1,8-naphthyridine compounds

Abstract

There is described 1,8-naphthyridin-2(1H)-one compounds with bronchodilating and hypotensive properties prepared by reaction of 2,6-diaminopyridine with an appropriate .beta.-diketone providing a 2-aminonaphthyridine compound which upon treatment with nitrous acid is converted to the 2-oxo product. Alternatively, an appropriate .beta.-diketone can be reacted with an alkyl alkoxycarbonylacetimidate, the alkyl 2-aminonicotinate thus formed converted to the hydrazide, which upon treatment with a sulfonyl halide forms the N-sulfonyl hydrazide derivative. This intermediate is reacted with an alkali metal carbonate to provide the 2-aminonicotinaldehyde which upon reaction with an ester of a substituted aliphatic carboxylic acid provides the desired product. In some cases the aminonicotinaldehyde is generated in situ in the presence of the ester thereby giving the desired product in one step from the N-sulfonyl hydrazide derivative.