Effect of the benzoic acid additives on the catalytic activity of tetrabuthoxytitanium in the synthesis of benzanilide

Abstract

Catalytic activity of tetrabutoxytitanium in the synthesis of benzanilide is changed at its precoordination with benzoic acid in boiling ortho-xylene. Upon increase in the amount of added benzoic acid the catalyst activity increases and then decreases. In the presence of aniline, benzoic acid does not activate tetrabutoxytitanium that may result from its binding to the H-complex with aniline. The formation of such complexes was confirmed indirectly by 1H NMR spectroscopy. Under comparable conditions, the effective catalysts for the benzanilide synthesis are polytitanates obtained from tetrabutoxytitanium at its interaction with water and benzoic acid, and the still bottoms after their vacuum distillation.