US2944944A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pyrrolmone purification
Assignee: —
•
Filing: —
•
Granted: 1960-07-12
•
Expires: 1977-07-12
Abstract
No abstract record available.
Inventors
No inventors recorded.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 03:27
CPC Classifications
C; C07; C07C; C07C17/00; C07C17/38; C07C17/395; C07D; C07D207/00; C07D207/02; C07D207/18; C07D207/22; C07D207/24; C07D207/26; C07D207/263; C07D207/267
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
32 words
THE PROCESS FOR THE PURIFICATION OF PYRROLIDONE, WHICH COMPRISES ADMIXING PHOSPHOROUS PENTOXIDE WITH CRUDE PYRROLIDONE, SUBJECTING THE MIXTURE TO DISTILLATION UNDER REDUCED PRESSURE, AND COLLECTING SUBSTANTIALLY NEUTRAL PURIFIED PYRROLIDONE IN THE DISTILLATE.
Claim 2
Dependent Claim
32 words
THE PROCESS FOR THE PURIFICATION OF PYRROLIDONE, WHICH COMPRISES ADMIXING PHOSPHOROUS PENTOXIDE WITH CRUDE PYRROLIDONE, SUBJECTING THE MIXTURE TO DISTILLATION UNDER REDUCED PRESSURE, AND COLLECTING SUBSTANTIALLY NEUTRAL PURIFIED PYRROLIDONE IN THE DISTILLATE.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-07-12 | 1964-01-11 | 1964-07-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-07-12 | 1968-01-11 | 1968-07-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-07-12 | 1972-01-11 | 1972-07-12 | $7700.00 | Window Closed / Lapsed |