US4977254A
Expired / Lapsed
US
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Process for the chlorination of sugars
Assignee: Tate and Lyle PLC
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Filing: 1989-08-02
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Granted: 1990-12-11
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Expires: 2009-08-02
Abstract
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: N.sup.+ R.sup.1 R.sup.2 R.sup.3 R.sup.4 Cl.sup.- (I) wherein R 1 , R 2 and R 3 , which may be the same or different, each represent a lower alkyl group, and R 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: (a) reaction of the sugar or partly protected sugar derivative with thionyl chloride in the presence of pyridine to form a persulphite; (b) isolation of the polysulphite to remove free pyridine; and (c) reaction of the isolated polysulphite with thionyl chloride in an inert solvent or suspension medium in the presence of a quaternary salt of the general formula (I).
Inventors
- 👤 Nigel J. Homer
- 👤 Graham Jackson
- 👤 George H. Sankey
- 👤 Philip J. Simpson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 05:27
CPC Classifications
C; C07; C07H; C07H5/00; C07H5/02; C07H11/00; C07H13/00; C07H13/02; C07H13/04
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
214 words
In the process for the chlorination of sucrose and partly protected sucrose derivatives 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, the improvement consisting 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 formula: N.sup.+ R.sup.1 R.sup.2 R.sup.3 R.sup.4 Cl.sup.- (I) wherein R 1 , R 2 and R 3 , which may be the same or different, each represent a lower alkyl group, and R 4 represents an arylalkyl group with at least seven carbon atoms; and, when the sucrose or partly protected sucrose derivative has more than three unprotected hydroxyl groups, the process comprises the following stages: (a) reaction of the sucrose or partly protected sucrose derivative with thionyl chloride in the presence of pyridine to form a persulphite; (b) isolation of the polysulphite to remove free pyridine; and (c) reaction of the isolated polysulphite with thionyl chloride in an inert solvent or suspension medium in the presence of a quaternary salt of the general formula (I).
Claim 2
Dependent Claim
214 words
In the process for the chlorination of sucrose and partly protected sucrose derivatives 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, the improvement consisting 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 formula: N.sup.+ R.sup.1 R.sup.2 R.sup.3 R.sup.4 Cl.sup.- (I) wherein R 1 , R 2 and R 3 , which may be the same or different, each represent a lower alkyl group, and R 4 represents an arylalkyl group with at least seven carbon atoms; and, when the sucrose or partly protected sucrose derivative has more than three unprotected hydroxyl groups, the process comprises the following stages: (a) reaction of the sucrose or partly protected sucrose derivative with thionyl chloride in the presence of pyridine to form a persulphite; (b) isolation of the polysulphite to remove free pyridine; and (c) reaction of the isolated polysulphite with thionyl chloride in an inert solvent or suspension medium in the presence of a quaternary salt of the general formula (I).
Claim 3
Dependent Claim
23 words
The process of claim 1, in which the quaternary salt of formula I is one in which R 4 represents a benzyl group.
Claim 4
Dependent Claim
33 words
The process of claim 1, in which the quaternary salt of formula I is one in which R 1 , R 2 and R 3 each represent a methyl, ethyl or propyl group.
Claim 5
Dependent Claim
34 words
The process of claim 1, in which the amount of quaternary salt of formula I used in the reaction medium is about 0.2 to 0.4 molar equivalent, based on the sucrose or sucrose derivative.
Claim 6
Dependent Claim
19 words
The process of claim 1, in which the thionyl chloride used in stage is present in a molar excess.
Claim 7
Dependent Claim
16 words
The process of claim 5, in which the thionyl chloride is present in about 10% excess.
Claim 8
Dependent Claim
53 words
The process of claim 1 which, when the partly protected sucrose derivative has less than four unprotected hydroxyl groups, comprises reaction of the partly protected sucrose derivative with thionyl chloride in an inert solvent or suspension medium in the presence of a quaternary salt of the formula (I), without isolation of the polysulphite.
Claim 9
Dependent Claim
17 words
The process of claim 7, in which the thionyl chloride used is present in a molar excess.
Claim 10
Dependent Claim
25 words
The process of claim 8, in which the thionyl chloride is present in an amount of about 1.25 to 1.75 ME per free hydroxy group.
Claim 11
Dependent Claim
26 words
The process of claim 9, in which the thionyl chloride is present in an amount of about 1.3 to 1.4 molar equivalents per free hydroxyl group.
Claim 12
Dependent Claim
16 words
The process of claim 1, in which the partly protected sugar derivative is a sucrose 2,3,6,3',4'-pentaester.
Claim 13
Dependent Claim
34 words
A process for the preparation of sucralose, comprising chlorination of a sucrose 2,3,6,3',4'-pentaester by a process according to claim 11 to form a sucralose pentaester, and de-esterification of the sucralose pentaester to form sucralose.
Claim 14
Dependent Claim
17 words
A process according to claim 1, in which the partly protected sucrose derivative is a sucrose 6-ester.
Claim 15
Dependent Claim
42 words
A process for the preparation of sucralose, comprising chlorination of a sucrose 6-ester by a process according to claim 13 to form a sucralose 6-ester, esterification of this intermediate to form a sucralose pentaester and de-esterification of the pentaester to form sucralose.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-12-10 | 1994-06-11 | 1994-12-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-12-10 | 1998-06-11 | 1998-12-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-12-10 | 2002-06-11 | 2002-12-11 | $7700.00 | Window Closed / Lapsed |