Method for purifying cyclic esters

US6800767B2 · kind B2 · utility

Assignee

• Brussels Biotech · BE

Inventors

• Frederic Van Gansberghe · Brussels, BE
• Philippe Coszach · Escanaffles, BE
• Patricia Di Salvatore · Brussels, BE
• Jean-Christophe Bogaert · Escanaffles, BE

Key dates

• Filing date: Jan 13, 2003
• Grant date: Oct 5, 2004
• Expiry date: Jan 13, 2023

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07D319/12
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

The invention concerns a method for purifying the dimeric cyclic esters of lactic (or glycolic) acid starting from a raw lactide (or glycolide) comprising impurities, the method consisting in: extractive and controlled crystallization of the raw lactide, in aqueous medium, controlling the geometry of the formed crystals and carrying out a separation of phases into lactide and impurities; separation of the resulting suspension of crystals, into a phase poor in lactide and loaded with impurities, and a wet cake rich in lactide crystals; drying the resulting wet cake; and recrystallization in melted medium of the resulting dried impure lactide and recuperating the purified lactide.