composto, composição, método terapêutico para tratar câncer em um mamífero, e, uso de um composto

摘要

The invention provides compounds of formula I: wherein Y is F, Cl or Br; or a pharmaceutically acceptable salt thereof. The compounds are effective antitumor agents. The invention also provides pharmaceutical compositions comprising a compound of formula I or a salt thereof, intermediates useful for preparing a compound of formula I, and therapeutic methods comprising administering a compound of formula I or a salt thereof to a mammal in need thereof.