US3794647A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for purifying lactams
Assignee: Inventa AG fuer Forschung und Patentverwertung
•
Filing: 1971-09-22
•
Granted: 1974-02-26
•
Expires: 1991-09-22
Abstract
Abstract A PROCESS FOR THE PURIFICATION OF LACTAMS OF EXTRACTION WHEREIN THE LACTAM IS TREATED IN THE CRYSTALLINE STATE WITH A SOLVENT CAPABLE OF DISSOLVING THE IMPURITIES SELECTIVELY.
Inventors
- 👤 R Henn
- 👤 H Schultze
- 👤 C Berther
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 16:29
CPC Classifications
C; C07; C07D; C07D201/00; C07D201/16
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
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) | 1977-02-25 | 1977-08-27 | 1978-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-25 | 1981-08-27 | 1982-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-25 | 1985-08-27 | 1986-02-26 | $7700.00 | Window Closed / Lapsed |