Low Temperature Chlorination of Carbohydrates
AssigneeLexington Pharmaceuticals Laboratories, LLC
InventorsWilliam Randal Erickson, Stephen Craig Fields
Life of this patent
Estimating the term…
Abstract
Disclosed is a method of chlorinating a carbohydrate or derivative thereof, for example, a sucrose-6-ester at the 4,1′, and 6′ positions, with irreversible removal of HCl formed during the reaction to form the chlorinated carbohydrate or derivative thereof, for example, a 4,1′,6′-trichloro-4,1′,6′-trideoxy-6-O-ester of galactosucrose (TGS-6E). The irreversible removal of HCl can be carried out by an irreversible physical process and/or an irreversible chemical process. Sucralose, an artificial sweetener, can be prepared by deesterification of the TGS-6E. The chlorination reaction takes place at low temperatures and the desired chlorinated product is obtained in high yields and in high purities.
Claims30
A method for chlorinating a carbohydrate or a derivative thereof comprising reacting the carbohydrate or derivative thereof with a chlorinating agent and irreversibly removing during chlorination the hydrogen chloride produced by the reaction of the chlorinating agent with the carbohydrate or derivative thereof.
A method for chlorinating a carbohydrate or a derivative thereof comprising:
- (i) dissolving the carbohydrate or derivative thereof in a polar or non-polar aprotic solvent to obtain a solution of the carbohydrate or derivative thereof;
- (ii) forming a chlorinating agent in and/or combining a pre-formed chlorinating agent in a solvent followed by dissolution of carbohydrate or derivative thereof to obtain a chlorination mixture;
- (iii) irreversibly removing during chlorination all or substantially all of the hydrogen chloride produced by the reaction of the chlorinating agent with the hydroxy group or groups of the carbohydrate and/or the carbohydrate or derivative thereof;
- (iv) optionally heating the reaction mixture from (iii) under an inert gas atmosphere to a temperature of 60° C. for a period of about 2 hours or more;
- and
- (v) optionally heating the reaction mixture to a temperature not more than 85° C., for a period of up to 16 hours, to obtain the chlorinated carbohydrate or derivative thereof.
Dependencies are inferred from the claim text.