| abstract |
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: n nwherein X represents nitrogen atom or CH; R 1 represents CH n F 3-n (wherein n is 1 or 2), hydroxy C 1 –C 6 alkyl, NHR 6 [wherein R 6 represents hydrogen atom or COR (wherein R represents hydrogen atom, C 1 –C 6 alkyl or C 1 –C 6 alkoxy)]; R 2 represents morpholino (which may be substituted with one to four C 1 –C 6 alkyl), thiomorpholino, piperidino, pyrrolidinyl (which may be substituted with hydroxy C 1 –C 6 alkyl), oxazolidinyl (which may be substituted with one or two C 1 –C 6 alkyl) or tetrahydro-1,4-thiazin-1-oxo-4-yl; R 3 and R 4 each represent hydrogen atom or C 1 –C 6 alkyl; and R 5 represents hydrogen atom, amino or hydroxyl. |