US2861994A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of 2,5-dimethylpiperazine
Assignee: Dow Chemical Co
•
Filing: 1956-02-23
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Granted: 1958-11-25
•
Expires: 1976-02-23
Abstract
No abstract record available.
Inventors
- 👤 Coker William Perkins
- 👤 Jr Greene Wallace Strother
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 17:47
CPC Classifications
C; C07; C07D; C07D295/00; C07D295/02; C07D295/023
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
49 words
METHOD WHICH COMPRISES SUBJECTING 2-AMINOPROPANOL-1 TO A RANEY NICKEL CATALYST MASS WHILE IT IS MAINTAINED, IN THE PRESENCE OF HYDROGEN, UNDER A PRESSURE BETWEEN ABOUT 750 AND 2,000 POUNDS PER SQUARE INCH AT A TEMPERATURE BETWEEN ABOUT 140*C. AND 220*C. TO CONVERT SUSTANTIAL PORTIONS OF THE 2-AMINOPROPANOL-1 TO 2,5DIMETHYLPIPERAZINE.
Claim 2
Dependent Claim
49 words
METHOD WHICH COMPRISES SUBJECTING 2-AMINOPROPANOL-1 TO A RANEY NICKEL CATALYST MASS WHILE IT IS MAINTAINED, IN THE PRESENCE OF HYDROGEN, UNDER A PRESSURE BETWEEN ABOUT 750 AND 2,000 POUNDS PER SQUARE INCH AT A TEMPERATURE BETWEEN ABOUT 140*C. AND 220*C. TO CONVERT SUSTANTIAL PORTIONS OF THE 2-AMINOPROPANOL-1 TO 2,5DIMETHYLPIPERAZINE.
References Cited (Backward Citations)
US2400022A
Cited
US2479657A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-11-24 | 1962-05-26 | 1962-11-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-11-24 | 1966-05-26 | 1966-11-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-11-24 | 1970-05-26 | 1970-11-25 | $7700.00 | Window Closed / Lapsed |