US2471047A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Synthesis of 4-hydroxycoumarins
Assignee: Wisconsin Alumni Research Foundation
•
Filing: 1947-02-21
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Granted: 1949-05-24
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Expires: 1967-02-21
Abstract
No abstract record available.
Inventors
- 👤 Mark A Stahmann
- 👤 Link Karl Paul
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 11:56
CPC Classifications
C; C07; C07D; C07D311/00; C07D311/02; C07D311/04; C07D311/42; C07D311/44; C07D311/46
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2349765A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1952-05-23 | 1952-11-22 | 1953-05-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1956-05-23 | 1956-11-22 | 1957-05-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1960-05-23 | 1960-11-22 | 1961-05-24 | $7700.00 | Window Closed / Lapsed |