US3586673A
Expired / Lapsed
US
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Preparation of symmetrically and unsymmetrically substituted stilbenebisbenzoxazoles
Assignee: Eastman Kodak Co
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Filing: 1968-02-05
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Granted: 1971-06-22
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Expires: 1988-02-05
Abstract
Abstract PROCESS FOR THE PREPARATION OF BOTH SYMMETRICAL AND UNSYMMETRICAL 4,4''-SUBSTITUTED STILBENE DERIVATIVES, HAVING 2-BENZOXAZOLYL, 2-BENZIMIDAZOLYL, OR 2-BENZOTHIAZOLYL SUBSTITUENTS. THE PROCESS COMPRISES FIRST REACTING A DIALKYL 4SUBSTITUTED BENZYLPHOSPHONATE WITH A 4-SUBSTITUTED BENZALDEHYDE TO FORM THE CORRESPONDING 4-HETEROCYCLIC-4''-CARBONYLSTILBENE COMPOUND, WHICH IS THEN TREATED WITH AN ACYL HALOGENATING AGENT TO FORM THE 4-HETEROCYCLIC-4''STILBENECARBONYL HALIDE. THE HALIDE IS THEN REACTED WITH AN O-AMINO-PHENYLENE COMPOUND TO FORM THE SUBJECT STILBENE DERIVATIVES. THESE STILBENE DERIVATIVES ARE USEFUL AS OPTICAL BRIGHTENERS.
Inventors
- 👤 Melvin S Bloom
- 👤 James A Hill
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 20:15
CPC Classifications
C; C07; C07D; C07D263/00; C07D263/52; C07D263/62; C07D263/64; C07D235/00; C07D235/02; C07D235/04; C07D235/18; C07D235/20; C07D277/00; C07D277/60; C07D277/62; C07D277/64; C07D277/66
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-06-21 | 1974-12-21 | 1975-06-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-21 | 1978-12-21 | 1979-06-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-21 | 1982-12-21 | 1983-06-22 | $7700.00 | Window Closed / Lapsed |