US3549633A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparation of 1-h-imidazo (4,5-b)pyrazin-2-ones
Assignee: Merck and Co Inc
•
Filing: 1968-11-20
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Granted: 1970-12-22
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Expires: 1988-11-20
Abstract
No abstract record available.
Inventors
- 👤 Edward J J Grabowski
- 👤 Edward W Tristram
- 👤 Roger J Tull
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 17:35
CPC Classifications
C; C07; C07D; C07D487/00; C07D487/02; C07D487/04; C07D241/00; C07D241/02; C07D241/10; C07D241/14; C07D241/24; C07D241/26
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US3410850A
Cited
US3361748A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-12-21 | 1974-06-22 | 1974-12-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-12-21 | 1978-06-22 | 1978-12-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-12-21 | 1982-06-22 | 1982-12-22 | $7700.00 | Window Closed / Lapsed |