Hydrochloric Acid → 2-Chloro-p-toluidine-5-sulfonic acid

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Reaction Steps

A mixture of 11.2 grams of 50% sodium hydroxide solution, 13.4 grams of 2-amino-5-methyl-benzene sulfonic acid .[.(o-anisidine).]. and 13.4 grams of 2-amino-4-chloro-5-methyl benzene sulfonic acid is prepared, and 300 ml. of water is added with stirring until clear. Ice is added to a volume of 488 ml. and the temperature is 0°±2° C., Concentrated hydrochloric acid (36.2 grams) is added with stirring over a period of 4 to 6 minutes. A solution of 10 grams of sodium nitride and 20 ml. of water is added, and the resulting mixture is stirred for 15 minutes at 10°-12° C. while testing for excess acid with Congo Red and for nitrite with potassium iodide paper.

Provenance & Evidence