Patent ID: 7138529

Claim:
A compound of formula (I) wherein R1 and R2 are independently selected from the group consisting of lower alkyl, lower alkoxy, aminoalkyl, aryl, aralkyl, substituted lower alkyl, substituted lower alkoxy, substituted lower aminoalkyl, substituted aryl and substituted aralkyl, wherein the substituent is selected from the group consisting of one or more of halogen, hydroxy, lower alkoxy, amino, alkylamino, diaklylamino, cyano and nitro; or R1 and R2 are taken together with the carbon atoms to which they are attached and the bond between these carbon atoms to form a 4–8 membered, substituted or unsubstituted, carbocyclic or heterocyclic ring, wherein any substituents are independently selected from the group consisting of halogen, hydroxy, lower alkyl, aryl, aralkyl, amino, alkylamino, dialkylamino, alkylsulfonyl, and alkoxycarbonyl; R3 is selected from the group consisting of lower alkyl, substituted or unsubstituted aryl, substituted or unsubstituted aralkyl, and substituted or unsubstituted cycloalkyl, wherein any substituents are selected from the group consisting of lower alkyl, lower alkoxy, halogen, cyano, trifluoromethyl, hydroxy, nitro, amino, alkylamino, dialkylamino, carboxy, aminocarbonyl, phenyl, benzyl, phenoxy and benzyloxy; and R4 is selected from the group consisting of lower alkyl, lower alkoxy, halogen, cyano, trifluoromethyl, hydroxy, nitro, amino, alkylamino, dialkylamino, alkylsulfonyl, and alkoxycarbonyl; and n is 0, 1, 2, 3, 4 or 5.