-chloro-3-methoxy-phenyl, 6- chloro-3-methoxy-phenyl, 2-chloro-4-methoxy-phenyl, 2-chloro-5-methoxy-phenyl, 3- fluoro-2-methoxy-phenyl, 4-fluoro-2-methoxy-phenyl, 5-fluoro-2-methoxy-phenyl, 6-

fluoro-2-methoxy-phenyl, 2-fluoro-3-methoxy-phenyl, 4-fluoro-3-methoxy-phenyl, 5- fluoro-3-methoxy-phenyl, 6-fluoro-3-methoxy-phenyl, 2-fluoro-4-methoxy-phenyl, 2- fluoro-5-methoxy-phenyl, 3-methyl-2-methoxy-phenyl, 4-methyl-2-methoxy-phenyl, 5- methyl-2-methoxy-phenyl, 6-methyl-2-methoxy-phenyl, 2-methyl-3-methoxy-phenyl, 4- methyl-3-methoxy-phenyl, 5-methyl-3-methoxy-phenyl, 6-methyl-3-methoxy-phenyl, 2- methyl-4-methoxy-phenyl, 2-methyl-5-methoxy-phenyl, 2-methanesulfanyl-phenyl, 2- methanesulfonyl-phenyl, 2-hydroxy-phenyl, 4-ethoxycarbonyl-phenyl, 2-ethyl-phenyl, 2- cyano-phenyl, or 4-methanesulfonyl-phenyl. In certain embodiments of formula I, Ar 1 is 3-methoxy-phenyl, 4-methoxy-phenyl, 2- chloro -phenyl, 3-chloro-phenyl, 4-chloro-phenyl, 2-methyl-phenyl, 3-methyl-phenyl, 4- methyl-phenyl, 2-fluoro-phenyl, 3-fluoro-phenyl, 4-fluoro-phenyl, 2-ethoxy-phenyl, 2- acetyl-phenyl, 2,3-dimethoxy-phenyl, 2,4-dimethoxy-phenyl, 2,5-dimethoxy-phenyl, 3,4- dimethoxy-phenyl, 3,5-dimethoxy-phenyl, 3,6-dimethoxy-phenyl, 2,3-dichloro-phenyl, 2,4-dichloro-phenyl, 2,5-dichloro-phenyl, 3,4-dichloro-phenyl, 3,5-dichloro-phenyl, 3,6- dichloro -phenyl, 2,3-difluoro-phenyl, 2,4-difluoro-phenyl, 2,5-difluoro-phenyl, 3,4- difluoro -phenyl, 3,5-difluoro-phenyl, 3,6-difluoro-phenyl, 2,3-dimethyl-phenyl, 2,4- dimethyl-phenyl, 2,5-dimethyl-phenyl, 3,4-dimethyl-phenyl, 3,5-dimethyl-phenyl, 3,6- dimethyl-phenyl, 3-chloro-2-methoxy-phenyl, 4-chloro-2-methoxy-phenyl, 5-chloro-2- methoxy-phenyl, 6-chloro-2-methoxy-phenyl, 2-chloro-3-methoxy-phenyl, 4-chloro-3- methoxy-phenyl, 5-chloro-3-methoxy-phenyl, 6-chloro-3-methoxy-phenyl, 2-chloro-4- methoxy-phenyl, 2-chloro-5-methoxy-phenyl, 3-fluoro-2-methoxy-phenyl, 4-fluoro-2- methoxy-phenyl, 5-fluoro-2-methoxy-phenyl, 6-fluoro-2-methoxy-phenyl, 2-fluoro-3- methoxy-phenyl, 4-fluoro-3-methoxy-phenyl, 5-fluoro-3-methoxy-phenyl, 6-fluoro-3- methoxy-phenyl, 2-fluoro-4-methoxy-phenyl, 2-fluoro-5-methoxy-phenyl, 3-methyl-2- methoxy-phenyl, 4-methyl-2-methoxy-phenyl, 5-methyl-2-methoxy-phenyl, 6-methyl-2- methoxy-phenyl, 2-methyl-3 -methoxy-phenyl, 4-methyl-3 -methoxy-phenyl, 5-methyl-3- methoxy-phenyl, 6-methyl-3 -methoxy-phenyl, 2-methyl-4-methoxy-phenyl, 2-methyl-5- methoxy-phenyl, 2-methanesulfanyl-phenyl, 2-methanesulfonyl-phenyl, 2-hydroxy- phenyl, 4-ethoxycarbonyl-phenyl, 2-ethyl-phenyl, 2-cyano-phenyl, or 4-methanesulfonyl- phenyl.

In certain embodiments of formula I, Ar 1 is phenyl, 2-methoxy-phenyl, 4-methoxy- phenyl, 4-chloro-phenyl, 4-methyl-phenyl, 2-methyl-phenyl, 2-chloro-phenyl, 2-fluoro- phenyl, 2-ethoxy-phenyl, 2-acetyl-phenyl, 2,4-dimethoxy-phenyl, 3,6-dimethoxy-phenyl,

5-fluoro-2-methoxy-phenyl, 5-chloro-2-methoxy-phenyl, 2,5-dichloro-phenyl, 2- hydroxymethyl-phenyl, 2,3-dichloro-phenyl, 2-methanesulfanyl-phenyl, 2,3-difluoro- phenyl, 2,4-dichloro-phenyl, 2-hydroxy-phenyl, 4-ethoxycarbonyl-phenyl, 2-ethyl-phenyl, 2-cyano-phenyl, 2,3-dimethoxy-phenyl, 4-methoxy-2-methyl-phenyl or A- methanesulfonyl-phenyl.

In certain embodiments of formula I, Ar 1 is 4-methoxy-phenyl, 4-chloro-phenyl, A- methyl-phenyl, 2-methyl-phenyl, 2-chloro-phenyl, 2-fluoro-phenyl, 2-ethoxy-phenyl, 2- acetyl-phenyl, 2,4-dimethoxy-phenyl, 3,6-dimethoxy-phenyl, 5-fluoro-2-methoxy-phenyl, 5-chloro-2-methoxy-phenyl, 2,5-dichloro-phenyl, 2-hydroxymethyl-phenyl, 2,3-dichloro- phenyl, 2-methanesulfanyl-phenyl, 2,3-difluoro-phenyl, 2,4-dichloro-phenyl, 2-hydroxy- phenyl, 4-ethoxycarbonyl-phenyl, 2-ethyl-phenyl, 2-cyano-phenyl, 2,3-dimethoxy-phenyl, 4-methoxy-2-methyl-phenyl or 4-methanesulfonyl-phenyl. In certain embodiments of formula I, Ar 1 is 2-methoxy-phenyl that is optionally substituted once at the 3-, A-, 5- or 6- position with fluoro, chloro, methyl or methoxy. In certain embodiments of formula I, Ar 1 is 2-methoxy-phenyl that is substituted once at the 3-, A-, 5- or 6- position with fluoro, chloro, methyl or methoxy. In certain embodiments of formula I, Ar 1 is 2-methoxy-phenyl. In certain embodiments of formula I, Ar 1 is optionally substituted heteroaryl. In certain embodiments of formula I, Ar 1 is pyridinyl, pyrimidinyl, thiophenyl or pyrrolyl, each optionally substituted once or twice with a group or groups independently selected from halo, Ci_ 6 alkyl, Ci_ 6 alkoxy, halo-Ci_ 6 alkyl, Ci_ 6 alkyl-carbonyl, Ci_ 6 alkoxy-carbonyl, Ci_ 6 alkyl-sulfonyl, amino sulfonyl, Ci_ 6 alkyl-sulfanyl, hydroxy-Ci_ 6 alkyl, amino, hydroxy, alkylenedioxy and cyano. In certain embodiments of formula I, Ar 1 is pyridinyl, pyrimidinyl, thiophenyl or pyrrolyl, each optionally substituted once or twice with a group or groups independently selected from fluoro, chloro, methyl, ethyl, methoxy, ethoxy, acetyl, methanesulfonyl, methanesulfanyl, hydro xymethyl, ethoxycarbonyl and cyano. In certain embodiments of formula I, Ar 1 is optionally substituted pyridinyl. In certain embodiments of formula I, Ar 1 is pyridinyl optionally substituted once or twice with a group or groups independently selected from halo, Ci_6alkyl, Ci_6alkoxy, halo-Ci_ βalkyl, Ci_ 6 alkyl-carbonyl, Ci_ 6 alkoxy-carbonyl, Ci_ 6 alkyl-sulfonyl, amino sulfonyl, Ci_ βalkyl-sulfanyl, hydroxy-Ci_6alkyl, amino, hydroxy, alkylenedioxy and cyano.

In certain embodiments of formula I, Ar 1 is pyridinyl optionally substituted once or twice with a group or groups independently selected from fluoro, chloro, methyl, ethyl, methoxy, ethoxy, acetyl, methanesulfonyl, methanesulfanyl, hydroxymethyl, ethoxycarbonyl and cyano. In certain embodiments of formula I, Ar 1 is pyridin-2-yl or pyridin-3-yl optionally substituted with methoxy or trifluoromethyl.

In certain embodiments of formula I, Ar 1 is 3-methoxy-pyridin-2-yl, 5-trifluoromethyl- pyridin-2-yl or 2-methoxy-pyridin-3-yl. In certain embodiments of the invention, Ar 2 is phenyl, optionally substituted one, two or three times, preferably once or twice, with a group or groups independently selected from Ci_ 6 alkoxy, Ci_ 6 alkyl, Ci _ βalkylsulfonyl, amino, amino sulfonyl, alkylenedioxy and halo, or pyridinyl. In certain embodiments of formula I, Ar 2 is optionally substituted phenyl. In certain embodiments of formula I, Ar 2 is phenyl optionally substituted once or twice with a group or groups independently selected from halo, Ci_6alkyl, Ci_6alkoxy, halo-Ci_ βalkyl, Ci_ 6 alkyl-carbonyl, Ci-ealkoxy-carbony^Ci-βalkyl-sulfonyl, Ci_ 6 alkyl-sulfanyl, hydroxy-Ci_6alkyl, amino, hydroxy, alkylenedioxy and cyano. In certain embodiments of formula I, Ar 2 is phenyl optionally substituted once or twice with a group or groups independently selected from fluoro, chloro, bromo, methyl, methoxy, aminosulfonyl, dimethylamino, methanesulfonyl or methylenedioxy. In certain embodiments of formula I, Ar 2 is phenyl, 2-methoxy-phenyl, 3-methoxy- phenyl, 4-methoxy-phenyl, 2-chloro-phenyl, 3-chloro-phenyl, 4-chloro-phenyl, 2-methyl- phenyl, 3-methyl-phenyl, 4-methyl-phenyl, 2-fluoro-phenyl, 3-fluoro-phenyl, 4-fluoro- phenyl, 2-ethoxy-phenyl, 2-acetyl-phenyl, 2,3-dimethoxy-phenyl, 2,4-dimethoxy-phenyl, 2,5-dimethoxy-phenyl, 3,4-dimethoxy-phenyl, 3,5-dimethoxy-phenyl, 3,6-dimethoxy- phenyl, 2,3-dichloro-phenyl, 2,4-dichloro-phenyl, 2,5-dichloro-phenyl, 3,4-dichloro- phenyl, 3,5-dichloro-phenyl, 3,6-dichloro-phenyl, 2,3-difluoro-phenyl, 2,4-difluoro- phenyl, 2,5-difluoro-phenyl, 3,4-difluoro-phenyl, 3,5-difluoro-phenyl, 3,6-difluoro- phenyl, 2,3-dimethyl-phenyl, 2,4-dimethyl-phenyl, 2,5-dimethyl-phenyl, 3,4-dimethyl- phenyl, 3,5-dimethyl-phenyl, 3,6-dimethyl-phenyl, 3-chloro-2-methoxy-phenyl, 4- chloro-2-methoxy-phenyl, 5-chloro-2-methoxy-phenyl, 6-chloro-2-methoxy-phenyl, 2- chloro-3-methoxy-phenyl, 4-chloro-3-methoxy-phenyl, 5-chloro-3-methoxy-phenyl, 6-

chloro-3-methoxy-phenyl, 2-chloro-4-methoxy-phenyl, 2-chloro-5-methoxy-phenyl, 3- fluoro-2-methoxy-phenyl, 4-fluoro-2-methoxy-phenyl, 5-fluoro-2-methoxy-phenyl, 6- fluoro-2-methoxy-phenyl, 2-fluoro-3-methoxy-phenyl, 4-fluoro-3-methoxy-phenyl, 5- fluoro-3-methoxy-phenyl, 6-fluoro-3-methoxy-phenyl, 2-fluoro-4-methoxy-phenyl, 2- fluoro-5-methoxy-phenyl, 3-methyl-2-methoxy-phenyl, 4-methyl-2-methoxy-phenyl, 5- methyl-2-methoxy-phenyl, 6-methyl-2-methoxy-phenyl, 2-methyl-3-methoxy-phenyl, A- methyl-3-methoxy-phenyl, 5-methyl-3-methoxy-phenyl, 6-methyl-3-methoxy-phenyl, 2- methyl-4-methoxy-phenyl, 2-methyl-5-methoxy-phenyl, 2-methanesulfanyl-phenyl, 2- hydroxy-phenyl, 4-ethoxycarbonyl-phenyl, 2-ethyl-phenyl, 2-cyano-phenyl, A- methanesulfonyl-phenyl, 4-aminosulfonyl-phenyl, 4-dimethylamino-phenyl or 3-bromo- 4-methoxy-phenyl.

In certain embodiments of formula I, Ar 2 is phenyl, 2-methoxy-phenyl, 3-methoxy- phenyl, 4-methoxy-phenyl, 2-chloro-phenyl, 3-chloro-phenyl, 4-chloro-phenyl, 2-methyl- phenyl, 3-methyl-phenyl, 4-methyl-phenyl, 2-fluoro-phenyl, 3-fluoro-phenyl, 4-fluoro- phenyl, 2-ethoxy-phenyl, 2-acetyl-phenyl, 2,3-dimethoxy-phenyl, 2,4-dimethoxy-phenyl, 2,5-dimethoxy-phenyl, 3,5-dimethoxy-phenyl, 3,6-dimethoxy-phenyl, 2,3-dichloro- phenyl, 2,4-dichloro-phenyl, 2,5-dichloro-phenyl, 3,4-dichloro-phenyl, 3,5-dichloro- phenyl, 3,6-dichloro-phenyl, 2,3-difluoro-phenyl, 2,4-difluoro-phenyl, 2,5-difluoro- phenyl, 3,4-difluoro-phenyl, 3,5-difluoro-phenyl, 3,6-difluoro-phenyl, 2,3-dimethyl- phenyl, 2,4-dimethyl-phenyl, 2,5-dimethyl-phenyl, 3,4-dimethyl-phenyl, 3,5-dimethyl- phenyl, 3,6-dimethyl-phenyl, 3-chloro-2-methoxy-phenyl, 4-chloro-2-methoxy-phenyl, 5-chloro-2-methoxy-phenyl, 6-chloro-2-methoxy-phenyl, 2-chloro-3-methoxy-phenyl, A- chloro-3-methoxy-phenyl, 5-chloro-3-methoxy-phenyl, 6-chloro-3-methoxy-phenyl, 2- chloro-4-methoxy-phenyl, 2-chloro-5-methoxy-phenyl, 3-fluoro-2-methoxy-phenyl, A- fluoro-2-methoxy-phenyl, 5-fluoro-2-methoxy-phenyl, 6-fluoro-2-methoxy-phenyl, 2- fluoro-3-methoxy-phenyl, 4-fluoro-3-methoxy-phenyl, 5-fluoro-3-methoxy-phenyl, 6- fluoro-3-methoxy-phenyl, 2-fluoro-4-methoxy-phenyl, 2-fluoro-5-methoxy-phenyl, 3- methyl-2-methoxy-phenyl, 4-methyl-2-methoxy-phenyl, 5-methyl-2-methoxy-phenyl, 6- methyl-2-methoxy-phenyl, 2-methyl-3-methoxy-phenyl, 4-methyl-3-methoxy-phenyl, 5- methyl-3-methoxy-phenyl, 6-methyl-3-methoxy-phenyl, 2-methyl-4-methoxy-phenyl, 2- methyl-5-methoxy-phenyl, 2-methanesulfanyl-phenyl, 2-hydroxy-phenyl, A- ethoxycarbonyl-phenyl, 2-ethyl-phenyl, 2-cyano-phenyl, 4-methanesulfonyl-phenyl, A- aminosulfonyl-phenyl, 4-dimethylamino-phenyl or 3-bromo-4-methoxy-phenyl.

In certain embodiments of formula I, Ar 2 is phenyl, 3-methoxy-phenyl, 4-methoxy- phenyl, 3,4-dimethoxy-phenyl, 4-aminosulfonyl-phenyl, 4-chloro-phenyl, 3,4-dichloro- phenyl, 3-bromo-4-methoxy-phenyl, 2-fluoro-phenyl, 3,4-difluoro-phenyl, 4-methyl- phenyl, 3-methyl-phenyl, 4-fluoro-phenyl, 4-dimethylamino-phenyl, 2-methyl-phenyl, 3,4-ethylenedioxy-phenyl or 4-methanesulfonylphenyl.

In certain embodiments of formula I, Ar 2 is phenyl, 3-methoxy-phenyl, 4-methoxy- phenyl, 4-aminosulfonyl-phenyl, 4-chloro-phenyl, 3,4-dichloro-phenyl, 3-bromo-4- methoxy-phenyl, 2-fluoro-phenyl, 3,4-difluoro-phenyl, 4-methyl-phenyl, 3-methyl- phenyl, 4-fluoro-phenyl, 4-dimethylamino-phenyl, 2-methyl-phenyl, 3,4-ethylenedioxy- phenyl or 4-methanesulfonylphenyl.

In certain embodiments of formula I, Ar 2 is optionally substituted heteroaryl. In certain embodiments of formula I, Ar 2 is pyridinyl, pyrimidinyl, thiophenyl or pyrrolyl, each optionally substituted once or twice with a group or groups independently selected from halo, Ci_ 6 alkyl, Ci_ 6 alkoxy, halo-Ci_ 6 alkyl, Ci_ 6 alkyl-carbonyl, Ci_ 6 alkoxy-carbonyl, Ci_ 6 alkyl-sulfonyl, amino sulfonyl, Ci_ 6 alkyl-sulfanyl, hydroxy-Ci_ 6 alkyl, amino, hydroxy, alkylenedioxy and cyano.

In certain embodiments of formula I, Ar 2 is pyridinyl, pyrimidinyl, thiophenyl or pyrrolyl, each optionally substituted once or twice with a group or groups independently selected from fluoro, chloro, methyl, ethyl, methoxy, ethoxy, acetyl, methanesulfonyl, methanesulfanyl, hydro xymethyl, ethoxycarbonyl and cyano.

In certain embodiments of formula I, Ar 2 is optionally substituted pyridinyl. In certain embodiments of formula I, Ar 2 is pyridinyl optionally substituted once or twice with a group or groups independently selected from halo, Ci_6alkyl, Ci_6alkoxy, halo-Ci_ βalkyl, Ci_ 6 alkyl-carbonyl, Ci-ealkoxy-carbony^Ci-βalkyl-sulfonyl, Ci_ 6 alkyl-sulfanyl, hydroxy-Ci_6alkyl, amino, hydroxy, alkylenedioxy and cyano.

In certain embodiments of formula I, Ar 2 is pyridinyl optionally substituted once or twice with a group or groups independently selected from fluoro, chloro, bromo, methyl, methoxy, aminosulfonyl, methanesulfonyl or methylenedioxy. In certain embodiments of formula I, Ar 2 is pyridin-2-yl, pyridin-3-yl or pyridin-4-yl. In certain embodiments the invention provides compounds of formula I wherein: n is 2 or 3; R 1 is hydrogen; R 2 is hydrogen;

Ar 1 is 2-methoxy-phenyl, 3-methoxy-phenyl, 4-methoxy-phenyl, 2-chloro-phenyl, 3-chloro-phenyl, 4-chloro-phenyl, 2-methyl-phenyl, 3-methyl-phenyl, 4-methyl-phenyl, 2-fluoro-phenyl, 3 -fluoro -phenyl, 4-fluoro-phenyl, 2-ethoxy-phenyl, 2-acetyl-phenyl, 2,3-dimethoxy-phenyl, 2,4-dimethoxy-phenyl, 2,5-dimethoxy-phenyl, 3,4-dimethoxy- phenyl, 3,5-dimethoxy-phenyl, 3,6-dimethoxy-phenyl, 2,3-dichloro-phenyl, 2,4-dichloro- phenyl, 2,5-dichloro-phenyl, 3,4-dichloro-phenyl, 3,5-dichloro-phenyl, 3,6-dichloro- phenyl, 2,3-difluoro-phenyl, 2,4-difluoro-phenyl, 2,5-difluoro-phenyl, 3,4-difluoro- phenyl, 3,5-difluoro-phenyl, 3,6-difluoro-phenyl, 2,3-dimethyl-phenyl, 2,4-dimethyl- phenyl, 2,5-dimethyl-phenyl, 3,4-dimethyl-phenyl, 3,5-dimethyl-phenyl, 3,6-dimethyl- phenyl, 3-chloro-2-methoxy-phenyl, 4-chloro-2-methoxy-phenyl, 5-chloro-2-methoxy- phenyl, 6-chloro-2-methoxy-phenyl, 2-chloro-3-methoxy-phenyl, 4-chloro-3-methoxy- phenyl, 5-chloro-3-methoxy-phenyl, 6-chloro-3-methoxy-phenyl, 2-chloro-4-methoxy- phenyl, 2-chloro-5-methoxy-phenyl, 3-fluoro-2-methoxy-phenyl, 4-fluoro-2-methoxy- phenyl, 5-fluoro-2-methoxy-phenyl, 6-fluoro-2-methoxy-phenyl, 2-fluoro-3-methoxy- phenyl, 4-fluoro-3-methoxy-phenyl, 5-fluoro-3-methoxy-phenyl, 6-fluoro-3-methoxy- phenyl, 2-fluoro-4-methoxy-phenyl, 2-fluoro-5-methoxy-phenyl, 3-methyl-2-methoxy- phenyl, 4-methyl-2-methoxy-phenyl, 5-methyl-2-methoxy-phenyl, 6-methyl-2-methoxy- phenyl, 2-methyl-3-methoxy-phenyl, 4-methyl-3-methoxy-phenyl, 5-methyl-3-methoxy- phenyl, 6-methyl-3-methoxy-phenyl, 2-methyl-4-methoxy-phenyl, 2-methyl-5-methoxy- phenyl, 2-methanesulfanyl-phenyl, 2-methanesulfonyl-phenyl, 2-hydroxy-phenyl, 4- ethoxycarbonyl-phenyl, 2-ethyl-phenyl, 2-cyano-phenyl, or 4-methanesulfonyl-phenyl; and

Ar 2 is phenyl, 2-methoxy-phenyl, 3-methoxy-phenyl, 4-methoxy-phenyl, 2- chloro -phenyl, 3-chloro-phenyl, 4-chloro-phenyl, 2-methyl-phenyl, 3-methyl-phenyl, A- methyl-phenyl, 2-fluoro-phenyl, 3-fluoro-phenyl, 4-fluoro-phenyl, 2-ethoxy-phenyl, 2- acetyl-phenyl, 2,3-dimethoxy-phenyl, 2,4-dimethoxy-phenyl, 2,5-dimethoxy-phenyl, 3,5- dimethoxy-phenyl, 3,6-dimethoxy-phenyl, 2,3-dichloro-phenyl, 2,4-dichloro-phenyl, 2,5- dichloro-phenyl, 3,4-dichloro-phenyl, 3,5-dichloro-phenyl, 3,6-dichloro-phenyl, 2,3- difluoro-phenyl, 2,4-difluoro-phenyl, 2,5-difluoro-phenyl, 3,4-difluoro-phenyl, 3,5- difluoro -phenyl, 3,6-difluoro-phenyl, 2,3-dimethyl-phenyl, 2,4-dimethyl-phenyl, 2,5- dimethyl-phenyl, 3,4-dimethyl-phenyl, 3,5-dimethyl-phenyl, 3,6-dimethyl-phenyl, 3- chloro-2-methoxy-phenyl, 4-chloro-2-methoxy-phenyl, 5-chloro-2-methoxy-phenyl, 6- chloro-2-methoxy-phenyl, 2-chloro-3-methoxy-phenyl, 4-chloro-3-methoxy-phenyl, 5-

chloro-3-methoxy-phenyl, β-chloro-S-methoxy-phenyl, 2-chloro-4-methoxy-phenyl, 2- chloro-5-methoxy-phenyl, 3-fluoro-2-methoxy-phenyl, 4-fluoro-2-methoxy-phenyl, 5- fluoro-2-methoxy-phenyl, 6-fluoro-2-methoxy-phenyl, 2-fluoro-3-methoxy-phenyl, 4- fluoro-3-methoxy-phenyl, 5-fluoro-3-methoxy-phenyl, 6-fluoro-3-methoxy-phenyl, 2- fluoro-4-methoxy-phenyl, 2-fluoro-5-methoxy-phenyl, 3-methyl-2-methoxy-phenyl, 4- methyl-2-methoxy-phenyl, 5-methyl-2-methoxy-phenyl, 6-methyl-2-methoxy-phenyl, 2- methyl-3-methoxy-phenyl, 4-methyl-3-methoxy-phenyl, 5-methyl-3-methoxy-phenyl, 6- methyl-3-methoxy-phenyl, 2-methyl-4-methoxy-phenyl, 2-methyl-5-methoxy-phenyl, 2- methanesulfanyl-phenyl, 2-hydroxy-phenyl, 4-ethoxycarbonyl-phenyl, 2-ethyl-phenyl, 2- cyano-phenyl, 4-methanesulfonyl-phenyl, 4-aminosulfonyl-phenyl, 4-dimethylamino- phenyl or 3-bromo-4-methoxy-phenyl.

In certain embodiments the invention provides compounds of formula I wherein: n is 2 or 3; R 1 is hydrogen; R 2 is hydrogen;

Ar 1 is 3-methoxy-phenyl, 4-methoxy-phenyl, 2-chloro-phenyl, 3-chloro-phenyl, 4-chloro-phenyl, 2-methyl-phenyl, 3-methyl-phenyl, 4-methyl-phenyl, 2-fluoro-phenyl, 3-fluoro-phenyl, 4-fluoro-phenyl, 2-ethoxy-phenyl, 2-acetyl-phenyl, 2,3-dimethoxy- phenyl, 2,4-dimethoxy-phenyl, 2,5-dimethoxy-phenyl, 3,4-dimethoxy-phenyl, 3,5- dimethoxy-phenyl, 3,6-dimethoxy-phenyl, 2,3-dichloro-phenyl, 2,4-dichloro-phenyl, 2,5- dichloro -phenyl, 3,4-dichloro-phenyl, 3,5-dichloro-phenyl, 3,6-dichloro-phenyl, 2,3- difluoro -phenyl, 2,4-difluoro-phenyl, 2,5-difluoro-phenyl, 3,4-difluoro-phenyl, 3,5- difluoro -phenyl, 3,6-difluoro-phenyl, 2,3-dimethyl-phenyl, 2,4-dimethyl-phenyl, 2,5- dimethyl-phenyl, 3,4-dimethyl-phenyl, 3,5-dimethyl-phenyl, 3,6-dimethyl-phenyl, 3- chloro-2-methoxy-phenyl, 4-chloro-2-methoxy-phenyl, 5-chloro-2-methoxy-phenyl, 6- chloro-2-methoxy-phenyl, 2-chloro-3-methoxy-phenyl, 4-chloro-3-methoxy-phenyl, 5- chloro-3-methoxy-phenyl, 6-chloro-3-methoxy-phenyl, 2-chloro-4-methoxy-phenyl, 2- chloro-5-methoxy-phenyl, 3-fluoro-2-methoxy-phenyl, 4-fluoro-2-methoxy-phenyl, 5- fluoro-2-methoxy-phenyl, 6-fluoro-2-methoxy-phenyl, 2-fluoro-3-methoxy-phenyl, 4- fluoro-3-methoxy-phenyl, 5-fluoro-3-methoxy-phenyl, 6-fluoro-3-methoxy-phenyl, 2- fluoro-4-methoxy-phenyl, 2-fluoro-5-methoxy-phenyl, 3-methyl-2-methoxy-phenyl, A- methyl-2-methoxy-phenyl, 5-methyl-2-methoxy-phenyl, 6-methyl-2-methoxy-phenyl, 2- methyl-3-methoxy-phenyl, 4-methyl-3-methoxy-phenyl, 5-methyl-3-methoxy-phenyl, 6-

methyl-3-methoxy-phenyl, 2-methyl-4-methoxy-phenyl, 2-methyl-5-methoxy-phenyl, 2- methanesulfanyl-phenyl, 2-methanesulfonyl-phenyl, 2-hydroxy-phenyl, A- ethoxycarbonyl-phenyl, 2-ethyl-phenyl, 2-cyano-phenyl, or 4-methanesulfonyl-phenyl; and Ar 2 is phenyl, 2-methoxy-phenyl, 3-methoxy-phenyl, 4-methoxy-phenyl, 2- chloro -phenyl, 3-chloro-phenyl, 4-chloro-phenyl, 2-methyl-phenyl, 3-methyl-phenyl, A- methyl-phenyl, 2-fluoro-phenyl, 3-fluoro-phenyl, 4-fluoro-phenyl, 2-ethoxy-phenyl, 2- acetyl-phenyl, 2,3-dimethoxy-phenyl, 2,4-dimethoxy-phenyl, 2,5-dimethoxy-phenyl, 3,4- dimethoxy-phenyl, 3,5-dimethoxy-phenyl, 3,6-dimethoxy-phenyl, 2,3-dichloro-phenyl, 2,4-dichloro-phenyl, 2,5-dichloro-phenyl, 3,4-dichloro-phenyl, 3,5-dichloro-phenyl, 3,6- dichloro -phenyl, 2,3-difluoro-phenyl, 2,4-difluoro-phenyl, 2,5-difluoro-phenyl, 3,4- difluoro -phenyl, 3,5-difluoro-phenyl, 3,6-difluoro-phenyl, 2,3-dimethyl-phenyl, 2,4- dimethyl-phenyl, 2,5-dimethyl-phenyl, 3,4-dimethyl-phenyl, 3,5-dimethyl-phenyl, 3,6- dimethyl-phenyl, 3-chloro-2-methoxy-phenyl, 4-chloro-2-methoxy-phenyl, 5-chloro-2- methoxy-phenyl, 6-chloro-2-methoxy-phenyl, 2-chloro-3-methoxy-phenyl, 4-chloro-3- methoxy-phenyl, 5-chloro-3-methoxy-phenyl, 6-chloro-3-methoxy-phenyl, 2-chloro-4- methoxy-phenyl, 2-chloro-5-methoxy-phenyl, 3-fluoro-2-methoxy-phenyl, 4-fluoro-2- methoxy-phenyl, 5-fluoro-2-methoxy-phenyl, 6-fluoro-2-methoxy-phenyl, 2-fluoro-3- methoxy-phenyl, 4-fluoro-3-methoxy-phenyl, 5-fluoro-3-methoxy-phenyl, 6-fluoro-3- methoxy-phenyl, 2-fluoro-4-methoxy-phenyl, 2-fluoro-5-methoxy-phenyl, 3-methyl-2- methoxy-phenyl, 4-methyl-2-methoxy-phenyl, 5-methyl-2-methoxy-phenyl, 6-methyl-2- methoxy-phenyl, 2-methyl-3 -methoxy-phenyl, 4-methyl-3 -methoxy-phenyl, 5-methyl-3- methoxy-phenyl, 6-methyl-3 -methoxy-phenyl, 2-methyl-4-methoxy-phenyl, 2-methyl-5- methoxy-phenyl, 2-methanesulfanyl-phenyl, 2-hydroxy-phenyl, 4-ethoxycarbonyl-phenyl, 2-ethyl-phenyl, 2-cyano-phenyl, 4-methanesulfonyl-phenyl, 4-aminosulfonyl-phenyl, A- dimethylamino -phenyl or 3-bromo-4-methoxy-phenyl.

In certain embodiments the invention provides compounds of formula I wherein: n is 2 or 3; R 1 is hydrogen; R 2 is hydrogen;

Ar 1 is 2-methoxy-phenyl, 4-methoxy-phenyl, 4-chloro-phenyl, 4-methyl-phenyl, 2-methyl-phenyl, 2-chloro-phenyl, 2-fluoro-phenyl, 2-ethoxy-phenyl, 2-acetyl-phenyl, 2,4-dimethoxy-phenyl, 3,6-dimethoxy-phenyl, 5-fluoro-2-methoxy-phenyl, 5-chloro-2-

methoxy-phenyl, 2,5-dichloro-phenyl, 2-hydroxymethyl-phenyl, 2,3-dichloro-phenyl, 2- methanesulfanyl-phenyl, 2,3-difluoro-phenyl, 2,4-dichloro-phenyl, 2-hydroxy-phenyl, 4- ethoxycarbonyl-phenyl, 2-ethyl-phenyl, 2-cyano-phenyl, 2,3-dimethoxy-phenyl, 4- methoxy-2-methyl-phenyl or 4-methanesulfonyl-phenyl; and Ar 2 is phenyl, 3-methoxy-phenyl, 4-methoxy-phenyl, 4-aminosulfonyl-phenyl, 4- chloro -phenyl, 3,4-dichloro-phenyl, 3-bromo-4-methoxy-phenyl, 2-fluoro-phenyl, 3,4- difluoro -phenyl, 4-methyl-phenyl, 3-methyl-phenyl, 4-fluoro-phenyl, 4-dimethylamino- phenyl, 2-methyl-phenyl, 3,4-ethylenedioxy-phenyl or 4-methanesulfonylphenyl. In certain embodiments the invention provides compounds of formula I wherein: n is 2 or 3;

R 1 is hydrogen; R 2 is hydrogen;

Ar 1 is 4-methoxy-phenyl, 4-chloro-phenyl, 4-methyl-phenyl, 2-methyl-phenyl, 2- chloro -phenyl, 2-fluoro-phenyl, 2-ethoxy-phenyl, 2-acetyl-phenyl, 2,4-dimethoxy-phenyl, 3,6-dimethoxy-phenyl, 5-fluoro-2-methoxy-phenyl, 5-chloro-2-methoxy-phenyl, 2,5- dichloro-phenyl, 2-hydroxymethyl-phenyl, 2,3-dichloro-phenyl, 2-methanesulfanyl- phenyl, 2,3-difluoro-phenyl, 2,4-dichloro-phenyl, 2-hydroxy-phenyl, 4-ethoxycarbonyl- phenyl, 2-ethyl-phenyl, 2-cyano-phenyl, 2,3-dimethoxy-phenyl, 4-methoxy-2-methyl- phenyl or 4-methanesulfonyl-phenyl; and Ar 2 is phenyl, 3-methoxy-phenyl, 4-methoxy-phenyl, 3,4-dimethoxy-phenyl, 4- aminosulfonyl-phenyl, 4-chloro-phenyl, 3,4-dichloro-phenyl, 3-bromo-4-methoxy- phenyl, 2-fluoro-phenyl, 3,4-difluoro-phenyl, 4-methyl-phenyl, 3-methyl-phenyl, 4- fluoro -phenyl, 4-dimethylamino-phenyl, 2-methyl-phenyl, 3,4-ethylenedioxy-phenyl or 4-methanesulfonylphenyl. In certain embodiments of the invention the subject compounds are of formula II:

wherein:

p is from 1 to 3; q is from O to 3; and each R 3 and R 4 is independently: halo; Ci_ 6 alkyl;

Ci_6alkoxy; halo-Ci_ 6 alkyl;

C i _ 6 alky 1- carbony 1;

C i _ 6 alkoxy-carbonyl; Ci_ 6 alkyl-sulfonyl;

C i -βalky 1- sulfanyl; amino; hydro xy-C i -βalkyl; hydroxy; cyano; or two of R 3 may form alkylenedioxy; or two of R 4 may form alkylenedioxy; provided that when p is 1, q is 2 and R is methoxy at the 2-position of the phenyl ring to which it is attached, then R 4 is not methoxy at the 3- and 4-positions of the phenyl ring to which they are attached.

In certain embodiments of formula II, p is from 0 to 2. In certain embodiments of formula II, p is 1 or 2.

In certain embodiments of formula II, each R 3 is independently fluoro, chloro, methyl, ethyl, hydroxy, methoxy, ethoxy, acetyl, methanesulfonyl, methanesulfanyl, hydro xymethyl, ethoxycarbonyl or cyano.

In certain embodiments of formula II, q is from 0 to 2. In certain embodiments of formula II, q is 1 or 2.

In certain embodiments of formula II, each R 4 is independently fluoro, chloro, bromo, methyl, methoxy, aminosulfonyl, dimethylamino, or methanesulfonyl, or two of R may form methylenedioxy.

In certain embodiments of formula II, p is 1 and R 3 is methoxy.

The invention also provides a method for treating indications mediated by or associated with a nicotinic alpha 7 modulator, the method comprising administering to a subject in need thereof an effective amount of a compound of formula I

or a pharmaceutically acceptable salt thereof, wherein: n is from 1 to 3;

Ar 1 and Ar 2 each independently is optionally substituted phenyl or optionally substituted pyridinyl; R 1 is hydrogen or Ci_ 6 alkyl;

R 2 is hydrogen, or R 2 may form an alkylene bridge with Ar 2 .

Where any of R 1 , R 2 and R 3 herein are alkyl or contain an alkyl moiety, such alkyl is preferably lower alkyl, i.e. d-Cβalkyl, and more preferably Ci-C4alkyl. Representative compounds in accordance with the methods of the invention are shown in Table 1.

TABLE 1

# Structure Name M+H

2'-Methoxy-5-tetrazol- 1 - 400 yl-biphenyl-3-carboxylic acid phenethyl-amide

2'-Methoxy-5-tetrazol- 1 - 430 yl-biphenyl-3-carboxylic acid [2-(4-methoxy- phenyl)-ethyl] -amide

2'-Methoxy-5-tetrazol- 1 - 430 yl-biphenyl-3-carboxylic acid [2-(3-methoxy- phenyl)-ethyl] -amide

2'-Methoxy-5-tetrazol- 1 - 479 yl-biphenyl-3-carboxylic acid [2-(4-sulfamoyl- phenyl)-ethyl] -amide

2'-Methoxy-5-tetrazol- 1 - 434 yl-biphenyl-3-carboxylic acid [2-(4-chloro-phenyl)- ethyl] -amide

2'-Methoxy-5-tetrazol- 1 - 468 yl-biphenyl-3-carboxylic acid [2-(3,4-dichloro- phenyl)-ethyl] -amide

2'-Methoxy-5-tetrazol- 1 - 509 yl-biphenyl-3-carboxylic acid [2-(3-bromo-4- methoxy-phenyl)-ethyl] - amide

2'-Methoxy-5-tetrazol- 1 - 418 yl-biphenyl-3-carboxylic acid [2-(2-fluoro-phenyl)- ethyl] -amide

2'-Methoxy-5-tetrazol- 1 - 436 yl-biphenyl-3-carboxylic acid [2-(3,4-difluoro- phenyl)-ethyl] -amide

2'-Methoxy-5-tetrazol- 1 - 414 yl-biphenyl-3-carboxylic acid (2-p-tolyl-ethyl)- amide

2'-Methoxy-5-tetrazol- 1 - 414 yl-biphenyl-3-carboxylic acid (2-o-tolyl-ethyl)- amide

2'-Chloro-5-tetrazol- 1 -yl- 464 biphenyl-3 -carboxylic acid [2-(3,4-dimethoxy- phenyl)-ethyl] -amide

2'-Fluoro-5-tetrazol- 1 -yl- 448 biphenyl-3 -carboxylic acid [2-(3,4-dimethoxy- phenyl)-ethyl] -amide

2'-Ethoxy-5-tetrazol- 1 -yl- 474 biphenyl-3 -carboxylic acid [2-(3,4-dimethoxy- phenyl)-ethyl] -amide

2'-Acetyl-5-tetrazol- 1 -yl- 472 biphenyl-3 -carboxylic acid [2-(3,4-dimethoxy- phenyl)-ethyl] -amide

2',4'-Dimethoxy-5- 490 tetrazol- 1 -yl-biphenyl-3- carboxylic acid [2-(3,4- dimethoxy-phenyl)-ethyl] - amide

2',5'-Dimethoxy-5- 490 tetrazol- 1 -yl-biphenyl-3- carboxylic acid [2-(3,4- dimethoxy-phenyl)-ethyl] - amide

Synthesis

Compounds of the present invention can be made by a variety of methods depicted in the illustrative synthetic reaction schemes shown and described below.

In general, the compounds of present invention may be synthesized by reacting a compound of formula (1)

with an amine of formula (2)

to give a compound of formula I wherein Ar 1 , Ar 2 , R 1 , R 2 and n are as defined above. Moreover, present invention relates to compounds obtainable by the synthesis process(es) as described herein. The starting materials and reagents used in preparing these compounds generally are either available from commercial suppliers, such as Aldrich Chemical Co., or are prepared by methods known to those skilled in the art following procedures set forth in references such as Fieser and Fieser's Reagents for Organic Synthesis; Wiley & Sons: New York, 1991, Volumes 1-15; Rodd's Chemistry of Carbon Compounds, Elsevier Science Publishers, 1989, Volumes 1-5 and Supplemental ; and Organic Reactions, Wiley & Sons: New York, 1991, Volumes 1-40. The following synthetic reaction schemes are merely illustrative of some methods by which the compounds of the present invention can be synthesized, and various modifications to these synthetic reaction schemes can be made and will be suggested to one skilled in the art having referred to the disclosure contained in this Application. The starting materials and the intermediates of the synthetic reaction schemes can be isolated and purified if desired using conventional techniques, including but not limited to, filtration, distillation, crystallization, chromatography, and the like. Such materials can be characterized using conventional means, including physical constants and spectral data.

Unless specified to the contrary, the reactions described herein preferably are conducted under an inert atmosphere at atmospheric pressure at a reaction temperature range of from about -78 0 C to about 150 0 C, more preferably from about 0 0 C to about 125 0 C, and most preferably and conveniently at about room (or ambient) temperature, e.g., about

2O 0 C.

Scheme A below illustrates one synthetic procedure usable to prepare compounds of the invention, wherein R is lower alkyl, and n, p, q, R 3 , and R 4 are as defined herein.

SCHEME A In step 1 of Scheme A, nitrobenzoic acid a undergoes iodination to afford nitro- iodobenzoic acid b. In step 2 compound b is treated with phenylboronic acid c in the presence of a suitable palladium catalyst to provide biphenyl carboxylic acid d. Compound d undergoes esterification in step 3 by reaction with lower alcohol ROH in the presence of acid to afford biphenyl carboxylic acid ester compound e. In step 4 the nitro group of compound e is reduced to an amino group to afford biphenyl amine compound f. Compound f is reacted with sodium azide in step 5 to give biphenyl tetrazole compound g. Hydrolysis of the carboxylate ester group of compound g in step 6 affords biphenyl carboxylic acid compound h. In step 7, an amide coupling reaction is

carried out by reaction of carboxylic acid compound h with amine compound i, to afford biphenyl tetrazole amide compound j, which is a compound of formula I in accordance with the invention.

Many variations on the procedure of Scheme A are possible and will suggest themselves to those skilled in the art. For example, the iodine used in step 1 may be replaced with bromine in certain embodiments. Reduction of the nitro group to an amino group may be carried out on compound b prior to the Buchwald reaction of step 2. Details of the procedure of Scheme A are provided in the Experimental section below.

Utility The compounds of the invention are usable for the treatment of diseases or conditions associated with the nicotinic alpha 7 (α7nACh) receptor, including treatment of psychotic diseases, neurodegenerative diseases, and cognitive impairments involving a dysfunction of the cholinergic system, and conditions of memory and/or cognition impairment, including, for example, schizophrenia, anxiety, mania, depression, manic depression, Tourette's syndrome, Parkinson's disease, Huntington's disease, cognitive disorders (such as Alzheimer's disease, Lewy Body Dementia, Amyotrophic Lateral Sclerosis, memory impairment, memory loss, cognition deficit, attention deficit, Attention Deficit Hyperactivity Disorder), and other uses such as treatment of nicotine addiction, inducing smoking cessation, treating pain (i.e., analgesic use), providing neuroprotection, and treating jetlag. The compounds of the invention are useful for enhancing cognition in Alzheimer's patients and patients having cognition impairment or cognitive disorders associated with schizophrenia, anxiety, mania, depression, manic depression, Tourette's syndrome, Parkinson's disease, Huntington's disease, Lewy Body Dementia, Amyotrophic Lateral Sclerosis, memory impairment, memory loss, cognition deficit, attention deficit or Attention Deficit Hyperactivity Disorder.

Thus, the invention provides a method of treating a patient or subject, specifically a mammal and especially a human, suffering from psychotic diseases, neurodegenerative diseases involving a dysfunction of the cholinergic system, and conditions of memory and/or cognition impairment, including, for example, schizophrenia, anxiety, mania, depression, manic depression [examples of psychotic disorders], Tourette's syndrome, Parkinson's disease, Huntington's disease [examples of neurodegenerative diseases], and/or cognitive disorders (such as Alzheimer's disease, Lewy Body Dementia, Amyotrophic Lateral Sclerosis, memory impairment, memory loss, cognition deficit,

attention deficit, Attention Deficit Hyperactivity Disorder) comprising administering to the patient an effective amount of a compound of the invention.

Neurodegenerative disorders include, but are not limited to, treatment and/or prophylaxis of Alzheimer's diseases, Pick's disease, diffuse Lewy Body disease, progressive supranuclear palsy (Steel-Richardson syndrome), multisystem degeneration (Shy-Drager syndrome), motor neuron diseases including amyotrophic lateral sclerosis, degenerative ataxias, cortical basal degeneration, ALS-Parkinson's-Dementia complex of Guam, subacute sclerosing panencephalitis, Huntington's disease, Parkinson's disease, synucleinopathies, primary progressive aphasia, striatonigral degeneration, Machado- Joseph disease/spinocerebellar ataxia type 3, olivopontocerebellar degenerations, Gilles De La Tourette's disease, bulbar, pseudobulbar palsy, spinal muscular atrophy, spinobulbar muscular atrophy (Kennedy's disease), primary lateral sclerosis, familial spastic paraplegia, Werdnig-Hoffmann disease, Kugelberg-Welander disease, Tay-Sach's disease, Sandhoff disease, familial spastic disease, Wohlfart-Kugelberg-Welander disease, spastic paraparesis, progressive multifocal leukoencephalopathy, prion diseases (such as Creutzfeldt- Jakob, Gerstmann-Straussler-Scheinker disease, Kuru and fatal familial insomnia), and neurodegenerative disorders resulting from cerebral ischemia or infarction including embolic occlusion and thrombotic occlusion as well as intracranial hemorrhage of any type (including, but not limited to, epidural, subdural, subarachnoid and intracerebral), and intracranial and intravertebral lesions (including, but not limited to, contusion, penetration, shear, compression and laceration).

In addition, the compounds of the invention may be used to treat age-related dementia and other dementias and conditions with memory loss including age-related memory loss, senility, vascular dementia, diffuse white matter disease (Binswanger's disease), dementia of endocrine or metabolic origin, dementia of head trauma and diffuse brain damage, dementia pugilistica and frontal lobe dementia. Thus, the invention provides a method of treating a patient, especially a human, suffering from age-related dementia and other dementias and conditions with memory loss, as well as enhancing cognitive memory in Alzheimer's patients, comprising administering to the patient an effective amount of a compound of the invention.

The invention provides methods of treating subjects suffering from memory impairment due to, for example, Alzheimer's disease, mild cognitive impairment due to aging, schizophrenia, Parkinson's disease, Huntington's disease, Pick's disease, Creutzfeldt-

Jakob disease, depression, aging, head trauma, stroke, CNS hypoxia, cerebral senility, multiinfarct dementia and other neurological conditions, as well as HIV and cardiovascular diseases, comprising administering an effective amount of a compound of the invention. Amyloid precursor protein (APP) and Aβ peptides derived therefrom, e.g., Aβi_4o , Aβi_4 2 , and other fragments, are known to be involved in the pathology of Alzheimer's disease. The Aβi_42 peptides are not only implicated in neurotoxicity but also are known to inhibit cholinergic transmitter function. Further, it has been determined that Aβ peptides bind to α7nACh receptors. Agents which block the binding of the Aβ peptides to α-7 nAChRs are thus useful for treating neurodegenerative diseases. In addition, stimulation α7nACh receptors can protect neurons against cytotoxicity associated with Aβ peptides. Thus, the invention provides a method of treating and/or preventing dementia in an Alzheimer's patient which comprises administering to the subject a therapeutically effective amount of a compound according to Formulas I-IV to inhibit the binding of an amyloid beta peptide (preferably, Aβi_ 42 ) with nACh receptors, preferable α7nACh receptors, most preferably, human α7nACh receptors (as well as a method for treating and/or preventing other clinical manifestations of Alzheimer's disease that include, but are not limited to, cognitive and language deficits, apraxias, depression, delusions and other neuropsychiatric symptoms and signs, and movement and gait abnormalities). The invention also provides methods for treating other amyloidosis diseases, for example, hereditary cerebral angiopathy, nonneuropathic hereditary amyloid, Down's syndrome, macroglobulinemia, secondary familial Mediterranean fever, Muckle- Wells syndrome, multiple myeloma, pancreatic- and cardiac-related amyloidosis, chronic hemodialysis anthropathy, and Finnish and Iowa amyloidosis. Nicotinic receptors have been implicated as playing a role in the body's response to alcohol ingestion, and the compounds of the invention are useful in the treatment of alcohol withdrawal and in anti- intoxication therapy.

Agonists for the α7nACh receptor subtypes can also be used for neuroprotection against damage associated with strokes and ischemia and glutamate-induced excitotoxicity, and the invention thus provides a method of treating a patient to provide for neuroprotection against damage associated with strokes and ischemia and glutamate-induced excitotoxicity comprising administering to the patient an effective amount of a compound of the invention.

Agonists for the α7nACh receptor subtypes can also be used in the treatment of nicotine addiction, inducing smoking cessation, treating pain, and treating jetlag, obesity, diabetes, and inflammation, and the invention thus provides a method of treating a patient suffering from nicotine addiction, pain, jetlag, obesity, diabetes, and/or inflammation, or a method of inducing smoking cessation in a patient comprising administering to the patient an effective amount of a compound of the invention

The inflammatory reflex is an autonomic nervous system response to an inflammatory signal. Upon sensing an inflammatory stimulus, the autonomic nervous system responds through the vagus nerve by releasing acetylcholine and activating nicotinic α7 receptors on macrophages. These macrophages in turn release cytokines. Dysfunctions in this pathway have been linked to human inflammatory diseases including rheumatoid arthritis, diabetes and sepsis. Macrophages express the nicotinic α7 receptor and it is likely this receptor that mediates the cholinergic anti-inflammatory response. Therefore, compounds of the invention may be useful for treating a patient (e.g., a mammal, such as a human) suffering from an inflammatory disease or disorder, such as, but not limited to, rheumatoid arthritis, diabetes or sepsis.

The compounds of the invention are expected to find utility as analgesics in the treatment of diseases and conditions associated with pain from a wide variety of causes, including, but not limited to, inflammatory pain, surgical pain, visceral pain, dental pain, premenstrual pain, central pain, pain due to burns, migraine or cluster headaches, nerve injury, neuritis, neuralgias, poisoning, ischemic injury, interstitial cystitis, cancer pain, viral, parasitic or bacterial infection, post-traumatic injuries (including fractures and sports injuries), and pain associated with functional bowel disorders such as irritable bowel syndrome. Further, compounds of the invention are useful for treating respiratory disorders, including chronic obstructive pulmonary disorder (COPD), asthma, bronchospasm, and the like.

In addition, due to their affinity to α7nACh receptors, labeled derivatives of the compounds of Formulas I-IV (e.g., C 11 or F 18 labeled derivatives), can be used in neuroimaging of the receptors within, e.g., the brain. Thus, using such labeled agents in vivo imaging of the receptors can be performed using, e.g., PET imaging. The invention also provides a method of treating a patient suffering from, for example, mild cognitive impairment (MCI), vascular dementia (VaD), age-associated cognitive

decline (AACD), amnesia associated w/open-heart-surgery, cardiac arrest, and/or general anesthesia, memory deficits from early exposure of anesthetic agents, sleep deprivation induced cognitive impairment, chronic fatigue syndrome, narcolepsy, AIDS- related dementia, epilepsy-related cognitive impairment, Down's syndrome, Alcoholism related dementia, drug/substance induced memory impairments, Dementia Puglistica (Boxer Syndrome), and animal dementia (e.g., dogs, cats, horses, etc.) comprising administering to the patient an effective amount of a compound of the invention.

Administration and Pharmaceutical Composition The invention includes pharmaceutical compositions comprising at least one compound of the present invention, or an individual isomer, racemic or non-racemic mixture of isomers or a pharmaceutically acceptable salt or solvate thereof, together with at least one pharmaceutically acceptable carrier, and optionally other therapeutic and/or prophylactic ingredients. In general, the compounds of the invention will be administered in a therapeutically effective amount by any of the accepted modes of administration for agents that serve similar utilities. Suitable dosage ranges are typically 1-500 mg daily, preferably 1-100 mg daily, and most preferably 1-30 mg daily, depending upon numerous factors such as the severity of the disease to be treated, the age and relative health of the subject, the potency of the compound used, the route and form of administration, the indication towards which the administration is directed, and the preferences and experience of the medical practitioner involved. One of ordinary skill in the art of treating such diseases will be able, without undue experimentation and in reliance upon personal knowledge and the disclosure of this Application, to ascertain a therapeutically effective amount of the compounds of the present invention for a given disease. Compounds of the invention may be administered as pharmaceutical formulations including those suitable for oral (including buccal and sub-lingual), rectal, nasal, topical, pulmonary, vaginal, or parenteral (including intramuscular, intraarterial, intrathecal, subcutaneous and intravenous) administration or in a form suitable for administration by inhalation or insufflation. The preferred manner of administration is generally oral using a convenient daily dosage regimen which can be adjusted according to the degree of affliction.

A compound or compounds of the invention, together with one or more conventional adjuvants, carriers, or diluents, may be placed into the form of pharmaceutical

compositions and unit dosages. The pharmaceutical compositions and unit dosage forms may be comprised of conventional ingredients in conventional proportions, with or without additional active compounds or principles, and the unit dosage forms may contain any suitable effective amount of the active ingredient commensurate with the intended daily dosage range to be employed. The pharmaceutical compositions may be employed as solids, such as tablets or filled capsules, semisolids, powders, sustained release formulations, or liquids such as solutions, suspensions, emulsions, elixirs, or filled capsules for oral use; or in the form of suppositories for rectal or vaginal administration; or in the form of sterile injectable solutions for parenteral use. Formulations containing about one (1) milligram of active ingredient or, more broadly, about 0.01 to about one hundred (100) milligrams, per tablet, are accordingly suitable representative unit dosage forms.

The compounds of the invention may be formulated in a wide variety of oral administration dosage forms. The pharmaceutical compositions and dosage forms may comprise a compound or compounds of the present invention or pharmaceutically acceptable salts thereof as the active component. The pharmaceutically acceptable carriers may be either solid or liquid. Solid form preparations include powders, tablets, pills, capsules, cachets, suppositories, and dispersible granules. A solid carrier may be one or more substances which may also act as diluents, flavouring agents, solubilizers, lubricants, suspending agents, binders, preservatives, tablet disintegrating agents, or an encapsulating material. In powders, the carrier generally is a finely divided solid which is a mixture with the finely divided active component. In tablets, the active component generally is mixed with the carrier having the necessary binding capacity in suitable proportions and compacted in the shape and size desired. The powders and tablets preferably contain from about one (1) to about seventy (70) percent of the active compound. Suitable carriers include but are not limited to magnesium carbonate, magnesium stearate, talc, sugar, lactose, pectin, dextrin, starch, gelatine, tragacanth, methylcellulose, sodium carboxymethylcellulose, a low melting wax, cocoa butter, and the like. The term "preparation" is intended to include the formulation of the active compound with encapsulating material as carrier, providing a capsule in which the active component, with or without carriers, is surrounded by a carrier, which is in association with it. Similarly, cachets and lozenges are included. Tablets, powders, capsules, pills, cachets, and lozenges may be as solid forms suitable for oral administration.

Other forms suitable for oral administration include liquid form preparations including emulsions, syrups, elixirs, aqueous solutions, aqueous suspensions, or solid form preparations which are intended to be converted shortly before use to liquid form preparations. Emulsions may be prepared in solutions, for example, in aqueous propylene glycol solutions or may contain emulsifying agents, for example, such as lecithin, sorbitan monooleate, or acacia. Aqueous solutions can be prepared by dissolving the active component in water and adding suitable colorants, flavors, stabilizers, and thickening agents. Aqueous suspensions can be prepared by dispersing the finely divided active component in water with viscous material, such as natural or synthetic gums, resins, methylcellulose, sodium carboxymethylcellulose, and other well known suspending agents. Solid form preparations include solutions, suspensions, and emulsions, and may contain, in addition to the active component, colorants, flavors, stabilizers, buffers, artificial and natural sweeteners, dispersants, thickeners, solubilizing agents, and the like. The compounds of the invention may be formulated for parenteral administration (e.g., by injection, for example bolus injection or continuous infusion) and may be presented in unit dose form in ampoules, pre-fϊlled syringes, small volume infusion or in multi-dose containers with an added preservative. The compositions may take such forms as suspensions, solutions, or emulsions in oily or aqueous vehicles, for example solutions in aqueous polyethylene glycol. Examples of oily or nonaqueous carriers, diluents, solvents or vehicles include propylene glycol, polyethylene glycol, vegetable oils (e.g., olive oil), and injectable organic esters (e.g., ethyl oleate), and may contain formulatory agents such as preserving, wetting, emulsifying or suspending, stabilizing and/or dispersing agents. Alternatively, the active ingredient may be in powder form, obtained by aseptic isolation of sterile solid or by lyophilization from solution for constitution before use with a suitable vehicle, e.g., sterile, pyrogen-free water.

The compounds of the invention may be formulated for topical administration to the epidermis as ointments, creams or lotions, or as a transdermal patch. Ointments and creams may, for example, be formulated with an aqueous or oily base with the addition of suitable thickening and/or gelling agents. Lotions may be formulated with an aqueous or oily base and will in general also containing one or more emulsifying agents, stabilizing agents, dispersing agents, suspending agents, thickening agents, or coloring agents. Formulations suitable for topical administration in the mouth include lozenges

comprising active agents in a flavored base, usually sucrose and acacia or tragacanth; pastilles comprising the active ingredient in an inert base such as gelatine and glycerine or sucrose and acacia; and mouthwashes comprising the active ingredient in a suitable liquid carrier. The compounds of the invention may be formulated for administration as suppositories. A low melting wax, such as a mixture of fatty acid glycerides or cocoa butter is first melted and the active component is dispersed homogeneously, for example, by stirring. The molten homogeneous mixture is then poured into convenient sized molds, allowed to cool, and to solidify. The compounds of the invention may be formulated for vaginal administration. Pessaries, tampons, creams, gels, pastes, foams or sprays containing in addition to the active ingredient such carriers as are known in the art to be appropriate. The subject compounds may be formulated for nasal administration. The solutions or suspensions are applied directly to the nasal cavity by conventional means, for example, with a dropper, pipette or spray. The formulations may be provided in a single or multidose form. In the latter case of a dropper or pipette, this may be achieved by the patient administering an appropriate, predetermined volume of the solution or suspension. In the case of a spray, this may be achieved for example by means of a metering atomizing spray pump. The compounds of the invention may be formulated for aerosol administration, particularly to the respiratory tract and including intranasal administration. The compound will generally have a small particle size for example of the order of five (5) microns or less. Such a particle size may be obtained by means known in the art, for example by micronization. The active ingredient is provided in a pressurized pack with a suitable propellant such as a chlorofluoro carbon (CFC), for example, dichlorodifluoromethane, trichlorofluoromethane, or dichlorotetrafluoroethane, or carbon dioxide or other suitable gas. The aerosol may conveniently also contain a surfactant such as lecithin. The dose of drug may be controlled by a metered valve. Alternatively the active ingredients may be provided in a form of a dry powder, for example a powder mix of the compound in a suitable powder base such as lactose, starch, starch derivatives such as hydroxypropylmethyl cellulose and polyvinylpyrrolidine (PVP). The powder carrier will form a gel in the nasal cavity. The powder composition may be presented in

unit dose form for example in capsules or cartridges of e.g., gelatine or blister packs from which the powder may be administered by means of an inhaler.

When desired, formulations can be prepared with enteric coatings adapted for sustained or controlled release administration of the active ingredient. For example, the compounds of the present invention can be formulated in transdermal or subcutaneous drug delivery devices. These delivery systems are advantageous when sustained release of the compound is necessary and when patient compliance with a treatment regimen is crucial. Compounds in transdermal delivery systems are frequently attached to a skin- adhesive solid support. The compound of interest can also be combined with a penetration enhancer, e.g., Azone (l-dodecylazacycloheptan-2-one). Sustained release delivery systems are inserted subcutaneously into the subdermal layer by surgery or injection. The subdermal implants encapsulate the compound in a lipid soluble membrane, e.g., silicone rubber, or a biodegradable polymer, e.g., polylactic acid. The pharmaceutical preparations are preferably in unit dosage forms. In such form, the preparation is subdivided into unit doses containing appropriate quantities of the active component. The unit dosage form can be a packaged preparation, the package containing discrete quantities of preparation, such as packeted tablets, capsules, and powders in vials or ampoules. Also, the unit dosage form can be a capsule, tablet, cachet, or lozenge itself, or it can be the appropriate number of any of these in packaged form. Other suitable pharmaceutical carriers and their formulations are described in Remington: The Science and Practice of Pharmacy 1995, edited by E. W. Martin, Mack Publishing Company, 19th edition, Easton, Pennsylvania. Representative pharmaceutical formulations containing a compound of the present invention are described below.

Examples The following preparations and examples are given to enable those skilled in the art to more clearly understand and to practice the present invention. They should not be considered as limiting the scope of the invention, but merely as being illustrative and representative thereof.The following abbreviations may be used in the Examples.

ABBREVIATIONS CDI 1,1-carbonyl-diimidazole

DCM dichloromethane/methylene chloride

DMF N,N-dimethylformamide

DMAP 4-dimethylaminopyridine

EDCI 1 -ethyl-3-(3 '-dimethylaminopropyl)carbodiimide EtOAc ethyl acetate

EtOH ethanol tBuOH tert-butanol gc gas chromatography

HMPA hexamethylphosphoramide

HOAc acetic acid

HOBt N-Hydroxybenzotriazo Ie hplc high performance liquid chromatography mCPBA m-chloroperbenzoic acid

MeCN acetonitrile

MeOH methanol

NMP N-methyl pyrrolidinone

TEA triethylamine

TFA trifluoro acetic acid

THF tetrahydrofuran

LDA lithium diisopropylamine

LHMDS Lithium bis(trimethylsilyl)amide

TBAF tetrabutylammonium fluoride

TLC thin layer chromatography

Preparation 1

2'-Methoxy-5-tetrazol-l-yl-biphenyl-3-carboxylic acid methyl ester

The synthetic procedure described in this Preparation was carried out according to the process shown in Scheme C.

SCHEME C

Step 1 3-Iodo-5-nitro-benzoic acid

To a mixture of 3 -Nitro -benzoic acid (114 g, 0.68 mol) and I 2 (138.2 g) was added dropwise H 2 SO 4 (cone, 230 mL). The reaction mixture was stirred at 85 0 C for 18 hours, then was cooled and poured onto ice. The resulting mixture was partitioned between EtOAc and saturated aqueous NaHSO 3 . The combined organic layers were washed with water, dried over Na 2 SO 4 , filtered and concentrated under reduced pressure to give 108 g of 3-iodo-5-nitro-benzoic acid as a pale yellow solid, MS (M+H) = 294. Step 2 2'-Methoxy-5-nitro-biphenyl-3-carboxylic acid 3-Iodo-5-nitro-benzoic acid (10.0 g, 34 mmol) was dissolved in 17.5 mL warm EtOH. Toluene (17.5 mL) was added, followed by 2-methoxy-phenyl-boronic acid (5.7 g), Palladium tetra(triphenylphosphine) (1.26 g) and aqueous Cs 2 CO 3 solution (12.23 g in 12.5 mL H 2 O). The reaction mixture was stirred under Argon atmosphere at 130 0 C for 18 hours, then cooled to room temperature. Solvent was removed under reduced pressure, and the residue was partitioned between aqueous IN HCl and EtOAc. The combined organic layers were washed with water, dried over Na 2 SO 4 , filtered and concentrated under reduced pressure. The resulting solid residue was added to a mixture of methylene chloride (50 mL)and hexanes (10 mL) and stirred for two hours. The mixture was filtered, and the resulting white solid was washed with cold methylene chloride/hexanes (5:1) and dried to give 8.62 g of 2'-methoxy-5-nitro-biphenyl-3-carboxylic acid, MS (M+H) = 274.

Step 3 2'-Methoxy-5-nitro-biphenyl-3-carboxylic acid methyl ester 2'-Methoxy-5-nitro-biphenyl-3-carboxylic acid (8.62 g, 31.5 mmol) was added to a mixture of MeOH (89 mL) and cone, aqueous HCl (4.9 mL). The reaction mixture was stirred at 80 0 C for 24 hours, and then stirred for 18 hours at room temperature. The reaction mixture was filtered, and the resulting solid was washed with MeOH and dried to give 8.2 g of 2'-methoxy-5-nitro-biphenyl-3-carboxylic acid methyl ester, MS (M+H) = 288.

Step 4 5-Amino-2'-methoxy-biphenyl-3-carboxylic acid methyl ester 2'-Methoxy-5-nitro-biphenyl-3-carboxylic acid methyl ester (8.2 g, 28.5 mmol) and SnCl 2 dihydrate (35 g) in EtOAc (300 mL) was heated to reflux and stirred for 18 hours, then cooled and stirred at room temperature for 48 hours. Saturated aqueous NaHCO 3 was added until the aqueous portion of the mixture reached pH 10. The organic layer was separated, and the aqueous layer was washed with EtOAc. The combined organic

layers were washed with water, dried over Na 2 SO 4 , filtered and concentrated under reduced pressure to give 7.2 g of S-amino-l'-methoxy-biphenyl-S-carboxylic acid methyl ester, MS (M+H) = 258.

Step 5 2'-Methoxy-5-tetrazol-l-yl-biphenyl-3-carboxylic acid methyl ester To a suspension of 5-amino-2'-methoxy-biphenyl-3-carboxylic acid methyl ester (7.2 g, 28 mmol) in trimethoxymethane (22.8 mL) was added NaN 3 (5.7 g) followed by HOAc (285 mL). The reaction mixture was stirred at room temperature for 30 minutes, then stirred at 100 0 C for three hours, and then stirred at room temperature for 18 hours. The resulting mixture was partitioned between water and methylene chloride, and the combined organic layers were washed with water, dried over Na 2 SO 4 , filtered and concentrated under reduced pressure to give 8.6 g of 2'-methoxy-5-tetrazol-l-yl- biphenyl-3-carboxylic acid methyl ester, MS (M+H) = 311. Step 6 2'-Methoxy-5-tetrazol-l-yl-biphenyl-3-carboxylic acid A mixture of 2'-methoxy-5-tetrazol-l-yl-biphenyl-3-carboxylic acid methyl ester (8.6 g, 27.7 mmol), 3N aqueous NaOH (28.5 mL) and MeOH (28.5 mL) was stirred at room temperature for 18 hours. The reaction mixture was filtered and the collected solid was partitioned between IN aqueous HCl and methylene chloride. A white precipitate formed in the methylene chloride layer and was collected by filtration, washed with water and methylene chloride, and dried to give 4.2 g (46%) of 2'-methoxy-5-tetrazol-l- yl-biphenyl-3-carboxylic acid, MP = 214.0-215.3 0 C, MS (M+H) = 297.

Similarly prepared, but replacing 2-methoxy-phenyl-boronic acid with 4-methoxy- phenyl-boronic acid, was 4'-methoxy-5-tetrazol-l -yl-biphenyl-3-carboxylic acid, MS (M+H) = 297. Similarly prepared, but replacing 2-methoxy-phenyl-boronic acid with 4-chloro-phenyl- boronic acid, was 4'-chloro-5-tetrazol-l -yl-biphenyl-3-carboxylic acid, MS (M+H) = 301. Similarly prepared, but replacing 2-methoxy-phenyl-boronic acid with 4-methyl-phenyl- boronic acid, was 4'-methyl-5-tetrazol-l -yl-biphenyl-3-carboxylic acid, MS (M+H) = 281. Similarly prepared, but replacing 2-methoxy-phenyl-boronic acid with 2-methyl-phenyl- boronic acid, was 2'-methyl-5-tetrazol-l -yl-biphenyl-3-carboxylic acid, MS (M+H) = 281.

Similarly prepared, but replacing 2-methoxy-phenyl-boronic acid with 2-chloro-phenyl- boronic acid, was 2'-chloro-5-tetrazol-l -yl-biphenyl-3-carboxylic acid, MS (M+H) = 301.

Similarly prepared, but replacing 2-methoxy-phenyl-boronic acid with 2-fluoro-phenyl- boronic acid, was 2'-fluoro-5-tetrazol-l-yl-biphenyl-3-carboxylic acid, MS (M+H) = 285.

Similarly prepared, but replacing 2-methoxy-phenyl-boronic acid with 2-ethoxy-phenyl- boronic acid, was 2'-ethoxy-5-tetrazol-l-yl-biphenyl-3-carboxylic acid, MS (M+H) = 311. Similarly prepared, but replacing 2-methoxy-phenyl-boronic acid with 2-acetyl-phenyl- boronic acid, was 2'-acetyl-5-tetrazol-l-yl-biphenyl-3-carboxylic acid, MS (M+H) = 309.

Similarly prepared, but replacing 2-methoxy-phenyl-boronic acid with 2,4-dimethoxy- phenyl-boronic acid, was 2',4'-dimethoxy-5-tetrazol-l-yl-biphenyl-3-carboxylic acid, MS

(M+H) = 327. Similarly prepared, but replacing 2-methoxy-phenyl-boronic acid with 2,5-dimethoxy- phenyl-boronic acid, was 2',5'-dimethoxy-5-tetrazol-l-yl-biphenyl-3-carboxylic acid, MS

(M+H) = 327.

Similarly prepared, but replacing 2-methoxy-phenyl-boronic acid with 5-fluoro-2- methoxy-phenyl-boronic acid, was 5'-fluoro-2'-methoxy-5-tetrazol-l-yl-biphenyl-3- carboxylic acid, MS (M+H) = 315.

Similarly prepared, but replacing 2-methoxy-phenyl-boronic acid with 5-chloro-2- methoxy-phenyl-boronic acid, was 5'-chloro-2'-methoxy-5-tetrazol-l-yl-biphenyl-3- carboxylic acid, MS (M+H) = 331.

Similarly prepared, but replacing 2-methoxy-phenyl-boronic acid with 2,5-dichloro- phenyl-boronic acid, was 2',5'-dichloro-5-tetrazol-l-yl-biphenyl-3-carboxylic acid, MS

(M+H) = 335.

Similarly prepared, but replacing 2-methoxy-phenyl-boronic acid with 2,3-dichloro- phenyl-boronic acid, was 2',3'-dichloro-5-tetrazol-l-yl-biphenyl-3-carboxylic acid, MS

(M+H) = 335. Similarly prepared, but replacing 2-methoxy-phenyl-boronic acid with 2-hydroxymethyl- phenyl-boronic acid, was 2'-hydroxymethyl-5-tetrazol-l-yl-biphenyl-3-carboxylic acid,

MS (M+H) = 297.

Similarly prepared, but replacing 2-methoxy-phenyl-boronic acid with 2- methanesulfanyl-phenyl-boronic acid, was 2'-methanesulfanyl-5-tetrazol-l-yl-biphenyl- 3-carboxylic acid, MS (M+H) = 313.

Similarly prepared, but replacing 2-methoxy-phenyl-boronic acid with 2,3-difluoro- phenyl-boronic acid, was 2',3'-difluloro-5-tetrazol-l-yl-biphenyl-3-carboxylic acid, MS

(M+H) = 303.

Similarly prepared, but replacing 2-methoxy-phenyl-boronic acid with 2,4-dichloro- phenyl-boronic acid, was 2',4'-dichloro-5-tetrazol-l-yl-biphenyl-3-carboxylic acid, MS (M+H) = 335.

Similarly prepared, but replacing 2-methoxy-phenyl-boronic acid with 2-ethyl-phenyl- boronic acid, was 2'-ethyl-5-tetrazol-l-yl-biphenyl-3-carboxylic acid, MS (M+H) = 295. Similarly prepared, but replacing 2-methoxy-phenyl-boronic acid with 2-cyano-phenyl- boronic acid, was 2'-cyano-5-tetrazol-l-yl-biphenyl-3-carboxylic acid, MS (M+H) = 292. Similarly prepared, but replacing 2-methoxy-phenyl-boronic acid with 2,3-dimethoxy- phenyl-boronic acid, was 2',3'-dimethoxy-5-tetrazol-l-yl-biphenyl-3-carboxylic acid, 327.

Similarly prepared, but replacing 2-methoxy-phenyl-boronic acid with 4-methoxy-2- methyl-phenyl-boronic acid, was 4'-methoxy-2'-methyl-5-tetrazol-l-yl-biphenyl-3- carboxylic acid, MS (M+H) = 311.

Preparation 2

3-(3-Methoxy-pyridin-2-yl)-5-tetrazol- 1 -yl-benzoic acid

The synthetic procedure described in this Preparation was carried out according to the process shown in Scheme D.

SCHEME D

Step 1 3-Amino-5-boronyl-benzoic acid methyl ester

3-boronyl-5-nitro-benzoic acid methyl ester (11.6 g, 51.1 mmol) and 10% Pd/C (1.05 g) were added to 110 mL EtOH in a one liter Parr vessel. The reaction mixture was shaken under 42 psi (2.9 Bar) for 20 minutes. The reaction mixture was purged with nitrogen and filtered through Na 2 SO 4 and Celite. The filtrate was concentrated under reduced pressure to give 9.89 g of 3-amino-5-boronyl-benzoic acid methyl ester.

Step 2 3-Amino-5-(3-methoxy-pyridin-2-yl)-benzoic acid methyl ester 3-amino-5-boronyl-benzoic acid methyl ester (7.6 g. 34 mmol), 2-bromo-3-methoxy- pyridine (5.8 g, 30.9 mmol), palladium tetra(triphenylphosphine) (3.6 g, 3.1 mmol), and CS2CO3 (25.3 g, 77.5 mmol) were added to a mixture of EtOH (30 mL) and water (60 mL). The reaction mixture was vacuum-purged and then stirred at 90° C for 44 hours. The reaction mixture was cooled and partitioned between water and ETOAc. The combined organic layers were washed with water, dried over Na 2 SO 4 , filtered and concentrated under reduced pressure. The residue was transferred onto Celite, which was then loaded onto a column of 200 g silica and eluted with EtOAc/hexanes (5%-100%) to give 530 mg of 3-amino-5-(3-methoxy-pyridin-2-yl)-benzoic acid methyl ester, MS (M+H) = 259.

Step 3 3-(3-Methoxy-pyridin-2-yl)-5-tetrazol-l-yl-benzoic acid methyl ester A suspension of 3-amino-5-(3-methoxy-pyridin-2-yl)-benzoic acid methyl ester (530 mg, 1.96 mmol) in trimethoxymethane (1.5 mL) was stirred under nitrogen for 5 minutes. NaN 3 (390 mg, 5.9 mmol) was added slowly, followed by HOAc (10 mL). The reaction mixture was stirred at room temperature for 72 hours, then was concentrated under reduced pressure. The residue was partitioned between water and EtOAc. The combined organic layers were washed with water, dried over Na 2 SO 4 , filtered and concentrated under reduced pressure. The residue was purified via flash chromatography through 80 g of silica using EtOAc/hexanes (20%- 100%) to give 170 mg of 3-(3-methoxy-pyridin-2- yl)-5-tetrazol-l-yl-benzoic acid methyl ester, MS (M+H) = 312. Step 4 3-(3-Methoxy-pyridin-2-yl)-5-tetrazol-l-yl-benzoic acid 3-(3-Methoxy-pyridin-2-yl)-5-tetrazol-l-yl-benzoic acid methyl ester (170 mg, 0.52 mmol) was added to a mixture of THF (20 mL) and MeOH (5 mL) and cooled to ice bath temperature under nitrogen atmosphere. LiOH H 2 O (8.8 g, 2.1 mmol) was added, and the reaction mixture was stirred for 18 hours at room temperature. The reaction mixture was concentrated under reduced pressure and 10.0 g of water ice and 10 mL of 10% aqueous HOAc were added to the residue. The resulting mixture was filtered, and the filtrate was washed with 10% aqueous HOAc. The collected solid was dried under vacuum at 60 0 C for 3 horus to give 140 mg of 3-(3-methoxy-pyridin-2-yl)-5-tetrazol-l-yl-benzoic acid, MS (M+H) = 298.

Similarly prepared, but replacing 2-bromo-3-methoxy-pyridine with 2-bromo-5- trifluoromethyl-pyridine in step 2, was 3-tetrazol-l-yl-5-(5-trifluoromethyl-pyridin-2-yl)- benzoic acid, MS (M+H) = 336.

Similarly prepared, but replacing 2-bromo-3-methoxy-pyridine with 2-bromo-5- methanesulfonyl-pyridine in step 2, was 3-tetrazol-l-yl-5-(5-methanesulfonyl-pyridin-2- yl)-benzoic acid, MS (M+H) = 316.

Similarly prepared, but replacing 2-bromo-3-methoxy-pyridine with 2-methoxy-5- bromo-pyrimidine in step 2, was 3-tetrazol-l-yl-5-(2-methoxy-pyrimidin-5-yl)-benzoic acid, MS (M+H) = 269.

Similarly prepared, but replacing 2-bromo-3-methoxy-pyridine with 3-bromo-l -ethyl- pyrrol in step 2, was 3-tetrazol-l-yl-5-(l-ethyl-pyrrol-3-yl)-benzoic acid, MS (M+H) = 254.

Similarly prepared, but replacing 2-bromo-3-methoxy-pyridine with thiophene-2- carboxylic acid tert-butyl ester in step 2, was 5-(3-carboxy-5-tetrazol-l-yl-phenyl)- thiophene-2-carboxylic acid tert-butyl ester, MS (M+H) = 373

Example 1 2'-Methoxy-5-tetrazol- 1 -yl-biphenyl-3-carboxylic acid [2-(3-methoxy-phenyP)-ethyl]- amide

The synthetic procedure described in this Example was carried out according to the process shown in Scheme E.

SCHEME E

2'-Methoxy-5-tetrazol-l -yl-biphenyl-3-carboxylic acid 0.9 g, 3 mmol), 2-(3-methoxy- phenyl)-ethylamine (0.5 mL), EDCI (0.6 g), HOBt (0.4 g) were added to methylene chloride (9 mL), and the reaction mixture was stirred at room temperature for 18 hours. The reaction mixture was partitioned between IN aqueous HCl and EtOAc, and the combined organic layers were washed with water, dried over Na 2 SO 4 , filtered and

concentrated under reduced pressure. The residue was purified by flash chromatography

(3-20%, 5% NH 4 OH in MeOH/methylene chloride) to give 1.5 g of 2'-methoxy-5- tetrazol-l-yl-biphenyl-3-carboxylic acid [2-(3-methoxy-phenyl)-ethyl] -amide as a white solid, MS (M+H) = 430. Similarly prepared, but replacing 2-(3-methoxy-phenyl)-ethylamine with 2-(4-methoxy- phenyl)-ethylamine, was 2'-methoxy-5-tetrazol-l-yl-biphenyl-3-carboxylic acid [2-(4- methoxy-phenyl)-ethyl] -amide, MS (M+H) = 430.

Similarly prepared, but replacing 2-(3-methoxy-phenyl)-ethylamine with phenyl)- ethylamine, was 2'-methoxy-5-tetrazol-l-yl-biphenyl-3-carboxylic acid phenethyl-amide, MS (M+H) = 400.

Similarly prepared, but replacing 2-(3-methoxy-phenyl)-ethylamine with 2-(4-chloro- phenyl)-ethylamine, was 2'-methoxy-5-tetrazol-l-yl-biphenyl-3-carboxylic acid [2-(4- chloro-phenyl)-ethyl]-amide, MS (M+H) = 434.

Similarly prepared, but replacing 2-(3-methoxy-phenyl)-ethylamine with 2-(3,4-dichloro- phenyl)-ethylamine was 2'-methoxy-5-tetrazol-l-yl-biphenyl-3-carboxylic acid [2-(3,4- dichloro-phenyl)-ethyl]-amide, MS (M+H) = 468.

Similarly prepared, but replacing 2-(3-methoxy-phenyl)-ethylamine with 2-(3-bromo-4- methoxy-phenyl)-ethylamine, was 2'-methoxy-5-tetrazol-l-yl-biphenyl-3-carboxylic acid

[2-(3-bromo-4-methoxy-phenyl)-ethyl]-amide, MS (M+H) = 509 Similarly prepared, but replacing 2-(3-methoxy-phenyl)-ethylamine with 2-(2-fluoro- phenyl)-ethylamine, was 2'-Methoxy-5-tetrazol-l-yl-biphenyl-3-carboxylic acid [2-(2- fluoro-phenyl)-ethyl]-amide, MS (M+H) = 418.

Similarly prepared, but replacing 2-(3-methoxy-phenyl)-ethylamine with 2-(3,4-difluoro- phenyl)-ethylamine, was 2'-methoxy-5-tetrazol-l-yl-biphenyl-3-carboxylic acid [2-(3,4- difluoro-phenyl)-ethyl]-amide, MS (M+H) = 436.

Similarly prepared, but replacing 2-(3-methoxy-phenyl)-ethylamine with 2-p-tolyl- ethylamine was 2'-methoxy-5-tetrazol-l-yl-biphenyl-3-carboxylic acid (2-/?-tolyl-ethyl)- amide, MS (M+H) = 414.

Similarly prepared, but replacing 2-(3-methoxy-phenyl)-ethylamine with 2-o-tolyl- ethylamine was 2'-methoxy-5-tetrazol-l-yl-biphenyl-3-carboxylic acid (2-o-tolyl-ethyl)- amide, MS (M+H) = 414.

Similarly prepared, but replacing 2-(3-methoxy-phenyl)-ethylamine with 2-m-tolyl- ethylamine was 2'-methoxy-5-tetrazol-l -yl-biphenyl-3-carboxylic acid (2-m-tolyl-ethyl)- amide, MS (M+H) = 414.

Similarly prepared, but replacing 2-(3-methoxy-phenyl)-ethylamine with 2- benzo[l,3]dioxol-5-yl-ethylamine, was 2'-methoxy-5-tetrazol-l-yl-biphenyl-3-carboxylic acid (2-benzo[l,3]dioxol-5-yl-ethyl)-amide, MS (M+H) = 444. Similarly prepared, but replacing 2-(3-methoxy-phenyl)-ethylamine with 2-(3- methanesulfonyl-phenyl)-ethylamine, was 2'-methoxy-5-tetrazol- 1 -yl-biphenyl-3- carboxylic acid [2-(4-methanesulfonyl-phenyl)-ethyl]-amide, MS (M+H) = 480. Similarly prepared, but replacing 2-(3-methoxy-phenyl)-ethylamine with 2-(4- dimethylamino-phenyl)-ethylamine was 2'-methoxy-5-tetrazol- 1 -yl-biphenyl-3- carboxylic acid [2-(4-dimethylamino-phenyl)-ethyl]-amide, MP = 192.8-194.1 0 C. Similarly prepared, but replacing 2-(3-methoxy-phenyl)-ethylamine with 3-(3,3- dimethoxy-phenyl)-propylamine, was 2'-methoxy-5-tetrazol- 1 -yl-biphenyl-3-carboxylic acid [3-(3,4-dimethoxy-phenyl)-propyl]-amide, MS (M+H) = 474.

Similarly prepared, but replacing 2-(3-methoxy-phenyl)-ethylamine with 3,4-dimethoxy- benzylamine, was 2'-methoxy-5-tetrazol-l -yl-biphenyl-3-carboxylic acid 3,4-dimethoxy- benzylamide, MS (M+H) = 446. Similarly prepared, but replacing 2-(3-methoxy-phenyl)-ethylamine with 2-pyridin-2-yl- ethylamine, was 2'-methoxy-5-tetrazol-l -yl-biphenyl-3-carboxylic acid (2-pyridin-2-yl- ethyl)-amide, MS (M+H) = 401.

Similarly prepared, but replacing 2-(3-methoxy-phenyl)-ethylamine with 2-pyridin-3-yl- ethylamine, was 2'-methoxy-5-tetrazol-l -yl-biphenyl-3-carboxylic acid (2-pyridin-3-yl- ethyl)-amide, MS (M+H) = 401. Similarly prepared, but replacing 2-(3-methoxy-phenyl)-ethylamine with 2-pyridin-4-yl- ethylamine, was 2'-methoxy-5-tetrazol-l -yl-biphenyl-3-carboxylic acid (2-pyridin-4-yl- ethyl)-amide, MS (M+H) = 401.

Additional compounds prepared using the above procedure, but replacing 2'-methoxy-5- tetrazol-1 -yl-biphenyl-3-carboxylic acid with other carboxylic acid compounds from Preparation 1, are shown in Table 1.

Example 2 N-r2-(4-Fluoro-phenyl)-ethyll-3-(3-methoxy-pyridin-2-yl)-5-t etrazol-l-yl-benzamide

The synthetic procedure described in this Example was carried out according to the process shown in Scheme F.

SCHEME F 3-(3-Methoxy-pyridin-2-yl)-5-tetrazol-l-yl-benzoic acid (140 mg) and dissolved in dry NMP (15 mL), and CDI (80 mg, 0.49 mmol) was added. The reaction mixture was stirred for 40 minutes, and then 2-(4-fluorophenyl)-ethylamine (0.16 mL, 1.22 mmol) was added. The reaction mixture was stirred for 24 hours at room temperature, and then poured into 30 mL water. The resulting mixture was extracted with EtOAc, and the combined organic layers were washed with water and brine, dried over Na 2 SO 4 , filtered and concentrated under reduced pressure. The residue was purified via flash chromatography using EtOAc/hexanes (30%- 100%) to give 15 mg ofN-[2-(4-fluoro- phenyl)-ethyl]-3-(3-methoxy-pyridin-2-yl)-5-tetrazol-l-yl-be nzamide, MS (M+H) = 419. Similarly prepared, but replacing 2-(4-fluorophenyl)-ethylamine with C-(6-Methoxy- l,2,3,4-tetrahydro-naphthalen-l-yl)-methylamine, was 3-(3-Methoxy-pyridin-2-yl)-N-(7- methoxy- 1 ,2,3 ,4-tetrahydro-naphthalen- 1 -ylmethyl)-5-tetrazol- 1 -yl-benzamide, MP = 135.0-136.0 0 C.

Similarly prepared, but replacing 3-(3-methoxy-pyridin-2-yl)-5-tetrazol-l-yl-benzoic acid with 3-tetrazol-l-yl-5-(5-methanesulfonyl-pyridin-2-yl)-benzoic acid, was N-[2-(2- fluoro-phenyl)-ethyl]-3-(5-methanesulfonyl-pyridin-2-yl)-5-t etrazol- 1 -yl-benzamide, MS (M+H) = 467.

Similarly prepared, but replacing 3-(3-methoxy-pyridin-2-yl)-5-tetrazol-l-yl-benzoic acid with 3-tetrazol-l-yl-5-(2-methoxy-pyrimidin-5-yl)-benzoic acid, was N-[2-(2- fluoro-phenyl)-ethyl]-3-(2-methoxy-pyrimidin-5-yl)-5-tetrazo l- 1 -yl-benzamide, MS (M+H) = 420.

Similarly prepared, but replacing 3-(3-methoxy-pyridin-2-yl)-5-tetrazol-l-yl-benzoic acid with 3-tetrazol-l-yl-5-(l-ethyl-pyrrol-3-yl)-benzoic acid, was 3-( 1 -ethyl- lH-pyrro 1- 3-yl)-N-[2-(2-fluoro-phenyl)-ethyl]-5-tetrazol-l -yl-benzamide, MS (M+H) = 405.

Similarly prepared, but replacing 3-(3-methoxy-pyridin-2-yl)-5-tetrazol-l-yl-benzoic acid with 5-(3-carboxy-5-tetrazol-l-yl-phenyl)-thiophene-2-carboxylic acid tert-butyl ester, was 5- {3-[2-(2-fluoro-phenyl)-ethylcarbamoyl]-5-tetrazol- 1 -yl-phenyl} -thiophene- 2-carboxylic acid tert-butyl ester, MS (M+H) = 494.

Example 3 Formulations

Pharmaceutical preparations for delivery by various routes are formulated as shown in the following Tables. "Active ingredient" or "Active compound" as used in the Tables means one or more of the Compounds of Formula I.

Composition for Oral Administration

Ingredient % wtJwt.

Active ingredient 20.0%

Lactose 79.5%

Magnesium stearate 0.5%

The ingredients are mixed and dispensed into capsules containing about 100 mg each; one capsule would approximate a total daily dosage.

Composition for Oral Administration

The ingredients are combined and granulated using a solvent such as methanol. The formulation is then dried and formed into tablets (containing about 20 mg of active compound) with an appropriate tablet machine.

Composition for Oral Administration

Ingredient Amount

Active compound 1.0 g

Fumaric acid 0.5 g

Sodium chloride 2.O g

Methyl paraben 0.15 g

Propyl paraben 0.05 g

Granulated sugar 25.5 g

Sorbitol (70% solution) 12.85 g

Veegum K (Vanderbilt Co.) 1.0 g

Flavoring 0.035 ml

Colorings 0.5 mg

Distilled water q.s. to 100 ml

The ingredients are mixed to form a suspension for oral administration.

Parenteral Formulation

The active ingredient is dissolved in a portion of the water for injection. A sufficient quantity of sodium chloride is then added with stirring to make the solution isotonic. The solution is made up to weight with the remainder of the water for injection, filtered through a 0.2 micron membrane filter and packaged under sterile conditions.

Su ository Formulation

The ingredients are melted together and mixed on a steam bath, and poured into molds containing 2.5 g total weight.

To ical Formulation

All of the ingredients, except water, are combined and heated to about 60 0 C with stirring. A sufficient quantity of water at about 60 0 C is then added with vigorous stirring to emulsify the ingredients, and water then added q.s. about 100 g.

Nasal Spray Formulations

Several aqueous suspensions containing from about 0.025-0.5 percent active compound are prepared as nasal spray formulations. The formulations optionally contain inactive ingredients such as, for example, micro crystalline cellulose, sodium carboxymethylcellulose, dextrose, and the like. Hydrochloric acid may be added to adjust pH. The nasal spray formulations may be delivered via a nasal spray metered pump typically delivering about 50-100 microliters of formulation per actuation. A typical dosing schedule is 2-4 sprays every 4-12 hours.

Example 4 Nicotinic alpha 7 Modulation Assay

Cell Cultures

Cell Culture Growth Media: FlO medium (Invitrogen), 2.5% Fetal Bovine Serum (FBS, Summit Biotechnology); 15% heat inactivated donor Horse Serum (Invitrogen), 250 μg/ml Hygromycin B (Invitrogen); and 10OnM Methyllicaconite (MLA, Sigma) are added to each new culture by 50-fold dilution of stock solution prepared in H 2 O at 5μM. GH4C1 cells (rat pituitary-derived cell line) stably expressing human nicotinic alpha7 WT receptor (RPA clone #34.7) are cultivated in cell culture growth media (described above) at 37C in a humidified atmosphere containing 4%CO 2 . Fresh cell stock cultures are initiated with cells at 0.1-0.2 x 10 6 /ml, 50 ml media per T225 flask and are grown for 2 or 3 days prior to use in FLIPR assay. Cells harvested two days after intiation of stock flask typically yields ~25 x 10 6 / T225 flask and 3 days after intiation of stock flask typically yields -40 x 10 6 / T225 flask.

One day prior to assay, cells are placed in in fresh cell culture growth media supplemented with 10OnM fresh MLA. To accomplish media change, suspension cells of the culture are removed and 45 ml fresh cell culture growth media (containing 10OnM fresh MLA) is immediately added to the stock flask as large numbers of cells remain adherent to the surface. The cells in suspension are then collected by centrifugation, resuspended in 5 ml fresh cell culture growth media and returned to the original culture flask. Buffer Solutions

Buffer solutions used in the assay are HBSS FLIPR buffer (Invitrogen), 2mM CaCl 2 (Sigma), 10 mM HEPES (Invitrogen), 2.5mM Probenecid (Sigma), and 0.1% BSA (Sigma)

FLIPR Assay

The alpha 7 nAChR assay is a cell-based functional readout designed to determine the effect of test compounds to either directly activate nicotinic receptor channels and/or to modulate activation by the native agonist acetylcholine (ACh, Sigma). On day one of the assay, attached cells are lifted using lx-concentration Versene (Gibco, Cat-No. 15040), combined with cells in suspension, and collected by centrifugation (5 min, 162 x g). The cell pellet is resuspended in FLIPR buffer at 0.5 x 10 6 /ml and cells dispensed into sample wells of a 96-well poly-d- lysine coated black/clear plate (Becton Dickinson) at 0.5 x 10 5 cells per well. Sample wells are then supplemented with FLUO- 3AM dye (TefLabs, stock solution prepared at 2.5mM in anhydrous DMSO containing 10% Pluronic acid) in FLIPR buffer at lμM final assay concentration (FAC). Dye loading of cells occurs by incubation of plates for one hour at 37C in a humidified atmosphere containing 4%CO 2 . To remove extracellular dye, FLIPR plates are washed using a Biotek EL405 plate washer leaving a residual volume of 0.1 ml FLIPR buffer per sample well.

Assay of test compound effect on activation of the alpha7 nicotinic receptor channel is done by measurement of cytosolic [Ca 2+ ] elevation as reported by increased FLUO-3 fluorescence using a two addition experimental design and FLIPR™ (Molecular Devices). Following a 30 second baseline recording, test compounds are added online (dilution scheme below) and cell response is recorded for an additional 5 minutes. After a second addition of ACh (30μM, FAC), plates are read for an additional 4 minutes. Test Compound Preparation

Multiple concentrations of test compounds are examined in parallel on each 96 well assay plate. In order to achieve 100 μM (1.00E-4 M) for the highest FAC of test compound, 24 μl of 10 mM test compound stock solution (100% DMSO) is added directly to 576 μl of FLIPR buffer (i.e. highest [test compound] =0.4 mM = 4-fold FAC). Starting with the 0.4 mM test compound sample, test compounds are then diluted serially in FLIPR buffer (using Biomek 2000) resulting in the following test compound FACs : vehicle, 1.00E-4 M, 3.16E-5, 1.00E-5 M, 3.16E-6, 1.00E-6 M, 3.16E-7, 1.00E-7 M. Maximum FAC for DMSO = 1% in the sample wells exposed to the the highest FAC of test compound of 100 μM. Negative controls were madeby vehicle addition, followed by ACh addition. Positive controls were made by lμM PNU-120596 addition, followed by ACh addition.

Compound Activity

Values for IC50/EC50, intrinsic agonist activity and positive allosteric modulation for alpha 7 nAChR were determined using ACTIVITYBASE™ data analysis software. For dose-response data, either the fitted mid-point of the curve (inflection) or the point at which the curve crosses a threshold activity value (typically 50% of control) may be used to determin IC50/EC50.

Using the above assay, the compounds of the invention were determined to be positive allosteric modulators for alpha 7 nAChR. For example, the compound 2'-methoxy-5- tetrazol-l-yl-biphenyl-3-carboxylic acid [2-(4-sulfamoyl-phenyl)-ethyl]-amide showed an EC50 of 0.0421, and positive allosteric modulation of 467.65.

Further biological data are shown in the table I below:

"Modn" means positive allosteric modulation.

While the present invention has been described with reference to the specific embodiments thereof, it should be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the true

spirit and scope of the invention. In addition, many modifications may be made to adapt a particular situation, material, composition of matter, process, process step or steps, to the objective spirit and scope of the present invention. All such modifications are intended to be within the scope of the claims appended hereto.