Patent ID: 6939875

Claim:
A compound of formula (I): and pharmaceutically acceptable salts thereof, wherein: X 0 is S; X 1 is absent, O, S, —CH 2 —, —CH 2 —CH 2 —, or —CH═CH—; Ar 1 and Ar 2 are each independently unsubstituted or substituted phenyl or pyridinyl; is absent; R 1 and R 2 are selected from hydrogen, lower alkyl, lower alkoxy, haloalkyl, —O—(CH 2 ) m CF 3 , halogen, nitro, cyano, —OH, —SH or —CF 3 ; R 3 and R 4 are selected from hydrogen, lower alkyl, lower alkoxy, haloalkyl, —O—(CH 2 ) m CF 3 , halogen, nitro, cyano, —OH, —SH or —CF 3 ; provided that at least one of R 1 -R 4 is H, lower alkyl, lower alkoxy, haloalkyl, —O—(CH 2 ) m CF 3 , halogen, nitro, cyano, —OH, —SH or —CF 3 ; m is 0 to 5; q is 0 to 1; and r is 0 to 1.