SYNTHESIS OF POLY(p-BENZENESULPHONAMIDE) - 1. PREPARATION OF SULPHANILIC ACID DERIVATIVES FOR USE AS INTERMEDIATES.

A description is given of the preparation of two groups of possible precursors of the polymer starting with sulphanilic acid. The first group includes N-sulphinylaniline-4-sulphochloride, aniline-4-sulphochloride hydrochloride and aniline-4-sulphochloride. The key to the synthesis of these intermediates is the conversion of sulphanilic acid to N-sulphinylaniline-4-sulphochloride by reaction with thionyl chloride in the presence of a catalytic amount of dimethyl formamide. For the synthesis of poly(N-methylbenzenesulphonamide), N-methylsulphanilic acid has been converted into N-methylaniline-4-sulphochloride hydrochloride by treatment with thionyl chloride.