Patent ID: 8058427

Claim:
A compound of formula (I): wherein each of R 1 , R 2 , R 3 , and R 4 , independently, is H, alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, heterocycloalkyl, heterocycloalkenyl, aryl, heteroaryl, halo, nitro, cyano, amino, hydroxy, alkoxy, aryloxy, C(O)R a , C(O)OR a , C(O)NR a R b , C(S)R b , or C(NR b )R a , in which each of R a and R b , independently, is H, alkyl, alkenyl, alkynyl, hydroxy, alkoxy, amino, cycloalkyl, cycloalkenyl, heterocycloalkyl, heterocycloalkenyl, aryl, or heteroaryl; or R 1 and R 2 , together with the carbon atoms to which they are bonded, are cycloalkenyl, heterocycloalkenyl, aryl, or heteroaryl; or R 2 and R 3 , together with the carbon atoms to which they are bonded, are cycloalkenyl or heterocycloalkenyl; or R 3 and R 4 , together with the carbon atoms to which they are bonded, are cycloalkenyl, heterocycloalkenyl, aryl, or heteroaryl; R 5 is C(O)R c , in which R c is aryl substituted at the 2- or 3-position with halo, nitro, cyano, or alkoxy; R 6 is aryl; and X is O.