Sulfuric Acid → 3-(N-methylamino)aniline-4-sulfonic acid

Participants

Reaction Conditions

Reaction Steps

97 g of 1,3-diaminobenzene-4-sulfonic acid were stirred with 250 ml of water and, after the addition of 38 ml of 98% w/w formic acid, boiled at 95°-100° C. The mixture was then cooled to 30° C., and 65 g of ice were added, the pH being adjusted to 6.5 to 7.0 with 60.5 ml of 50% w/w caustic soda solution. There were then added 45 ml of 50% w/w caustic soda solution and 70 ml of dimethyl sulfate, and stirring was continued for 30 minutes. The mixture was then acidified with 43 ml of 96% w/w sulfuric acid and stirred at 100° C. for 3 hours. The mixture was then cooled, and the precipitated 3-(N-methylamino)aniline-4-sulfonic acid was isolated by filtration.

Provenance & Evidence