US3819622A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of producing 7beta-acylamido-3-methylceph-3-em-4-carboxylic acid esters
Assignee: Glaxo Laboratories Ltd
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Filing: 1972-07-17
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Granted: 1974-06-25
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Expires: 1992-07-17
Abstract
Abstract THE INVENTION RELATES TO A PROCESS FOR THE PREPARATION OF 7B-ACYLAMIDO-3-METHYLCEPH-3-EM-4-CARBOXYLIC ACID ESTERS FROM 6B-ACYLAMIDO-PENICILLANIC ACID 1-OXIDE ESTERS IN THE PRESENCE OF AN ACID CATALYST IN ADVANTAGEOUS YIELDS BY CAREFUL SELECTION OF THE SOLVENT USED IN THE REACTION, THE ACID CATALYST AND THE TEMPERATIVE AND DURATION OF THE REACTION.
Inventors
- 👤 B Cowley
- 👤 L Wetherill
- 👤 W White
- 👤 W Graham
- 👤 D Humber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 07:59
CPC Classifications
C; C07; C07D; C07D501/00; C07D501/02; C07D501/08; C07D501/10; A; A61; A61K; A61K31/00; A61K31/33; A61K31/395; A61K31/54; A61K31/542; A61K31/545
Claims Analysis
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References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-24 | 1977-12-24 | 1978-06-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-24 | 1981-12-24 | 1982-06-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-24 | 1985-12-24 | 1986-06-25 | $7700.00 | Window Closed / Lapsed |