Reactions of Pyridoxal Derivatives with Phenyl Iso(thio)cyanates

The reaction of phenyl isocyanate with pyridoxal is carried out with the participation of hydroxymethyl and phenolic groups with the formation of dicarbamate derivatives. The reactions of pyridoxal azomethines with phenyl isocyanate, depending on the structure and the ratio of the starting reagents, lead to the formation of mono-, di- or tricarbamate derivatives. The product of addition of azomethine pyridoxal to phenyl isocyanate with the participation of a hydroxymethyl group was obtained.