A Novel Method for the Preparation of 3-Amino-4-hydroxybenzenesulfonamide Precursors of “Acid Alizarin Violet N” Derivatives

Abstract Chlorosulfonation of 2-nitroanisole gave 4-methoxy-3-nitrobenzenesulfonyl chloride (7) which was converted with N-butyl(3-phenylpropyl) amine into benzenesulfonamide (8). Hydrolysis of the ether and reduction of the nitro group of 8 followed by diazotization and coupling with 2-naphthol gave N-Butyl-N-(3-phenylpropyl)-4-hydroxy-3-(2-hydroxy-1-naphthyl) azobenzenesulfonamide (1d).