Patent US2993889A successfully refreshed from Google Patents.
US2993889A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Separation of a lactam from an acid
Assignee: —
•
Filing: —
•
Granted: 1961-07-25
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Expires: 1978-07-25
Abstract
No abstract record available.
Inventors
No inventors recorded.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 18:17
CPC Classifications
C; C07; C07D; C07D201/00; C07D201/16; C07D201/02; C07D201/08
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
95 words
IN A PROCESS FOR THE SEPARATION OF A LACTAM FROM AN ACID REACTION MIXTURE WHEREIN THE ACID REACTION MIXTURE IS NEUTRALIZED AND THE RESULTING LACTAM-CONTAINING TOP LAYER IS SUBSEQUENTLY SEPARATED OFF AND EXTRACTED WITH AN ORGANIC SOLVENT, THE IMPROVEMENT WHICH COMPRISES NEUTRALIZING THE ACID REACTION MIXTURE TO AN EXTENT SUCH THAT THE PH OF THE RESULTING BOTTOM LAYER DOES NOT RISE ABOVE 5.5, THEREAFTER SEPARATING OFF THE LACTAM-CONTAINING TOP LAYER, AND FURTHER NEUTRALIZING SAID TOP LAYER TO SUCH AN EXTENT THAT THE PH OF THE AQUEOUS PHASE THEREIN REMAINS HIGHER THAN 5.0 THROUGHOUT THE EXTRACTION.
Claim 2
Dependent Claim
95 words
IN A PROCESS FOR THE SEPARATION OF A LACTAM FROM AN ACID REACTION MIXTURE WHEREIN THE ACID REACTION MIXTURE IS NEUTRALIZED AND THE RESULTING LACTAM-CONTAINING TOP LAYER IS SUBSEQUENTLY SEPARATED OFF AND EXTRACTED WITH AN ORGANIC SOLVENT, THE IMPROVEMENT WHICH COMPRISES NEUTRALIZING THE ACID REACTION MIXTURE TO AN EXTENT SUCH THAT THE PH OF THE RESULTING BOTTOM LAYER DOES NOT RISE ABOVE 5.5, THEREAFTER SEPARATING OFF THE LACTAM-CONTAINING TOP LAYER, AND FURTHER NEUTRALIZING SAID TOP LAYER TO SUCH AN EXTENT THAT THE PH OF THE AQUEOUS PHASE THEREIN REMAINS HIGHER THAN 5.0 THROUGHOUT THE EXTRACTION.
References Cited (Backward Citations)
US2605261A
Cited
GB708034A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-07-24 | 1965-01-23 | 1965-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-07-24 | 1969-01-23 | 1969-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-07-24 | 1973-01-23 | 1973-07-25 | $7700.00 | Window Closed / Lapsed |