Patent US4007216A successfully refreshed from Google Patents.
US4007216A
Expired / Lapsed
US
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2-Methoxy-4-methyl-3-oxo-cyclopent-1-ene-1,4-dicarboxylic acid esters
Assignee: El Paso Products Co
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Filing: 1975-05-12
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Granted: 1977-02-08
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Expires: 1995-05-12
Abstract
Abstract The disclosure relates to a novel process for the preparation of 3-alkyl-cyclopentane-1,2-diones and, in particular, to a novel process for the preparation of 3-methyl-cyclopentane-1,2-dione also known as Maple Lactone. The process comprises condensation of esters of glutaric acid and oxalic acid in a polar aprotic solvent in the presence of an alkali metal alkoxide to form 3,5-dicarboalkoxy-cyclopentane-1,2-dione dialkali metal salts, alkylating said salts with an alkylating agent to form a 2-alkoxy-3,5-dicarboalkoxy-5-alkyl-cyclopent-1-ene removing said solvent therefrom, and hydrolyzing the remainder with a mineral acid to form a 3-alkyl-cyclopentane-1,2-dione.
Inventors
- 👤 Thurman Chestler McFearin, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 12:26
CPC Classifications
C; C07; C07C; C07C49/00; C07C49/587; C07C49/703; C07C49/707; C07C45/00; C07C45/51; C07C45/511; C07C45/513; C07C49/385; C07C49/395
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
6 words
As a composition of matter 2-methoxy-3,5-dicarboalkoxy-5-methylcyclopent-2-ene-1-one.
Claim 2
Dependent Claim
6 words
As a composition of matter 2-methoxy-3,5-dicarboalkoxy-5-methylcyclopent-2-ene-1-one.
References Cited (Backward Citations)
US2865962A
Cited
US3870711A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-02-08 | 1980-08-09 | 1981-02-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-02-08 | 1984-08-09 | 1985-02-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-02-08 | 1988-08-09 | 1989-02-08 | $7700.00 | Window Closed / Lapsed |