主权项 |
1. A compound selected from the group consisting of compounds of the formula where: R1-3 are independently substituted with hydrogen, methyl and benzyl groups, R4 is substituted with a hydrogen, or phenyl group, and wherein the phenyl or benzyl groups are independently substituted with up to 2 groups selected from H, OH, F, Cl, Br, glucuronide, sulfate, cyano, methyl, NH2, SH, CH2OH, CN, CF3, NHSO2CH3, N(CH3)2, NHCH3, N(CN)2, NHCN, C(CN)3, NH(C═O)NH2, NH(C═O)CH3, (C═NH)NH2, (C═NOH)NH2, O(C═O)OCH3, and NH(C═O)H, and pharmaceutically acceptable salts thereof. |