Patent US2790799A successfully refreshed from Google Patents.
US2790799A
Expired / Lapsed
US
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Cyclopentanophenanthrene derivatives and process for the production thereof
Assignee: Syntex SA
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Filing: 1953-11-27
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Granted: 1957-04-30
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Expires: 1973-11-27
Abstract
No abstract record available.
Inventors
- 👤 Djerassi Carl
- 👤 Sondheimer Franz
- 👤 Rosenkranz George
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 11:37
CPC Classifications
C; C07; C07J; C07J71/00; C07J75/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
80 words
A PROCESS FOR THE PREPARATION OF A COMPOUND SELECTED FROM THE GROUP CONSISTING OF 22A-SPIROSTAN-3AOL-11-ONE LOWER FATTY ACID ESTERS AND THE BENZOIC ACID ESTER THEREOF WHICH COMPRISES TREATING THE CORRESPONDING ESTER OF $7,9(11)-22A-SPIROSTASIENE-3A-OL WITH SODIUM DICHROMATE TO PRODUCE THE CORRESPONDING ESTER OF $8-22ASPIROSTEN-3A-OL-7,11-DIONE, TREATING THE $8-ESTER WITH A REDUCING AGENT TO PRODUCE THE CORRESPONDING 22A-SPIROSTAN-3A-OL-7,11-DONE ESTER, AND THEREAFTER SELECTIVELY REMOVING THE 7-KETO GROUP FROM THE 7.11-DIONE ESTER BY FORMING THE 7-THIOKETAL THEREOF FOLLOWED BY RANEY NICKEL DESULFURIZATION OF THE THIOKETAL.
Claim 2
Dependent Claim
80 words
A PROCESS FOR THE PREPARATION OF A COMPOUND SELECTED FROM THE GROUP CONSISTING OF 22A-SPIROSTAN-3AOL-11-ONE LOWER FATTY ACID ESTERS AND THE BENZOIC ACID ESTER THEREOF WHICH COMPRISES TREATING THE CORRESPONDING ESTER OF $7,9(11)-22A-SPIROSTASIENE-3A-OL WITH SODIUM DICHROMATE TO PRODUCE THE CORRESPONDING ESTER OF $8-22ASPIROSTEN-3A-OL-7,11-DIONE, TREATING THE $8-ESTER WITH A REDUCING AGENT TO PRODUCE THE CORRESPONDING 22A-SPIROSTAN-3A-OL-7,11-DONE ESTER, AND THEREAFTER SELECTIVELY REMOVING THE 7-KETO GROUP FROM THE 7.11-DIONE ESTER BY FORMING THE 7-THIOKETAL THEREOF FOLLOWED BY RANEY NICKEL DESULFURIZATION OF THE THIOKETAL.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-04-29 | 1960-10-29 | 1961-04-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-04-29 | 1964-10-29 | 1965-04-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-04-29 | 1968-10-29 | 1969-04-30 | $7700.00 | Window Closed / Lapsed |