Patent US1889704A successfully refreshed from Google Patents.
US1889704A
Expired / Lapsed
US
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Compounds of the acridine series and process of making them
Assignee: Winthrop Chemical Co Inc
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Filing: 1929-11-15
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Granted: 1932-11-29
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Expires: 1949-11-15
Abstract
No abstract record available.
Inventors
- 👤 Schulemann Werner
- 👤 Mietzsch Fritz
- 👤 Wingler August
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 18:10
CPC Classifications
C; C07; C07D; C07D219/00; C07D219/04; C07D219/08; C07D219/10; C07D219/12
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) | 1935-11-29 | 1936-05-30 | 1936-11-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1939-11-29 | 1940-05-30 | 1940-11-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1943-11-29 | 1944-05-30 | 1944-11-29 | $7700.00 | Window Closed / Lapsed |