Diethyl Ether → Ethyl 1-(2,4-difluorophenyl)-6-fluoro-1,4-dihydro-7-methoxy-4-oxo-1,8-naphthyridine-3-carboxylate

Participants

Reaction Steps

In 4 ml of benzene was suspended 200 mg of ethyl 2-[2-(2,4-difluorophenylamino)-5-fluoro-6-methoxynicotinoyl]acetate, and 71 mg of N,N-dimethylformamide dimethylacetal was added thereto, after which the resulting mixture was subjected to reaction under reflux for 9 hours. The solvent was removed by distillation under reduced pressure, and to the residue thus obtained was added 2 ml of diethyl ether, after which the crystals thus deposited were collected by filtration to obtain 130 mg (yield 63.3%) of ethyl 1-(2,4-difluorophenyl)-6-fluoro-1,4-dihydro-7-methoxy-4-oxo-1,8-naphthyridine-3-carboxylate having a melting point of 190°-192° C.

Provenance & Evidence