Acid catalysis in the mutarotation of N-(p-chlorophenyl)-β-D-glucopyranosylamine in methanolic medium

Abstract

The relationship has been studied between the rate of mutarotation of N-(p-chlorophenyl)-β-D-glucopyranosylamine and the concentration of a variety of substituted benzoic acids in methanol at 25 °C. Catalytic constants of these acids and of 2,6-dinitrophenol have been found to obey the Brønsted law of catalysis, the value of α being equal to 0.99. The mechanism of specific acid catalysis has been suggested for the anomerisation of N-(p-chlorophenyl)-β-D-glucopyranosylamine. It is concluded that in methanolic benzoate buffer solutions the reaction is of the general acid catalysis type.