US2992236A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of citraconic anhydride
Assignee: Pfizer Inc
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Filing: 1957-07-29
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Granted: 1961-07-11
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Expires: 1977-07-29
Abstract
No abstract record available.
Inventors
- 👤 Bavley Abraham
- 👤 Marshall F Humphrey
- 👤 Charles J Knuth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 01:01
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/54; C07C51/56
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-07-10 | 1965-01-09 | 1965-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-07-10 | 1969-01-09 | 1969-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-07-10 | 1973-01-09 | 1973-07-11 | $7700.00 | Window Closed / Lapsed |