Patent US3658893A successfully refreshed from Google Patents.
US3658893A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of o-benzoylbenzoic acid
Assignee: BASF SE
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Filing: 1970-03-23
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Granted: 1972-04-25
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Expires: 1990-03-23
Abstract
Abstract PRODUCTION OF O-BENZOYLBENZOIC ACID BY OXIDATION OF AN INDAN WITH NITRIC ACID AND/OR A CHROMIUM (VI) COMPOUND. THE PRODUCT IS A VALUABLE STARTING MATERIAL FOR MANY SYNTHESE, PARTICULARLY FOR THE PRODUCTION OF ANTHRAQUINONE.
Inventors
- 👤 Hans Juergen Sturm
- 👤 Herbert Armbrust
- 👤 Manfred Eisert
- 👤 Hans-Georg Schecker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 15:28
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/16; C07C51/31
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) | 1975-04-25 | 1975-10-25 | 1976-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-25 | 1979-10-25 | 1980-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-25 | 1983-10-25 | 1984-04-25 | $7700.00 | Window Closed / Lapsed |