Patent US3655694A successfully refreshed from Google Patents.
US3655694A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Novel alpha-pyrones
Assignee: EIDP Inc
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Filing: 1971-02-11
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Granted: 1972-04-11
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Expires: 1991-02-11
Abstract
Abstract CERTAIN NOVEL A-PYRONES ARE USEFUL INTERMEDIATES IN THE PREPARATION OF ETHANOOCTAHYDROPHENANTHRENE DERIVATIVES, WHICH ARE EFFECTIVE ANTIFERTILITY AGENTS. THE NOVEL PYRONES ARE MADE FROM APPROPRIATELY SUBSTITUTED A-TETRALONES BY REACTION WITH ETHYL ETHOXYMETHYLENECYANOACETATE IN GLYME IN THE PRESENCE OF SODIUM ETHOXIDE UNDER A NITROGEN ATMOSPHERE.
Inventors
- 👤 Kyu Tai Lee
- 👤 Joel G Whitney
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 15:34
CPC Classifications
C; C07; C07D; C07D311/00; C07D311/02; C07D311/78; C07D311/92
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) | 1975-04-11 | 1975-10-11 | 1976-04-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-11 | 1979-10-11 | 1980-04-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-11 | 1983-10-11 | 1984-04-11 | $7700.00 | Window Closed / Lapsed |