US2671806A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Purification of chlortetracycline
Assignee: Wyeth Holdings LLC
•
Filing: 1950-02-02
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Granted: 1954-03-09
•
Expires: 1970-02-02
Abstract
No abstract record available.
Inventors
- 👤 Winterbottom Robert
- 👤 Eichler Peter
- 👤 Pidacks Charles
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 23:30
CPC Classifications
C; C07; C07C; C07C233/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
49 words
A METHOD FOR THE PURIFICATION OF CHLORTETRACYCLINE WHICH COMPRISES DISSOLVING A CRUDE CHLORTETRACYCLINE AND SUFFICIENT OF A NITROGENOUS BASE TO SUBSTANTIALLY NEUTRALIZE AND SOLUBILIZE ALL OF THE CHLORTETRACYCLINE, IN AN HYDROXYLATED ORGANIC SOLVENT, SEPARATING ANY UNDISSOLVED MATERIAL AND PRECIPITATING THE CHLORTETRACYCLINE THEREFROM BY THE ADDITION OF A HYDROHALIDE ACID.
Claim 2
Independent Claim
49 words
A METHOD FOR THE PURIFICATION OF CHLORTETRACYCLINE WHICH COMPRISES DISSOLVING A CRUDE CHLORTETRACYCLINE AND SUFFICIENT OF A NITROGENOUS BASE TO SUBSTANTIALLY NEUTRALIZE AND SOLUBILIZE ALL OF THE CHLORTETRACYCLINE, IN AN HYDROXYLATED ORGANIC SOLVENT, SEPARATING ANY UNDISSOLVED MATERIAL AND PRECIPITATING THE CHLORTETRACYCLINE THEREFROM BY THE ADDITION OF A HYDROHALIDE ACID.
References Cited (Backward Citations)
US2482055A
Cited
US2516080A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1957-03-08 | 1957-09-07 | 1958-03-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-03-08 | 1961-09-07 | 1962-03-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-03-08 | 1965-09-07 | 1966-03-09 | $7700.00 | Window Closed / Lapsed |