Patent ID: 7728141

Claim:
A compound of structural formula I: and pharmaceutically acceptable salts thereof, wherein: R 1 is selected from: (1) hydrogen, (2) halogen, (3) C 1-4 alkyl, (4) —CN, (5) —C(O)R 7 , (6) —OR d , (7) —NR 5 R 6 , and (8) pyrrolidinyl, wherein: alkyl moieties are unsubstituted or substituted with one substituent independently selected from R a ; R 2 is selected from: —NR 5 R 6 , and C 1-6 alkyl; R 3 is hydrogen; R 4 is selected from: (1) hydrogen, and (2) —CH 2 —R 8 ; R 5 is selected from: (1) hydrogen, (2) C 1-6 alkyl, (3) trifluoromethyl, and (4) methylcarbonyl, R 6 is each selected from: (1) hydrogen, (2) C 1-6 alkyl, (3) phenyl, (4) benzyl, (5) trifluoromethyl, (6) —C(O)—R c , (7) —CO 2 R c , and (8) —S(O) 2 CH 3 , or R 5 and R 6 together form ═CH—N(CH 3 ) 2 ; R 7 is selected from: (1) hydrogen, (2) C 1-3 alkyl, (3) —OR e , and (4) —NR d R e , wherein the alkyl moieties are unsubstituted or substituted with one, two, or three substituents independently selected from R a ; R 8 is selected from: (1) hydrogen, (2) —(CH 2 ) n OC(O)CH 3 , (3) C 1-6 alkyl, (4) C 3-6 cycloalkyl, (5) tetrahydrofuranyl, (6) phenyl, and (7) pyridyl; wherein the alkyl moieties are unsubstituted or substituted with one substituent independently selected from —OR e , and the tetrahydrofuranyl, phenyl, and pyridyl moieties are unsubstituted or substituted with one, or two substituents independently selected from OR e , halogen, —NR e R f , —COCH 3 , —C(O)OCH 3 , —CN, and C 1-3 alkyl; Ar 1 and Ar 2 are each phenyl, unsubstituted or substituted with one or two substituents independently selected from R b ; each R a is independently selected from: —OR e , halogen, —NR e R f , —C(O)R c , —CO 2 R c , —OC(O)R c , —CN, CF 3 , and —OCF 3 ; each R b is independently selected from: (1) R a , and (2) C 1-10 alkyl; each R c is independently selected from: hydrogen, C 1-6 alkyl, and —NR d R d ; wherein each alkyl moiety may be substituted with one or two substituents selected from R h and oxo; each R d is independently selected from hydrogen, and C 1-6 alkyl; R e and R f are is independently selected from hydrogen and C 1-3 alkyl; each R h is independently selected from: (1) halogen, (2) C 1-10 alkyl, (3) —OR i , (4) —NR i R i , and (5) —OC(O)R i , each R i is independently selected from: (1) hydrogen, (2) C 1-3 alkyl, (3) trifluoromethyl, and (4) cyclopropyl; wherein each alkyl and cycloalkyl moiety is unsubstituted or substituted with one substituent selected from oxo, hydroxy, methoxy, acetoxy, halogen, cyano, and trifluoromethyl; and n is 1; or a pharmaceutically acceptable salt thereof.