in one aspect , the compounds of this invention are represented by formula ( i ): r 1 is 2 - benzimidazole , 2 - imidazopyridine , or 2 - quinazoline ; optionally substituted with fluoro , amino , or hydroxy ; r 2 is phenyl , optionally substituted with one to five substituents , each substituent independently being chloro , fluoro , bromo , c 1 - c 4 alkyl , trifluoromethyl , hydroxy , or carboxy ; l 1 and l 2 are independently c 1 - c 4 alkyl , c 1 - c 4 alkenyl , c 1 - c 4 alkynyl , c 1 - c 4 alkoxy , amino , aminoc 1 - c 4 alkyl , hydroxyc 1 - c 4 alkyl , carbonyl , cycloc 3 - c 6 alkyl or aminocarbonyl ; a 1 , a 2 , and a 3 are each hydrogen or i ) a 1 and a 2 form a two carbon bridge or ii ) a 1 and a 3 form a two carbon bridge ; and optionally substituted with x , wherein x is hydroxy , amino , c 1 - c 4 alkylamino , di ( c 1 - c 4 ) alkylamino , c 1 - c 4 alkyl , ester , carbamate , carbonate , or ether . in an embodiment , the compound of this invention is represented by formula ( i ) or a pharmaceutically acceptable salt thereof , wherein r 2 is phenyl , optionally substituted with one to five substituents , each substituent independently being chloro , fluoro , bromo , c 1 - c 4 alkyl , trifluoromethyl , hydroxy , or carboxy ; l 1 and l 2 are independently c 1 - c 4 alkyl , c 1 - c 4 alkenyl , c 1 - c 4 alkynyl , c 1 - c 4 alkoxy , amino , aminoc 1 - c 4 alkyl , hydroxyc 1 - c 4 alkyl , carbonyl , cycloc 3 - c 6 alkyl or aminocarbonyl ; a 1 , a 2 , and a 3 are each hydrogen or i ) a 1 and a 2 form a two carbon bridge or ii ) a 1 and a 3 form a two carbon bridge ; and optionally substituted with x , wherein x is hydroxy , amino , c 1 - c 4 alkylamino , di ( c 1 - c 4 ) alkylamino , c 1 - c 4 alkyl , ester , carbamate , carbonate , or ether . as used herein , “ alkyl ” as well as other groups having the prefix “ alk ” such as , for example , alkoxy , alkanoyl , alkenyl , alkynyl and the like , means carbon chains which may be linear or branched or combinations thereof . examples of alkyl groups include methyl , ethyl , propyl , isopropyl , butyl , sec - and tert - butyl , pentyl , hexyl , heptyl and the like . “ alkenyl ”, “ alkynyl ” and other like terms include carbon chains containing at least one unsaturated c — c bond . the term “ cycloalkyl ” means carbocycles containing no heteroatoms , and includes mono -, bi - and tricyclic saturated carbocycles , as well as fused ring systems . such fused ring systems can include one ring that is partially or fully unsaturated such as a benzene ring to form fused ring systems such as benzofused carbocycles . cycloalkyl includes such fused ring systems as spirofused ling systems . examples of cycloalkyl include cyclopropyl , cyclobutyl , cyclopentyl , cyclohexyl , decahydronaphthalene , adamantane , indanyl , indenyl , fluorenyl , 1 , 2 , 3 , 4 - tetrahydronaphalene and the like . similarly , “ cycloalkenyl ” means carbocycles containing no heteroatoms and at least one non - aromatic c — c double bond , and include mono -, bi - and tricyclic partially saturated carbocycles , as well as benzofused cycloalkenes . examples of cycloalkenyl include cyclohexenyl , indenyl , and the like . unless otherwise stated , the terms “ carbonyl ” and “ aminocarbonyl ” include short c 1 - c 2 termini . the terms include , for example , — co —, — conh —, — ch 2 co —, — ch 2 conh —, — c 2 h 4 co —, — c 2 h 4 conh —, — coch 2 —, — conhch 2 —, — coc 2 h 4 —, — conhc 2 h 4 —, — ch 2 coch 2 —, — ch 2 conhch 2 —, — ch 2 coc 2 h 4 —, — ch 2 conhc 2 h 4 —, — c 2 h 4 coc 2 h 4 -, and — c 2 h 4 conhc 2 h 4 —. similarly , unless otherwise stated , the term “ aminoc 1 - c 4 alkyl ” includes short c 1 - c 2 termini . the term includes , for example , — ch 2 nh —, — c 2 h 4 nh —, — c 3 h — 6 nh —, — c 4 h 8 nh —, — ch 2 nhch 2 —, — c 2 h 4 nhch 2 —, — c 3 h 6 nhch 2 —, — c 4 h 8 nhch 2 —, — ch 2 nhc 2 h 4 —, — c 2 h 4 nhc 2 h 4 —, — c 3 h 6 nhc 2 h 4 —, — c 4 h 8 nhc 2 h 4 —, — nhch 2 —, — nhc 2 h 4 —, — nhc 3 h 6 —, — nhc 4 h 8 —, — ch 2 nhc 2 h 4 —, — ch 2 nhc 3 h 6 —, — ch 2 nhc 4 h 8 —, — c 2 h 4 nhc 3 h 6 —, and — c 2 h 4 nhc 4 h 8 —. unless otherwise stated , the term “ carbamate ” is used to include — ocooc 1 - c 4 alkyl , — nhcooc 1 - c 4 alkyl , and — oconhc 1 - c 4 alkyl . the term “ sem ” is used to describe — ch 2 — o — ch 2 ch 2 — si ( ch 3 ) 3 . the term “ c 0 ” means that the carbon is not present . thus , “ c 0 - c 5 ” means that there are from none to five carbons present — that is , five , four , three , two , one , or no carbons present . accordingly , “ c 0 - c 5 alkyl ” means a direct bond for the case of “ c 0 ”. the term “ optionally substituted ” is intended to include both substituted and unsubstituted . thus , for example , optionally substituted aryl could represent a pentafluorophenyl or a phenyl ring . compounds described herein contain one or more asymmetric centers and may thus give rise to diastereomers and optical isomers . the present invention includes all such possible diastereomers as well as their racemic mixtures , their substantially pure resolved enantiomers , all possible geometric isomers , and pharmaceutically acceptable salts thereof . the above formula i is shown without a definitive stereochemistry at certain positions . the present invention includes all stereoisomers of formula i and pharmaceutically acceptable salts thereof . further , mixtures of stereoisomers as well as isolated specific stereoisomers are also included . during the course of the synthetic procedures used to prepare such compounds , or in using racemization or epimerization procedures known to those skilled in the art , the products of such procedures can be a mixture of stereoisomers . the term “ pharmaceutically acceptable salts ” refers to salts prepared from pharmaceutically acceptable non - toxic bases or acids . when the compound of the present invention is acidic , its corresponding salt can be conveniently prepared from pharmaceutically acceptable non - toxic bases , including inorganic bases and organic bases . salts derived from such inorganic bases include aluminum , ammonium , calcium , copper ( ic and ous ), ferric , ferrous , lithium , magnesium , manganese ( ic and ous ), potassium , sodium , zinc and the like salts . particularly preferred are the ammonium , calcium , magnesium , potassium and sodium salts . salts derived from pharmaceutically acceptable organic non - toxic bases include salts of primary , secondary , and tertiary amines , as well as cyclic amines and substituted amines such as naturally occurring and synthesized substituted amines . other pharmaceutically acceptable organic non - toxic bases from which salts can be formed include ion exchange resins such as , for example , arginine , betaine , caffeine , choline , n , n ′- dibenzylethylenediamine , diethylamine , 2 - diethylaminoethanol , 2 - dimethylaminoethanol , ethanolamine , ethylenediamine , n - ethylmorpholine , n - ethylpiperidine , glucamine , glucosamine , histidine , hydrabamine , isopropylamine , lysine , methylglucamine , morpholine , piperazine , piperidine , polyamine resins , procaine , purines , theobromine , triethylamine , trimethylamine , tripropylamine , tromethamine and the like . when the compound of the present invention is basic , its corresponding salt can be conveniently prepared from pharmaceutically acceptable non - toxic acids , including inorganic and organic acids . such acids include , for example , acetic , benzenesulfonic , benzoic , camphorsulfonic , citric , ethanesulfonic , fumaric , gluconic , glutamic , hydrobromic , hydrochloric , isethionic , lactic , maleic , malic , mandelic , methanesulfonic , mucic , nitric , pamoic , pantothenic , phosphoric , succinic , sulfuric , tartaric , p - toluenesulfonic acid and the like . particularly preferred are citric , hydrobromic , hydrochloric , maleic , phosphoric , sulfuric , and tartaric acids . the pharmaceutical compositions of the present invention comprise a compound represented by formula i ( or pharmaceutically acceptable salts thereof ) as an active ingredient , a pharmaceutically acceptable carrier and optionally other therapeutic ingredients or adjuvants . the compositions include compositions suitable for oral , rectal , topical , and parenteral ( including subcutaneous , intramuscular , and intravenous ) administration , although the most suitable route in any given case will depend on the particular host , and nature and severity of the conditions for which the active ingredient is being administered . the pharmaceutical compositions may be conveniently presented in unit dosage form and prepared by any of the methods well known in the art of pharmacy . in practice , the compounds represented by formula i , or pharmaceutically acceptable salts thereof , of this invention can be combined as the active ingredient in intimate admixture with a pharmaceutical carrier according to conventional pharmaceutical compounding techniques . the carrier may take a wide variety of forms depending on the form of preparation desired for administration , e . g ., oral or parenteral ( including intravenous ). thus , the pharmaceutical compositions of the present invention can be presented as discrete units suitable for oral administration such as capsules , cachets or tablets each containing a predetermined amount of the active ingredient . further , the compositions can be presented as a powder , as granules , as a solution , as a suspension in an aqueous liquid , as a non - aqueous liquid , as an oil - in - water emulsion or as a water - in - oil liquid emulsion . in addition to the common dosage forms set out above , the compound represented by formula i , or pharmaceutically acceptable salts thereof , may also be administered by controlled release means and / or delivery devices . the compositions may be prepared by any of the methods of pharmacy . in general , such methods include a step of bringing into association the active ingredient with the carrier that constitutes one or more necessary ingredients . in general , the compositions are prepared by uniformly and intimately admixing the active ingredient with liquid carriers or finely divided solid carriers or both . the product can then be conveniently shaped into the desired presentation . thus , the pharmaceutical compositions of this invention may include a pharmaceutically acceptable carrier and a compound or a pharmaceutically acceptable salt of formula i . the compounds of formula i , or pharmaceutically acceptable salts thereof , can also be included in pharmaceutical compositions in combination with one or more other therapeutically active compounds . the pharmaceutical carrier employed can be , for example , a solid , liquid , or gas . examples of solid carriers include lactose , terra alba , sucrose , talc , gelatin , agar , pectin , acacia , magnesium stearate , and stearic acid . examples of liquid carriers are sugar syrup , peanut oil , olive oil , and water . examples of gaseous carriers include carbon dioxide and nitrogen . in preparing the compositions for oral dosage form , any convenient pharmaceutical media may be employed . for example , water , glycols , oils , alcohols , flavoring agents , preservatives , coloring agents and the like may be used to form oral liquid preparations such as suspensions , elixirs and solutions ; while carriers such as starches , sugars , microcrystalline cellulose , diluents , granulating agents , lubricants , binders , disintegrating agents , and the like may be used to form oral solid preparations such as powders , capsules and tablets . because of their ease of administration , tablets and capsules are the preferred oral dosage units whereby solid pharmaceutical carriers are employed . optionally , tablets may be coated by standard aqueous or nonaqueous techniques . a tablet containing the composition of this invention may be prepared by compression or molding , optionally with one or more accessory ingredients or adjuvants . compressed tablets may be prepared by compressing , in a suitable machine , the active ingredient in a free - flowing form such as powder or granules , optionally mixed with a binder , lubricant , inert diluent , surface active or dispersing agent . molded tablets may be made by molding in a suitable machine , a mixture of the powdered compound moistened with an inert liquid diluent . each tablet preferably contains from about 1 mg to about 500 mg of the active ingredient and each cachet or capsule preferably containing from about 1 to about 500 mg of the active ingredient . pharmaceutical compositions of the present invention suitable for parenteral administration may be prepared as solutions or suspensions of the active compounds in water . a suitable surfactant can be included such as , for example , hydroxypropylcellulose . dispersions can also be prepared in glycerol , liquid polyethylene glycols , and mixtures thereof in oils . further , a preservative can be included to prevent the detrimental growth of microorganisms . pharmaceutical compositions of the present invention suitable for injectable use include sterile aqueous solutions or dispersions . furthermore , the compositions can be in the form of sterile powders for the extemporaneous preparation of such sterile injectable solutions or dispersions . in all cases , the final injectable form must be sterile and must be effectively fluid for easy syringability . the pharmaceutical compositions must be stable under the conditions of manufacture and storage ; thus , preferably should be preserved against the contaminating action of microorganisms such as bacteria and fungi . the carrier can be a solvent or dispersion medium containing , for example , water , ethanol , polyol ( e . g . glycerol , propylene glycol and liquid polyethylene glycol ), vegetable oils , and suitable mixtures thereof . pharmaceutical compositions of the present invention can be in a form suitable for topical use such as , for example , an aerosol , cream , ointment , lotion , dusting powder , or the like . further , the compositions can be in a form suitable for use in transdermal devices . these formulations may be prepared , utilizing a compound represented by formula i of this invention , or pharmaceutically acceptable salts thereof , via conventional processing methods . as an example , a cream or ointment is prepared by mixing hydrophilic material and water , together with about 5 wt % to about 10 wt % of the compound , to produce a cream or ointment having a desired consistency . pharmaceutical compositions of this invention can be in a form suitable for rectal administration wherein the carrier is a solid . it is preferable that the mixture forms unit dose suppositories . suitable carriers include cocoa butter and other materials commonly used in the art . the suppositories may be conveniently formed by first admixing the composition with the softened or melted carrier ( s ) followed by chilling and shaping in moulds . in addition to the aforementioned carrier ingredients , the pharmaceutical formulations described above may include , as appropriate , one or more additional carrier ingredients such as diluents , buffers , flavoring agents , binders , surface - active agents , thickeners , lubricants , preservatives ( including anti - oxidants ) and the like . furthermore , other adjuvants can be included to render the formulation isotonic with the blood of the intended recipient . compositions containing a compound described by formula 1 , or pharmaceutically acceptable salts thereof , may also be prepared in powder or liquid concentrate form . assessing the activity of selected compounds to inhibit nr1a / 2b nmda receptor activation ( flipr assay ) the activity of selected compounds to inhibit nr1a / 2b nmda receptor activation measured as nr1a / 2b receptor - mediated ca 2 + influx is assessed by the following procedure : nr1a / 2b receptor transfected l ( tk ) cells are plated in 96 - well format fat 3 × 10 cells per plate and grown for one - two days in normal growth media ( dulbeccos mem with na pyruvate , 4500 mgglucose , pen / strep , glutamine , 10 % fcs and 0 . 5 mg / ml geneticin ). nr1a / 2b - expression in these cells is induced by the addition of 4 nm dexamethasone in the presence of 500 μm ketamine for 16 - 24 hours . after receptor induction cells are washed using a labsystem cellwasher two times with assay buffer ( hanks balanced salt solution ( hbss - mg ++ free ) containing 20 mm hepes , 0 . 1 % bsa , 2 mm cacl 2 and 250 μm probenecid ). the cells of each 96 well cell plate are loaded with the ca sensitive dye fluo - 3 ( molecular probes , inc .) at 4μm in assay buffer containing 0 . 5 % fbs , and 0 . 04 % pluronic f - 127 ( molecular probes , inc .) for lh at 37 ° c . avoiding light . the cells are then washed with the cellwasher four times with assay buffer leaving them in 100 μl buffer . test compounds in solution are pipetted by flipr ( fluorometric imaging plate reader ) into each test well for a 2 min pretreatment . during this time the fluorescence intensity is recorded ( excitation at 488 nm and emission at 530 nm ). the glutamate / glycine 50 μl agonist solution ( final concentration 1 μm / 1 μm ) is then added by flipr into each well already containing 150 μl of buffer ( containing the test compound or vehicle ) and the fluorescence is continuously monitored for 10 min . the endpoint fluorescence values are used to determine an ic 50 value comparing the agonist - stimulated signal for the vehicle alone sample and that for the cells incubated with each concentration of test compound . determining the apparent dissociation constant ( ki ) of compounds for human nr1a / nr2b receptors ( binding assay ): the radioligand binding assay is performed at room temperature in 96 - well microtiter plates with a final assay volume of 1 . 0 ml in 20 mm hepes buffer ( ph 7 . 4 ) containing 150 mm nacl . solutions of test compounds were prepared in dmso and serially diluted with dmso to yield 20 μl of each of 10 solutions differing by 3 - fold in concentration . non - specific binding ( nsb ) using hot amd - 1 ( 10 μm final concentration ) and total binding ( tb ) by using dmso ( 2 % final concentration ). a solution of nr1a / nr2b receptors ( 40 μm final concentration ) and tritiated amd - 2 ( 1 nm final concentration ) were added to the test compounds . after 3 h of incubation at room temperature , samples are filtered through packard gf / b filters ( presoaked in 0 . 05 % pei , polyethyleninine sigma p - 3143 ) and washed 10 times with 1 ml of cold 20 mm hepes buffer per wash . after vacuum drying of the filter plates , 40 μl of packard microscint - 20 was added and bound radioactivity determined in a packard topcount . the apparent dissociation constant ( ki ), the maximum percentage inhibition (% i max ), the minimum percentage inhibition (% i min ) and the hill slope ( nh ) were determined by a non - linear least squares fitting the bound cpm data to equation # 1 below . equation # 1 : cpm   bound = ( sb )  ( %   i max - %   i min ) ( 1 + ( [ drug ] / ( ki  [ l - 844 , 345 ] / k d ) ) nh ) + nsb + ( sb )  ( 1 - %   i max ) where , k d is the apparent dissociation constant for the radioligand for the receptor as determined by hot saturation and sb is the specifically bound cpm determined from the difference of tb and nsb . compounds amd - 1 and amd - 2 can be synthesized in accordance with the following general reaction schemes . in accordance with scheme 1 , hydrogen chloride is bubbled through a solution of the appropriately substituted benzonitrile 1 in methanol at room temperature . the volatiles are removed under reduced pressure and the resulting residue is triturated with ether and filtered to yield the desired imidate 2 . imidate 2 is dissolved in methanol at ambient temperature , treated with amine 3 at ambient temperature and stirred under argon . the volatiles are removed under reduced pressure and the residue purified by preparative hplc or trituration with ether to afford amidine ia . in accordance with scheme 2 , at room temperature under argon , amine 3a is dissolved in ether and was treated with 1 - m hydrogen chloride in ether ( 1 equiv .) in a single portion . the resulting precipitate is stirred vigorously for 10 minutes . the volatiles are removed under reduced pressure . the residue is suspended in toluene , cooled to 0 ° c . under argon , treated with 2 . 0 - m trimethylaluminum ( 1 . 05 equiv .) in a dropwise manner , and stirred for 45 minutes at room temperature to afford intermediate 6 ( not isolated ). compound 6 is added to a solution of nitrile 1 in toluene . the reaction is heated to 80 ° c . without stirring in a sealed tube for 18 h , cooled to ambient temperature , poured onto a silica gel column and eluted with methanol / dichloromethane to give the amidine 4 . tritiated amd - 1 was prepared by the following procedure : a mixture of amd - 1 , hydrochloride salt , ( 5 mg , 0 . 012 mmol ) in dioxane ( 0 . 2 ml ) containing triethylamine ( 4 μl ) was treated with hexamethylditin ( 5 μl ), a catalytic amount of palladium catalyst and heated at 100 ° c . for 45 minutes . the reaction was cooled to room temperature , filtered through a glass wool plug , rinsed with methanol and concentrated in vacuo to give 10 . 7 mg of a brown oil . the oil was dissolved in methylene chloride and passed through a small silica column eluting with methylene chloride followed by 5 % methanol / methylene chloride . fractions containing the trimethylstannane ( rf 0 . 26 in 10 % methanol / methylene chloride ) were pooled and concentrated in vacuo to give 4 . 5 mg of the trimethylstannane as a clear colorless oil . this material was further purified by hplc ( c18 econosil , 10 × 250 mm , 20 minute linear gradient , 30 % mecn : 70 % h 2 o ( 0 . 1 % tfa ). to 90 % mecn , 3ml / min , 254 nm , retention time 15 minutes ) to give 3 mg of the trimethylstannane . a na 125 i shipping vial ( 10 mci , amersham ) was charged with a stir bar , an iodobead , 50 μl of methanol and stirred five minutes at room temperature . a solution of the trimethylstannane ( 0 . 1 mg ) in 50 μl of methanol containing 5 μl of trifluoroacetic acid was added and the reaction was stirred for five minutes . the reaction was quenched with 50 μl of ammonium hydroxide and purified by hplc ( c18 vydac protein and peptide column , 4 . 6 × 250 mm , 20 minute linear gradient , 30 % mecn : 70 % h 2 0 ( 0 . 1 % tfa ) to 90 % mecn , 1 ml / min , retention time 11 minutes ). fractions containing the radioactive product were pooled and concentrated in vacuo to give 989 μci of [ 125 i ] amd - 1 with a specific activity of 898ci / mmol as measured by uv absorbance at 272 nm . tritiated amd - 2 was prepared by the following procedure : the phenol of amd - 2 ( 2 mg , 0 . 008 mmol ) dissolved in dimethylformamide ( 0 . 6 ml ) and potasium carbonate ( 1 . 2 mg ) for 1 hr . high specific activity tritiated methyl iodide ( 50 mci , 0 . 0006 mmol , in toluene 1 ml , american radiolabeled chemicals ) was added at room temperature and stirred for 2 hours . the reaction mixture was filtered using a whatman ptfe 0 . 45 μm syringeless filter device to remove any insoluable potassium carbonate , washed with abs . ethanol ( 2 ml , pharmco ), and the combined filtrates were concentrated to dryness at room temperature using a rotary evaporator ; this also removed any unreacted tritiated methyl iodide . the residue was purified by hplc chromatography on a phenomenx luna c8 semi - prep column ( luna 5 micro c8 ( 2 ), 250 × 10 . 0 mm ) using a gradient system of 20 / 80 acetonitrile / water with 0 . 1 % trifluoroacetic acid to 100 % acetronitrile with 0 . 1 % trifluoroacetic acid in 20 min . total activity of the product was 8 mci . further purification was effected by absorption onto a waters c - 18 sep - pak column ( waters sep - pak plus c18 ) and elution with water followed by absolute ethanol . the product was diluted with absolute ethanol ( 10 ml ) before submission for final analysis . the compounds of this invention exhibit less than 50 μm in the flibr and binding assays . thus , the compounds and pharmaceutical compositions of this invention have been found to exhibit biological activity as nmda nr2b antagonists . accordingly , another aspect of the invention is the treatment of pain , migraine , depression , anxiety , schizophrenia , parkinson &# 39 ; s disease , or stroke — maladies that are amenable to amelioration through inhibition of nmda nr2b receptors — by the administration of an effective amount of the compounds of this invention . the following examples are provided to more fully illustrate the present invention , and are not to be construed as limiting the scope of the claims in any manner . the compounds of this invention can be prepared according to scheme 1 shown below : the compounds of this invention can be prepared according to scheme 2 shown below : the compounds of this invention can be prepared according to scheme 3 shown below : the compounds of this invention can be prepared according to scheme 4 shown below : the compounds of this invention can be prepared according to scheme 5 shown below : the compounds of this invention can be prepared according to scheme 6 shown below : to a stirred solution of 20 g of 1 , 4 - dioxa - spiro [ 4 . 5 ] decan - 8 - one and 35 g of diethyl benzylphosphonate in 60 ml of 1 , 3 - dimethyl - 2 - imidazolidinone dried over 4 å mol sieves was added 7 g of 60 % nah oil dispersion . the mixture was allowed to stir overnight , diluted with 500 ml of water and extracted with 3 × 100 ml of ether . combined extracts were dried over magnesium sulfate and concentrated under reduced pressure . chromatography over silica gel eluting with a gradient of 5 : 95 ethyl acetate : hexane to 1 : 3 ethyl acetate : hexane gave 28 g of olefin as a colorless oil . a solution of 28 g of 8 - benzylidene - 1 , 4 - dioxa - spiro [ 4 . 5 ] decane and 1 g of 5 % palladium on carbon in 250 ml of ethanol was allowed to stir overnight under 1 atm of hydrogen the catalyst was filtered off and the solution concentrated to give 28 g of 8 - benzyl - 1 , 4 - dioxa - spiro [ 4 . 5 ] decane as an oil . a mixture of 28 g of 8 - benzyl - 1 , 4 - dioxa - spiro [ 4 . 5 ] decane , 100 ml of water , 10 ml of methanol and 20 g of amberlite ™ ir - 120 + was heated to reflux for 5 h . after cooling , removal of solvents under reduced pressure gave 24 g of 4 - benzyl - cyclohexanone as an oil . a stirred solution of 0 . 5 g of 4 - benzyl - cyclohexanone , 1 . 0 g of 2 - benzimidazolylmethyltriphenylphosphonium chloride and 15 ml of anhydrous dmso was heated gently until a clear solution was obtained , then cooled to room temperature . to this solution was added 90 mg of 60 % sodium hydride oil dispersion . the resulting orange solution was stirred for 48 h at room temperature , then quenched with 200 ml of water and extracted into 3 × 50 ml portions of ethyl acetate . the combined extracts were dried over magnesium sulfate and concentrated . purification by preparative tlc eluting with 25 % ethyl acetate in hexane gave 220 mg of a white solid : ms ( m + 1 )= 303 . 4 ; 1 h nmr ( 400 mhz , cdcl 3 ) 7 . 5 ( m , 2h ), 7 . 2 - 7 . 0 ( 3 × m , 7h ), 6 . 2 ( s , 1h ), 3 . 75 ( d , 1h ), 2 . 45 ( dd , 2h ), 2 . 3 ( d , 1h ), 2 . 2 ( t , 1h ), 2 . 05 ( m , 1h ), 1 . 8 ( m , 4h ), 1 . 05 ( m , 2h ). hydrogenation of 0 . 10 g of 2 -( 4benzyl - cyclohexylidenemethyl )- 1h - benzimidazole over 0 . 05 g of 5 % platinum on carbon in 10 ml of ethanol at 1 atm overnight gave 0 . 1 g of 2 -( 4 - benzyl - cyclohexylmethyl )- 1h - benoimidazole as a 2 : 1 mixture of cis and trans isomers . chromatography on a chiralpak ™ column eluting with a gradient of 70 : 30 to 30 : 70 hexane and 2 - propanol gave 2 -( 4 - benzyl - cyclohexylmethyl )- 1h - benoimidazole : rt =????? ? min ; ms ( m + 1 )=; 1 h nmr ( 400 mhz , cdcl 3 ) later fractions yielded 2 -( 4 - benzyl - cyclohexylmethyl )- 1h - benoimidazole ; ms ( m + 1 ) =; 1 h nmr ( 400 mhz , cdcl 3 ) example 3 was prepared by the following procedure . to a stirred solution of 20 mg of 2 -( 4benzyl - cyclohexylidenemethyl )- 1h - benzimidazole in 10 ml of thf cooled in an ice bath was added 1 ml of 1m borane • thf . after stirring for 24 h warming to room temperature , 0 . 5 ml of water was added followed by 0 . 5 ml of 6n sodium hydroxide and 0 . 5 ml of 30 % hydrogen peroxide . after 30 min , the solution was diluted with 100 ml of chloroform , washed 2 × 10 ml of water , dried over magnesium sulfate and concentrated to dryness . preparative thin - layer chromatography eluting with 25 % ethyl acetate in hexane gave 11 mg of (±)- cis and trans ( 1h - benzimidazol - 2 - yl )-( 4 - benzyl - cyclohexyl )- methanol as a gummy resin : ms ( m + 1 )= 321 . 4 ; 1 h nmr ( 400 mhz , cdcl 3 ) 7 . 6 ( m , 2h ), 7 . 2 ( m , 7h ), 4 . 85 and 4 . 8 ( 2 × d , 1h ), 2 . 6 and 2 . 42 ( 2 × d , 2h ). to a stirred solution of 1 g of 3 - mono - ethylene ketal of bicyclo [ 3 . 2 . 1 ] octane - 3 , 8 - dione ( prepared by jones oxidation of the mono - ethylene ketal of 3 - endo - hydroxy - bicyclo [ 3 . 2 . 1 ] octan - 8 - one which was prepared by the procedure described by m . povarny , p . schreiber , g . kraiss and k . nador , tetrahedron letters , 25 : 1311 - 12 ( 1984 ) and 2 . 4 g of diethyl 4 - chlorobenzylphosphonate in 5 ml of 1 , 3 - dimethyl - 2 - imidazolidinone dried over 4 å mol sieves was added 0 . 30 g of 60 % nah oil dispersion . the mixture was allowed to stir overnight , diluted with 200 ml of water and extracted with 3 × 100 ml of ethyl acetate . combined extracts were dried over magnesium sulfate and concentrated under reduced pressure . low pressure chromatography over silica gel eluting with a gradient of 5 : 95 ethyl acetate : hexane to 1 : 3 ethyl acetate : hexane gave 1 . 9 g of the ethylene ketal of 3 -( 4chloro - benzylidene )- bicyclo [ 3 . 2 . 1 ] octan - 8 - one as a colorless oil . hydrogenation of 1 . 9 g of the ethylene ketal of 3 -( 4chloro - benzylidene )- bicyclo [ 3 . 2 . 1 ) octan - 8 - one over 0 . 4 g of 5 % platinum on carbon in 50 ml of ethans under 1 atm of hydrogen for 3 h gave 1 . 9 g the ethylene ketal of 3 -( 4chloro - benzyl )- bicyclo [ 3 . 2 . 1 ] octans - 8 - one as a thick oil : 1 h nmr ( 400 mhz , cdcl 3 ): the crude product was a 3 : 1 mixture of exo : endo by peak integration of the exo benzylic protons at 2 . 45 ( d ): endo benzylic protons at 2 . 78 ( d ). a stirred mixture of 1 . 9 g of the ethylene ketal of 3 -( 4 - chloro - benzyl )- bicylo [ 3 . 2 . 1 ] octan - 8 - one , 10 ml of dioxane , 50 ml of water and 5 g of amberlite ™ ir - 120 + was heated to teflux for 8 h , cooled , filtered and extracted into 5 × 50 ml of ether . combined extracts were dried over magnesium sulfate and concentrated . the crude 3 : 1 mixture of exo and endo 3 -( 4 - chloro - benzyl )- bicyclo [ 3 . 2 . 1 ] octan - 8 - one , 1 . 3 g , was an oil . to a stirred solution of 0 . 25 g of 2 - benzimidazolylmethyl triphenyl phosphonium chloride and 0 . 1 g of 3 -( 4 - chloro - benzyl )- bicyclo [ 3 . 2 . 1 ] octan - 8 - one in 5 ml of dmso ( heat to dissolve ) at room temperature was added 60 mg of sodium hydride 60 % oil dispersion . after the orange - red mixture was stirred for 24 h , conversion was complete and the solution was diluted with 100 ml of water and extracted into 3 × 25 ml of ethyl acetate . combined extracts were dried over magnesium sulfate and concentrated . purification by chromatography , eluting with 50 % ethyl acetate in hexane gave 40 mg of 2 -[ 3 -( 4chloro - benzyl )- bicyclo [ 3 . 2 . 1 ] oct - 8 - ylidenemethyl ]- 1h - benzimidazole . hydrogenation of 40 mg of the ethylene ketal of 3 -( 4 - chloro - benzylidene )- bicyclo [ 3 . 2 . 1 ] octan - 8 - one over 0 . 05 g of 5 % platinum on carbon in 10 ml of ethanol under 1 atm of hydrogen for 3 h gave 40 mg of 2 -[ 3 -( 4 - chloro - benzyl )- bicyclo [ 3 . 2 . 2 ] oct - 8 - ylmethyl - 1h - benzimidazole as a mixture of 3 - exo - 8 - exo and 3 - exo - 8 - endo isomers . preparative tlc eluting with 50 % ethyl acetate in hexane gave two bands . the major upper band was the 3 - exo - 8 - exo 2 -[ 3 -( 4 - chloro - benzyl )- bicyclo [ 3 . 2 . 1 ] oct - 8 - ylmethyl ]- 1h - benzimidazole : 1 h nmr ( m + 1 )= 321 . 4 ; 1 h nmr ( 400 mhz , cdcl 3 ) 7 . 6 ( m , 2h ), 7 . 2 ( m , 7h ), 4 . 85 and 4 . 8 ( 2 × d , 1h ), 2 . 6 and 2 . 42 ( 2 × d , 2h ). a mixture of 250 mg of 3 : 1 mixture of exo and endo 3 -( 4 - chloro - benzyl )- bicyclo [ 3 . 2 . 1 ] octan - 8 - one , 400 mg of 2 - aminomethylbenzimidazole dihydrochloride , 150 mg of anhydrous sodium acetate , 10 ml of 1 , 2 - dichloroethane and 400 mg of sodium triacetoxyborohydride was stirred overnight in a stoppered flask . the mixture was diluted with 50 ml of chloroform and washed with 20 ml of saturated sodium carbonate . the organic extract was dried over magnesium sulfate and concentrated under reduced pressure . preparative tlc eluting with 225 : 25 : 5 chloroform : methanol : concentrated ammonium hydroxide gave in the fastest band the product as a mixture of two isomers . crystallization and preparative tlc with 75 : 25 : 10 tetrahydrofuran : hexane : triethylamine or chromatography on chiralpak ™ ad eluting with 90 : 10 0 . 1 % diethylamine in hexane : ethanol gave 150 mg of pure 3 - exo - 8 - exo ( 1h - benzimidazol - 2 - ylmethyl )-[ 3 -( 4chlorobenzyl )- bicyclo [ 3 . 2 . 1 ] oct - 8 - yl ]- amine : rt = 5 . 8 min ; ms ( m + 1 )= 380 . 9 ; 1 h nmr ( 400 mhz , cdcl 3 ) 9 . 5 ( br , 1h ), 7 . 7 ( br , 1h ), 7 . 5 ( br , 1h ), 7 . 2 ( m , 4h ), 7 . 1 ( d , 2h ), 4 . 1 ( s , 2h ), 2 . 8 ( m , 1h ), 2 . 5 ( d , 2h ), 2 . 1 ( s , 2h ), 2 - 1 . 2 ( complex , 11h ). later fractions gave 50 mg of pure 3 - endo - 8 - exo ( 1h - benzimidazol - 2 - ylmethyl )-[ 3 -( 4 - chloro - benzyl )- bicyclo [ 3 . 2 . 1 ] oct - 8 - yl ]- amine : rt = 9 min ; ms ( m + 1 )= 380 . 9 ; 1 h nmr ( 400 mhz , cdcl 3 ) 9 . 5 ( br , 1h ), 7 . 7 ( br , 1h ), 7 . 5 ( br , 1h ), 7 . 2 ( m , 4h ), 7 . 1 ( d , 2h ), 4 . 18 ( s , 2h ), 2 . 82 ( m , 1h ), 2 . 78 ( d , 2h ), 2 . 06 ( s , 2h ), 2 . 1 - 1 . 2 ( complex , 11h ). example 6 was prepared in a similar manner to examples 4 and 5 above . a mixture of 250 mg of 3 : 1 mixture of exo and endo 5 -( 4 - chloro - benzyl )- bicyclo [ 2 . 2 . 2 ] octan - 2 - one was prepared from 5 - acetoxy - 5 - cyanobicyclo [ 2 . 2 . 2 ] octan - 2 - one in three sequential steps without isolating intermediate products . the first two steps were similar to those described in steps 1 and 2 of example 4 above , sequential treatment with sodium borohydride in ethanol , sodium hydroxide , formed 5 - hydroxybicyclo [ 2 . 2 . 2 ] octan - 2 - one . olefination , hydrogenation , and swern oxidation of the product , 5 -( 4 - chloro - benzyl )- bicyclo [ 2 . 2 . 2 ] octan - 2 - ol followed . to the resulting product was added 400 mg of 2 - aminomethylbenzimidazole dihydrochloride , 150 mg of anhydrous sodium acetate , 10 ml of 1 , 2 - dichloroethane and 400 mg of sodium triacetoxyborohydride , and stirred overnight in a stoppered flask . the mixture was diluted with 50 ml of chloroform and washed with 20 ml of saturated sodium carbonate . the organic extract was dried over magnesium sulfate and concentrated under reduced pressure . preparative tlc eluting with 95 : 5 : 5 ethyl acetate : methanol : triethyl amine gave ( 1h - benzimidazol - 2 - ylmethyl )-[ 5 -( 4 - chloro - benzyl )- bicyclo [ 2 . 2 . 2 ] oct - 2 - yl ]- amine as a racemic mixture of four diastereomers : ms ( m + 1 )= 380 . 9 ; 1 h nmr ( 400 mhz , cdcl 3 ) 7 . 6 ( br s , 1h ), 7 . 2 ( m , 4h ), 7 . 05 ( m , 2h ), 4 . 04 and 4 . 06 ( 2 × s , 2h ), 2 . 85 ( m , 1h ), 2 . 6 - 5 ( m , 3h ), 2 . 0 - 1 . 0 ( complex , 12h ). example 7 was prepared by the following procedure , referring to scheme 4 above : to a solution of ethyl 4 - oxocyclohexanecarboxylate ( compound a ) ( 8 . 3 g , 48 . 8 mmol ), tert - butyl diethylphosphonoacetate ( 13 . 5 g , 53 . 7 mmol ), and activated 4 å sieves ( 30 g ) in anhydrous thf ( 250 ml ) at reflux was added anhydrous lioh ( 3 . 8 g , 161 . 0 mmol ) in small portions . after refluxing 6 h , the reaction was cooled and partitioned between water and ethyl acetate . the organic layer was dried with mgso 4 and concentrated to give 13 g of a colorless oil . flash chromatography on silica ( 10 % etoac in hexane ) yielded ( b ) 4 - tert - butoxycarbonylmethylenecyclohexanecarboxylic acid tert - butyl ester ( 12 . 5 g , 95 %) as a colorless oil . 1 h nmr ( 400 mhz , cdcl 3 ) δ 5 . 60 ( s , 1h ), 4 . 15 ( q , 2h ), 3 . 60 ( m , 1h ), 2 . 55 ( m , 1h ), 2 . 35 ( m , 1h ), 2 . 21 - 2 . 02 ( m , 4h ), 1 . 78 - 1 . 62 ( m , 2h ), 1 . 48 ( s , 9h ), 1 . 25 ( t , 3h ); mass spectrum m / z 213 [( m - tbu )+; calcd for c 11 h 17 o 4 : 213 ]. a solution of diester ( b ) ( 12 . 5 g , 46 . 3 mmol ) and 10 % palladium on activated carbon ( 5 g ) in absolute ethanol ( 200 ml ) was exposed to a hydrogen atmosphere ( at balloon pressure ) and stirred vigorously for lh . after removal of catalyst by filtration and concentration , the resultant colorless oil was dissolved in methylene chloride ( 150 ml ) and tea ( 75 ml ) and stirred for 15 min . all volatiles were removed by rotary evaporation and the resultant colorless oil placed under high vacuum to give ( c ) 4 - carboxymethyl - cyclohexanecarboxylic acid ethyl ester ( 9 . 9 g , 99 %) as a white solid . data for cis / trans mixture : 1 h nmr ( 400 mhz , cd 3 od ) δ 4 . 13 ( 2q , 4h ), 2 . 58 ( m , 1h ), 2 . 30 - 2 . 20 ( m , 1h ), 2 . 20 ( 2d , 4h ), 2 . 05 - 1 . 80 ( m , 7h ), 1 . 80 - 1 . 55 ( m , 5h ), 1 . 50 - 1 . 38 ( m , 3h ), 1 . 32 - 1 . 25 ( m , 1h ), 1 . 25 ( 2t , 6h ), 1 . 10 - 1 . 00 ( m , 2h ); mass spectrum m / z 215 [( m + h ) + ; calcd for c 11 h 19 o 4 : 215 ]. to a solution of acid ( c ) ( 10 . 5 g , 49 . 0 mmol ), edc ( 9 . 4 g , 49 . 0 mmol ) and hoat ( 6 . 7 g , 49 . 0 mmol ) in 80 ml anhydrous dmf was added phenylenediamine ( 5 . 3 g , 49 . 0 mmol ) and the reaction mixture stirred for lh . the reaction mixture was partitioned between saturated aqueous nahco 3 and etoac and the organic portion washed 3 × with water . the organic layer was dried with mgso 4 and concentrated to yield 14 g of a yellow oil . the crude material was dissolved in toluene / tfa ( 1 : 1 300 ml ), heated to 90 ° c . and stirred overnight . the reaction mixture was then concentrated and purified by column chromatography on silica using 1 : 1 etoac / hexane followed by 90 : 10 : 1 ch 2 cl 2 / meoh / nh 4 oh to give ( d ) 4 -( 1h - benzimidazol - 2 - ylmethyl )- cyclohexanecarboxylic acid ethyl ester ( 7 . 5 g , 53 %) as a colorless oil . data for cis / trans mixture : 1 h nmr ( 400 mhz , cdcl 3 ) δ 7 . 62 ( 2d , 4 h ), 7 . 38 ( 2d , 4h ), 2 . 70 ( 2d , 4h ), 2 . 48 ( m , 1h ), 2 . 10 - 1 . 90 ( m , 5h ), 1 . 70 - 1 . 58 ( m , 4 h ), 1 . 60 - 1 . 53 ( m , 3h ), 1 . 49 - 1 . 38 ( m , 4h ), 1 . 63 - 1 . 50 ( m , 1h ), 1 . 40 ( 2t , 6h ), 0 . 90 - 0 . 70 ( m , 2h ); mass spectrum m / z 287 [( m + h ) + ; calcd for c 17 h 23 n 2 o 2 : 287 ]. the cis / trans mixture of 4 -( 1h - benzimidazol - 2 - ylmethyl )- cyclohexanecarboxylic acid ethyl esters ( d ) ( 600 mg , 2 . 1 mmol ) was dissolved in a minimal amount of thf ( 5 ml ) and mixed with concentrated aqueous lioh ( 2 ml ). the reaction was stirred vigorously and heated at 65 ° c . for 3 h . after cooling and concentration , the crude material was dissolved in 1 : 1 water / ch 3 cn and subjected to preparative reverse - phase hplc to yield ( e ) cis - 4 -( 1h - benzimidazol - 2 - ylmethyl )- cyclohexanecarboxylic acid ( 200 mg , 37 %): 1 h nmr ( 400 mhz , cd 3 od ) δ 7 . 77 ( m , 2 h ), 7 . 60 ( m , 2h ), 3 . 11 ( d , 2h ), 2 . 62 ( m , 1h ), 2 . 10 ( m , 3h ), 1 . 65 ( m , 4h ), 1 . 43 ( m , 2h ); mass spectrum m / z 259 [( m + h ) + ; calcd for c 15 h 19 n 2 o 2 : 259 ]. later fractions gave the trans isomer ( f ) ( 276 mg , 51 %): 1 h nmr ( 400 mhz , cd 3 od ) δ 7 . 77 ( m , 2h ), 7 . 59 ( m , 2h ), 3 . 08 ( d , 2h ), 2 . 28 ( m , 1h ), 2 . 05 ( d , 2h ), 1 . 95 ( m , 1h ), 1 . 84 ( d , 2h ), 1 . 46 ( dq , 2h ), 1 . 20 ( dq , 2h ); mass spectrum m / z 259 [( m + h ) + ; calcd for c 15 h 19 n 2 o 2 : 259 ]. to a solution of ( e ) cis - 4 -( 1h - benzimidazol - 2 - ylmethyl )- cyclohexanecarboxylic acid ( 271 mg , 1 . 05 mmol ), edc ( 200 mg , 1 . 05 mmol ) and hoat ( 142 mg , 1 . 05 mmol ) in anhydrous dmf ( 4 ml ) was added 2 - fluorobenzylamine ( 131 mg , 1 . 05 mmol ) and the reaction mixture was stirred for lh . the reaction mixture was partitioned between saturated aqueous nahco 3 and etoac and the organic layer washed 2 × with water . the etoac was dried with mgso 4 and concentrated to give a yellow solid . the crude material was triturated with 2 : 2 : 1 water / ch 3 cn / dmso and the resultant white solid filtered off . repetitive concentration and trituration of the filtrate in the same manner gave cis - 4 -( 1h - benzimidazol - 2 - ylmethyl )- cyclohexanecarboxylic acid 2 - fluoro - benzylamide ( f ) ( 230 mg , 60 %) as a white solid . the ( f ) compound was stirred in 1m hcl / ether ( 10 ml ) for 1 h and concentrated to give the hcl salt of ex . 7 ( 250 mg ): 1 h nmr ( 400 mhz , cd 3 od ) δ 7 . 50 ( br s 2h ), 7 . 35 - 7 . 25 ( m , 2h ), 7 . 22 - 7 . 05 ( m , 4h ), 4 . 43 ( s , 2h ), 2 . 92 ( d , 2h ), 2 . 41 ( m , 1h ), 2 . 23 ( m , 1h ), 1 . 93 ( m , 2h ), 1 . 60 ( m , 6h ); mass spectrum m / z 366 [( m + h ) + ; calcd for c 22 h 25 n 3 of : 366 ]. example 8 was prepared by the following procedure . to a solution of trans - 4 -( 1h - benzimidazol - 2 - ylmethyl )- cyclohexanecarboxylic acid ( f ) ( 444 mg , 1 . 72 mmol ), edc ( 328 mg , 1 . 72 mmol ) and hoat ( 234 mg , 1 . 72 mmol ) in anhydrous dmf ( 4 ml ) was added benzylamine ( 184 mg , 1 . 72 mmol ). the resulting reaction mixture was stirred for 15 h . the reaction mixture was partitioned between saturated aqueous nahco 3 and etoac and the organic layer washed 2 × with water , and dried with mgso 4 . concentration gave trans - 4 -( 1h - benzimidazol - 2 - ylmethyl )- cyclohexanecarboxylic acid benzylamide ( 400 mg , 67 %) as a white solid . 1 h nmr ( 400 mhz , cd 3 od ) δ 7 . 49 ( br s , 2h ), 7 . 30 - 7 . 17 ( m , 7h ), 4 . 34 ( s , 2h ), 2 . 78 ( d , 2h ), 2 . 21 ( m , 1h ), 1 . 84 ( m , 5h ), 1 . 55 ( q , 2h ), 1 . 16 ( q , 2h ); mass spectrum m / z 348 [( m + h ) + ; calcd for c 22 h 26 n 3 o : 348 ]. all compounds analogous to example 8 were prepared from carboxylic acid ( f ) via the above procedure using the appropriate amine and purified by reverse - phase hplc . compounds of the present invention can be prepared according to scheme 7 shown below : referring to scheme 7 above , example 9 was prepared by the following procedure . to a suspension of 4 - amino - cyclohexanecarboxylic acid ( g ) ( 5 g , 35 mmol ) in etoh ( 175 ml ) at 0 ° c . was added socl 2 ( 12 . 6 ml , 174 mmol ) dropwise via a syringe . the reaction mixture was warmed to room temperature and stirred for 16 h . after concentration of the reaction mixture , ether was added and the suspension was filtered to give 4 - amino - cyclohexanecarboxylic acid ethyl ester ( h ) ( mixture of cis / trans ) as a white solid ( 4 . 8 g ): 1 h nmr ( 300mz , cdcl 3 ) δ 8 . 35 ( br s , 3h ), 4 . 18 ( m , 2h ), 3 . 36 - 3 . 15 ( m , 1h ), 2 . 54 ( m , 1h ), 2 . 30 - 1 . 45 ( series of m , 1h ), 1 . 13 ( t , 3 h ); mass spectrum m / z 172 [( m + h ) + ; calcd for c 9 h 18 no 2 : 172 ]. a mixture of 2 - chlorobenzimidazole ( i ) ( 0 . 9 g , 5 . 9 mmol ) and ethyl - 4 - amino - cyclohexane carboxylate ( 1 . 1 g , 5 . 4 mmol ) were placed in a glass high pressure a tube . diisopropylethylamine ( 2 . 8 ml , 16 . 2 mmol ) was added , the reaction vessel was sealed and heated to 200 ° c . for 4 h and allowed to cool to room temperature . next was added 5 ml etoh and heated to dissolve the reaction mixture . the reaction mixture was partitioned between aqueous nahco 3 and etoac , and the organic layer was washed with water and brine , dried over mgso 4 , filtered and concentrated . purification of the crude product on silica gel ( gradient , 1 : 1 hexanes : etoac to etoac ) gave the cis 4 -( 1h - benzimidazol - 2 - ylamino )- cyclohexanecarboxylic acid ethyl ester ( j ) ( 0 . 5 g ) and the trans 4 -( 1h - benzimidazol - 2 - ylamino )- cyclohexanecarboxylic acid ethyl ester ( k ) ( 0 . 5 g ) data for ( j ): 1 h nmr ( 300 mhz , cdcl 3 ) δ 7 . 28 ( br s , 2h ), 7 . 02 ( m , 2h ), 5 . 16 ( br s , 1h ), 4 . 15 ( q , 2h ), 3 . 97 ( br s , 1h ), 2 . 40 ( br s , 1h ), 1 . 80 - 1 . 54 ( m , 8h ), 1 . 22 ( t , 3h ); mass spectrum m / z 288 [( m + h ) + ; calcd for c 16 h 22 n 3 o 2 : 288 ]. later fractions gave the trans isomer ( k ) ( 0 . 5 g ): 1 h nmr ( 300mh , cdcl 3 ) δ 7 . 28 ( br s , 2h ), 7 . 02 ( m , 2h ), 4 . 82 ( br s , 1h ), 4 . 15 ( q , 2h ), 3 . 64 ( m , 1h ), 2 . 20 ( br d , 3h ), 1 . 96 ( br d , 2h ), 1 . 42 ( m , 2h ), 1 . 22 ( t , 3 h ), 1 . 20 ( m , 2h ); mass spectrum m / z 288 [( m + h ) + ; calcd for c 16 h 22 n 3 o 2 : 288 ]. a solution of trans 4 -( 1h - benzimidazol - 2 - ylamino )- cyclohexanecarboxylic acid ethyl ester ( k ) ( 500 mg , 1 . 7 mmol ) in dioxane ( 4 ml ) and hcl ( 6 n , 8 ml ) was heated to 60 ° c . for 16 h . after cooling , concentration of the reaction mixture gave trans 4 -( 1h - benzimidazol - 2 - ylamino )- cyclohexanecarboxylic acid as a white solid ( m ) ( 420 mg ): 1 h nmr ( 300 mhz , cd 3 od ) δ 7 . 39 ( m , 2h ), 7 . 28 ( m , 2h ), 3 . 57 ( m , 1h ), 2 . 35 ( m , 1h ), 2 . 18 ( br t , 4h ), 1 . 65 - 1 . 40 ( m , 4h ); mass spectrum m / z 260 [( m + h ) + ; calcd for c 14 h 18 n 3 o 2 : 260 ]. to a solution of trans 4 -( 1h - benzimidazol - 2 - ylamino )- cyclohexanecarboxylic acid ( m ) ( 20 mg , 0 . 07 mmol ) in dmf ( 0 . 2 ml ) was added edc ( 26 mg , 0 . 14 mmol ), hobt ( 18 mg , 0 . 14 mmol ), triethylamine ( 0 . 007 ml , 0 . 14 mmol ) and benzyl amine ( 0 . 007 ml , 0 . 7 mmol ). the reaction mixture was stirred at room temperature for 1 h followed by quenching with aqueous nahco 3 and etoac . the layers were separated and the organic was washed twice with water , dried over na 2 so 4 , filtered and concentrated . purification of the crude oil by preparative reverse - phase hplc gave trans 4 -( 1h - benzimidazol - 2 - ylamino )- cyclohexanecarboxylic acid benzylamide ( example 9 ) ( 14 mg ): 1 h nmr ( 300 mhz , cd 3 od ) δ 7 . 40 - 7 . 20 ( m , 9h ), 4 . 39 ( s , 2h ), 3 . 55 ( m , 1h ), 2 . 31 ( m , 1h ), 2 . 20 ( br d , 2h ), 1 . 98 ( br d , 2h ), 1 . 77 ( m , 2h ), 1 . 50 ( m , 2h ); mass spectrum m / z 349 [( m + h ) + ; calcd for c 21 h 25 n 4 o : 349 ]. referring to scheme 7 , example 10 was prepared by the following procedure . in a similar manner to example 9 above , cis 4 -( 1h - benzimidazol - 2 - ylamino )- cyclohexanecarboxylic acid ethyl ester ( j ) was saponified and gave the cis 4 -( 1h - benzimidazol - 2 - ylamino )- cyclohexanecarboxylic acid ( l ): 1 h nmr ( 300mhz , cd 3 od ) δ 7 . 39 ( m , 2h ), 7 . 28 ( m , 2h ), 3 . 64 ( m , 1h ), 2 . 60 ( m , 1h ), 2 . 10 m , 2 1 ), 1 . 95 ( m , 2h ), 1 . 81 - 1 . 65 ( m , 4h ); mass spectrum m / z 260 [( m + h ) + ; calcd for c 14 h 18 n 3 o 2 : 260 ]. to a solution of cis 4 -( 1h - benzimidazol - 2 - ylamino )- cyclohexanecarboxylic acid ( l ) ( 20 mg , 0 . 07 mmol ) in dmf ( 0 . 2 ml ) was added edc ( 26 mg , 0 . 14 mmol ), hobt ( 18 mg , 0 . 14 mmol ), triethylamine ( 0 . 019 ml , 0 . 14 mmol ) and benzyl amine ( 0 . 007 ml , 0 . 7mmol ). the reaction mixture was stirred at room temperature for lh followed by quenching with aqueous nahco 3 and etoac . the layers were separated and the organic was washed twice with water , dried over na 2 so 4 , filtered and concentrated . purification of the crude oil by preparative reverse - phase hplc gave cis 4 -( 1h - benzimidazol - 2 - ylamino )- cyclohexanecarboxylic acid benzylamide ( example 10 ) ( 12 mg ): 1 h nmr ( 300 mhz , cd 3 od ) δ 7 . 40 - 7 . 20 ( m , 9h ), 4 . 39 ( s , 2h ), 3 . 81 ( m , 1h ), 2 . 45 ( m , 1h ), 2 . 02 - 1 . 77 ( m , 8h ); mass spectrum m / z 349 [( m + h ) + ; calcd for c 21 h 25 n 4 o : 349 ]. all compounds analogous to example 10 were prepared from carboxylic acid ( m ) via the above procedure using the appropriate amine and purified by reverse - phase hplc . example 11 was prepared in a manner similar to example 5 , but substituting 4 - benzyl - cyclohexanone , the product of example 1 , step 3 , for exo and * endo 3 -( 4 - chloro - benzyl )- bicyclo [ 3 . 2 . 1 ] octan - 8 - one . the procedure gave a 1 : 1 mixture of cis and trans ( 1h - benzoimidazol - 2 - ylmethyl )-( 4 - benzyl - cyclohexyl )- amine . chromatography on chiralpaka ™ od eluting with 60 : 40 of 0 . 1 % diethylamine in hexane : 2 - propanol gave first ( 1h - benzoimidazol - 2 - ylmethyl )-( 4 - cis - benzyl - cyclohexyl )- amine : rt = 4 . 69 min ; ms ( m + 1 )= 320 ; 1 h nmr ( 400 mhz , cdcl 3 ) δ 7 . 6 ( m , 2h ), 7 . 35 - 7 . 25 ( in , 5h ), 7 . 18 ( m , 2h ), 4 . 2 ( s , 2h ), 2 . 85 ( m , 1h ), 2 . 55 ( d , 21 ), 1 . 75 ( m , 3h ), 1 . 7 - 1 . 55 ( m , 2h ), 1 . 5 ( m , 2h ), 1 . 4 ( m , 3h ). later fractions gave ( 1h - benzoimidazol - 2 - ylmethyl )-( 4 - trans - benzyl - cyclohexyl )- amine : rt = 5 . 67 min ; ms ( m + 1 )= 320 ; 1 h nmr ( 400 mhz , cdcl 3 ) δ 7 . 6 ( m , 2h ), 7 . 35 - 7 . 25 ( m , 5h ), 7 . 18 ( m , 2h ), 4 . 2 ( s , 2h ), 2 . 5 ( d , 2h ), 1 . 95 ( d , 2h ), 1 . 72 ( d , 2h ), 1 . 7 - 1 . 55 ( m , 2h ), 1 . 5 ( m , 2h ), 1 . 4 ( m , 3h ). a mixture of 2 g of 4 - benzylcyclohexanone , the product of example 1 , step 3 , 16 g of ammonium acetate , 100 ml of methanol and 2 . 5 g of sodium cyanoborohydride was stirred for 5 days at room temperature . after cooling in an ice bath , the reaction was carefully quenched in an efficient fume hood by dropwise addition of 25 ml of 1n hcl . after stirring for 10 min , sodium hydroxide pellets were added to the cold solution until the ph ( indicator paper ) was about 10 . the mixture was concentrated under reduced pressure , diluted with 100 ml of water , made basic by addition of more sodium hydroxide pellets and extracted into 4 × 100 ml portions of chloroform . after drying over magnesium sulfate , the extracts were concentrated x under reduced pressure and then dried under vacuum overnight . analysis by tlc ( silica gel , elution with 90 : 10 : 1 chloroform : methanol : conc . ammonium hydroxide ) indicated no 4 - benzylcyclohexanone or 4 - benzylcyclohexanol was present , only 2 new bands which correspond to a mixture of cis - and trans 4 - benzyl - cyclohexylamine , which was an oil . following the sample experimental procedure described by j . j . perkins , a . e . zartman , and r . s . meissner , tetrahedron letters , 40 : 1103 - 1106 ( 1999 ), but substituting a mixture of cis - and trans 4 - benzyl - cyclohexylaamine for cyclohexylamine , gave a mixture of cis and trans ( 1h - benziimidazol - 2 - yl )-( 4 - benzyl - cyclohexyl )- amine . chromatography on silica gel eluting with 90 : 10 cbloroform : methanol gave ( 1h - benziimidazol - 2 - yl )-( 4 - cis - benzyl - cyclohexyl )- amine : ms ( m + 1 )= 306 ; 1 h nmr ( 400 mhz , cdcl 3 ) δ 2 . 42 ( d , 2h ), 2 . 10 ( d , 2h ), 1 . 70 ( d , 2h ). later fractions gave ( 1h - benziimidazol - 2 - yl )-( 4 - trans - benzyl - cyclohexyl )- amine : ms ( m + 1 )= 306 ; 1 h nmr ( 400 mhz , cdcl 3 ) δ 2 . 55 ( m , 2h ), 2 . 15 ( d , 2h ), 1 . 70 ( d , 2h ). example 13 was prepared by following the above procedure for example 7 except using n - methylbenzylamine instead of 2 - fluorobenzylamine : mass spectrum m / z 361 [( m + h ) + ; calcd for c 23 h 28 n 3 o : 362 ]. compounds of the present invention can be prepared according to scheme 8 shown below : olefin ( b ) ( 0 . 3 g , 1 . 18 mmol ) was dissolved in etoac ( 5 ml ) and cooled to − 20 ° c . rh on alumina catalyst ( 0 . 06 g ) was added , the reaction vessel was pressurized to 1500 psi with hydrogen gas , and the mixture was shaken for 5 h . after removal of the catalyst by filtration and concentration , the resultant colorless oil was dissolved in methylene chloride ( 5 ml ) and tfa ( 3 ml ) and stirred for 15 min . all volatiles were removed by rotary evaporation and the resultant colorless oil placed under high vacuum to give compound ( n ) as a 6 : 1 cis to trans mixture . to a solution of acid ( n ) ( 300 mg , 1 . 4 mmol ) in dm ( 10 ml ) was added edc ( 268 mg , 1 . 40 mmol ), hoat ( 190 mg , 1 . 40 mmol ) and methanesulfonic acid ( 3 , 4 - diamino - phenyl )- amide ( ii ) ( 281 mg , 1 . 40 mmol ). the reaction mixture was stirred at room temperature for 16 h followed by quenching with aqueous nahco 3 and etoac . the layers were separated and the organic was washed twice with water , dried over na 2 so 4 , filtered and concentrated . the resulting crude product was dissolved in acetic acid ( 10 ml ) and a heated to 130 ° c . for 15 min . the reaction mixture was cooled , concentrated and partitioned between aqueous nahco 3 and etoac . the organic layer was dried over na 2 so 4 , filtered and concentrated . the crude oil was used without purification . the crude ester was dissolved in hbr / h 2 0 ( 48 %, 10 ml ) and was then heated to 100 ° c . for 30 min . the resulting reaction mixture was cooled , concentrated and purified by preparative reverse - phase hplc , to give compound ( zz ) as the pure cis isomer : 1 h nmr ( 300 mhz , cd 3 od ) δ 7 . 75 ( d , 1h ), 7 . 69 ( d , 1h ), 7 . 39 ( dd , 1h ), 3 . 09 ( d , 2h ), 2 . 99 ( s , 3h ), 2 . 60 ( m , 1h ), 2 . 08 ( m , 3h ), 1 . 62 ( m , 4h ); 1 . 40 ( m , 2h ) ppm ; mass spectrum m / z 352 [( m + h ) + ; calcd for c 16 h 22 n 3 o 4 s : 352 ]. example 14 was prepared by the following procedure : to a solution of ( zz ) ( 10 mg , 0 . 03 mmol ), edc ( 10 mg , 0 . 06 mmol ) and hoat ( 8 mg , 0 . 06 mmol ) in anhydrous dmf ( 0 . 3 ml ) was added 2 - fluorobenzylamine ( 2 mg , 0 . 06 mmol ) and the reaction mixture was stirred for 2 h . the reaction mixture was partitioned between saturated aqueous nahco 3 and etoac . the organic layer was washed 2 × with water . the etoac was dried with mgso 4 and concentrated . the resulting crude material was purified by reverse phase hplc to give example 14 : mass spectrum n / z 459 [( m + h ) + ; calcd for c 23 h 28 fn 4 o 3 s : 459 ]. example 15 was prepared by following the above procedure for example 14 except 2 , 6 - diflouorobenzylamine was used instead of 2 - fluorobenzylamine : mass spectrum m / z 477 [( m + h ) + ; calcd for c 23 h 27 f 2 n 4 o 3 s : 477 ]. compound ( zz1 ) was prepared by following the above procedure for compound ( zz ) except 4 - methoxy - 1 , 2 - phenylenediamine was used instead of methanesulfonic acid ( 3 , 4 - diamino - phenyl )- amide : mass spectrum m / z 275 [( m + h ) + ; calcd for c 15 h 19 n 2 o 3 : 275 ]. example 16 was prepared by following the above procedure for example 14 except compound ( zz1 ) was used instead of compound ( zz ): mass spectrum m / z 382 [( m + h ) + ; calcd for c 22 h 24 fn 3 o 2 : 382 ]. example 17 was prepared by following the above procedure for example 15 except compound ( zz1 ) was used instead of compound ( zz ): mass spectrum m / z 400 [( m + h ) + ; calcd for c 22 h 24 f 2 n 3 o 2 : 400 ]. compound ( zz2 was prepared by following the above procedure for compound ( zz ) except ethanesulfonic acid ( 3 , 4 - diamino - phenyl )- amide was used instead of methanesulfonic acid ( 3 , 4 - diamino - phenyl )- amide : mass spectrum m / z 366 [( m + h ) + ; calcd for c 17 h 24 n 3 o 4 s : 366 ]. example 18 was prepared by following the above procedure for example 14 except compound ( zz2 ) was used instead of compound ( zz ): mass spectrum m / z 473 [( m + h ) + ; calcd for c 24 h 30 fn 4 o 3 s : 473 ]. example 19 was prepared by following the above procedure for example 15 except compound ( zz2 ) was used instead of compound ( zz ): mass spectrum m / z 491 [( m + h ) + ; calcd for c 24 h 29 f 2 n 4 o 3 s : 491 ]. compounds of the present invention can be prepared according to scheme 9 shown below : compound ( zz3 ) was prepared by following the above procedure for compound zz except 3 - hydroxy - 1 , 2 - phenylenediamine was used instead of methanesulfonic acid ( 3 , 4 - diamino - phenyl )- amide : mass spectrum m / z 275 [( m + h ) + ; calcd for c 15 h 19 n 2 o 3 : 275 ]. example 20 was prepared by following the above procedure for example 14 except compound ( zz3 ) was used instead of compound ( zz ): mass spectrum m / z 382 [( m + h ) + ; calcd for c 22 h 25 fn 3 o 2 : xx ]. example 20 was prepared by following the above procedure for example 14 except compound ( zz3 ) was used instead of compound ( zz ), and benzylamine was used instead of 2 - fluorobenzylamine : mass spectrum m / z 364 [( m + h ) + ; calcd for c 22 h 26 n 3 o 2 : 364 ]. compounds of the present invention can be prepared according to scheme 10 shown below : 4 - bromomandelic acid ( o ) ( 3 . 0 g , 13 . 0 mmol ) was dissolved in meoh ( 75 ml ) and placed in a pressure bomb . to that resulting solution was added ( pph 3 ) 2 pdcl 2 ( 0 . 91 g , 1 . 3 mmol ) and triethylamine ( 5 . 4 ml , 39 mmol ). the reaction mixture was pressurized with co ( 100psi ) and heated to 100 ° c . for 60 h . after cooling , the mixture was filtered , concentrated and purified by reverse phase hplc to give ester ( p ): 1 h nmr ( 400 mhz , cd 3 od ) δ 8 . 03 ( d , 2h ), 7 . 61 ( d , 2h ), 5 . 25 ( s , 1 h ), 3 . 90 ( s , 3h ) ppm . compound ( p ) ( 0 . 35 g , 1 . 7 mmol ) was dissolved in meoh ( 10 ml ) and rh on alumina catalyst ( 0 . 05 g ) was added . the reaction vessel was pressurized to 50 psi with hydrogen gas , and the mixture was shaken for 24 h . after filtration and concentration , the product ( q ) was used without purification as a 3 : 1 cis : trans mixture of isomers : mass spectrum m / z 217 [( m + h ) + ; calcd for c 10 h 17 o 5 : 217 ]. to a solution of acid ( q ) ( 100 mg , 0 . 46 mmol ) in dmf ( 6 ml ) was added edc ( 97 mg , 0 . 51 mmol ), hoat ( 70 mg , 0 . 51 mmol ) and methanesulfonic acid ( 3 , 4 - diamino - phenyl )- amide ( ii ) ( 100 mg , 0 . 46 mmol ). the reaction mixture was stirred at room temperature for lh followed by quenching with aqueous nahco 3 and etoac . the layers were separated and the organic was washed twice with water , dried over na 2 so 4 , filtered and concentrated . the resulting crude product was dissolved in acetic acid ( 5 ml ) and heated to 130 ° c . for 15 min . the reaction mixture was cooled , concentrated and partitioned between aqueous nahco 3 and etoac . the organic layer was dried over na 2 so 4 , filtered and concentrated . the resulting crude oil was without purification the crude ester was dissolved in hbr / h 2 0 ( 48 %, 3 ml ) and then was heated to 100 ° c . for 10 min . the reaction mixture was cooled , concentrated and purified by preparative reverse - phase hplc , to give ( r ) as the pure cis isomer : mass spectrum m / z 368 [( m + h ) + ; calcd for c 16 h 22 n 3 o 5 s : 368 ]. example 22 was prepared by the following procedure : to a solution of ( r ) ( 35 mg , 0 . 1 mmol ), edc ( 36 mg , 0 . 2 mmol ) and hoat ( 26 mg , 0 . 2 mmol ) in anhydrous dmf ( 2 ml ) was added 2 - fluorobenzylamine ( 24 mg , 0 . 2 mmol ) and the resulting reaction mixture was stirred for 3 h . the reaction mixture was then partitioned between saturated aqueous nahco 3 and etoac , and the organic layer washed 2 × with water . the etoac was dried with mgso 4 and concentrated . the resulting crude material was purified by reverse phase hplc to give example 22 : 1 h nmr ( 300 mhz , cd 3 od ) δ 7 . 74 ( m , 2h ), 7 . 41 ( d , 1h ), 7 . 25 ( m , 2h ); 7 . 09 ( m , 2h ), 5 . 06 ( d , 1h ), 4 . 40 ( s , 2h ), 3 . 00 ( s , 3h ), 2 . 47 ( m , 1h ), 2 . 10 ( m , 3h ), 1 . 6 ( m , 6h ) ppm ; mass spectrum m / z 475 [( m + h ) + ; calcd for c 23 h 28 fn 4 o 4 s : 475 ]. example 23 was prepared by following the above procedure for example 22 except 2 , 6 - diflouorobenzylamine was used instead of 2 - fluorobenzylamine : mass spectrum m / z 493 [( m + h ) + ; calcd for c 23 h 27 f 2 n 4 o 4 s : 493 ]. compound ( s ) was prepared by following the above procedure for ( r ) except ethanesulfonic acid ( 3 , 4 - diamino - phenyl )- amide was used instead of methanesulfonic acid ( 3 , 4 - diamino - phenyl )- amide : mass spectrum m / z 382 [( m + h ) + ; calcd for c 17 h 24 n 3 o 5 s : 382 ]. example 24 was prepared by following the above procedure for example 22 except acid ( s ) was used instead of ( r ): mass spectrum m / z 489 [( m + h ) + ; calcd for c 24 h 30 fn 4 o 4 s : 489 ]. example 25 was prepared by following the above procedure for example 23 except acid compound ( s ) was used instead of compound ( r ): mass spectrum m / z 507 [( m + h ) + ; calcd for c 24 h 29 f 2 n 4 o 4 s : 507 ]. acid ( t ) was prepared by following the above procedure for compound ( r ) except phenylene diamine was used instead of methanesulfonic acid ( 3 , 4 - diamino - phenyl )- amide : mass spectrum m / z 275 [( m + h ) + ; calcd for c 15 h 19 n 2 o 3 : 275 ]. example 26 was prepared by following the above procedure for example 22 except acid ( t ) was used instead of compound ( r ): mass spectrum m / z 382 [( m + h ) + ; calcd for c 22 h 25 fn 3 o 2 : 382 ]. racemate example 26 was separated into its enantiomers by chiral hplc on a chiralpack ad column ( 250 × 4 . 6 cm ) eluting with 75 % hexane + 0 . 1 % diethylamine and 25 % 2 - propanol . the faster eluting compound was example 26a . the slower eluting compound was example 26b . example 27 was prepared by the following procedure : to a solution of amide ( this does not seem to be an example above ) l - 478 , 227 ( 200 mg , 0 . 52 mmol ) in thf ( 1 ml ) was added bh3 - thf ( 1m , 5 . 0 ml ). the reaction mixture was heated to 50 ° c . for 12 h , cooled and carefully quenched with hcl ( 1m ). the resulting mixture was partitioned between etoac / aqueous nahco 3 . the organic layer was dried over na 2 so 4 , filtered , concentrated and purifed by reverse phase hplc to give example 27 : 1 h nmr ( 400 mhz , cd 3 od ) δ 7 . 71 ( m , 2h ), 7 . 57 ( m , 3 h ), 7 . 18 ( t , 2h ); 4 . 35 ( s , 2h ), 3 . 14 ( t , 4h ), 2 . 21 ( m , 1h ), 2 . 00 ( m , 1h ), 1 . 75 - 1 . 40 ( m , 8h ) ppm ; mass spectrum n / z 370 [( m + h ) + ; calcd for c 22 h 26 f 2 n 3 : 370 ]. example 28 was prepared by following the above procedure for example 27 except acid example 19 was used instead of l - 478 , 227 : mass spectrum m / z 477 [( m + h ) + ; calcd for c 24 h 31 f 2 n 4 o 2 s : 477 ]. compounds of the present invention can be prepared according to scheme 11 shown below : compound ( v ) was prepared by the following procedure : to a solution of acid ( n ) ( 900 mg , 4 . 2 mmol ) in dmf ( 10 ml ) was added edc ( 886 mg , 4 . 6 mmol ), hoat ( 629 mg , 4 . 6 mmol ) and 4 - nitro - 1 , 2 - phenylenediamne ( 643 mg , 4 . 2 mmol ). the resulting reaction mixture was stirred at room temperature for 16 h followed by quenching with aqueous nahco 3 and etoac . the layers were separated and the organic layer was washed twice with water , dried over na 2 so 4 , filtered and concentrated . the resulting crude product was dissolved in acetic acid ( 5 ml ) and heated to 130 ° c . for 1 . 5 h . the reaction mixture was cooled , concentrated and partitioned between aqueous nahco 3 and etoac , and the organic layer was dried over na 2 so 4 , filtered and concentrated . the resulting crude oil was used without purification : mass spectrum m / z 332 [( m + h ) + ; calcd for c 17 h 22 n 3 o 4 : 332 ]. example 29 was prepared by the following procedure : ester compound ( v ) ( 450 mg , 1 . 36 mmol ) was dissolved in bbr / h 2 o ( 48 %, 5 ml ) and heated to 100 ° c . for 10 min . the reaction mixture was cooled , concentrated and the corresponding resulting acid was used without further purification : mass spectrum m ( z 304 [( m + h ) + ; calcd for c 15 h 18 n 3 o 4 : 304 ]. to a solution of the above resulting acid ( 400 mg , 1 . 32 mmol ), edc ( 379 mg , 1 . 98 mmol ) and hoat ( 269 mg , 1 . 98 mmol ) in anhydrous dmf ( 5 ml ) was added 2 - fluorobenzylamine ( 247 mg , 1 . 98 mmol ) and the resulting reaction mixture was stirred for 2 h . the reaction mixture was partitioned between saturated aqueous nahco 3 and etoac and the organic layer was washed 2 × with water . the etoac was dried with mgso 4 and concentrate . the crude material was purified by reverse phase hplc to give example 29 : 1 h nmr ( 300mh , cd 3 od ) δ 8 . 61 ( d , 1h ), 8 . 42 ( dd , 1h ), 7 . 88 ( d , 1h ); 7 . 24 ( m , 2h ), 7 . 10 ( m ; 2h ), 4 . 40 ( s , 2h ), 3 . 10 ( d , 2h ), 2 . 43 ( m , 1h ), 2 . 17 ( m , 1h ), 1 . 90 ( m , 3h ), 1 . 61 ( m , 5h ) ppm ; mass spectrum m / z 411 [( m + h ) + ; calcd for c 22 h 24 fn 4 o 3 : 411 ]. example 30 was prepared by the following procedure : to a solution of example 29 ( 0 . 3 g , 0 . 73 mmol ) in etoh ( 4 ml ) was added 10 % pd / c ( 0 . 05 g ). the resulting reaction mixture was stirred under a balloon of hydrogen . after 2 h , the reaction mixture was filtered through celite , concentrated and the crude product purified by reverse phase hplc to give example 30 : mass spectrum ml / z 381 [( m + h ) + ; calcd for c 22 h 25 fn 4 o : 381 ]. example 31 was prepared by the following procedure : to a solution of example 30 ( 15 mg , 0 . 04 mmol ) in dichloromethane ( 1 ml ) was added triethylamine ( 11 μl , 0 . 08 mmol ) and sulfonyl chloride compound ( u ) ( 12 mg , 0 . 04 mmol ). the resulting mixture was stiffed at room temperature for 30 min , concentrated and purified by reverse phase hplc to give example 31 : mass spectrum m / z 660 [( m + h ) + ; calcd for c 35 h 39 fn 5 o 5 s : 660 ]. example 32 was prepared by the following procedure : to a room temperature solution of example 31 ( 10 mg , 0 . 015 mmol ) in etoh ( 0 . 5 ml ) was added hydrazine ( 4 μl , 0 . 15 mmol ) and the reaction mixture was stirred for 2 h . the reaction mixture was concentrated and purified by reverse phase hplc to give example 32 : mass spectrum m / z 530 [( m + h ) + ; calcd for c 27 h 37 fn 5 o 3 s : 530 ]. example 33 was prepared by the following procedure : to a room temperature solution of example 32 ( 8 mg , 0015 mmol ) in dichloromethane ( 1 ml ) and meoh ( 0 . 2 ml ) was added fluoroscein - 5 - isothiocyanate ( 5 mg , 0 . 02 mmol ) and triethylamine ( 10 μl ). the resulting mixture was stirred for 30 min , concentrated , and purified by reverse phase hplc to give example 33 : mass spectrum m / z 919 [( m + h ) + ; calcd for c 48 h 48 fn 6 o 8 s 2 : 919 ]. examples 34 - 106 were prepared by procedures similar to those described above . in table 1 below , the substituents are shown wherein x 1 corresponds to the nh group of the amide :