3-Ethoxy-carbonyl-7,8-difluoro-1-methyl-4-oxo-1,4-dihydro-benzo[b][1,8]naphthyridine 、
N,N-diethylazetidin-3-amine dihydrochloride 在
crude product 、
甲醇 、 8-(3-Diethylamino-1-azetidinyl)-3-ethoxy-carbonyl-7-fluoro-1-methyl-4-oxo-1,4-dihydrobenzo[b][1,8]naphthyridine 作用下,
以are obtained in the form of a yellow solid, melting point 260° C.的产率得到8-(3-Diethylamino-1-azetidinyl)-3-ethoxy-carbonyl-7-fluoro-1-methyl-4-oxo-1,4-dihydrobenzo[b][1,8]naphthyridine