Patent US2521679A successfully refreshed from Google Patents.
Patent US3830823A successfully refreshed from Google Patents.
US3830823A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the preparation of deethyleburnamonines
Assignee: CENTRE D ETUDES POUR L IND PHARMA FR
•
Filing: 1973-01-15
•
Granted: 1974-08-20
•
Expires: 1993-01-15
Abstract
Abstract THIS INVENTION RELATES TO A PROCESS FOR THE PREPARATION OF D,1-12-OXO-1,2,5,6,12,13,13A, 13B-OCTAHYDRO-3H-INDOLO (3,2,1-D,E)PYRIDO(3,2,1-I,J)1,5)NAPHTHYRIDINES, COMPRISING REACTING 2,3,4,6,7,12-HEXAHYDRO-INDOLO(2,3-A)QUINOLIZINE WITH AN ALKYL HALOACETATE, REACTING THE RESULTING COMPOUND WITH PRECHLORIC ACID, TO GIVE ETHYL 1-(1,2,3,4,6,7,HEXAHYDRO-IBDOLO(2,3-A) QUINOLIZINIUM) ACETATE PERCHLORATE, AND THEN CYCLIZING AND REDUCING THE RESULTING PERCHLORATE.
Inventors
- 👤 A Castaigne
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 14:04
CPC Classifications
C; C07; C07D; C07D471/00; C07D471/12; C07D471/14; C07D461/00
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) | 1977-08-19 | 1978-02-18 | 1978-08-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-19 | 1982-02-18 | 1982-08-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-19 | 1986-02-18 | 1986-08-20 | $7700.00 | Window Closed / Lapsed |