Patent ID: 7410993

Claim:
A compound having the structure of Formula I: and its pharmaceutically acceptable salts, pharmaceutically acceptable enantiomers, diastereomers or N-oxides, wherein R 1 represents hydrogen, lower (C 1 -C 4 ) alkyl, lower perhaloalkyl (C 1 -C 4 ), aryl or aralkyl; R 2 represents hydrogen, lower (C 1 -C 4 ) alkyl, lower perhaloalkyl (C 1 -C 4 ), aralkyl, alkylamino, alkoxyalkyl, alkoxyaryl or alkoxycarbonyl; and R 3 , R 4 , R 5 and R 6 independently represent hydrogen, lower (C 1 -C 4 ) alkyl, lower perhaloalkyl (C 1 -C 4 ), cyano, hydroxy, nitro, lower alkoxycarbonyl, halogen (e.g., F, Cl, Br, I), lower alkoxy (C 1 -C 4 ), lower perhaloalkoxy (C 1 -C 4 ), amino or lower alkylamino.