Patent US3794680A successfully refreshed from Google Patents.
US3794680A
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US
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Preparation of pure(+_)-transchrysanthemic acid
Assignee: Sumitomo Chemical Co Ltd
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Filing: 1970-03-16
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Granted: 1974-02-26
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Expires: 1990-03-16
Abstract
Abstract A PROCES FOR OBTAINING ($)-TRANS-CHRYSANTHEMIC ACID FROM A MIXTURE OF ($)-TRANS- AND ($)-CIS-CHRYSANTHEMIC ACIDS WHICH COMPRISES TREATING SAID MIXTURE IN THE PRESENCE OF AN ACID CATALYST UNDER NON-AQUEOUS CONDITION. THE ACID CATALYST IS LEWIS ACID SUCH AS BORON TRIFLUORIDE, STANNIC CHLORIDE, FERRIC CHLORIDE AND ZINC CHLORIDE, AN INORGANIC ACID SUCH AS SULFURIC ACID AND PHOSPHORIC ACID, ORGANIC STRONG ACID SUCH AS P-TOLUENESULFONIC ACID AND TRIFLUOROCETIC ACID, AND THE LIKE.
Inventors
- 👤 M Matsui
- 👤 K Ueda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 19:07
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/42; C07C51/487; C07C61/00; C07C61/04
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) | 1977-02-25 | 1977-08-27 | 1978-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-25 | 1981-08-27 | 1982-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-25 | 1985-08-27 | 1986-02-26 | $7700.00 | Window Closed / Lapsed |