Patent US3775417A successfully refreshed from Google Patents.
US3775417A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Selective hydrogenation of tri-and tetrazoloisoquinolines
Assignee: Mallinckrodt Chemical Works
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Filing: 1971-08-05
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Granted: 1973-11-27
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Expires: 1991-08-05
Abstract
Abstract TRI- AND TETRAZOLOISOQUINOLINES, SUCH AS 3-AMINO-S-TRIAZOLO(3,4-A)ISOQUINOLINE OR 5 - METHYLTHIOTETRAZOLO(5,1-A) ISOQUINOLINE, ARE SELECTIVELY HYDROGENATED IN THE 5,6 POSITION AT A TEMPERATURE WITHIN THE RANGE OF FROM ABOUT 50* TO ABOUT 160*C. PROVIDED THAT THE TEMPERATURE SELECTED IS NOT MORE THAN ABOUT 50*C. HIGHER THAN THE TEMPERATURE AT WHICH HYDROGENATION IS FIRST OBSERVED, IN THE PRESENCE OF A CATALYTIC QUANITYT OF A NICKEL, PLATINUM, OR PALLADIUM HYDROGENATION CATALYST, FOR A PERIOD OF TIME AND AT A PRESSURE SUFFICIENT TO HYDROGENATE THE 5,6 POSITON.
Inventors
- 👤 Ruiter E De
- 👤 H Reimlinger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 02:46
CPC Classifications
C; C07; C07D; C07D471/00; C07D471/02; C07D471/04
Claims Analysis
Total Claims: 0
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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) | 1976-11-26 | 1977-05-28 | 1977-11-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-26 | 1981-05-28 | 1981-11-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-26 | 1985-05-28 | 1985-11-27 | $7700.00 | Window Closed / Lapsed |