US3790620A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Aryl esters of phenyl ketene carboxylic acids
Assignee: Pfizer Inc
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Filing: 1969-10-31
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Granted: 1974-02-05
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Expires: 1989-10-31
Abstract
Abstract ARYLCHLORO (AND BROMO) CARBONYL KETENES, ARYLCARBOXY KETENE ESTERS AND ARYL CARBOTHIOLIC PHENYLESTERS DERIVED THEREFROM, METHODS FOR THEIR PREPARATION AND THE USE OF THE ESTERS AS ACYLATING AGENTS FOR THE PRODUCTION OF ESTERS OF A-CARBOXY AND A-CARBOTHIOLIC ARYLACETYL DERIVATIVES OF 6-AMINO-PENICILLANIC ACID AND, BY HYDROLYSIS, THE CORRESPONDING ACID DERIVATIVES ARE DESCRIBED.
Inventors
- 👤 K Butler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 23:50
CPC Classifications
C; C07; C07C; C07C59/00; C07C59/40; C07C59/76; C07C59/84; C07C59/88; C07C59/90; 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) | 1977-02-04 | 1977-08-06 | 1978-02-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-04 | 1981-08-06 | 1982-02-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-04 | 1985-08-06 | 1986-02-05 | $7700.00 | Window Closed / Lapsed |