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Patent US3639418A successfully refreshed from Google Patents.
US3639418A
Expired / Lapsed
US
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Bishydantoins
Assignee: Bayer AG
•
Filing: 1968-02-19
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Granted: 1972-02-01
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Expires: 1988-02-19
Abstract
Abstract CARBOXYLIC ACID ESTERS CONTAINING HYDANTION OR THIOHYDANTION GROUPS WHICH CAN BE PREPARED BY REACTING AN ETHYLENE-1,2-CARBOXYLIC ACID DIESTER WITH A PRIMARY POLYAMINE TO YIELD AN AMINO SUCCINIC ACID GROUP CONTAINING INTERMEDIATE, FURTHER REACTING THE INTERMEDIATE WITH A MONOISO(THIO)CYANATE AND CYCLISING THE RESULTING REACTED INTERMEDIATE IMMEDIATELY OR SUBSEQUENTLY.
Inventors
- 👤 Rudolf Merten
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:47
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/0605; C08G73/0616; C07; C07D; C07D233/00; C07D233/54; C07D233/66; C07D233/72; C07D233/76; C08G18/00; C08G18/06; C08G18/28; C08G18/30; C08G18/38; C08G18/3819; C08G18/3821; C08G63/00; C08G63/68; C08G63/685; C08G63/6854; C08L; C08L75/00; Y; Y10; Y10S; Y10S260/00; Y10S260/34
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) | 1975-01-31 | 1975-08-02 | 1976-02-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-31 | 1979-08-02 | 1980-02-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-31 | 1983-08-02 | 1984-02-01 | $7700.00 | Window Closed / Lapsed |