METHOD FOR CATALYTIC SYNTHESIS OF LACTIDE IN THE PRESENCE OF INORGANIC ADDITIVES Russian patent published in 2019 - IPC C07D319/12 

FIELD: biochemistry.

SUBSTANCE: invention relates to a method of producing a valuable monomer – lactide – for producing polylactic acid (polylactide), which is a biocompatible and biodegradable polymer. Polylactide is widely used in medicine for production of endoprostheses, surgical suture materials, pins, as well as in drug delivery systems. Disclosed is a catalytic method of producing lactide, involving oligomerisation of a mixture of alkyl, alkyl di- and alkyl trilactates in a nitrogen atmosphere and subsequent thermal decomposition of the obtained oligoalkyl lactate at low pressure and temperature in range from 180 to 200 °C using compounds of alkali and rare-earth metals as less toxic inorganic additives, where metal is one of following elements of said series: Na, K, Y, La, Ce, Pr, Nd, Sm, Yb, Lu.

EFFECT: technical result consists in obtaining mixture of alkyl lactates not contaminated with toxic impurities, reducing time of oligomerisation and thermal destruction processes.

1 cl, 3 ex