7-(4-Benzyl-1-piperazinyl)-1,4-dihydro-4-oxo-1-vinyl-1,8-naphthyridine-3-carboxylic acid

1,2,3,6,9,10-hexahydro-6,9-dioxoimidazo<1,2,3-ij><1,8>naphthyridine-5-carboxylic acid

4-oxo-7-piperazin-1-yl-1-vinyl-1,4-dihydro-[1,8]naphthyridine-3-carboxylic acid