PYRIDONECARBOXYLIC ACID DERIVATIVES

摘要

- 72 This invention relates to compounds represented by the following general formula or their pharmaceutically acceptable salts or esters, a process for preparation thereof and antitumor agents containing them as an effective ingredient III wherein R1 represents a straight- chain, branched or cyclic lower alkyl group or a phenyl group optionally substituted by fluorine atom(s), R2 and R3 each represent a hydrogen atom or a straight - chain, branched or cyclic lower alkyl group, R1 represents a hydrogen atom or -N (R5) R6 wherein R5 and R6 each represent a hydrogen atom or a straight-chain, branched or cyclic lower alkyl group, X represents a nitrogen atom or C - Y wherein Y represents a hydrogen atom, halogen atom, methyl group or methoxy group, m and n each represent an integer of 0 or 1, and ? represents a single bond or double bond.