Hydrochloric Acid → 5-Benzothiazolesulfonic acid, 2-amino-

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Reaction Steps

218 g 2-amino-nitrobenzene-5-sulfonic acid were added to 1100 ml of a 1.0 Molar Sulphuric acid at 5° C. and diazotated. The resulting suspension was slowly added to a solution of 180 ml water, 152 g NH4SCN and 5 g Cu(SCN)2 at 0 to 5° C. and stirred for additional 3 hours at room temperature. The reaction mixture was poured into a hot (90 to 95° C.) suspension of 1000 ml water, 500 g iron powder and 17 g of a 37% hydrochloric acid and the resulting suspension was stirred till the reduction was completed. The mixtures was brought to a pH of more than 9 and the iron slurry was filtered off. The product was precipitated by lowering the pH, filtered off, washed and dryed. This yields 200 g product (2-Amino-benzthiazole-5-sulfonic acid) as an press cake.

Provenance & Evidence