The preparation of sodium 4-Amino-3-nitro-benzenesulfonate and some related compounds

Abstract

The sodium salt of 4-amino-3-nitrobenzenesulfonic acid (O-nitroaniline-p-sulfonic acid) has been prepared by the action of dilute sodium hydroxide solution on ethyl [(4-chlorosulfonyl-2-nitro)- phenyllcarbamate. Central to this synthesis is the finding that the N-ethoxycarbonyl group, when located ortho to a nitro group (but not to a bromo group), is readily removed by dilute sodium hydroxide solution.