US2835667A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of enol-ethers and ketals of ketosteroids
Assignee: Francesco Vismara SpA
•
Filing: 1955-06-20
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Granted: 1958-05-20
•
Expires: 1975-06-20
Abstract
No abstract record available.
Inventors
- 👤 Ercoli Alberto
- 👤 Ruggieri Pietro De
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 07:27
CPC Classifications
C; C07; C07J; C07J21/00; C07J1/00; C07J5/00; C07J75/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
71 words
A PROCESS FOR THE PREPARATION OF DERIVATIVES OF 3KETOSTEROIDS, SELECTED FROM THE GROUP CONSISTING OF 3ENOL ETHERS AND 3-CYCLIC KETALS OF THE PREGNANE AND ANDROSTANE SERIES WHEREIN THE 3-KETOSTEROID IS REACTED WITH AN ALCOHOL, SELECTED FROM THE GROUP CONSISTING OF MONOVALENT AND DIVALENT ALCOHOLS IN THE PRESENCE OF AN ARYLSULFONIC ACID AS CATALYST IN BOILING ISOCTANE (2,2,4-TRIMETHYLPENTANE) WHICH CONTINUOUSLY REMOVES, BY DISTILLATION IN AZEOTROPIC MIXTURE, THE WATER FORMED DURING THE REACTION.
Claim 2
Dependent Claim
71 words
A PROCESS FOR THE PREPARATION OF DERIVATIVES OF 3KETOSTEROIDS, SELECTED FROM THE GROUP CONSISTING OF 3ENOL ETHERS AND 3-CYCLIC KETALS OF THE PREGNANE AND ANDROSTANE SERIES WHEREIN THE 3-KETOSTEROID IS REACTED WITH AN ALCOHOL, SELECTED FROM THE GROUP CONSISTING OF MONOVALENT AND DIVALENT ALCOHOLS IN THE PRESENCE OF AN ARYLSULFONIC ACID AS CATALYST IN BOILING ISOCTANE (2,2,4-TRIMETHYLPENTANE) WHICH CONTINUOUSLY REMOVES, BY DISTILLATION IN AZEOTROPIC MIXTURE, THE WATER FORMED DURING THE REACTION.
References Cited (Backward Citations)
US2183589A
Cited
US2263785A
Cited
US2386331A
Cited
US2302636A
Cited
US2555344A
Cited
US2521586A
Cited
US2707184A
Cited
US2700666A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-05-19 | 1961-11-18 | 1962-05-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-05-19 | 1965-11-18 | 1966-05-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-05-19 | 1969-11-18 | 1970-05-20 | $7700.00 | Window Closed / Lapsed |