Patent ID: 8148384

Claim:
A compound having formula (I) or a salt thereof, wherein A 1 is H or R 1 ; A 2 is H or R 4 ; R 1 is phenyl; which is substituted with one or two of independently selected alkyl, heterocycloalkyl, OR 16 , SR 16 , S(O)R 16 , SO 2 R 16 , C(O)R 16 , CO(O)R 16 , OC(O)R 16 , OC(O)OR 16 , NH 2 , NHR 16 , N(R 16 ) 2 , C(O)NH 2 , C(O)NHR 16 , C(O)N(R 16 ) 2 , SO 2 NH 2 , SO 2 NHR 16 , SO 2 N(R 16 ) 2 , CF 3 , CF 2 CF 3 , C(O)H, C(O)OH, OH, N 3 , NO 2 , OCF 3 , OCF 2 CF 3 , F, Cl, Br or I; R 4 is alkyl, alkenyl or alkynyl, each of which is unsubstituted or substituted with one or two of independently selected CF 3 , F, Cl, Br or I; A 3 is R 15 ; R 15 is alkyl, which is substituted with one or two of independently selected NH 2 , NHW 1 , N(W 1 ) 2 , or heterocycloalkyl; wherein the heterocycloalkyl is unsubstituted or substituted with one or two of independently selected alkyl, OR 16 , or OH; W 1 is phenyl or alkyl; wherein the phenyl is unsubstituted or substituted with one or two of independently selected alkyl, OR 16 , NH 2 , CF 3 , CF 2 CF 3 , OH, NO 2 , OCF 3 , OCF 2 CF 3 , F, Cl, Br or I; and R 16 is H or alkyl.