US3705897A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for converting delta**2 cephalosporin to delta**3 cephalosporin
Assignee: Eli Lilly and Co
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Filing: 1970-07-07
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Granted: 1972-12-12
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Expires: 1990-07-07
Abstract
Abstract A 3-HALOMETHYL $2 CEPHALOSPORIN IS ISOMERIZED TO THE CORRESPONDING 3-HALOMETHYL $3 CEPHALOSPORIN BY OXIDATION OF THE $2 COMPOUND TO THE SULFOXIDE, ISOMERIZATION OF THE DOUBLE BOND FROM THE 2- TO THE 3-POSITION BY TREATMENT WITH A TERTIARY AMINE, AND REDUCTION OF THE SULFOXIDE TO THE SULFIDE. THESE 3-HALOMETHYL $3 CEPHALOSPORINS ARE READILY CONVERTED TO 3-FUNCTIONALIZEDMETHYL $3 CEPHALOSPORINS, ESPECIALLY TO THE 3-ALKYLTHIOMETHYL $3 CEPHALOSPORINS.
Inventors
- 👤 Charles F Murphy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 18:56
CPC Classifications
C; C07; C07D; C07D501/00; C07D501/02; C07D501/04
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) | 1975-12-12 | 1976-06-12 | 1976-12-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-12-12 | 1980-06-12 | 1980-12-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-12-12 | 1984-06-12 | 1984-12-12 | $7700.00 | Window Closed / Lapsed |