US3200122A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the preparation of 2:9-dimethyl-quinacridine-7:14-dione
Assignee: BASF Schweiz AG
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Filing: 1963-10-07
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Granted: 1965-08-10
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Expires: 1983-10-07
Abstract
No abstract record available.
Inventors
- 👤 Streiff Henri
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 09:56
CPC Classifications
C; C09; C09B; C09B48/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
68 words
A PROCESS FOR THE PREPARATION OF 2:9-DIMETHYLQUINACRIDINE-7:14-DIONE, WHEREIN SULFURIC ACID OF AT LEAST 70% STRENGTH WHICH ALSO MAY CONTAIN FREE SO2 IS ALLOWED TO ACT ON 2:5-DI-(PARA-TOLUIDINO)-TEREPHTHALIC ACID, TO EFFECT CYCLISATION AND SULFONATION, AND THE SULFONIC ACID GROUPS THAT HAVE BEEN INTRODUCED ARE SPLIT OFF WITH SULFURIC ACID OF 70 TO 92% STRENGTH AT A TEMPERATURE BETWEEN 100 AND 180*C. BY HEATING WITHOUT THE APPLICATION OF SUPERATMOSPHERIC PRESSURE.
Claim 2
Dependent Claim
68 words
A PROCESS FOR THE PREPARATION OF 2:9-DIMETHYLQUINACRIDINE-7:14-DIONE, WHEREIN SULFURIC ACID OF AT LEAST 70% STRENGTH WHICH ALSO MAY CONTAIN FREE SO2 IS ALLOWED TO ACT ON 2:5-DI-(PARA-TOLUIDINO)-TEREPHTHALIC ACID, TO EFFECT CYCLISATION AND SULFONATION, AND THE SULFONIC ACID GROUPS THAT HAVE BEEN INTRODUCED ARE SPLIT OFF WITH SULFURIC ACID OF 70 TO 92% STRENGTH AT A TEMPERATURE BETWEEN 100 AND 180*C. BY HEATING WITHOUT THE APPLICATION OF SUPERATMOSPHERIC PRESSURE.
References Cited (Backward Citations)
GB896803A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1968-08-09 | 1969-02-08 | 1969-08-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-08-09 | 1973-02-08 | 1973-08-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-08-09 | 1977-02-08 | 1977-08-10 | $7700.00 | Window Closed / Lapsed |