Amination of NN′-dibenzenesulphonyl-1,4-benzoquinone di-imines: photochemical formation of benzimidazoles

Abstract

2-Methyl- and 2,5-dimethyl-NN′-dibenzenesulphonyl-1,4-benzoquinone di-imines undergo side-chain amination by piperidine or piperazine, a process that has analogy in the quinone series. Geometrical isomerism in several of these di-imines is discussed on the basis of n.m.r. spectroscopic evidence. Certain of the nuclear aminated di-imine derivatives are converted photochemically into benzimidazole derivatives. The scope of this novel process is investigated.