Process of preparing penicillamine

摘要

Penicillamine or a homolog thereof is made by reacting an aldehyde branched at the alpha -carbon atom, sulfur and ammonia to form a thiazoline- DELTA 3; converting the latter compound by reaction with anhydrous hydrogen cyanide into the corresponding thiazolidine-4-carbonitrile; hydrolyzing the nitrile with an aqueous concentrated hydrochloric acid containing at least 30% by weight of hydrogen chloride at a temperature between 40 DEG and 70 DEG C to form the hydrochloric salt of the thiazolidine-4-acid amide and then, at a higher temperature continuing the hydrolysis to form the salt of the thiazolidine-4-carboxylic acid together with the ammonium salt. The ammonium salt is then separated from the mixture and the carboxylic acid hydrochloride is hydrolytically decomposed whereby the penicillamine is obtained.