US3758498A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of maleimides
Assignee: Hoechst AG
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Filing: 1971-03-22
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Granted: 1973-09-11
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Expires: 1991-03-22
Abstract
Abstract PREPARATION OF N-SUBSTITUTED MALEIMIDES BY HEATING THE CORRESPONDING N-SUBSTITUTED MALEAMIC ACIDS OR MONO-AMMONIUM MALEIC ACID SALTS IN THE PRESENCE OF STREAM TO A TEMPERATURE WITHIN THE RANGE OF FROM ABOUT 100* TO 400*C.
Inventors
- 👤 P Pfuller
- 👤 W Kuhn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 11:27
CPC Classifications
C; C07; C07D; C07D207/00; C07D207/02; C07D207/44; C07D207/444; C07D207/448; C08; C08F; C08F22/00; C08F22/36; C23; C23F; C23F11/00; C23F11/08; C23F11/10; C23F11/14; C23F11/145
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) | 1976-09-10 | 1977-03-12 | 1977-09-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-10 | 1981-03-12 | 1981-09-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-10 | 1985-03-12 | 1985-09-11 | $7700.00 | Window Closed / Lapsed |