Patent US4021805A successfully refreshed from Google Patents.
EP0192287A2
Expired / Lapsed
EP
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Process for the preparation of fluorinated pyridines
Assignee: Shell Internationale Research Maatschappij BV
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Filing: 1986-01-27
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Granted: —
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Expires: 2006-01-27
Abstract
Abstract Process for the preparation of fluorinated pyridines in which a chlorine-containing pyridine derivative is contacted at elevated temperature with an alkali-metal fluoride in a solvent wherein the solvent comprises a mixture of at least one aprotic amide and at least one aromatic hydrocarbon.
Inventors
- 👤 Paulus Alexander Maria Grotenhuis
- 👤 Peter Ernst Prillwitz
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 01:16
CPC Classifications
C; C07; C07D; C07D213/00; C07D213/02; C07D213/04; C07D213/60; C07D213/72; C07D213/73; C07D213/61
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
44 words
Process for the preparation of a fluorinated pyridine in which a chlorine-containing pyridine derivative is contacted at elevated temperature with an alkali-metal fluoride in a solvent, wherein the solvent comprises a mixture of at least one aprotic amide and at lest one aromatic hydrocarbon.
Claim 2
Dependent Claim
44 words
Process for the preparation of a fluorinated pyridine in which a chlorine-containing pyridine derivative is contacted at elevated temperature with an alkali-metal fluoride in a solvent, wherein the solvent comprises a mixture of at least one aprotic amide and at lest one aromatic hydrocarbon.
Claim 3
Dependent Claim
13 words
Process according to claim 1, in which the chlorine-containing pyridine derivative is pentachloropyridine.
Claim 4
Dependent Claim
15 words
Process according to claim 1 or 2, in which the alkali-metal fluoride is potassium fluoride.
Claim 5
Dependent Claim
30 words
Process according to any of claims 1 to 3, in which the molar ratio of alkali-metal fluoride and chlorine atoms to be replaced is in the range 1:1 and 1.3:1.
Claim 6
Dependent Claim
20 words
5 Process according to any one of claims 1 to 4, in which the aprotic amide is N-methylpyrrolidone or N,N-dimethylacetamide.
Claim 7
Dependent Claim
17 words
Process according to any one of claims 1 to 5, in which the aromatic hydrocarbon is toluene.
Claim 8
Dependent Claim
29 words
Process according to any one of claims 1 to 6, in which the weight ratio of aprotic amide to aromatic hydrocarbon is in the range from 65:35 to 20:80.
Claim 9
Dependent Claim
27 words
Process according to any of claims 1 to 7, in which the solvent is present in an amount from 170 to 750g per mol of alkali-metal fluoride.
Claim 10
Dependent Claim
22 words
Process according to any of claims 1 to 8, in which the elevated temperature is in the range from 90 to 170°C.
Claim 11
Dependent Claim
21 words
Process according to any of claims 1 to 9, in which a phase transfer catalyst is included in the reaction mixture.
Claim 12
Dependent Claim
18 words
Process according to claim 10, in which the phase transfer catalyst is tetra (C 1-4 alkyl) ammonium halide.
Claim 13
Dependent Claim
52 words
Process according to any of claims 1 to 11 wherein the fluorinated pyridine is difluorcpyridine, in which pentachloropyridine is contacted at elevated temperature with alkali-metal fluoride in a molar ratio alkali metal fluoride: pentachloropyridine in the range 3:1 to 3.9:1 in the solvent, followed by treatment of the resulting 3,5-dichloro-2,46-trifluoropyridine with ammonia.
References Cited (Backward Citations)
No citation records indexed.
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