Process for the preparation of glycolide and lactide

摘要

Glycolide (Ia) or lactides (Ib) <IMAGE> are prepared by thermocatalytic cleavage of condensation products of glycolic acid or, respectively, an alpha -hydroxypropionic acid while removing Ia or Ib, respectively, from the reaction mixture by distillation, converting the distillate into the solid phase by cooling, and purifying the resulting crude product by washing it with an ether having 4 to 12 carbon atoms.