US3702854A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Synthesis of 2-phenyl benzofurans
Assignee: Individual
•
Filing: 1970-03-27
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Granted: 1972-11-14
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Expires: 1990-03-27
Abstract
Abstract FLAVYLIUM SALTS ARE CONVERTED INTO BENZOFURAN DERIVATIVES WHICH ARE UNSUBSTITUTED AT THE 3 POSITION. THE KEY ITEM OF THE SYNTHESIS IS THAT INTERMEDIATES ARE NOT ISOLATED: STEPS OF OXIDATION, ALKALI TREATMENT, AND ACID TREATMENT ARE APPLIED IN SEQUENCE WITHOUT ISOLATING ANY OF THE INTERMEDIATES WHEREBY THE DESIRED END PRODUCT IS OBTAINED DIRECTLY AND IN HIGH YIELD.
Inventors
- 👤 Leonard Jurd
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 09:38
CPC Classifications
C; C07; C07D; C07D307/00; C07D307/77; C07D307/78; C07D307/79; C07D307/80
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) | 1975-11-14 | 1976-05-15 | 1976-11-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-11-14 | 1980-05-15 | 1980-11-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-11-14 | 1984-05-15 | 1984-11-14 | $7700.00 | Window Closed / Lapsed |