Chlorination of carbohydrates and other alcohols

Claim 1

In a process for the preparation of 1,6-dichloro-1,6-dideoxy-β-D-fructofuranosyl-4-chloro-4-deoxy-α-galactopyranoside comprising the steps of: (a) reacting sucrose with a tritylating agent; (b) acetylating the tritylated reaction product with an acetylating agent to obtain 6,1',6'-tri-O-tritylsucrose penta-acetate; (c) detritylating the 6,1',6'-tri-O-tritylsucrose penta-acetate to obtain 2,3,4,3',4'-penta-O-acetylsucrose; (d) isomerizing the 2,3,4,3',4'-penta-O-acetylsucrose to obtain 2,3,6,3',4'-penta-O-acetylsucrose; (e) chlorinating 2,3,6,3',4'-penta-O-acetylsucrose with a chlorinating reagent to obtain 4,1',6'-trichloro-4,1',6'-trideoxygalactosucrose pentaacetate; and (f) deacetylating the chlorinating product; the improvement comprising effecting the chlorinating step utilizing a chlorinating reagent selected from the group consisting of triphenylphosphine oxide/thionyl chloride, triphenylphosphine oxide/phosgene, triphenylphosphine sulfide/thionyl chloride and triphenylphosphine sulfide/phosgene in the presence of an aromatic hydrocarbon solvent at a temperature up to about 120° C.