US3775424A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Furo(3,4-b)pyridine-7(5h)-ones
Assignee: Appvion LLC
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Filing: 1971-12-06
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Granted: 1973-11-27
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Expires: 1991-12-06
Abstract
Abstract A NOVEL CHROMOGENIC COMPOUND OF NORMALLY COLORLESS FORM IS DISCLOSED, HAVING THE STRUCTURAL FORMULA: 7-(O=),5,5-DI(X-)-5,7-DIHYDROFURO(3,4-B)PYRIDINE, OR 7-(O=),5,5-DI(X-)-5,7-DIHYDROFURO(3,4-B)PYRAZINE WHEREIN EACH X IS (1-R-PYRROLYL)-, (4-((R)2-N-),2-R-PHENYL)-, OR (1,2,5-TRI(R-)INDOL-3-YL)- WHEREIN EACH R IS HYDROGEN, AN ALKYL RADICAL HAVING 1 TO 4 CARBON ATOMS, AN ALKOXY RADICAL HAVING 1 TO 4 CARBON ATOMS OR A PHENYL RADICAL. THESE COLORLESS, BUT COLORABLE DYES ARE EMPLOYED IN PRESSURE-SENSITIVE RECORD MATERIAL AND MARK-FORMING MANIFOLD SYSTEMS.
Inventors
- 👤 S Farber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 17:53
CPC Classifications
C; C07; C07D; C07D491/00; C07D491/02; C07D491/04; B; B41; B41M; B41M5/00; B41M5/124; B41M5/132; B41M5/136; B41M5/145; C09; C09B; C09B11/00; C09B11/04; C09B11/26
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) | 1976-11-26 | 1977-05-28 | 1977-11-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-26 | 1981-05-28 | 1981-11-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-26 | 1985-05-28 | 1985-11-27 | $7700.00 | Window Closed / Lapsed |