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US3753980A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the preparation of 14-anhydrobufaline
Assignee: Hoechst AG
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Filing: 1971-10-29
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Granted: 1973-08-21
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Expires: 1991-10-29
Abstract
Abstract A PROCESS FOR THE PREPARATION OF 14-ANHYDROBUFALINE BY HYDROGENATING CATALYTICALLY 3-KETO-21-HYDROXY-$4,14,20CHOLATRIENIC ACID 21-LACTONE TREATING 3-KETO-21-HYDROXY5B-CHLOA-14,20-DIENE ACID-21-LACTONE OBTAINED WITH ELEMENTARY SULFUR IN AN INERT HIGH-BOILING SOLVENT AND REDUCING THE ANHYDROBUFALONE BY MEANS OF TRIMETHYL PHOSPHITE IN ISOPROPANOL IN THE PRESENCE OF IRIDIUM-IV-HYDROCHLORIC ACID.
Inventors
- 👤 W Haede
- 👤 W Fritsch
- 👤 K Radscheit
- 👤 U Stache
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:06
CPC Classifications
C; C07; C07J; C07J19/00
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) | 1976-08-20 | 1977-02-19 | 1977-08-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-20 | 1981-02-19 | 1981-08-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-20 | 1985-02-19 | 1985-08-21 | $7700.00 | Window Closed / Lapsed |