Compounds of formula (I) in which R3 is chosen from hydrogen, cyano, nitro, acetyl and C(=O)NH2, and Ar is optionally substituted monocyclic or bicyclic aryl or heteroaryl, are useful as antitumor agents.
式(I)中R3为氢、
氰、硝基、乙酰基和C(=O)NH2中的一种,Ar为可选取带有取代基的单环或双环芳基或杂环芳基,作为抗肿瘤剂是有用的。