US3787438A
Expired / Lapsed
US
⏱️ 0.0 years remaining
4,6-dihydroxy-n,n'bis(3-oxo-1-isoindolinylidene)isophthalamide and substitution products
Assignee: Wyeth Holdings LLC
•
Filing: 1972-03-13
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Granted: 1974-01-22
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Expires: 1992-03-13
Abstract
Abstract THE 4,6-DIHYDROXY- N,N''BIS(3-OXO-1-ISOINDOLINYLIDENE) ISOPHTHALAMIDES, BOTH UNSUBSTITUTED, AND IN WHICH THE ISOPHTHALIC ACID RING IS SUBSTITUTED IN THE 2 AND/OR 5 POSITION BY INDEPENDENTLY, CHLORINE, BROMINE AND LOWER ALKYL, AND IN THE ISOINDOLE RINGS IN ONE OR MORE OF THE 4, 5, 6, AND 7 POSITIONS BY CHLORINE OR BROMINE ARE YELLOW COMPOUNDS WHICH IN PIGMENTARY SIZE ARE EXCELLENT YELLOW PIGMENTS.
Inventors
- 👤 D Thomas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 20:02
CPC Classifications
C; C07; C07D; C07D209/00; C07D209/02; C07D209/44; C07D209/50; C09; C09B; C09B57/00; C09B57/04
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) | 1977-01-21 | 1977-07-23 | 1978-01-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-21 | 1981-07-23 | 1982-01-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-21 | 1985-07-23 | 1986-01-22 | $7700.00 | Window Closed / Lapsed |