Water → 5-Oxo-1,3-oxathiolane-2-carboxylic acid

Participants

Reaction Steps

Toluene (700 mL), mercaptoacetic acid (38 mL, 50.03 g, 0.543 mol), and p-toluenesulfonic acid (1.0 g) were added to a solution of glyoxylic acid monohydrate (50.0 g, 0.543 mol) in 200 mL of THF in a 2 L round bottom flask equipped with a Dean-Stark trap and condenser. The resultant reaction mixture was refluxed for 3 hours until 24.0 mL of H2O was azeotropically removed. The reaction mixture was cooled, followed by removal of solvent under reduced pressure to yield an off-white solid. This material was purified by recrystallization (hexanes-EtOAc) to give 60.0 g of the product as a crystalline white solid: m.p. 140°-143° C.; 1H NMR (DMSO) δ 3.84 (q, 2H, JAB=16.7 Hz), 6.00 (s, 1H).

Provenance & Evidence