Patent US3686183A successfully refreshed from Google Patents.
US3686183A
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Preparation of optical isomers of arylalkylacetic acids
Assignee: Roche Palo Alto LLC
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Filing: 1969-03-24
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Granted: 1972-08-22
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Expires: 1989-03-24
Abstract
Abstract SOLUTION OF A-SUBSTITUTED D- OR 1-ARYLACETIC ACID SALTS OF ASYMMERTIC OPTICALLY ACTIVE NITROGENEOUS BASES ARE HEATED TO ELEVATED TEMPERATURES TO CAUSE RACEMIZATION. BY REPEATED CRYSTALLIZATION AND RACEMIZATION STEPS WITH FINAL CONVERSION TO THE ACID, A DL-ACID CAN BE CONVERTED TO AN OPTICALLY SPECIFIC D- OR 1-ACID. THE A-SUBSTITUTED ARYLACETIC ACIDS ARE USEFUL AS ANTI-INFLAMMATORY, ANALGESIS, ANTIPYRETIC AND ANTI-PRUTITIC AGENTS.
Inventors
- 👤 Norman H Dyson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 05:28
CPC Classifications
C; C07; C07C; C07C59/00; C07C59/40; C07C59/58; C07C59/64; C07C57/00; C07C57/30; C07C57/38; C07C57/40; C07C59/42; C07C59/56; C07C63/00; C07C63/33; C07C63/337; C07C63/34
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) | 1975-08-22 | 1976-02-21 | 1976-08-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-22 | 1980-02-21 | 1980-08-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-22 | 1984-02-21 | 1984-08-22 | $7700.00 | Window Closed / Lapsed |