Patent US3660397A successfully refreshed from Google Patents.
US3660397A
Expired / Lapsed
US
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Imidazo(4 5-b)pyrazines
Assignee: Merck and Co Inc
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Filing: 1970-04-17
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Granted: 1972-05-02
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Expires: 1990-04-17
Abstract
Abstract IMIDAZO(4,5,B) PYRAZINES BEATING A HYDROGEN OR HYDROCARBYL SUBSTITUENT IN THE TWO POSITION ARE PREPARED BY CYCLIZATION OF A 2-AMINO-3-ACYLAMINO PYRAZINE.
Inventors
- 👤 James H Jones
- 👤 Edward J Cragoe Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:57
CPC Classifications
C; C07; C07D; C07D487/00; C07D487/02; C07D487/04; C07D241/00; C07D241/02; C07D241/10; C07D241/14; C07D241/20; C07D241/24; C07D241/26
Claims Analysis
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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) | 1975-05-02 | 1975-11-01 | 1976-05-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-02 | 1979-11-01 | 1980-05-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-02 | 1983-11-01 | 1984-05-02 | $7700.00 | Window Closed / Lapsed |