| 主权项 |
1. A compound having the following structure, or a pharmaceutically acceptable salt thereof: wherein each of each of rings A, B and C is independently a substituted or unsubstituted carbocyclic ring, bicyclic ring, aromatic ring, or heterocyclic ring; each X1, X2, X3 and X4 is C or one of X1, X2, X3 and X4 may be N; Z is NO2 or CN; each R1 is independently H, halogen, OH, CN, (C1-C6)alkyl, (C2-C6)alkenyl, (C2-C6) alkynyl, (C1-C6) alkoxy, (C3-C7) cycloalkyl, (C1-C6) alkylthio, NRaRb, RaRb or haloalkyl; each occurrence of Ra and Rb is independently hydrogen or (C1-C6)alkyl, or Ra and Rb, form a saturated or unsaturated heterocyclic ring containing from three to seven ring atoms, which ring may optionally contain another heteroatom selected from the group consisting of nitrogen, oxygen and sulfur and may be optionally substituted by from one to three groups which may be the same or different selected from the group consisting of (C1-C4)alkyl, phenyl and benzyl; and m is 1-4; provided the compound of structure I is not: |
