Studies on the rearrangement of 1-1 and 2-naphthylsulphamic acids

Abstract

The rearrangement of sodium 1-naphthylsulphamate in dioxan–sulphuric acid gives 1-aminonaphthalene-4-sulphonic acid as the main product. 1-Aminonaphthalene-2-sulphonic acid is not formed under the conditions used for the rearrangement. Studies with [³⁵S]sulphuric acid and sodium 1-naphthyl[³⁵S]sulphamate indicate that the rearrangement is partly intramolecular in dioxan–sulphuric acid. Mechanisms for both the inter- and intra-molecular paths are presented. Sodium 2-naphthylsulphamate does not rearrange under these conditions nor does it rearrange under conditions previously reported as being suitable for its rearrangement.