Synthesis and properties of esters and amides of pyridine- and 1,2-azolcarbonic acids

Based on esters of nicotinic and isonicotinic acids with hydroxybenzaldehydes, a series of functionally substituted derivatives containing isoxazole and isothiazole heterocycles in the molecule have been synthesized. Azomethines were obtained by condensation of nicotinates and isonicotinates with p-bromoaniline and m-aminophenol, which have been reduced with sodium triacetoxyborohydride to give the corresponding amines. Acylation of amino derivatives of nicotinates and isonicotinates with 5-arylisoxazole- and 4,5-dichloroisothiazolecarbonyl chlorides leads to the esters and amides with isoxazole and isothiazole residues.