US3838168A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Alpha-methylenation of gamma-butyrolactones
Assignee: Dow Chemical Co
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Filing: 1972-09-26
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Granted: 1974-09-24
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Expires: 1992-09-26
Abstract
Abstract A PROCESS FORMAKING A-METHYLENATED Y-BUTYROLACTONES HAVING THE FORMULA 3-(CH2=),4-R1,4-R2,5-R3,5-R4-TETRAHYDROFURAN-2-ONE WHEREIN R1-R4 ARE HYDROGEN OR INERT, SUBSTANTIALLY NONINTERFERING ORGANIC GROUPS, COMPRISES REACTING THE CORRESPONDING A-CARBOXYL-Y-BUYOLACTONE WITH FORMALDEHYDE IN AN ACIDINE MEDIUM, AND PREFERABLY IN THE PRESENCE OF A DIALKYLAMINE CATALYST. IN EXAMPLE, A-CARBOXY-Y-PHENYL-YBUTYROLACTONE WAS REACTED WITH FORMALDEHYDE IN THE PRESENCE OF DIETHYLEMINE AND IN A GLACIAL ACETIC ACID/SODIUM ACETATE REACTION MEDIUM TO GIVE THE CORRESPONDING A-METHYLENATED PRODUCT.
Inventors
- 👤 W Parker
- 👤 F Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 17:35
CPC Classifications
C; C07; C07D; C07D315/00; C07D307/00; C07D307/02; C07D307/34; C07D307/56; C07D307/58; C07D493/00; C07D493/02; C07D493/04
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-23 | 1978-03-25 | 1978-09-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-23 | 1982-03-25 | 1982-09-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-23 | 1986-03-25 | 1986-09-24 | $7700.00 | Window Closed / Lapsed |