Ethyl 1-(2,4-difluorophenyl)-7-choro-6-fluoro-4-oxo-hydropyridino[2,3-b] pyridine-3-carboxylate

for the following products 1,8-Naphthyridine-3-carboxylic acid 7-chloro-1-(2,4-difluorophenyl)-6-fluoro-1,4-dihydro-4-oxo-, ethyl ester | 7-Chloro-1-(2,4-difluoro-phenyl)-6-fluoro-4-oxo-1,4-dihydro-[1,8]naphthyridine-3-carboxylic acid ethyl ester | 7-Chloro-1-(2,4-difluorophenyl)-6-fluoro-1,4-dihydro-4-oxo-1,8-naphthyridine-3-carboxylicacid ethyl ester | Ethyl 1-(2,4-difluorophenyl)-7-chloro-6-fluoro-4-oxopyridino[2,3-b]pyridine-3-carboxylate and Ethyl 1-(2,4-difluorophenyl)-7-choro-6-fluoro-4-oxo-hydropyridino[2,3-b] pyridine-3-carboxylate