US3287451A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the preparation of 2, 3-dichloropyrazine
Assignee: Pfizer Italia SRL
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Filing: 1964-11-09
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Granted: 1966-11-22
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Expires: 1984-11-09
Abstract
No abstract record available.
Inventors
- 👤 Carrara Adolfo
- 👤 Leone Anselmo
- 👤 Fabris Danilo
Bibliographic Details
Application Number
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Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 19:57
CPC Classifications
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Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
83 words
A PROCESS FOR THE PREPARATION OF 2,3-DICHLORPYRAZINE, WHICH COMPRISES REACTING PIPERAZINE HEXAHYDRATE DISSOLVED IN WATER WITH PHOSGENE, IN THE PRESENCE OF AN ACID ACCEPTOR, IN A CHLORINATED LOWER ALIPHATIC HYDROCARBON AT A TEMPERATURE BETWEEN -10* AND +20*C., PREFERABLY BETWEEN -5* AND 0*C., TO YIELD N,N''-BISCHLOROCARBONYLCHLORINE AT A TEMPERATURE OF FROM 150* TO 170*C., IN THE PRESENCE OF CATALYTIC AMOUNTS OF A COMPOUND SELECTED FROM THE GROUP CONSISTING OF ALUMINUM CHLORIDE, FERRIC CHLORIDE AND ANTIMONY CHLORIDE, FOR 9 TO 15 HOURS TO YIELD 2,3-DICHLOROPYRAZINE.
Claim 2
Dependent Claim
83 words
A PROCESS FOR THE PREPARATION OF 2,3-DICHLORPYRAZINE, WHICH COMPRISES REACTING PIPERAZINE HEXAHYDRATE DISSOLVED IN WATER WITH PHOSGENE, IN THE PRESENCE OF AN ACID ACCEPTOR, IN A CHLORINATED LOWER ALIPHATIC HYDROCARBON AT A TEMPERATURE BETWEEN -10* AND +20*C., PREFERABLY BETWEEN -5* AND 0*C., TO YIELD N,N''-BISCHLOROCARBONYLCHLORINE AT A TEMPERATURE OF FROM 150* TO 170*C., IN THE PRESENCE OF CATALYTIC AMOUNTS OF A COMPOUND SELECTED FROM THE GROUP CONSISTING OF ALUMINUM CHLORIDE, FERRIC CHLORIDE AND ANTIMONY CHLORIDE, FOR 9 TO 15 HOURS TO YIELD 2,3-DICHLOROPYRAZINE.
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) | 1969-11-21 | 1970-05-23 | 1970-11-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-11-21 | 1974-05-23 | 1974-11-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-11-21 | 1978-05-23 | 1978-11-22 | $7700.00 | Window Closed / Lapsed |