US4480102A
Expired / Lapsed
US
⏱️ 0.0 years remaining
2,3-Difluoro-5-(trifluoromethyl)pyridine and methods of making and using the same
Assignee: Dow Chemical Co
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Filing: 1982-07-23
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Granted: 1984-10-30
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Expires: 2002-07-23
Abstract
Abstract Novel 2,3-difluoro-5-(trifluoromethyl)pyridine is prepared by fluorinating 3-chloro-2-fluoro-5-(trifluoromethyl)pyridine under favorable conditions. The compound is useful as a chemical intermediate in the preparation of herbicides.
Inventors
- 👤 John A. Werner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 08:16
CPC Classifications
C; C07; C07D; C07D213/00; C07D213/02; C07D213/04; C07D213/60; C07D213/62; C07D213/63; C07D213/64; C07D213/643; C07D213/61
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
25 words
A method of preparing 2,3-difluoro-5-(trifluoromethyl)pyridine which comprises reacting 3-chloro-2-fluoro-5-(trifluoromethyl)pyridine with CsF in the presence of a solvent at a temperature greater than about 85° C.
Claim 2
Independent Claim
25 words
A method of preparing 2,3-difluoro-5-(trifluoromethyl)pyridine which comprises reacting 3-chloro-2-fluoro-5-(trifluoromethyl)pyridine with CsF in the presence of a solvent at a temperature greater than about 85° C.
Claim 3
Dependent Claim
13 words
The method of claim 1 wherein said solvent is dimethyl sulfoxide or sulfolane.
Claim 4
Dependent Claim
28 words
The method of claim 2 wherein said CsF is present in at least about an equimolar amount based on the molar amount of 3-chloro-2-fluoro-5-(trifluoromethyl)pyridine present in the reaction.
Claim 5
Dependent Claim
23 words
The method of claim 3 wherein said solvent is dimethyl sulfoxide and said temperature is between about 120° C. and about 140° C.
Claim 6
Dependent Claim
17 words
The method of claim 4 wherein said temperature is between about 120° C. and about 125° C.
Claim 7
Dependent Claim
18 words
The method of claim 5 further comprising the step of recovering the desired product from the reaction mixture.
Claim 8
Dependent Claim
22 words
The method of claim 3 wherein said solvent is sulfolane and said temperature is between about 150° C. and about 170° C.
Claim 9
Dependent Claim
18 words
The method of claim 7 further comprising the step of recovering the desired product from the reaction mixture.
Claim 10
Dependent Claim
22 words
The method of claim 1 wherein said 3-chloro-2-fluoro-5-(trifluoromethyl)pyridine is formed in situ by fluorinating 2,3-dichloro-5-(trifluoromethyl)pyridine in the 2-position of the pyridine ring.
Claim 11
Dependent Claim
15 words
The method of claim 1 wherein said 3-chloro-2-fluoro-5-(trifluoromethyl)pyridine is formed in situ by fluorinating 2,3-dichloro-5-(trichloromethyl)pyridine.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-10-30 | 1988-04-30 | 1988-10-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-30 | 1992-04-30 | 1992-10-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-30 | 1996-04-30 | 1996-10-30 | $7700.00 | Window Closed / Lapsed |