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US4582900A
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Water-soluble mixed ethers of β-cyclodextrin and a process for their preparation
Assignee: Consortium fuer Elektrochemische Industrie GmbH
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Filing: 1984-12-14
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Granted: 1986-04-15
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Expires: 2004-12-14
Abstract
Abstract The invention relates to novel water-soluble mixed ethers of β-cyclodextrin (β-CD) with ether substituents comprising (C 1 and C 2 ) alkyl, hydroxy(C 2 to C 4 )alkyl and carboxy(C 1 and C 2 )alkyl such as methylhydroxyethyl-β-CD or hydroxyethyl-carboxy-methyl-β-CD; hydroxyethyl-hydroxy propyl ethers are excepted. The process of the invention comprises reacting β-cyclodextrin with at least two different alkylating, hydroxyalkylating and/or carboxyalkylating etherifying agents (for example, methyl chloride, ethylene oxide and/or chloroacetic acid) in a basic, liquid reaction medium containing an alkali-metal hydroxide, water and, optionally, at least one organic solvent (for example, dimethoxyethane or isopropanol).
Inventors
- 👤 Lothar Brandt
- 👤 Utz-Hellmuth Felcht
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 08:41
CPC Classifications
C; C08; C08B; C08B37/00; C08B37/0006; C08B37/0009; C08B37/0012
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
55 words
A water-soluble mixed ether of β-cyclodextrin wherein each ether substituent is a member selected from the group consisting of C 1 and C 2 alkyl, hydroxy(C 2 to C 4 )alkyl and carboxy(C 1 and C 2 )alkyl, with the proviso that the sole ether substituents are not the sole couple of hydroxyethyl and hydroxypropyl.
Claim 2
Dependent Claim
55 words
A water-soluble mixed ether of β-cyclodextrin wherein each ether substituent is a member selected from the group consisting of C 1 and C 2 alkyl, hydroxy(C 2 to C 4 )alkyl and carboxy(C 1 and C 2 )alkyl, with the proviso that the sole ether substituents are not the sole couple of hydroxyethyl and hydroxypropyl.
Claim 3
Dependent Claim
22 words
A mixed ether as claimed in claim 1 having a degree of substitution (DS) between 0.28 and 3.0 for each ether group.
Claim 4
Dependent Claim
25 words
A mixed ether as claimed in claim 2 wherein at least one ether substituent is methyl and at least one other ether substituent is hydroxyethyl.
Claim 5
Dependent Claim
25 words
A mixed ether as claimed in claim 2 wherein at least one ether substituent is methyl and at least one other ether substituent is hydroxypropyl.
Claim 6
Dependent Claim
25 words
A mixed ether as claimed in claim 2 wherein at least one ether substituent is methyl and at least one other ether substituent is carboxymethyl.
Claim 7
Dependent Claim
25 words
A mixed ether as claimed in claim 1 comprising at least two ether substituents selected from the group consisting of methyl, hydroxyethyl, hydroxypropyl and carboxymethyl.
Claim 8
Dependent Claim
16 words
A mixed ether as claimed in claim 1 wherein one of the ether substituents is methyl.
Claim 9
Dependent Claim
26 words
A mixed ether as claimed in claim 7 wherein each further ether substituent is a member selected from the group consisting of hydroxyethyl, hydroxypropyl and carboxymethyl.
Claim 10
Dependent Claim
22 words
A mixed ether as claimed in claim 8 having a degree of substitution (DS) between 0.28 and 3.0 for each ether group.
Claim 11
Dependent Claim
39 words
A process for preparing a mixed ether as claimed in claim 1, which comprises reacting β-cyclodextrin with at least two different alkylating, hydroxyalkylating and/or carboxyalkylating etherifying agents in a basic, liquid reaction medium containing an alkali-metal hydroxide and water.
Claim 12
Dependent Claim
15 words
A process as claimed in claim 10 wherein the reaction medium further contains organic solvent.
Claim 13
Dependent Claim
52 words
A process as claimed in claim 11, wherein the organic solvent comprises at least one member selected from the group consisting of a dialk(C 1 to C 3 )oxyethane, a C 2 to C 5 alkanol, a (C 1 to C 4 )alkoxy(C 2 or C 3 )alkanol and an aliphatic ketone.
Claim 14
Dependent Claim
23 words
A process as claimed in claim 12, which comprises reacting the β-cyclodextrin with at least two different etherifying agents in one single step.
Claim 15
Dependent Claim
23 words
A process as claimed in claim 12, which comprises reacting the β-cyclodextrin with at least one etherifying agent in each of two steps.
Claim 16
Dependent Claim
45 words
A process as claimed in claim 10, wherein the etherifying agents comprise at least two etherifying agents selected from the group consisting of C 1 and C 2 alkyl chlorides, C 2 to C 4 alkylene oxides and C 2 and C 3 chloroalkane acids.
Claim 17
Dependent Claim
23 words
A process as claimed in claim 15, which comprises reacting the β-cyclodextrin with at least two different etherifying agents in one single step.
Claim 18
Dependent Claim
23 words
A process as claimed in claim 15, which comprises reacting the β-cyclodextrin with at least one etherifying agent in each of two steps.
Claim 19
Dependent Claim
23 words
A process as claimed in claim 10, which comprises reacting the β-cyclodextrin with at least two different etherifying agents in one single step.
Claim 20
Dependent Claim
25 words
A process as claimed in claim 10, which comprises reacting the β-cyclodextrin with at least one etherifying agent in each of at least two steps.
Claim 21
Dependent Claim
26 words
A process as claimed in claim 10 for preparing a mixed ether having a degree of substitution (DS) between 0.28 and 3.0 for each ether group.
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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) | 1989-04-14 | 1989-10-14 | 1990-04-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-04-14 | 1993-10-14 | 1994-04-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-04-14 | 1997-10-14 | 1998-04-15 | $7700.00 | Window Closed / Lapsed |