Patent US5305182A successfully refreshed from Google Patents.
Patent US3823140A successfully refreshed from Google Patents.
US3823140A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Delta 3-4-carboxy-3-oxobutyl cephalosporins
Assignee: Glaxo Laboratories Ltd
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Filing: 1971-03-23
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Granted: 1974-07-09
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Expires: 1991-03-23
Abstract
Abstract THE INVENTION IS CONCERNED WITH &3-4-CARBOXYL CEPHALOSPORIN ANTIBIOTICS POSSESSING A 3-OXOBUTYL GROUP AT THE 3-POSITION. THE INVENTION ALSO DESCRIBES PROCESSES FOR THE PREPARATION OF SUCH COMPOUNDS.
Inventors
- 👤 J Clark
- 👤 W Underwood
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 09:26
CPC Classifications
C; C07; C07D; C07D501/00; C07D501/14; C07D501/16; C07D501/20; C07D501/24
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) | 1977-07-08 | 1978-01-07 | 1978-07-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-08 | 1982-01-07 | 1982-07-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-08 | 1986-01-07 | 1986-07-09 | $7700.00 | Window Closed / Lapsed |