Patent ID: 8480800

Claim:
A compound of formula I: or a salt thereof, wherein n at all occurrences is 1; R 1 is H or C 1 -C 10 alkyl, R 2 is C 1 -C 10 alkyl, or R 1 and R 2 , together with the carbon to which they are attached, form a C 3 -C 12 cycloalkyl ring optionally substituted with C 1 -C 6 alkyl; R 3 is H, C 1 -C 10 alkyl, or phenyl; R 4 is H, C 1 -C 10 alkyl optionally substituted with hydroxy, -(C(R 6 )(R 7 )) m —N(R 8 )(R 9 ), or Y, wherein m is an integer from 1 to 6, and R 6 and R 7 are independently H or C 1 -C 10 alkyl; R 5 , R 8 , and R 9 are independently H, C 1 -C 10 alkyl optionally substituted with hydroxy, or Y; and Y is a group of formula: