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Patent US4835294A successfully refreshed from Google Patents.
US4835294A
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2-Substituted-6-methyl-1,3-dioxan-4-one
Assignee: Avecia Ltd
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Filing: 1987-10-05
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Granted: 1989-05-30
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Expires: 2007-10-05
Abstract
Abstract Novel substituted dioxanones obtained from (R)-3-hydroxybutyric acid, for example 2,2-dimethoxy-6-methyl-1,3-dioxan-4-one, a method for their preparation and processes using the dioxanones as starting material. The dioxanones can be used in particular as intermediates in the preparation of (S)-4-methyl-β-butyrolactone.
Inventors
- 👤 Dieter Seebach
- 👤 Axel Griesbeck
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:35
CPC Classifications
C; C07; C07D; C07D315/00; C07C; C07C227/00; C07C227/30; C07C227/32; C07D319/00; C07D319/04; C07D319/06
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
42 words
A compound of the formula (I): ##STR8## wherein R 1 is C 1-4 alkylamino or di-C 1-4 alkylamino and R 2 is hydrogen; or R 1 is C 1-4 alkoxy and R 2 is hydrogen, C 1-4 alkyl or C 1-4 alkoxy.
Claim 2
Dependent Claim
42 words
A compound of the formula (I): ##STR8## wherein R 1 is C 1-4 alkylamino or di-C 1-4 alkylamino and R 2 is hydrogen; or R 1 is C 1-4 alkoxy and R 2 is hydrogen, C 1-4 alkyl or C 1-4 alkoxy.
Claim 3
Dependent Claim
16 words
A compound according to claim 1 wherein R 1 is dimethylamino and R 2 is hydrogen.
Claim 4
Dependent Claim
23 words
A compound according to claim 1 wherein R 1 is methoxy or ethoxy and R 2 is hydrogen, methyl, ethyl, methoxy or ethoxy.
Claim 5
Dependent Claim
17 words
A compound according to claim 1 wherein both R 1 and R 2 are methoxy or ethoxy.
Claim 6
Dependent Claim
15 words
A compound according to claim 1 wherein R 1 and R 2 are both methoxy.
References Cited (Backward Citations)
EP0244143A2
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-05-29 | 1992-11-28 | 1993-05-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-05-29 | 1996-11-28 | 1997-05-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-05-29 | 2000-11-28 | 2001-05-30 | $7700.00 | Window Closed / Lapsed |