Patent ID: 7582773

Claim:
A compound of the formula: or a pharmaceutically acceptable salt or ester form thereof, wherein R 1 is C 1 -C 6 alkyl, C 1 -C 6 perfluoroalkyl, C 3 -C 8 cycloalkyl, aryl, or arylalkyl; R 2 is C 1 -C 6 alkyl, C 1 -C 6 perfluoroalkyl, C 3 -C 8 cycloalkyl, aryl, or arylalkyl; or R 1 and R 2 form a C 5 -C 8 carbocyclic ring; R 3 , R 4 and R 5 are, independently, hydrogen, C 1 -C 6 alkyl, C 3 -C 8 cycloalkyl, halogen, hydroxy, C 6 -C 14 aryl, C 1 -C 3 perfluoroalkyl, C 1 -C 3 alkoxy, or C 1 -C 3 perfluoroalkoxy; R 6 is hydrogen, C 1 -C 6 alkyl, C 1 -C 6 arylalkyl, C 1 -C 6 alkanoyl, or aroyl; R 7 is hydrogen; n is an integer of 0-6; and A is COOH, or an acid mimic.