Patent US3663563A successfully refreshed from Google Patents.
US3663563A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Esters of 6-aminopenicillanic acid
Assignee: Beecham Group PLC
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Filing: 1969-07-22
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Granted: 1972-05-16
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Expires: 1989-07-22
Abstract
Abstract ESTERS OF 6-AMINOPENICILLANIC AND ARE DISCLOSED. THESE HAVE UTILITY AS INTERMEDIATES IN THE PREPARATION OF SEMISYNTHETIC PENICILLINS.
Inventors
- 👤 George Robert Fosker
- 👤 John Herbert Charles Nayler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 02:32
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) | 1975-05-16 | 1975-11-15 | 1976-05-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-16 | 1979-11-15 | 1980-05-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-16 | 1983-11-15 | 1984-05-16 | $7700.00 | Window Closed / Lapsed |