Patent ID: 9035076
Filing Date: 2015-05-19
Classification: C07D

Abstract:
1. A process for recovering lactic acid values from a starting lactide composition, comprising a) subjecting a starting lactide composition to a temperature of up to 170° C. in the presence of a racemization catalyst for a time sufficient to racemize at least a portion of the lactide in the starting lactide composition to form a racemized lactide mixture that contains meso-lactide, S,S-lactide and R,R-lactide in relative proportions different than in the starting lactide composition, where the racemization catalyst selected from the group consisting of an N,N′-dialkyl piperazine compound having the structure: wherein each R is independently alkyl or aryl-substituted alkyl, a substituted pyridine compound having the structure wherein X is an electron-donating group, an alkali metal salt of an alkanoic acid having one to 6 carbon atoms and an alkali metal phosphate having the structure wherein M is an alkali metal, A is hydrogen or an alkali metal, and R 3 is hydrogen, an alkali metal or an organic group bonded to the adjacent atom through a carbon atom.