o-Nitroaniline derivatives. Part III. Cyclisation of N-p-nitrobenzyl-N-p-tolylsulphonyl-o-nitroaniline by sodium methoxide: formation of an N-methoxybenzimidazole derivative

Abstract

The reaction of the title sulphonamide with sodium methoxide gives a mixture of 1-hydroxy- and 1-methoxy-2-p-nitrophenylbenzimidazole, the latter apparently being formed by in situ methylation of the former. One step in the proposed mechanism involves the formation of methyl toluene-p-sulphonate: this compound is the most likely methylating agent in the reaction.