PURPOSE: To provide the subject new pyrazinophenanthrolinecarboxylic acid compounds useful as an antibacterial agent and effective also to methicillin- resistant Staphylococcus aureus.
CONSTITUTION: Compounds of formula I (R1 is 1-4C alkyl, phenyl, etc.; R2 is H, methyl, etc.; X is F, Cl, etc.), salts thereof or hydrates thereof, e.g. 6- fluoro-11-(2,4-difluorophenyl)-1,3,4,8-11,12,13,13a-octahydro-2-methyl-8, 12-dioxo-2H- pyrazino[1,2-i][1,7]phenanthroline-9-carboxylic acid. These compounds can be obtained by reacting a 4-oxoquinoline-3-carboxylic acid of formula II (Y is X; R3 is H or 1-4C alkyl) with an N-benzylethylenediamine of formula III in the presence of a base (preferably pyrimidine, etc.), subsequently debenzylating the resultant reaction product and then reacting the resultant compound of formula IV with a 4-bromocrotonic acid derivative.
ASAHARA NORITOSHI
MASUDA KAZUO
YAJIMA MASAO
TAKAGI JUN
