US2639284A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process of preparing monomethyl
Assignee: —
•
Filing: —
•
Granted: 1953-05-19
•
Expires: 1970-05-19
Abstract
No abstract record available.
Inventors
No inventors recorded.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 09:17
CPC Classifications
—
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
30 words
A PROCESS OF MAKING N-MONOMETHYLPIPERAZINE WHICH COMPRISES REACTING PIPERAZINE WITH FORMALDEHYDE, THEREBY FORMING POLYMETHYLENEPIPERAZINE, SBUJECTING SAID POLYMETHYLENEPIPERAZINE TO HYDROGENOLYSIS, THEREBY FORMING NMONOMETHYLPIPERAZINE, AND SEPARATING SAID NMONOMETHYLPIPERAZINE FROM THE REACTION MIXTURE.
Claim 2
Dependent Claim
30 words
A PROCESS OF MAKING N-MONOMETHYLPIPERAZINE WHICH COMPRISES REACTING PIPERAZINE WITH FORMALDEHYDE, THEREBY FORMING POLYMETHYLENEPIPERAZINE, SBUJECTING SAID POLYMETHYLENEPIPERAZINE TO HYDROGENOLYSIS, THEREBY FORMING NMONOMETHYLPIPERAZINE, AND SEPARATING SAID NMONOMETHYLPIPERAZINE FROM THE REACTION MIXTURE.
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) | 1956-05-18 | 1956-11-17 | 1957-05-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-05-18 | 1960-11-17 | 1961-05-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-05-18 | 1964-11-17 | 1965-05-19 | $7700.00 | Window Closed / Lapsed |