AZO DYESTUFF PREPARATION BY PHASE TRANSFER CATALYSED COUPLING IN A TWO-PHASE MEDIUM

摘要

Azo dyestuffs from difficult coupling components such as diphenylamine, carbazole and N-ethylcarbazole are prepared by conducting the coupling reaction in a mixture of water and a water-immiscible polar aprotic solvent in the presence of a phase transfer catalyst which contains an anionic water-solubilising group.