Hydrochloric Acid → Thiazolidine-2-thione-4-carboxylic acid

Participants

Reaction Steps

Sodium hydroxide (40 g, 1.0 mol), cysteine hydrochloride hydrate (50 g, 0.285 mol) and carbon disulfide (30 g, 0.4 mol) were added in that order to 200 ml water at room temperature. This mixture was stirred for 24 hours. At the end of this period, the reaction mixture was acidified to pH 6 with hydrochloric acid and evaporated to yield a yellow foam. Trituration of this foam with concentrated hydrochloric acid caused crystallization to occur. The white solid thus obtained was recrystallized from 6 N hydrochloric acid to yield 12.2 g (21.2%) of 4-carboxythiazolidine-2-thione, m.p. 183°-184°C with decomposition.

Provenance & Evidence