Hydrochloric Acid → 3-Amino-2-methyl-4-methylsulfanylbenzoic acid

Participants

Reaction Conditions

Reaction Steps

10 g of methyl 2-amino-4-methylbenzothiazole-5-carboxylate (0.045 mol.) were dissolved in a mixture of 120 ml of water, 120 ml of ethylene glycol and 50 g of NaOH, and the mixture was stirred at 130° C. for 20 h. The mixture was then diluted with 50 g of ice, 3 drops of (n-Bu)4N+OH— solution were added and finally, at 20° C., 6.25 ml of dimethyl sulfate (0.05 mol) in 15 ml of toluene were added dropwise. After 30 min, the mixture was acidified with conc. HCl and the precipitate was filtered off with suction, washed with water and dried.

Provenance & Evidence