Patent ID: 8957229
Filing Date: 2015-02-17
Classification: C07B,C07D

Abstract:
1. A method for producing an equimolar mixture of D,D-dilactide and L,L-dilactide, the method comprising steps of: using trioctylamine to convert L-lactic acid into trioctyl ammonium lactate; distilling the trioctyl ammonium lactate in the presence of dibutyltin oxide Bu obtaining a fraction that includes D,D-dilactide and L,L-dilactide and can still contain D,L-lactide; mixing the fraction with acetone; and recrystallizing to obtain colorless crystals having a melting point of 112° C. to 119° C., the crystals being composed at least substantially equimolarly of D,D-dilactide and L,L-dilactide.