Patent ID: 7553840

Claim:
A compound of formula I: or a pharmaceutically acceptable salt thereof, wherein: A 1 is optionally substituted heterocycle; each R 1 is independently halogen, hydrogen, C(O)R A , OR A , NR B R C , S(O 2 )R A , or optionally substituted alkyl, alkyl-aryl or alkyl-heterocycle; R 2 is independently halogen, hydrogen, C(O)R A , OR A , NR B R C , S(O 2 )R A , or optionally substituted alkyl, alkyl-aryl or alkyl-heterocycle; R 3 is hydrogen, C(O)R A , C(O)OR A , or optionally substituted alkyl, alkyl-aryl, alkyl-heterocycle, aryl, or heterocycle; R 4 is hydrogen or optionally substituted alkyl, alkyl-aryl, alkyl-heterocycle, aryl, or heterocycle; each R A is independently hydrogen or optionally substituted alkyl, alkyl-aryl or alkyl-heterocycle; each R B is independently hydrogen or optionally substituted alkyl, alkyl-aryl or alkyl-heterocycle; each R C is independently hydrogen or optionally substituted alkyl, alkyl-aryl or alkyl-heterocycle; and m is 1-4.