8.6.3.2 Phenylsulfamic Acids

These compounds rearrange on heating to give o -sulfonic acid derivative that further rearranges at high temperature to afford p -sulfonic acid derivatives. For example,

8.6.3.3 Hydrazobenzenes

These compounds undergo [5,5]-sigmatropic rearrangement in the presence of acid to give benzidines.

Mechanism

Examples: