| abstract |
NEW MATERIAL:A pyridonecarboxylic acid derivative shown by formula I (R 1 is H or carboxyl protecting group; R 2 is H, halogen, alkoxy, hydroxyl which may be protected, amino, lower alkylamino, etc.; R 3 is H, lower alkyl, amino which may be protected, lower alkylamino, etc.; R 4 is H, lower alkyl, halogen lower alkyl, etc., and R 4 together with bonded C forms cycloalkane ring; X is halogen; A is O, S or imino) and a salt thereof. n EXAMPLE: 10-Cycloprophyl-8,9-difluoro-3-methyl-7-oxo-2,3-dihydro-7H-pyrido[1,2,3- de] [1,4]benzoxazine-6-carboxylic acid ethyl ester. n USE: Useful as an antitumor agent. n PREPARATION: As shown by the reaction formula, a compound shown by formula II is used as a starting raw material to give a compound shown by formula I. n COPYRIGHT: (C)1990,JPO&Japio |