Preparation of epsilon -caprolactone

摘要

A process for the preparation of epsilon -caprolactone comprising: (a) reacting cyclohexanone with a solution of perpropionic acid in an organic solvent at a molar ratio of cyclohexanone;perpropionic acid of about 1.1-5:1 at a temperature of about 10 DEG to 80 DEG C. to form a reaction mixture consisting essentially of epsilon -caprolactone, propionic acid and organic solvent, (b) distilling the reaction mixture from (a) in a first distillation unit to obtain a distillate comprising the organic solvent and a distillation residue, (c) introducing the distillation residue from (b) at a point into a second distillation unit to obtain a distillate comprising propionic acid and unreacted cyclohexanone, removing from the second distillation unit, separately from one another and at a point below the point of introduction into the second distillation unit, epsilon -caprolactone and any high-boiling constituents, and, (d) distilling in a third distillation unit the distillate from (c) to obtain a distillate consisting essentially of propionic acid and a distillation residue comprising a mixture of propionic acid and cyclohexanone.