主权项 |
1. A compound of formula (I)wherein
R1 is R2 is A1, A2, A3, and A4 are each individually hydrogen, halo, alkyl, alkoxyl, —OH, —NH2, or —NO2; A8, A9, A10, A11, A12, A13, and A14 are each individual hydrogen and A15 is C1-C6 alkyl; ora salt thereof. |