Synthetic antibacterials. VII. N-(1,8-naphthyridin-7-yl)methylenamine derivatives.

Abstract

Treatment of ethyl 1,4-dihydro-1-ethyl-7-methyl-4-oxo-1,8-naphthyridine-3-carboxylate with selenium dioxide afforded a mixture of ethyl 1,4-dihydro-1-ethyl-7-formyl-4-oxo-1,8-naphthyridine-3-carboxylate (2) and 1,4-dihydro-1-ethyl-7-formyl-4-oxo-1,8-naphthyridine-3-carboxylic acid (3). Condensation of 2 or 3 with respective amines provided the corresponding N-(1,4-dihydro-3-ethoxycarbonyl-1-ethyl-4-oxo-1,8-naphthyridin-7-yl)methylenamine and N-(3-carboxy-1,4-dihydro-1-ethyl-4-oxo-1,8-naphthyridin-7-yl)methylenamine, respectively. These compounds were tested for in vitro antibacterial activity.