Patent US3558643A successfully refreshed from Google Patents.
US3558643A
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US
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Certain 4,4'-dioxy-diphenyl-(2-pyridyl)-methanes
Assignee: Instituto de Angeli SpA
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Filing: 1967-05-16
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Granted: 1971-01-26
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Expires: 1987-05-16
Abstract
Abstract IN A PROCESS FOR THE PREPARATION OF 4,4''-DIOXY-DIPHENYL(2-PYRIDYL)-METHANE, THE STAGE OF CONDENSATION OF A COMPOUND SELECTED FROM 2-PYRIDINALDEHYDE AND A REACTIVE DERIVATIVE THEREOF, IN THE PRESENCE OF A CONDENSING AGENT WITH A PHENOL OF FORMULA: THE GROUPS R1 AND R2 IN EACH BENZENE RING BEING AS ABOVE DEFINED; AND THE STAGE OF DEHALOGENATION OF THE SO OBTAINED COMPOUND OF FORMULA II BY NICHEL-RANEY ALLOY IN THE PRESENCE OF CAUSTIC ALKALIS. 2-(BIS(3-R1,4-HO,5-R2-PHENYL)-CH-)PYRIDINE WHERE R1 AND R2 REPRESENT A HALOGEN OR HYDROGEN ATOM AND AT LEAST ONE OF THE SUBSTITUENTS R1 AND R2 IS A HALOGEN ATOM-WITH FORMATION OF A COMPOUND OF GENERAL FORMULA: 2-R1,6-R2-PHENOL
Inventors
- 👤 Gianfranco Pala
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 01:06
CPC Classifications
C; C07; C07D; C07D213/00; C07D213/02; C07D213/04; C07D213/24; C07D213/28; C07D213/30
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) | 1974-01-25 | 1974-07-27 | 1975-01-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-25 | 1978-07-27 | 1979-01-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-25 | 1982-07-27 | 1983-01-26 | $7700.00 | Window Closed / Lapsed |