Patent ID: 7803799

Claim:
A compound of formula (I): wherein R 1 is C 3 -C 20 cycloalkyl, C 3 -C 20 cycloalkenyl, C 1 -C 20 heterocycloalkyl, C 1 -C 20 heterocycloalkenyl, aryl, or heteroaryl; R 2 is C(O)NR a R b , in which each of R a and R b , independently, is H, C 1 -C 10 alkyl, C 3 -C 20 cycloalkyl, C 1 -C 20 heterocycloalkyl, aryl, or heteroaryl; and each of R 3 , R 4 , R 5 , and R 6 , independently, is H, halo, C 1 -C 10 alkyl, C 2 -C 10 alkenyl, C 2 -C 10 alkynyl, C 3 -C 20 cycloalkyl, C 3 -C 20 cycloalkenyl, C 1 -C 20 heterocycloalkyl, C 1 -C 20 heterocycloalkenyl, aryl, or heteroaryl.