Patent US2812349A successfully refreshed from Google Patents.
US2812349A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Alkanoic acid esters of tetracycline antibiotics
Assignee: Pfizer Inc
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Filing: 1954-03-11
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Granted: 1957-11-05
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Expires: 1974-03-11
Abstract
No abstract record available.
Inventors
- 👤 Philip N Gordon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 05:57
CPC Classifications
C; C07; C07C; C07C233/00
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
56 words
A PROCESS FOR PREPARING AN ESTERIFIED TETRACYCLINE ANTIBIOTIC WHICH COMPRISES REATING A TETRACYCLINE ANTI-BIOTIC SELECTED FROM THE GROUP CONSISTING OF OXYTETRACYCLINE, CHLORTETRACYCLINE AND TETRACYCLINE WITH AT LEAST A MOLAR PROPORTION OF AN ALKYL CABOXYLIC ACID ANHYDRIDE HAVING UP TO 6 CARBON ATOMS IN A MINOR PROPORTION BY VOLUME OF DIOXANE AT A TEMPERATURE NOT EXCEEDING 35*C.
Claim 2
Dependent Claim
56 words
A PROCESS FOR PREPARING AN ESTERIFIED TETRACYCLINE ANTIBIOTIC WHICH COMPRISES REATING A TETRACYCLINE ANTI-BIOTIC SELECTED FROM THE GROUP CONSISTING OF OXYTETRACYCLINE, CHLORTETRACYCLINE AND TETRACYCLINE WITH AT LEAST A MOLAR PROPORTION OF AN ALKYL CABOXYLIC ACID ANHYDRIDE HAVING UP TO 6 CARBON ATOMS IN A MINOR PROPORTION BY VOLUME OF DIOXANE AT A TEMPERATURE NOT EXCEEDING 35*C.
Claim 3
Dependent Claim
43 words
A COMPOUND SELECTED FROM THE GROUP CONSISTING OF A 12A-MONOESTER OF OXYTETRACYCLINE, A 12A-MONESTER OF CHLORTETRACYCLINE, A 12-MONESTER OF TETRACYCLINE, AND A 5,12A-DIESTER OF OXYTETRACYCLINE, EACH ESTER GROUP HAVING UP TO 6 CARBON ATOMS AND BEING OF THE FORMULA RCOOWHEREIN R IS ALKYL.
Claim 4
Dependent Claim
43 words
A COMPOUND SELECTED FROM THE GROUP CONSISTING OF A 12A-MONOESTER OF OXYTETRACYCLINE, A 12A-MONESTER OF CHLORTETRACYCLINE, A 12-MONESTER OF TETRACYCLINE, AND A 5,12A-DIESTER OF OXYTETRACYCLINE, EACH ESTER GROUP HAVING UP TO 6 CARBON ATOMS AND BEING OF THE FORMULA RCOOWHEREIN R IS ALKYL.
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) | 1960-11-04 | 1961-05-06 | 1961-11-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-11-04 | 1965-05-06 | 1965-11-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-11-04 | 1969-05-06 | 1969-11-05 | $7700.00 | Window Closed / Lapsed |