Process for the chlorination of sugars
US4977254A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 2, 1989 |
| Grant date | Dec 11, 1990 |
| Priority date | — |
| Expiry date | Aug 2, 2009 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07H13/04
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
Sugars and partly protected sugar derivatives are chlorinated by reaction of unprotected hydroxyl groups with thionyl chloride to form a persulphite followed by decomposition of the sulphite groups to form chlorosulphites, displacement of the chlorosulphite groups and insertion of chlorine atoms at one or more positions, characterised in that formation and displacement of the chlorosulphite groups and insertion of chlorine atoms is effected by reaction with thionyl chloride in an inert solvent in the presence of a quaternary salt of the general formula: EQU N.sup.+ R.sup.1 R.sup.2 R.sup.3 R.sup.4 Cl.sup.- (I) wherein R.sup.1, R.sup.2 and R.sup.3, which may be the same or different, each represent a lower alkyl group, and R.sup.4 represents a hydrocarbon group with at least seven carbon atoms; and, when the sugar or partly protected sugar derivative has more than three unprotected hydroxyl groups, the process comprises the following stages: PA1 (a) reaction of the sugar or partly protected sugar derivative with thionyl chloride in the presence of pyridine to form a persulphite; PA1 (b) isolation of the polysulphite to remove free pyridine; and PA1 (c) reaction of the isolated polysu…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.