Patent US3639445A successfully refreshed from Google Patents.
US3639445A
Expired / Lapsed
US
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Process for making substituted crotonates
Assignee: Dow Chemical Co
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Filing: 1968-01-08
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Granted: 1972-02-01
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Expires: 1988-01-08
Abstract
Abstract ESTERS OF CROTONIC ACID HAVING AN ETHER SUBSTITUENT IN THE 3-POSITIONS ARE PREPARED BY REACTING AN ACETOACETIC ESTER WITH AN ACETAL UNDER ACID ESTERIFICATION CONDITIONS WHEREBY LOW BOILING REACTION BY PRODUCTS ARE DISTILLED FROM THE REACTION MIXTURE SUBSTANTIALLY AS THEY ARE FORMED.
Inventors
- 👤 Chester E Pawloski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 08:50
CPC Classifications
C; C07; C07C; C07C69/00; C07C69/66; C07C69/73; C07C69/734
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) | 1975-01-31 | 1975-08-02 | 1976-02-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-31 | 1979-08-02 | 1980-02-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-31 | 1983-08-02 | 1984-02-01 | $7700.00 | Window Closed / Lapsed |