Patent US3836591A successfully refreshed from Google Patents.
US3836591A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the preparation of diphenols
Assignee: Brichima SpA
•
Filing: 1972-01-17
•
Granted: 1974-09-17
•
Expires: 1992-01-17
Abstract
Abstract A PROCESS IS DISLCOSED FOR MAKING CATECHOL AND HYDROQUINONE USING HYDROGEN PEROXIDE TO HYDROXYLATE PHENOL IN THE PRESENCE OF A C1-4 ALKANOIC ACID USING TRIFLUOROACETIC ACID AS A CATALYST. THE REACTION TEMPERATURE IS FROM 50*-100* C. AND THE MOLAR RATIO OF PHENOL: HYDROGEN PEROXIDE IS FROM 4:1 TO 20:1.
Inventors
- 👤 P Maggioni
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 05:11
CPC Classifications
C; C07; C07C; C07C37/00; C07C37/60; Y; Y02; Y02P; Y02P20/00; Y02P20/50; Y02P20/52
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
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) | 1977-09-16 | 1978-03-18 | 1978-09-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-16 | 1982-03-18 | 1982-09-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-16 | 1986-03-18 | 1986-09-17 | $7700.00 | Window Closed / Lapsed |