US4845218A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of n-methylpiperazine
Assignee: BASF SE
•
Filing: 1987-02-17
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Granted: 1989-07-04
•
Expires: 2007-02-17
Abstract
Abstract A process for the preparation of N-methylpiperazine from diethanolamine and methylamine, wherein the reaction is carried out at elevated temperature and superatmospheric pressure in the presence of hydrogen over a metal-containing catalyst.
Inventors
- 👤 Wolfgang Schroeder
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 16:51
CPC Classifications
C; C07; C07D; C07D295/00; C07D295/02; C07D295/023
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
50 words
A process for the preparation of N-methylpiperazine from diethanolamine and methylamine which comprises: reacting diethanolamine with methylamine at, from the beginning of the reaction, an elevated temperature of 180° to 230° C. and a superatmospheric pressure of 50 to 300 bar in the presence of hydrogen, over a metal-containing catalyst.
Claim 2
Dependent Claim
50 words
A process for the preparation of N-methylpiperazine from diethanolamine and methylamine which comprises: reacting diethanolamine with methylamine at, from the beginning of the reaction, an elevated temperature of 180° to 230° C. and a superatmospheric pressure of 50 to 300 bar in the presence of hydrogen, over a metal-containing catalyst.
Claim 3
Dependent Claim
16 words
The process of claim 1, wherein the reaction is carried out in a substantially liquid phase.
Claim 4
Dependent Claim
12 words
The process of claim 1, wherein an excess of methylamine is employed.
Claim 5
Dependent Claim
11 words
The process of claim 1, wherein a copper-containing catalyst is employed.
Claim 6
Dependent Claim
20 words
The process of claim 1, wherein a molar ratio of diethanolamine to monomethylamine of from 1:5 to 1:20 is employed.
References Cited (Backward Citations)
US2911407A
Cited
US2525223A
Cited
US3037023A
Cited
US3112318A
Cited
GB902570A
Cited
GB1319495A
Cited
DE1953263A1
Cited
DE2531060A1
Cited
US3948900A
Cited
DE2445303A1
Cited
NL7605640A
Cited
GB1491390A
Cited
US4009124A
Cited
DE3125662A1
Cited
EP0137478A2
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-07-03 | 1993-01-02 | 1993-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-07-03 | 1997-01-02 | 1997-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-07-03 | 2001-01-02 | 2001-07-04 | $7700.00 | Window Closed / Lapsed |