Heterocyclic compound and antitumor agent containing the same as effective ingredient

摘要

The present invention relates to heterocyclic compounds represented by the formula I or pharmaceutically acceptable salts thereof and antitumor agents containing the heterocyclic compounds as effective components: wherein X represents nitrogen atom or CH; R₁ represents CH_nF_3-n (wherein n is 1 or 2), hydroxy C₁-C₆ alkyl, NHR₆ [wherein R₆ represents hydrogen atom or COR (wherein R represents hydrogen atom, C₁-C₆ alkyl or C₁-C₆ alkoxy)]; R₂ represents morpholino (which may be substituted with one to four C₁-C₆ alkyl), thiomorpholino, piperidino, pyrrolidinyl (which may be substituted with hydroxy C₁-C₆ alkyl), oxazolidinyl (which may be substituted with one or two C₁-C₆ alkyl) or tetrahydro-1,4-thiazin-1-oxo-4-yl; R₃ and R₄ each represent hydrogen atom or C₁-C₆ alkyl; and R₅ represents hydrogen atom, amino or hydroxyl.