Patent ID: 7696221

Claim:
A compound of the formula: or pharmaceutically acceptable salt thereof, wherein: R 1 is hydrogen, alkyl, halogen, aryl, thienyl, furanyl, or pyrrolyl; R 2 , R 3 , R 5 , and R 6 are, independently, hydrogen, hydroxy, lower alkyl, alkoxy, or halogen; R 4 is alkyl; R 7 is hydrogen, methyl, —(C═O)R 16 , —S(O) 2 R 17 , or —S(O) 2 N(R 18 )(R 19 ); R 16 is alkyl; R 17 is alkyl, alkenyl or alkynyl; and R 18 and R 19 are, independently, hydrogen, alkyl, alkenyl, or alkynyl.