US3795672A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the preparation of delta2-cephem-4-carboxylic acid esters
Assignee: Eli Lilly and Co
•
Filing: 1971-06-09
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Granted: 1974-03-05
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Expires: 1991-06-09
Abstract
Abstract ESTERS OF $2-CEPHEM-4-CARBOXYLIC ACIDS ARE PREPARED FROM $3-CEPHEM-4-CARBOCYLIC ACIDS BY FIRST CONVERTING THE $3 ACID TO THE CORRESPONDING ACID CHLORIDE AND TREATING THIS ACID WITH A TERTIARY AMINE BASE AND AN ALCOHOL.
Inventors
- 👤 C Murphy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 09:47
CPC Classifications
C; C07; C07D; C07D501/00; C07D501/14; C07D501/60
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) | 1977-03-04 | 1977-09-03 | 1978-03-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-04 | 1981-09-03 | 1982-03-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-04 | 1985-09-03 | 1986-03-05 | $7700.00 | Window Closed / Lapsed |