Functional Derivatives of 4-Formyl-2-methoxyphenyl Pyridine-4-carboxylate

Acylation of vanillin with isonicotinoyl chloride gave 4-formyl-2-methoxyphenyl pyridine-4-carboxylate which was converted into a number of functional derivatives, including those containing isoxazole and isothiazole heterocycles. In particular, the condensation of the title compound with primary amines afforded the corresponding Schiff bases. 4-Formyl-2-methoxyphenyl pyridine-4-carboxylate and one of the Schiff bases derived therefrom were reduced with sodium triacetoxohydridoborate to the corresponding alcohol and amine which were acylated with 5-arylisoxazole- and 4,5-dichloroisothiazole-3-carbonyl chlorides to obtain esters and amides having isoxazole and isothiazole fragments. The synthesized compounds readily formed complexes with palladium(II) chloride, which showed a high catalytic activity in the Suzuki reaction of 3-bromobenzoic acid with 4-methoxyphenylboronic acid in water in the absence of an organic solvent.