Patent US2809196A successfully refreshed from Google Patents.
US2809196A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Synthesis of piperazine
Assignee: EIDP Inc
•
Filing: 1955-08-30
•
Granted: 1957-10-08
•
Expires: 1975-08-30
Abstract
No abstract record available.
Inventors
- 👤 William R Miller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 01:10
CPC Classifications
C; C07; C07D; C07D295/00; C07D295/02; C07D295/023
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
65 words
A PROCESS FOR PREPARING PIPERAZINE WHICH COMPRISES HYDROGENATING IMINODIACETONITRILE UNDER A HYDROGEN PRESSURE OF 3000 TO 5000P.S.I.G. AT A TEMPERATURE IN THE RANGE OF ABOUT 75*C. TO NOT MORE THAN 125*C. IN A REACTION SOLVENT COMPRISING AT LEAST 5% BY WEIGHT OF AMMONIA IN THE PRESENCE OF A RANEY NICKEL CATALYST, THE CONCENTRATION OF IMINODIACETONITRILE IN THE SOLVENT BEING ABOUT 5 TO 15% BY WEIGHT.
Claim 2
Dependent Claim
65 words
A PROCESS FOR PREPARING PIPERAZINE WHICH COMPRISES HYDROGENATING IMINODIACETONITRILE UNDER A HYDROGEN PRESSURE OF 3000 TO 5000P.S.I.G. AT A TEMPERATURE IN THE RANGE OF ABOUT 75*C. TO NOT MORE THAN 125*C. IN A REACTION SOLVENT COMPRISING AT LEAST 5% BY WEIGHT OF AMMONIA IN THE PRESENCE OF A RANEY NICKEL CATALYST, THE CONCENTRATION OF IMINODIACETONITRILE IN THE SOLVENT BEING ABOUT 5 TO 15% BY WEIGHT.
References Cited (Backward Citations)
US2605263A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-10-07 | 1961-04-08 | 1961-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-10-07 | 1965-04-08 | 1965-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-10-07 | 1969-04-08 | 1969-10-08 | $7700.00 | Window Closed / Lapsed |