Patent ID: 8258317

Claim:
A method for directly producing a lactide, the method comprising: performing a transesterification reaction between two molecules of an ester of lactic acid having the following Chemical Formula (1) included in a starting material under an inert environment, in the presence of a titanium-based catalyst which includes at least one member selected from the group consisting of titanium tetraalkoxides having the formula (R′O) 4 Ti in which R′ is a lower alkyl group having 1 to 4 carbon atoms, titanium halides having the formula TiX 4 or TiX 3 in which X═F, CI or Br, alkoxy titanium halides having the formula (R′O) 4−x TiX x in which X═F, CI, or Br, x =1 to 3 and R′ is as defined above, titanium acetylacetonates having the formula Ti(acetylacetonate) 2 , and titanium alkoxide acetylacetonates having the formula Ti(acetylacetonate)(OR′) 2 in which R′ is as defined above, or a catalyst mixture containing the titanium-based catalyst, to produce a lactide of the following Chemical Formula (2) while simultaneously removing an alcohol of the formula ROH generated as a by-product, according to the following Reaction Scheme 1: wherein R is a lower alkyl group having 1 to 4 carbon atoms.