US3642837A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Anthraquinone compounds
Assignee: Imperial Chemical Industries Ltd
•
Filing: 1969-03-06
•
Granted: 1972-02-15
•
Expires: 1989-03-06
Abstract
Abstract ANTHRAQUINONE COMPOUNDS WHICH CONTAIN ONE OR TWO CHLOROMETHYL OR BROMOMETHYL GROUPS EACH OF WHICH IS IN ORTHO POSITION TO AN AMINO GROUP WHICH IS ATTACHED TO AN X-POSITION OF THE ANTHRAQUINONE NUCLEUS WHICH MAY CONTAIN ADDITIONAL SUBSTITUENTS, THE PREPARATION OF THE SAID COMPOUNDS FROM THE CORRESPONDING HYDROXYMETHYL DERIVATIVES, AND THE USE OF THE SAID COMPOUNDS AS INTERMEDIATES IN THE MANUFACTURE OF DYESTUFFS.
Inventors
- 👤 Colin William Greenhalgh
- 👤 David Francis Newton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 02:17
CPC Classifications
C; C09; C09B; C09B62/00; C09B62/44; C09B62/78; C09B62/80; C09B1/00; C09B1/16; C09B1/20; C09B1/22; C09B1/56
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) | 1975-02-14 | 1975-08-16 | 1976-02-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-14 | 1979-08-16 | 1980-02-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-14 | 1983-08-16 | 1984-02-15 | $7700.00 | Window Closed / Lapsed |