Abstract: A method for preparing sucralose with high yield, comprising the following preparation steps: First, negative effects of other impurities on reaction are reduced by first preparing a pure Vilsmeier chlorinating reagent. Second, side reactions are prevented by adding composite catalyst to increase selectivity of chlorination reaction. Third, by extracting less polar impurities using less polar solvent when sucralose-6-ester is undergoing deesterification, products are qualified at the very first time so that refining steps are avoided. Accordingly, product loss is reduced and product yield is increased. By using the present invention to prepare sucralose, product yield could be increased to more than 40%.

Abstract: A method of preparing sucralose-6-ester by catalysis and chlorination of phase transfer catalyst comprises the following steps: add phase transfer catalyst into a prepared Vilsmeier reagent and then drip in DMF solution of sucrose-6-ester at 5-10° C. to obtain a feed solution and after that maintain its temperature of the feed solution for 1-1.5 hours; next, increase temperature of the feed solution to 45-55° C. and maintain the temperature for 1-1.5 hours; next, increase the temperature to 75-85° C. and maintain the temperature for 1-1.5 hours; next, increase the temperature to 108-109° C., maintain the temperature for 2.5-3 hours and then remove a chlorine-containing solvent from the feed solution by concentration in reduced pressure for evaporation. After that, cool down the feed solution to room temperature and then pump in ammonia into the feed solution for neutralization.

Abstract: A method for preparing sucralose with high yield, comprising the following preparation steps: First, negative effects of other impurities on reaction are reduced by first preparing a pure Vilsmeier chlorinating reagent. Second, side reactions are prevented by adding composite catalyst to increase selectivity of chlorination reaction. Third, by extracting less polar impurities using less polar solvent when sucralose-6-ester is undergoing deesterification, products are qualified at the very first time so that refining steps are avoided. Accordingly, product loss is reduced and product yield is increased. By using the present invention to prepare sucralose, product yield could be increased to more than 40%.