1-环丙基-6,7,8-三氟-4-氧代-1,4-二氢喹啉-3-羧酸 、
2-(Formylaminomethyl)morpholine 以to give 1-cyclopropyl-6,8-difluoro-7-[2-(formylaminomethyl)morpholino]-1,4-dihydro-4-oxoquinoline-3-carboxylic acid, melting at 210°-213° C.的产率得到1-cyclopropyl-6,8-difluoro-7-[2-(formylaminomethyl)morpholino]-1,4-dihydro-4-oxoquinoline-3-carboxylic acid