US2662080A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for producing derivatives of hexahydropyrimidine and converting the same to 1, 3-diamines
Assignee: Shell Development Co
•
Filing: 1952-01-04
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Granted: 1953-12-08
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Expires: 1972-01-04
Abstract
No abstract record available.
Inventors
- 👤 Curtis W Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 06:01
CPC Classifications
C; C07; C07D; C07D239/00; C07D239/02; C07D239/06; C07D239/08; C07D239/10
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
23 words
IN A METHOD FOR PRODUCING 1,3-PROPANEDIAMINES, THE STEPS COMPRISING REACTING ACROLEIN WITH A MOLAR EXCESS OF A UREA-TYPE COMPOUND OF THE GENERAL STRUCTURE
References Cited (Backward Citations)
US2374485A
Cited
US2486648A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-12-07 | 1957-06-08 | 1957-12-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-12-07 | 1961-06-08 | 1961-12-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-12-07 | 1965-06-08 | 1965-12-08 | $7700.00 | Window Closed / Lapsed |