Studies on N-Hydroxy-4-aminoazo Dyes. I. Synthesis of N-Hydroxy-N-methyl-4-aminoazo Dyes and the Acyl Derivatives, and Their Degradation in Alkaline Solution

Abstract

Alkaline hydrolysis of N-benzoyloxy-N-methyl-4-aminoazobenzene (II) in the presence of ascorbic acid gave N-hydroxy-N-methyl-4-aminoazobenzene (I) which has been estimated as proximate compound of hepatocarcinogenic N-methyl-or N, N-dimethyl-4-aminoazobenzene. Several acyl derivatives of I including acetyl derivative were synthesized. Alkaline treatment of I or II in the presence of dissolved oxygen, yield 4-nitroazobenzene (IV) and 4, 4′-bisphenylazo-azoxybenzene (V), probably through intermediate forms, nitron and hydroxylamine compound.