Patent US3249613A successfully refreshed from Google Patents.
US3249613A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dimethylpiperazine production
Assignee: Jefferson Chemical Co Inc
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Filing: 1963-11-01
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Granted: 1966-05-03
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Expires: 1983-11-01
Abstract
No abstract record available.
Inventors
- 👤 Simon P Burns
- 👤 Philip H Moss
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 19:51
CPC Classifications
C; C07; C07D; C07D295/00; C07D295/02; C07D295/023
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
80 words
A METHOD FOR PREPARING 1,4-DIMETHYLPIPERAZINE WHICH COMPRISES: (A) ADDING A SOLUTION OF PIPERAZINE IN AN INERT SOLVENT TO AT LEAST ABOUT A 10% EXCESS OF FORMALDEHYDE IN AN INERT SOLVENT TO THEREBY OBTAIN 1,4-PIPERAZINEDIMETHANOL, SAID PIPERAZINE CONSTITUTING LESS THAN ABOUT 18 WT. PERCENT OF THE REACTION MIXTURE; AND (B) HYDROGENATING THE 1,4-PIPERAZINEDIMETHANOL TO 1,4DIMETHYLPIPERAZINE EMPLOYING A METALLIC HYDROGENATION CATALYST AT A TEMPERATURE OF FROM ABOUT 50* TO ABOUT 200*C. AND A PRESSURE OF FROM AOUT 50 TO ABOUT 3000 P.S.I.G.
Claim 2
Independent Claim
80 words
A METHOD FOR PREPARING 1,4-DIMETHYLPIPERAZINE WHICH COMPRISES: (A) ADDING A SOLUTION OF PIPERAZINE IN AN INERT SOLVENT TO AT LEAST ABOUT A 10% EXCESS OF FORMALDEHYDE IN AN INERT SOLVENT TO THEREBY OBTAIN 1,4-PIPERAZINEDIMETHANOL, SAID PIPERAZINE CONSTITUTING LESS THAN ABOUT 18 WT. PERCENT OF THE REACTION MIXTURE; AND (B) HYDROGENATING THE 1,4-PIPERAZINEDIMETHANOL TO 1,4DIMETHYLPIPERAZINE EMPLOYING A METALLIC HYDROGENATION CATALYST AT A TEMPERATURE OF FROM ABOUT 50* TO ABOUT 200*C. AND A PRESSURE OF FROM AOUT 50 TO ABOUT 3000 P.S.I.G.
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) | 1969-05-02 | 1969-11-01 | 1970-05-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-05-02 | 1973-11-01 | 1974-05-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-05-02 | 1977-11-01 | 1978-05-03 | $7700.00 | Window Closed / Lapsed |