Patent ID: 8653086

Claim:
A compound according to formula I: or a pharmaceutically acceptable salt thereof, wherein: x is 0 or 1; R 1 -R 6 are each independently H, —CN, —NO 2 , —NO, —OH, halogen, hydroxyalkyl, carboxyl, substituted carboxyl, aminocarbonyl, alkoxy, carbonyl or substituted carbonyl; R 7 is alkyl, alkyl amino, aminoacyl, hydroxyacyl, heteroaryl, heterocycloalkyl, alkyl heteroaryl or alkyl heterocycloalkyl; R 8 is H or alkyl; A is O or N; and Ar is represented by formula II: wherein R 20 is represented by formula III: wherein R 25 -R 31 are each independently H, halogen, lower alkyl, alkoxy, —O-alkyl amino, —NO 2 , —N 3 , carboxyl, substituted carboxyl, alkyl amino, carbonyl, substituted carbonyl, or aminocarbonyl; and R 21 -R 24 are each independently H, halogen, or —CN.