Patent US2776969A successfully refreshed from Google Patents.
US2776969A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of preparation of cyclopentanophenanthrene derivatives
Assignee: Syntex SA
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Filing: 1953-02-17
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Granted: 1957-01-08
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Expires: 1973-02-17
Abstract
No abstract record available.
Inventors
- 👤 Rosenkranz George
- 👤 Djerassi Carl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 13:42
CPC Classifications
C; C07; C07J; C07J71/00; C07J75/00
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
18 words
A COMPOUND SELECTED FROM THE GROUP CONSISTING OF $5-SIROSTEN-3B,11A-DIOL, LOWER FATTY ACID ESTERS AND BENZOIC ACID ESTERS THEREOF.
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) | 1960-01-08 | 1960-07-09 | 1961-01-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-01-08 | 1964-07-09 | 1965-01-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-01-08 | 1968-07-09 | 1969-01-08 | $7700.00 | Window Closed / Lapsed |