7-(HEXAHYDRO-3H-THIAZOLO(3,4-A)PYRAZINE)-SUBSTITUTED-6- FLUORO-4-OXO-1,4-DIHYDROQUINOLINE-3-CARBOXYLIC ACID DERIVATIVE

摘要

NEW MATERIAL:The compound of formula I (R is CH3, C2H5 or C3H7) and its salt. EXAMPLE:(-)-1-Ethyl-6-fluoro-7-{ haxahydro-3H-thiazolo [ 3,4-a ]pyrazin-7-yl}-4- oxo-1,4-dihydroquinoline-3-carboxylic acid. USE:A strong antibacterial agent against Gram-positive and Gram-negative bacteria. PREPARATION:The compound of formula I can be prepared e.g. by reacting the 6-fluoro-7-chloro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid derivative of formula II with the novel hexanehydro-3H-thiazolo-[3,4-a]pyrazine of formula IIIin the absence of solvent or in a solvent such as butanol. The novel compound of formula III can be obtained e.g. from (-)-thiazolidine-4-carboxylic acid ethyl ester.