Fused heterocyclic compounds

Abstract

A compound represented by the formula (I) [wherein W represents C(R ) or N; A represents optionally substituted aryl or optionally substituted heteroaryl; X represents -NR -Y -, -O-, -S-, -SO-, -SO2-, or -CHR - (wherein R represents hydrogen or an optionally substituted aliphatic hydrocarbon group, provided that R may be bonded to A to form an optionally substituted ring structure); R represents hydrogen or an optionally substituted group bonded through a carbon, nitrogen, or oxygen atom; and R represents hydrogen or an optionally substituted group bonded through a carbon or sulfur atom, provided that R may be bonded to R or R to form an optionally substituted ring structure] or a salt of the compound. Also provided is a tyrosinkinase inhibitor or a preventive/therapeutic agent for cancers which each contains the compound or a prodrug thereof.