1-Amino-2-(4-chlorophenylazo)-naphthalene-5-sulfonamide → 1-Naphthalenesulfonamide, 5,6-diamino-

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Reaction Conditions

Reaction Steps

To a solution of 18,1 g (80 mmol) stannous chloride dihydrate in 100 ml concentrated hydrochloric acid was added 10,0 g (27,7 mmol) 1-amino-2-(4-chlorophenylazo)-naphthalene-5-sulphonamide. The mixture was stirred at 70° C. for 3 h. After cooling to 25° C., the mixture was poured into 200 ml ice-water. The precipitate was filtered off and washed with 4N hydrochloric acid. The crude product was stirred with ice-water. The precipitate was filtered off and washed with ice-water and ethanol to give 6,7 g 1,2-diamino-naphthalene-5-sulphonamide as a hydrochloride salt.

Provenance & Evidence