NEW MATERIAL:A compound of formula I (R1 is H, R'1, lower alkenyl, cycloalkyl or aryl capable of having a substituent; R'1 is lower alkyl capable of having an OH or halogen atom; X1 and X2 are H, halogen, CN or lower alkyloxy; Y is halogen, lower alkyl, OH, SH, NH2, AR2, etc.; A is O or S; R2 is lower alkyl or aryl; Z is H, halogen, OH, SH, BR2, etc.; B is O, S, SO, SO2 or OSO2), an ester thereof and a salt thereof.
EXAMPLE: 1-Ethyl-5,6,7,8-tetrafluoro-1,4-dihydro-4-oxocinnoline-3-carboxylic acid.
USE: An antibiotic.
PREPARATION: A compound of formula V or VI obtained from a compound of formula II (R is lower alkyl; X is halogen) through a compound of formula III and further through a compound of formula IV is hydrolyzed by a conventional method to provide the compound of formula I (R1 is H or R'1).
MATSUMOTO JUNICHI
NAKAMURA SHINICHI
