US3661989A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing certain substituted bis-ureas
Assignee: Individual
•
Filing: 1967-05-31
•
Granted: 1972-05-09
•
Expires: 1987-05-31
Abstract
Abstract A PROCESS FOR PREPARING A COMPOUND HAVING THE FORMULA: (CH3-)2-N-CO-NH-R-NH-CO-N(-CH3)2 COMPRISING REACTING TWO MOLES OF DIMETHYL AMINE WITH ONE MOLE OF A DIISOCYANATE HAVING THE FORMULA: O=C=N-R-N=C=O WHEREIN R IN BOTH STRUCTURAL FORMULAE IS A DIVALENT AROMATIC RADICAL SELECTED FROM THE GROUP CONSISTING OF UNSUBSTITUTED PHENYLENE, METHYL SUBSTITUTED PHENYLENE, DIMETHYL DIPHENYLENE AND METHYLENE DIPHENYLENE WHEREIN SAID REACTION IS CARRIED OUT IN AN AQUEOUS MEDIUM AT A TEMPERATURE BETWEEN ABOUT 10*C. AND 30*C. AND WHEREIN THE INITIAL CONCENTRATION OF DIMETHYL AMINE IN SOLUTION IS BETWEEN ABOUT 10% AND 30%, BY WEIGHT, BASED ON THE WEIGHT OF THE SOLUTION.
Inventors
- 👤 Aleksandra Chrobok Nawakowski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 22:27
CPC Classifications
C; C07; C07C; C07C273/00; C07C273/18; C07C273/1809; C07C273/1818; C07C273/1827
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-05-09 | 1975-11-08 | 1976-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-09 | 1979-11-08 | 1980-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-09 | 1983-11-08 | 1984-05-09 | $7700.00 | Window Closed / Lapsed |