ANTITUMOR AGENTS

摘要

The invention provides compounds of formula I as described herein 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.