US2813869A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vapor phase synthesis of carbon-substituted pyrazines and piperazines
Assignee: Wyandotte Chemicals Corp
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Filing: 1957-03-29
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Granted: 1957-11-19
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Expires: 1977-03-29
Abstract
No abstract record available.
Inventors
- 👤 William K Langdon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 21:06
CPC Classifications
C; C07; C07D; C07D241/00; C07D241/02; C07D241/10; C07D241/12; C07D295/00; C07D295/02; C07D295/023
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
43 words
A METHOD FOR THE PREPARING CARBON-SUBSTITUTED PYRAZINES, CARBON-SUBSTITUTED PIPERAZINES AND MIXTURES THEREOF, WHICH COMPRISES, HEATING AN ALKANOLAMINE IN THE PRESENCE OF A COPPER HYDROGENATION/DEHYDROGENATION CATALYST IN THE VAPOR PHASE AT A TEMPERATURE IN THE RANGE FROM 175-400*C., SAID ALKANOLAMINE CORRESPONDING TO THE FORMULA
Claim 2
Independent Claim
43 words
A METHOD FOR THE PREPARING CARBON-SUBSTITUTED PYRAZINES, CARBON-SUBSTITUTED PIPERAZINES AND MIXTURES THEREOF, WHICH COMPRISES, HEATING AN ALKANOLAMINE IN THE PRESENCE OF A COPPER HYDROGENATION/DEHYDROGENATION CATALYST IN THE VAPOR PHASE AT A TEMPERATURE IN THE RANGE FROM 175-400*C., SAID ALKANOLAMINE CORRESPONDING TO THE FORMULA
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) | 1960-11-18 | 1961-05-20 | 1961-11-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-11-18 | 1965-05-20 | 1965-11-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-11-18 | 1969-05-20 | 1969-11-19 | $7700.00 | Window Closed / Lapsed |