Patent US3682896A successfully refreshed from Google Patents.
US3682896A
Expired / Lapsed
US
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Preparation of 6-acylaminopenicillanic acids
Assignee: Beecham Group PLC
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Filing: 1970-02-10
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Granted: 1972-08-08
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Expires: 1990-02-10
Abstract
Abstract 6-AMINOPENICILLANIC ACID AND 6-ACYLAMINOPENICILLANIC ACIDS ARE PREPARED FREE FROM IMMUNOGENIC MACROMOLECULES, FOR USE IN PRODUCING SEMI-SYNTHETIC PENICILLINS, BY A REACTION UNDER ANHYDROUS CONDITIONS AVOIDING THE USE OF ENZYMES AND WITHOUT HYUDROLYTIC CLEAVAGE OF THE BLACTAM RING STRUCTURE. THE PREFERRED PROCESS INCLUDES THE USE OF A NUCLEOPHILE IN AT LEAST A CATALYTIC AMOUNT FOR TREATING THE STARTING MATERIAL. A SUBSTANCE MAY ALSO BE EMPLOYED WHICH IS BOTH A NUCLEOPHILE AND AN ACID ACCEPTOR.
Inventors
- 👤 Kenneth David Hardy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 04:53
CPC Classifications
C; C07; C07D; C07D499/00
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) | 1975-08-08 | 1976-02-07 | 1976-08-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-08 | 1980-02-07 | 1980-08-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-08 | 1984-02-07 | 1984-08-08 | $7700.00 | Window Closed / Lapsed |