Patent Application: US-25231399-A

Abstract:
this invention relates a to a series of heterocyclic substituted piperazines of formula i methods of treatment , pharmaceutical compositions containing them , and intermediates used in their manufacture . the compounds of the invention selectively inhibit binding to the α - 1 a adrenergic receptor , a receptor which has been implicated in benign prostatic hyperplasia . as such the compounds are potentially useful in the treatment of this disease .

Description:
the terms used in describing the invention are commonly used and known to those skilled in the art . however , the terms that could have other meanings are defined . “ hbss ” refers to hank &# 39 ; s balanced salt solution . “ independently ” means that when there are more than one substituent , the substitutents may be different . the term “ alkyl ” refers to straight , cyclic and branched - chain alkyl groups and “ alkoxy ” refers o - alkyl where alkyl is as defined supra . “ dmap ” refers to dimethylaminopyridine , “ hobt ” refers to hydroxybenzotriazole hydrate , and “ edci ” refers to 1 -( 3 - dimethylaminopropyl )- 3 - ethylcarbodiimide hydrochloride . the term “ hatu ” refers to o -( 7 - azabenzotriazol - 1 - yl )- 1 , 1 , 3 , 3 - tetrametyluronium hexafluorophosphate and the symbol “ ph ” refers to phenyl , and “ aryl ” includes mono and fused aromatic rings such as phenyl and naphthyl . the symbol “ es ” refers to electrospray and the symbol “ ms ” refers to mass spectrum . some of the compounds of formula i include a chiral carbon atom . therefore those compounds may be prepared as stereoisomers , racemic mixtures or pure enantiomers . all stereoisomers , pure enantiomers and racemic mixtures are considered to be within the scope of this invention . the compounds of the invention may be prepared by the following schemes , where some schemes produce more than one embodiment of the invention . in those cases , the choice of scheme is a matter of discretion which is within the capabilities of chemists . a compound of formula i where x is nh , r 1 is hydrogen , r 2 is phenyl , r 3 is hydroxy , r 4 is hydrogen , and r 5 is 3 - trifluoromethylphenyl may be prepared using scheme 1 . 1 - azido - 3 -( p - toluenesulfonyloxy ) propan - 2 - ol 1a , is heated at about 100 ° c . with an appropriately substituted piperazine derivative , 1b for about 2 - 5 days to give the azide 1c . this azide is treated with pd / c and h 2 ( 50 psi ) in an inert solvent over 16 h to give the free amine 1d . this amine is treated with a 3 - acyl - 2 - substituted pyridine derivative , such as 2 -[( 3 - trifluoromethylphenyl ) amino ]- 3 - pyridinecarbonyl chloride , 1e , dmap and n , n - diisopropylethylamine in methylene chloride at about room temperature for 2 - 16 h to give the desired compound of formula i . this scheme may be used to prepare a number of compounds of formula i . for example , to prepare compounds where r 1 and r 2 vary , simply replace the illustrated 1b with any known substituted piperazines . although the illustrated product was prepared from the racemic azide 1a , the pure enantiomers of this azide are known and can be used in this scheme . to prepare compounds where r 5 is other than substituted phenyl , replace the acyl pyridine derivative 1e with another acyl pyridine . for example to prepare a compound where r 5 is phenylmethyl , replace the illustrated 1e with 2 -[( phenylmethyl ) amino ]- 3 - pyridinecarbonyl chloride . to prepare compounds where x is other than nh , replace the amino substituted acylpyridine with a thio or an oxy substituted pyridine . for example to prepare a compound where x is sulfur , r 1 is hydrogen , r 2 is phenyl , r 3 is hydroxy , r 4 is hydrogen , and r 5 is phenyl , replace the illustrated 1e with 2 -( phenylthio ) pyridine - 3 - carboxylic acid chloride . to prepare compounds where r 3 is c 1 - 5 alkoxy replace starting material 1c with 1 -[ 1 - azido - 2 - methoxypropan - 1 - yl ]- 4 -[ 2 - isopropoxyphenyl ] piperazine and carry out the remaining steps of the scheme . compounds where r 3 is carbonyl may be prepared by treating the products of scheme 1 with an oxidizing agent such as the swern &# 39 ; s reagent ( formed from oxalyl chloride and dmso ) at − 78 ° c . to room temperature over 30 min to 1 h . scheme 2 may be used to prepare compounds of formula i where x is sulfur , r 1 is fluoro , r 2 is ethyl , r 3 is hydrogen , r 4 is hydrogen , and r 5 is 4 - chlorophenyl . an appropriately substituted piperazine derivative 2a is treated with n - boc protected 3 - bromopropylamine and cesium carbonate in acetonitrile at reflux for 16 h to give the substituted piperazine derivative 2b . this derivative is converted to the free amine , 2c , by treatment with tfa and methylene chloride at room temperature over 2 - 6 h . derivative 2c is coupled with a substituted acyl pyridine derivative 2d using dmap , and n , n - diisopropylethylamine in methylene chloride at about room temperature for 2 - 6 h to give the desired compound of formula i . as described in scheme 1 , scheme 2 may be modified to give many compounds of formula i . another method of preparing compounds of the invention is illustrated by scheme 3 . treatment of derivative 2c and 2 - chloronicotinic acid with hobt , dmap , edci and n , n - diisopropylethylamine in methylene chloride at about room temperature for 2 - 6 h gives the chloropyridine 3a . treatment of this derivative with an aromatic alcohol such as 3b gives a compound of the invention where x is oxygen , r 1 is fluoro , r 2 is ethyl , r 3 is hydrogen , r 4 is hydrogen , and r 5 is 4 - methylphenyl . to produce compounds of the invention where r 4 is other than hydrogen , scheme 4 may be used . the amino group of intermediates 2c may be treated with an aldehyde 4a such as benzaldehyde to give the imine 4b . this intermediate may be reduced with nabh 4 at room temperature to give the monoamine 4c . this amine is coupled with a substituted acyl pyridine derivative , using dmap and n , n - diisopropylethylamine in methylene chloride at about room temperature for 2 - 6 h to give the desired compound of formula i . as described in previous schemes , scheme 4 may be modified to give a number of compounds of formula i . for example , to produce a compound where r 3 is hydroxy , replace 2c with intermediate 1d and follow the remaining steps of scheme 4 . to produce pure enantiomers of compounds of formula i where r 3 is hydroxy , scheme 5 may be used . ( s )(+) epichlorohydrin ( 97 % ee ) may be treated with benzylamine in a suitable organic solvent such as hexane at about room temperature for about 48 - 72 hours to give hydroxy compound 5a . this intermediate may be treated with a boc reagent agent such as di - tert - butyl dicarbonate , and an organic base such as triethylamine in an inert solvent such as thf at about 0 ° c . to about room temperature over 10 to 24 h to give the n - protected derivative 5b . this intermediate may be treated with piperazine derivative , 5c , a base such as potassium hydroxide , in an alcoholic solvent such as methanol at about 0 ° c . to about room temperature over about 1 to about 3 days to give the coupled derivative 5d . this compound may be deprotected by treatment with an acid such as tfa at about room temperature over 18 - 24 h to give free amine 5e . this amine may be debenzylated with using a palladium catalyst and ammonium formate in an alcoholic solvent such as etoh at about 45 - 60 ° c . over 20 h to give the primary amine 5f . this amine may be coupled to acids of type 5g using peptide coupling agents such as hatu to give a compound of formula i . as described in scheme i , scheme 5 may be modified to give a number of compounds of formula i . although the claimed compounds are useful as antagonists of α1 a - ar , some compounds are more active than others and are either preferred or particularly preferred . the preferred compounds of the invention include compounds where : as indicated by the biological activity , the compounds of formula i may be used in pharmaceutical compositions to treat patients ( humans and other mammals ) with disorders related to inhibiting the activity of the α1 a adrenergic receptor . the preferred route is oral administration , however compounds oral doses range from about 0 . 01 to about 100 mg / kg daily ; where the optimal dose range is about 0 . 1 to about 25 mg / kg / per day . infusion doses can range from about 0 . 001 - 1 mg / kg / min of inhibitor , admixed with a pharmaceutical carrier over a period ranging from several minutes to several days may be administered by intravenous infusion . the pharmaceutical compositions can be prepared using conventional pharmaceutical excipients and compounding techniques . oral dosage forms may be elixers , syrups , capsules tablets and the like . where the typical solid carrier is an inert substance such as lactose , starch , glucose , methyl cellulose , magnesium sterate , dicalcium phosphate , mannitol and the like ; and typical liquid oral excipients include ethanol , glycerol , water and the like . all excipients may be mixed as needed with disintegrants , diluents , granulating agents , lubricants , binders and the like using conventional techniques known to those skilled in the art of preparing dosage forms . parenteral dosage forms may be prepared using water or another sterile carrier . typically the compounds of formula i are isolated and used as free bases , however the compounds may be isolated and used as their pharmaceutically acceptable salts . examples of such salts include hydrobromic , hydroiodic , hydrochloric , perchloric , sulfuric , maleic , fumaric , malic , tartatic , citric , benzoic , mandelic , methanesulfonic , hydroethanesulfonic , benzenesulfonic , oxalic , pamoic , 2 - naphthalenesulfonic , p - toluenesulfonic , cyclohexanesulfamic and saccharic . in order to illustrate the invention the following examples are included . these examples do not limit the invention . they are meant only to suggest a method of practicing the invention . those knowledgeable in the treatment of benign prostatic hyperplasia , chemical synthesis , pharmaceutical compounding as well as other specialties , may find other methods of practicing the invention . however those methods are deemed to be within the scope of this invention . the fumarate salt of 1 -( 2 - isopropoxyphenyl )- piperazine ( 3 . 91 g , 12 mmol ) was basified with 20 % naoh ( aq ) ( 100 ml ) and extracted with methylene chloride . the combined organic layers were dried ( na 2 so 4 ) and concentrated to give an oil ( 2 . 74 g ). a mixture of the oil and 1 - azido - 3 -( p - toluenesulfonyloxy ) propan - 2 - ol ( 3 . 25 g , 12 mmol , antonin holy , collect . czech . chem . comm . 1989 , 54 ( 2 ), 446 ) was stirred at 100 ° c . for 36 h . the cooled mixture was diluted with water and extracted with ether , dried ( na 2 so 4 ) and concentrated . the product was purified by column chromatography ( silica gel ) to yield compound 1 as ( 2 . 92 g , 76 %) as a light - brown solid : ms ( es ) m / z : 320 ( mh + ); anal . calcd for c 16 h 25 n 5 o 2 : c , 60 . 17 ; h , 7 . 89 ; n , 21 . 93 . found : c , 60 . 45 ; h , 7 . 83 ; n , 22 . 01 . 10 % hcl ( 6 ml ) was added to a mixture of compound 1 ( 2 . 43 g , 7 . 6 mmol ) and 10 % pd / c ( 1 . 22 g ) in meoh ( 60 ml ) and the mixture was hydrogenated under h 2 ( 50 psi ) in a parr shaker for 16 h at 20 ° c . the mixture was filtered through celite and the filtrate was concentrated . the residue was basified with 20 % naoh and extracted with methylene chloride . the combined organic layers were dried ( na 2 so 4 ) and concentrated to yield compound 2 as a yellowish oil ( 2 . 2 g , 95 %): ms ( es ) m / z : 294 ( mh + ). a mixture of compound 2 ( 100 mg , 0 . 341 mmol ), 2 - phenoxypyridine - 3 - carbonyl chloride ( 81 mg , 0 . 341 mmol ), dmap ( cat .) and n , n - diisopropylethylamine ( 0 . 23 ml ) in methylene chloride ( 2 ml ) was stirred at 20 ° c . for 16 h . the mixture was concentrated , diluted with water and extracted with etoac . the combined organic layer was dried ( na 2 so 4 ) and concentrated . the product was purified by column chromatography ( silica gel ) to yield 116 mg ( 69 %) of compound 3 as a foam : 1 h nmr ( 300 mhz , cdcl 3 ) δ 8 . 59 ( d , j = 6 . 3 hz , 1 h ), 8 . 32 ( brs , 1 h ), 8 . 20 ( d , j = 3 . 1 hz , 1 h ), 7 . 44 ( m , 2 h ), 7 . 21 ( m , 4 h ), 6 . 87 ( m , 4 h ), 4 . 57 ( m , 1 h ), 3 . 98 ( m , 1 h ), 3 . 75 ( m , 1 h ), 3 . 5 ( m , 1 h ), 3 . 06 ( m , 4 h ), 2 . 79 ( m , 2 h ), 2 . 48 ( m , 4 h ), 1 . 33 ( d , j = 5 . 9 hz , 6 h ); ms ( es ) m / z : 491 ( mh + ). 3 - bromopropylamine hydrobromide ( 5 g , 22 . 8 mmol ) was dissolved in 10 % naoh ( 50 ml ), extracted with methylene chloride and concentrated . to the free base in methylene chloride was added ( boc ) 2 o ( 5 . 23 g , 23 . 9 mmol ) and this mixture was stirred at 20 ° c . for 4 h . the methylene chloride layer was washed with h 2 o , diluted citric acid ( 6 %), nahco 3 and sat nacl solution , dried and concentrated . the product was purified by column chromatography ( silica gel ) to yield the protected amine ( 4 . 84 g , 89 %). the fumarate salt of 1 -( 2 - isopropoxyphenyl )- piperazine ( 5 . 1 g , 15 mmol ) was basified with 20 % naoh ( aq ) ( 100 ml ), extracted with methylene chloride , dried ( na 2 so 4 ) and concentrated to give a yellow oil ( 3 . 15 g ). a mixture of the oil , the protected amine ( 3 . 42 g , 14 . 3 mmol ), and cs 2 co 3 ( 4 . 66 g , 14 . 3 mmol ) in ch 3 cn ( 50 ml ) was heated at reflux overnight . the solid was filtered off and the filtrate was evaporated . the product was purified by column chromatography ( silica gel ) to yield compound 4 ( 4 . 4 g , 81 %): ms ( es ) m / z : 378 ( mh + ). compound 4 ( 0 . 185 g , 0 . 53 mmol ), was dissolved in 25 % tfa / methylene chloride ( 5 ml ) and stirred for 1 . 5 h . the solvent was removed and the tfa salt was washed with toluene ( 3 ×) and then basified with 20 % naoh ( aq ) followed by extracted with methylene chloride ( 3 ×), dried ( na 2 so 4 ) and concentrated to give a oil . this oil was dissolved in methylene chloride ( 4 ml ), diisopropylethyl amine ( 0 . 34 g , 2 . 64 mmol ), catalytic amount of dmap and 2 - phenoxypyridine - 3 - carbonyl chloride ( 0 . 12 g , 0 . 53 mmol ). the reaction was stirred at 20 ° c . under n 2 for 2 h and concentrated . the product was purified by column chromatography ( silica gel ) to yield compound 5 ( 0 . 2 g , 80 %): 1 h nmr ( 300 mhz , cdcl 3 ) δ 8 . 61 ( dd , j = 7 . 5 , 2 . 0 hz , 1 h ), 8 . 20 ( dd , j = 4 . 9 , 2 . 0 hz , 1 h ), 8 . 05 ( m , 1 h ), 7 . 46 ( m , 2h ), 7 . 29 ( d , j = 7 . 4 hz , 1h ), 7 . 15 ( m , 3h ), 6 . 88 ( m , 4h ), 4 . 56 ( m , 1h ), 3 . 59 ( q , j = 6 . 3 hz , 2h ), 3 . 03 ( m , 4h ), 2 . 56 ( m , 4h ), 2 . 49 ( t , j = 7 . 0 hz , 2h ), 1 . 87 ( m , 2h ), 1 . 32 ( d , j = 6 . 1 hz , 6h ); ms ( es ) m / z : 475 ( mh + ). the fumarate salt of 1 -( 2 - isopropoxyphenyl )- piperazine ( 112 . 5 g , 345 mmol ) was basified with 20 % naoh ( aq ) ( 500 ml ), extracted with methylene chloride ( 3 ×), dried ( na 2 so 4 ), and concentrated to give about 70 g oil . a mixture of the oil and ( 2s )- 3 - azido - 2 - hydroxypropyl p - toluenesulfonate ( 91 g , 335 mmol , kristina juricova , collect . czech . chem . comm . 1995 , 60 , 237 ) was stirred at 100 ° c . in nmp with triethylamine ( 70 g , 690 mmol ) for 30 h . the mixture was cooled , diluted with water and extracted with ether ( 3 × 500 ml ). the combined extracts were back washed with nacli ( sat ) ( 100 ml ), dried ( na 2 so 4 ) and concentrated . the product was purified by column chromatography ( silica gel ) and recrystallization ( methylene chloride / hexanes ) to yield 70 . 6 g ( 66 %) of compound 6 ( 98 . 8 % ee assay by chiralcel ad column ) as a off - white : [ α ] 25 d − 3 . 6 ° ( c = 1 , ch 3 oh ); 1 h nmr ( 300 mhz , cdcl 3 ) δ 6 . 91 ( m , 4 h ), 4 . 59 ( m , 1 h ), 3 . 93 ( m , 1 h ), 3 . 67 ( brs , 1 h ), 3 . 42 ( dd , j = 12 . 6 , 3 . 8 hz , 1 h ), 3 . 23 ( dd , j = 12 . 6 , 5 . 4 hz , 1 h ), 3 . 12 ( m , 4 h ), 2 . 83 ( m , 2 h ), 2 . 53 ( m , 3 h ), 2 . 42 ( dd , j = 12 . 2 , 3 . 8 hz , 1 h ), 1 . 34 ( d , j = 6 . 0 hz , 6 h ); ms ( es ) m / z : 320 ( mh + ). 10 % hcl ( 6 ml ), was added to a mixture of compound 6 ( 15 g , 47 mmol ) and 10 % pd / c ( 4 g ) in meoh ( 100 ml ). the mixture was hydrogenated under h 2 ( 50 psi ) in a parr shaker for 21 h at 20 ° c . the mixture was filtered through celite and the filtrate was concentrated . the residue was basified with 20 % naoh ( aq ) ( 75 ml ), extracted with methylene chloride ( 3 ×), dried ( na 2 so 4 ), and concentrated to yield compound 7 ( 14 g , ˜ 100 %) as a yellowish oil : [ α ] 25 d + 23 . 6 ° ( c = 1 , chcl 3 ); 1 h nmr ( 300 mhz , cdcl 3 ) δ 6 . 91 ( m , 4 h ), 4 . 59 ( m , 1 h ), 3 . 76 ( m , 1 h ), 3 . 12 ( m , 4 h ), 2 . 83 ( dd , j = 12 . 7 , 3 . 7 hz , 2 h ), 2 . 82 ( m , 1 h ), 2 . 25 - 2 . 68 ( m , 8 h ), 1 . 34 ( d , j = 6 . 1 hz , 6 h ); ms ( es ) m / z : 294 ( mh + ). piperazine 7 ( 8 g , 27 . 3 mmol ) was dissolved in a mixture of diisopropylethylamine ( 14 . 1 g , 109 . 2 mmol ) and methylene chloride ( 100 ml ). the resulting light - yellowish solution was added slowly into a solution of methylene chloride ( 50 ml ), 2 - phenoxynicotinic acid ( 5 . 87 g , 27 . 3 mmol ), edcl ( 5 . 24 g , 27 . 3 mmol ), hobt ( 3 . 69 g , 27 . 3 mmol ) and dmap ( 50 mg , cat .) at 20 ° c . and stirred for 18 h . water was added and the resulting mixture was extracted with ether ( 3 ×). the combined organic extracts were washed with nacl ( sat ) , dried ( na 2 so 4 ) and concentrated . the product was purified by column chromatography ( sio 2 , methylene chloride / acetone ) to yield compound 8 ( 8 . 4 g , 62 %) as a white foam : [ α ] 25 d + 14 . 8 ° ( c = 1 , chcl 3 ); 1 h nmr ( 300 mhz , cdcl 3 ) δ 8 . 60 ( dd , j = 7 . 5 , 2 hz , 1 h ), 8 . 31 ( brs , 1 h ), 8 . 22 ( dd , j = 4 . 7 , 2 hz , 1 h ), 7 . 43 ( brt , j = 7 . 7 hz , 2 h ), 7 . 14 - 7 . 30 ( m , 4 h ), 6 . 87 ( m , 4 h ), 4 . 58 ( m , 1 h ), 3 . 97 ( m , 1 h ), 3 . 75 ( m , 1 h ), 3 . 51 ( m , 1 h ), 3 . 06 ( m , 4 h ), 2 . 80 ( m , 2 h ), 2 . 49 ( m , 4 h ), 1 . 33 ( d , j = 6 . 0 hz , 6 h ); ms ( es ) m / z : 491 ( mh + ). a mixture of compound 2 ( 900 mg , 3 . 07 mmol ), 2 - chloronicotic acid ( 485 mg , 3 . 07 mmol ), edcl ( 589 mg , 3 . 07 mmol ), hobt ( 414 mg , 3 . 07 mmol ), dmap ( cat .) and n , n - diisopropylethylamine ( 2 ml ) in methylene chloride ( 20 ml ) was stirred at 20 ° c . for 20 h . the mixture was concentrated , diluted with water and extracted with ether . the organic layer was dried ( na 2 so 4 ) and concentrated . the product was purified by column chromatography ( silica gel ) to yield 580 mg ( 44 %) of compound 9 as a white foam : ms ( es ) m / z : 433 ( mh + ). a mixture of compound 9 ( 43 mg , 0 . 1 mmol ), 4 - methoxyphenol ( 124 mg , 1 mmol ) and cesium carbonate ( 65 mg , 0 . 2 mmol ) in nmp ( 1 ml ) was stirred at 110 ° c . for 20 h . the resulting mixture was cooled , water was added and this mixture was extracted with ether . the extract was dried ( na 2 so 4 ) and concentrated . the product was purified by column chromatography ( silica gel ) to yield compound 10 ( 36 mg , 69 %) as a white foam : ms ( es ) m / z : 521 ( mh + ). a mixture of compound 2 ( 100 mg , 0 . 341 mmol ), niflumic acid ( 96 mg , 0 . 341 mmol ), edcl ( 65 mg , 0 . 341 mmol ), hobt ( 46 mg , 0 . 34 mmol ), dmap ( cat .) and n , n - diisopropylethylamine ( 0 . 23 ml ) in methylene chloride ( 2 ml ) was stirred at 20 ° c . for 20 h . the mixture was concentrated . the product was purified by column chromatography ( silica gel ) to yield compound 11 ( 101 mg , 53 %) as a foam : ms ( es ) m / z : 558 ( mh + ). a mixture of compound 2 ( 100 mg , 0 . 341 mmol ), 2 -( 4 - chlorophenylthio ) pyridine - 3 - carboxylic acid ( 91 mg , 0 . 341 mmol ), edcl ( 65 mg , 0 . 341 mmol ), hobt ( 46 mg , 0 . 34 mmol ), dmap ( cat .) and n , n - diisopropylethylamine ( 0 . 23 ml ) in methylene chloride ( 2 ml ) was stirred at 20 ° c . for 20 h . the mixture was concentrated . the product was purified by column chromatography ( silica gel ) to yield compound 12 ( 128 mg , 70 %) as a foam : ms ( es ) m / z : 541 ( mh + ). a mixture of compound 2 ( 100 mg , 0 . 341 mmol ), 2 - methoxynicotinic acid ( 52 mg , 0 . 341 mmol ), edcl ( 65 mg , 0 . 341 mmol ), hobt ( 46 mg , 0 . 34 mmol ), dmap ( cat .) and n , n - diisopropylethylamine ( 0 . 23 ml ) in methylene chloride ( 2 ml ) was stirred at 20 ° c . for 20 h . the mixture was concentrated . 3 % k 2 co 3 ( aq ) was added and extracted with ether , dried ( na 2 so 4 ) and concentrated . the product was purified by column chromatography ( silica gel ) to yield compound 13 ( 32 mg , 22 %) as a foam : ms ( es ) m / z : 429 ( mh + ). compound 1 ( 0 . 8 g , 2 . 5 mmol ) was dissolved in 50 ml of anhydrous thf . the solution was cooled to 0 ° c . and 2 eq of 60 % nah ( 0 . 2 g , 5 . 0 mmol ) was added . the solution was stirred for 10 min and 1 . 5 eq of ch 3 l ( 0 . 53 g , 3 . 8 mmol ) was added . the reaction mixture was stirred at 0 ° c . for 2 h . nah ( 0 . 1 g , 2 . 5 mmol ) and 1 eq of ch 3 l ( 0 . 15 ml ) were added and the mixture was stirred for another 2 h . the reaction was quenched with sat nh 4 cl , the solvent was evaporated , and the aqueous layer was washed with methylene chloride ( 3 ×), dried ( na 2 so 4 ) and concentrated . the product was purified by column chromatography ( silica gel ) to yield of compound a ( 0 . 69 g , 83 %): ms ( es ) m / z : 334 ( mh + ). 10 % hcl ( 0 . 3 ml ) was added to a mixture of compound 14 ( 0 . 64 g , 1 . 9 mmol ) and 10 % pd / c ( 0 . 13 g ) in meoh ( 5 ml ) and the mixture was hydrogenated under h 2 ( 50 psi ) in a parr shaker overnight . the mixture was filtered through celite and the filtrate was concentrated . the residue was basified with 20 % naoh and extracted with methylene chloride ( 3 ×). the combined organic extract were dried ( na 2 so 4 ) and concentrated to give a yellow oil at quantitative yield . ms ( es ) m / z : 308 ( mh + ). compound 15 ( 0 . 15 g , 0 . 49 mmol ) was dissolved in methylene chloride ( 4 ml ) and diisopropylethyl amine ( 0 . 25 g , 1 . 95 mmol ) was added . to this solution was added a mixture of hatu ( 0 . 185 g , 0 . 49 mmol ) and 2 - phenoxynicotinic acid ( 0 . 11 g , 0 . 49mmol ). the reaction was stirred under n 2 overnight at rt , the solvent was evaporated and the residue was dissolved in etoac . this solution was washed with 3 % k 2 co 3 , the organic layer was dried ( na 2 so 4 ) and concentrated . the product was purified by flash chromatography ( sio 2 , methylene chloride / acetone = 10 : 1 , 8 : 1 , 6 ; 1 4 : 1 ) to yield compound 16 ( 0 . 16 g , 64 %) as an oil : 1 h nmr ( 300 mhz , cdcl 3 ) δ 8 . 61 ( dd , j = 7 . 4 hz , 1 h ), 8 . 27 ( brs , 1 h ), 8 . 23 ( m , 1 h ), 7 . 44 ( m , 2 h ), 7 . 26 ( m , 1 h ), 7 . 17 ( m , 3 h ), 6 . 87 ( m , 4 h ), 4 . 58 ( m , 1 h ), 3 . 92 ( m , 1 h ), 3 . 55 ( m , 2 h ), 3 . 42 ( s , 3 h ), 3 . 03 ( brs , 4 h ), 2 . 54 ( m , 6 h ), 1 . 33 ( d , j = 6 . 0 hz , 6 h ); ms ( es ) m / z : 308 ( mh + ). oxalyl chloride ( 0 . 03 g , 0 . 22 mmol ) was dissolved in 0 . 3 ml of methylene chloride . a mixture of dmso ( 0 . 035 ml , 0 . 49 mmol ) in methylene chloride ( 3 . 0 ml ) was added dropwise to this solution at − 78 ° c . the mixture was stirred at − 78 ° c . for 1 h . a solution of compound 3 ( 68414 , 0 . 1 g , 0 . 2 mmol ) in methylene chloride ( 0 . 4 ml ) was added slowly . the reaction mixture was stirred for 30 min and tea ( 0 . 14 ml , 1 . 02 mmol ) was added slowly . the mixture was allowed to warm up to room temperature , water was added and the resulting mixture was extracted with methylene chloride . the combined organic layers were dried ( na 2 so 4 ) and concentrated to give compound 17 ( 13 . 2 mg , 13 %): 1 h nmr ( 300 mhz , cdcl 3 ) δ 8 . 69 ( brs , 1 h ), 8 . 61 ( dd , j = 7 . 6 hz , 1 h ), 8 . 23 ( dd , j = 4 . 6 hz , 1 h ), 7 . 46 ( m , 2 h ), 7 . 28 ( m , 3 h ), 7 . 15 ( m , 1 h ), 6 . 89 ( m , 4 h ), 4 . 57 ( m , 3h ), 3 . 35 ( s , 2 h ), 3 . 15 ( brs , 4 h ), 2 . 70 ( brs , 4 h ), 1 . 33 ( d , j = 5 . 97 hz , 6 h ); ms ( es ) m / z : 489 ( mh + ). piperazine 7 ( 150 mg , 0 . 51 mmol ) was dissolved in a mixture of diisopropylethylamine ( 0 . 35 ml ) and methylene chloride ( 2 ml ). 2 -( 4 - methylphenoxy ) pyridine - 3 - carbonyl chloride ( 126 mg , 0 . 51 mmol ) and dmap ( cat .) were added into the above methylene chloride solution . the mixture was stirred at 20 ° c . for 16 h and concentrated . the product was purified by column chromatography ( silica gel ) to yield compound 18 ( 146 mg , 57 %) as a foam : ms ( es ) m / z : 505 ( mh + ). a mixture of ( s )-(+)- epichlorohydrin ( 10 g , 108 . 1 mmol , aldrich , 97 % ee ) and benzylamine ( 11 . 57 g , 108 . 1 mmol ) in hexane ( 40 ml ) were stirred at 20 ° c . for 62 h . white solid precipitated . more hexane (˜ 350 ml ) added , stirred for 20 min . and sonicated to break the big chunks of white solid . the white solid was collected by filtration and washed with hexane , dried under vacuum to give 19 . 8 g ( 92 %) white solid . the white solid was recrystallized from etoac / hexane to give 17 . 76 g ( 82 %) of 1 as a white crystallined solid ; 1 h nmr ( 300 mhz , cdcl 3 ) δ 7 . 31 ( m , 5 h ), 3 . 88 ( m , 1 h ), 3 . 79 ( m , 2 h ), 3 . 53 ( d , j = 5 . 3 hz , 2 h ), 2 . 89 ( m , 2 h ), 2 . 81 ( dd , j = 12 . 4 , 4 . 1 hz , 1 h ), 2 . 69 ( dd , j = 12 . 2 , 7 . 9 hz , 1 h ); ms ( es ): 200 ( mh +); anal . calcd . for c 10 h 14 nocl : c , 60 . 15 ; h , 7 . 07 ; n , 7 . 01 . found : c , 60 . 10 ; h , 7 . 02 ; n , 6 . 92 . boc 2 o ( 11 g , 50 . 1 mmol ) and triethylamine ( 10 . 12 g , 100 mmol ) were dissolved in thf ( 25 ml ) and cooled to 0 ° c . the amine 19 ( 10 g , 50 . 1 mmol ) was added in portions and stirred for 20 h while the temperature was warm up to 20 ° c . overnight . the solvent was concentrated in vacuo and water added . the mixture was extracted with ether ( 3 ×), dried ( na 2 so 4 ) and concentrated . the crude residue was recrystallized from etoac / hexane to give 9 . 9 g ( 66 %) of 20 as a white crystallined solid . the filtrate was concentrated ( 3 . 1 g as oil ) and more product was purified by column chromatography ( short column , 8 cm height of sio 2 , etoac / hexane as solvent ). the oil was recrystallized from etoac / hexane to give another 2 . 78 g ( 18 %) of 20 as a white crystalline solid ; [ α ] d 25 =− 10 . 20 ( c = 1 , chcl 3 ); 1 h nmr ( 300 mhz , cdcl 3 ) δ 7 . 22 - 7 . 36 ( m , 5 h ), 4 . 52 ( m , 2 h ), 4 . 30 ( brs , 0 . 5 h ), 3 . 96 ( m , 1 h ), 3 . 36 - 3 . 97 ( m , 4 h ), 1 . 47 ( s , 9 h ); ms ( es ): 322 ( m + na ); anal . calcd . for c 15 h 22 no 3 cl : c , 60 . 10 ; h , 7 . 40 ; n , 4 . 67 . found : c , 60 . 26 , h , 7 . 42 ; n , 4 . 63 koh ( 11 . 23 g , 200 . 5 mmol ) was dissolved in methanol ( 280 ml ), and the fumarate salt of 1 -( 2 - isopropoxyphenyl )- piperazine ( 10 . 9 g , 33 . 4 mmol ) was added and stirred at 20 ° c . for 20 min then cooled to 0 ° c . the boc - protected amine 20 ( 10 g , 33 . 4 mmol ) was added to the methanol solution at 0 ° c . and stirred for 20 h while the temperature was warm up to 20 ° c . overnight . the solvent was removed , water was added and the mixture was extracted with ether ( 3 ×), dried ( na 2 so 4 ) and concentrated . the product was purified by column chromatography ( short column , 8 cm height sio 2 , etoac / hexane as solvent ) to give 10 . 22 g ( 63 %) of 3 (˜ 100 % ee , chiralpak od 4 . 6 × 250 mm . 1 ml / min , 254 nm , mobile phase : 90 / 10 / 0 . 1 of hexane / ipa / 0 . 1 % diethylamine ) as a yellowish oil ; 1 h nmr ( 300 mhz , cdcl 3 ) δ 7 . 26 - 7 . 35 ( m , 5 h ), 6 . 91 ( m , 4 h ), 4 . 68 ( d , j = 15 . 6 hz , 1 h ), 4 . 59 ( m , 3 h ), 3 . 95 ( m , 1 h ), 3 . 35 ( m , 2 h ), 3 . 11 ( m , 4 h ), 2 . 75 ( m , 2 h ), 2 . 54 ( m , 2 h ), 2 . 38 ( m , 2 h ), 1 . 45 ( m , 9 h ), 1 . 34 ( d , j = 6 . 1 hz , 6 h ); ms ( es ): 484 ( mh + ). a mixture of compound 21 ( 233 mg , 0 . 48 mmol ) and 25 % tfa / methylene chloride ( 3 ml ) was stirred at 20 ° c . for 18 h . the solvent was concentrated in vacuo and the residue was basified with 20 % naoh ( aq ), extracted with methylene chloride ( 3 ×), dried ( na 2 so 4 ) and concentrated to give 174 mg (˜ 95 %) of 22 as an oil . used directly without further purification ; ms ( es ): 384 ( mh + ). to a mixture of 22 (˜ 154 mg , 0 . 4 mmol ) and 10 % pd / c ( 154 mg ) in etoh ( 3 ml ) was added ammonium formate ( 151 mg , 2 . 4 mmol ) and stirred at 55 - 60 ° c . for 20 h . the mixture was filtered thru celite and washed with methanol . the filtrate was concentrated . the product was purified by a short column ( 5 cm height of sio 2 ) to give 63 mg ( 54 %) of 23 as a oil ; [ α ] d 25 + 23 . 60 ° ( c = 1 , chcl3 ); 1h nmr ( 300 mhz , cdcl3 ) δ 6 . 91 ( m , 4 h ), 4 . 59 ( m , 1 h ), 3 . 76 ( m , 1 h ), 3 . 12 ( m , 4 h ), 2 . 83 ( dd , j = 12 . 7 , 3 . 7 hz , 2 h ), 2 . 82 ( m , 1 h ), 2 . 25 - 2 . 68 ( m , 8 h ), 1 . 34 ( d , j = 6 . 1 hz , 6 h ); ms ( es ): 294 ( mh + ). the biological activity and selectivity of compounds of the invention was demonstrated by the following assays . the first assay tested the ability of compounds of formula i to bind to membrane bound receptors α1 a - ar , α1 b - ar and α1 d - ar . the dna sequences of the three cloned human α1 - ar subtypes have been published . furthermore , the cloned cdnas have been expressed both transiently in cos cells and stably in a variety of mammalian cell lines ( hela , lm ( tk −), cho , rat − 1 fibroblast ) and have been shown to retain radioligand binding activity and the ability to couple to phosphoinositide hydrolysis . we used published dna sequence information to design primers for use in rt - pcr amplification of each subtype to obtain cloned cdnas . human poly a + rna was obtained from commercially available sources and included hippocampus and prostate samples , sources which have been cited in the literature . for the primary screen a radio ligand binding assay was used which employed membrane preparations from cells expressing the individual cloned receptor cdnas . radiolabeled ligands with binding activity on all three subtypes ( non - selective ) are commercially available ([ 125i ]- heat , [ 3h ]- prazosin ). each α1 receptor subtype was cloned from poly a + rna by the standard method of reverse transcription - polymerase chain reaction ( rt - pcr ). the following sources of polya + rna were used for the cloning of the α1 receptor subtypes : α1 a - ar , human hippocampus and prostate , α1 b - ar , human hippocampus , α1 d - ar , human hippocampus . the resulting cdnas were cloned into the pcdna3 mammalian expression vector ( invitrogen corp ., san diego calif .). each dna was sequenced for verification and to detect any possible mutations introduced during the amplification process . any deviation in sequence from the published consensus for each receptor subtype was corrected by site - directed mutagenesis . the three α1 - ar subtypes ( a , b , d ) were transfected into cos cells using a standard deae - dextran procedure with a chloroquine shock . in this procedure , each tissue culture dish ( 100 mm ) was inoculated with 3 . 5 × 10 6 cells and transfected with 10 μg of dna . approximately 72 hours post - transfection , the cells were harvested and cos membranes were prepared . transfected cos cells from 25 plates ( 100 mm ) were scraped and suspended in 15 ml of te buffer ( 50 mm tris - hcl , 5 mm edta , ph7 . 4 ). the suspension was disrupted with a homogenizer . it was then centrifuged at 1000 × g for 10 minutes at 40 ° c . the supernatant was centrifuged at 34 , 500 × g for 20 minutes at 4 ° c . the pellet was resuspended in 5 ml tne buffer ( 50 mm tris - hcl , 5 mm edta , 150 mm nacl , ph7 . 4 ). the resulting membrane preparation was aliquoted and stored at − 70 ° c . the protein concentration was determined following membrane solubilization with tritonx - 100 . the ability of each compound to bind to each of the α1 - ar subtypes was assessed in a receptor binding assay . [ 125i ]- heat , a non - selective α1 - ar ligand , was used as the radiolabeled ligand . each well of a 96 - well plate received : 140 μl tne , 25 μl [ 125i ]- heat diluted in tne ( 50 , 000 cpm ; final concentration 50 pm ), 10 μl test compound diluted in dmso ( final concentration 1 pm - 10 μm ), 25 ml cos cell membrane preparation expressing one of the three α1 - ar subtypes ( 0 . 05 - 0 . 2 mg membrane protein ). the plate was incubated for 1 hour at room temperature and the reaction mixtures were filtered through a packard gf / c unifilter filter plate . the filter plate was dried for 1 hour in a vacuum oven . scintillation fluid ( 25 ml ) was added to each well , and the filter plate was counted in a packard topcount scintillation counter . data was analyzed using graphpad prism software . tables a lists ic 50 values expressed in nanomolar concentration for select compounds of the invention in all receptor subtypes . the antagonist activity and the selectivity of compounds of the invention for prostate tissues over aortic tissues as well as their antagonists was demonstrated as follows . the contractile responses of rat prostatic tissue and rat aorta tissues were examined in the presence and absence of antagonist compounds . as an indication of the selectivity of antagonism , test compound effects on vascular smooth muscle contractility ( α1 b - ar and α1 d - ar ) were compared to the effects on prostatic smooth muscle ( α1 a - ar ). strips of prostatic tissue and aortic rings were obtained from long evans derived male rats weighing 275 grams and sacrificed by cervical dislocation . the prostate tissue was placed under 1 gram tension in a 10 ml bath containing phosphate buffered saline ph 7 . 4 at 32 ° c . and isometric tension was measured with force transducers . the aortic tissue was placed under 2 grams tension in a 10 ml bath containing phosphate buffered saline ph 7 . 4 at 37 ° c . the ability of test compound to reduce the norepinephrine - induced contractile response by 50 % ( ic 50 ) was determined . compound 3 inhibited the contractile response in aortic tissue with an ic 50 of 4 . 74 μm and in prostate tissue with an ic 50 of 0 . 143 μm . compound 35 inhibited the contractile response in aortic tissue with an ic 50 of 8 . 5 μm and in prostate tissue with an ic 50 of 0 . 18 μm . select compounds of the invention were tested for their ability to antagonize phenylephrine ( pe ) induced increases in intraurethral pressure in dogs . the selectivity of these compounds was demonstrated by comparing their effect upon pe induced increases in mean arterial pressure ( map ) in the dog . male beagle dogs were anesthetized and catheterized to measure intraurethral pressure ( iup ) in the prostatic urethra . mean arterial pressure ( map ) was measured using a catheter placed in the femoral artery . dogs were initially administered six i . v . bolus doses ( 1 to ≦ 32 mg / kg ) of phenylephrine ( pe ) to establish a control agonist dose - response curve . iup and map were recorded following each dose until the iup returned to baseline . the dogs then were given an i . v . bolus dose of the antagonist compound , followed by i . v . pe challenges of ascending doses , as in the control agonist dose - response curve . iup and map measurements following each pe challenge were recorded . the antagonist compound was tested over a dose range of 3 to 300 ug / kg in half - log increments . the interval between antagonist doses was at least 45 min and three experiments were performed for each test compound . fig1 illustrates the mean percentage reductions in iup and map for compound 8 . 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