Pyridonecarboxylic acids as antibacterial agents. V. Synthesis of 1-vinyl-1,4-dihydro-4-oxo-1,8- and 1,6-naphthyridine-3-carboxylic acids.

Abstract

A series of 7-substituted 1,4-dihydro-4-oxo-1-vinyl-1,8- and 1,6-naphthyridine-3-carboxylic acids (5a-e and 13a-c) was prepared. During the preparation of 5a, unexpected compounds (4, 7 and 8) were also obtained. Structural elucidation of these compounds was achieved on the basis of chemical and spectral (ultraviolet, mass and proton nuclear magnetic resonance) data. The structure-antibacterial activity relationships are discussed.