METHOD OF PRODUCING BIODEGRADABLE INTERMOLECULAR CYCLIC DIESTERS OF ALPHA-HYDROXYCARBOXYLIC ACIDS, METHOD FOR CONTINUOUS PRODUCTION OF POLYLACTIDE AND USE OF SAID METHODS Russian patent published in 2013 - IPC C07D319/12 B01D3/00 C08G63/08 

FIELD: chemistry.

SUBSTANCE: present invention relates to a method of producing a biodegradable intermolecular cyclic diester of alpha-hydroxycarboxylic acid. The method involves feeding a mixture of materials into a purification apparatus fitted with a column with a dividing wall, dividing the mixture of materials and extracting the purified diester. Said purification apparatus has the following components: a fractionating column, an outlet opening, a mass-exchange cap, a column with a dividing wall which is divided into two zones by a vertical dividing wall, an additional mass-exchange cap, an evaporator and an outlet opening on the collector side. The ratio of the length of the column with a dividing wall to the total length of the purification apparatus range from 0.5 to 0.9.

EFFECT: method enables cheap and efficient separation of diester from mixtures of materials when producing diester with high purity of material and/or optical purity.

19 cl, 9 dwg, 9 ex