US3297728A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the preparation of difluoro-steroids
Assignee: Pharmacia and Upjohn Co
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Filing: 1965-04-07
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Granted: 1967-01-10
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Expires: 1985-04-07
Abstract
No abstract record available.
Inventors
- 👤 Kagan Fred
- 👤 David G Martin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 23:34
CPC Classifications
C; C07; C07J; C07J9/00; C07J1/00; C07J5/00; C07J75/00
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
70 words
IN THE PROCESS OF REACTING A KETOSTEROID WITH SULFUR TETRAFLUORIDE IN THE PRESENCE OF A LEWIS ACID AND AN INERT SOLVENT WHEREBY OXYGEN IS REPLACED BY TWO FLUORINE ATOMS TO OBTAIN THE CORRESPONDING GEM-DIFLUORO STEROID, THE IMPROVEMENT WHICH COMPRISES CARRYING OUT THE REACTION WITH SAID LEWIS ACID PRESENT IN THE PROPORTION OF AT LEAST 3 MOLES PER MOLE OF KETOSTEROID FOR EACH KETO GROUP IN THE LATTER TO BE FLUORINATED.
Claim 2
Dependent Claim
70 words
IN THE PROCESS OF REACTING A KETOSTEROID WITH SULFUR TETRAFLUORIDE IN THE PRESENCE OF A LEWIS ACID AND AN INERT SOLVENT WHEREBY OXYGEN IS REPLACED BY TWO FLUORINE ATOMS TO OBTAIN THE CORRESPONDING GEM-DIFLUORO STEROID, THE IMPROVEMENT WHICH COMPRISES CARRYING OUT THE REACTION WITH SAID LEWIS ACID PRESENT IN THE PROPORTION OF AT LEAST 3 MOLES PER MOLE OF KETOSTEROID FOR EACH KETO GROUP IN THE LATTER TO BE FLUORINATED.
Claim 3
Dependent Claim
69 words
THE PROCESS WHICH COMPRISES FLUORINATING CHOLESTANE-3-ONE WITH SULFUR TETRAFLUORIDE IN THE PRESENCE OF HYDROGEN FLUORIDE AT A TEMPERATURE WITHIN THE RANGE OF ABOUT 0*C. TO ABOUT 30*C., SAID SULFUR TETRAFLUORIDE BEING PRESENT WITHIN THE RANGE OF 13 MOLES TO 100 MOLES PER MOLE OF STARTING STEROID AND SAID HYDROGEN FLUORIDE BEING PRESENT WITHIN THE RANGE OF 3 MOLES TO 30 MOLES PER MOLE OF STARTING STEROID, TO OBTAIN 3,3-DIFLUOROCHOLESTANE.
Claim 4
Dependent Claim
69 words
THE PROCESS WHICH COMPRISES FLUORINATING CHOLESTANE-3-ONE WITH SULFUR TETRAFLUORIDE IN THE PRESENCE OF HYDROGEN FLUORIDE AT A TEMPERATURE WITHIN THE RANGE OF ABOUT 0*C. TO ABOUT 30*C., SAID SULFUR TETRAFLUORIDE BEING PRESENT WITHIN THE RANGE OF 13 MOLES TO 100 MOLES PER MOLE OF STARTING STEROID AND SAID HYDROGEN FLUORIDE BEING PRESENT WITHIN THE RANGE OF 3 MOLES TO 30 MOLES PER MOLE OF STARTING STEROID, TO OBTAIN 3,3-DIFLUOROCHOLESTANE.
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) | 1970-01-09 | 1970-07-11 | 1971-01-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-01-09 | 1974-07-11 | 1975-01-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-01-09 | 1978-07-11 | 1979-01-10 | $7700.00 | Window Closed / Lapsed |