Methacrylic Acid → 3-(Acetylthio)-2-methylpropanoic acid

Participants

Reaction Conditions

Reaction Steps

With stirring, 1 mol of methacrylic acid was added to 1.4 mol of fresh-distilled thioacetic acid being kept under N2 atmosphere. To the extent it was still necessary to do so in view of the heat liberated in course of the reaction, the reaction mixture was heated slowly to approximately 95° C. (reflux) and, subsequently, maintained at this temperature for 1 to 2 hours. After removing the excess thioacetic acid by distillation at atmospheric pressure, crude DL-S-acetyl-β-mercaptoisobutyric acid was obtained by the process of vacuum distillation (about 135° C. at 4 mm Hg). To purify this crude product, it was poured out in 200 ml of hexane and the product crystallized out was filtered off and dried in the air. The yield was 70%; melting point: about 39° C. (literature: 40°-40.5° C.; Chemical Abstracts 38, 3616).

Provenance & Evidence