US4590315A
Expired / Lapsed
US
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Process for the preparation of halo aromatic compounds
Assignee: Occidental Chemical Corp
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Filing: 1984-10-15
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Granted: 1986-05-20
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Expires: 2004-10-15
Abstract
Abstract A process for the preparation of chloro-difluorobenzene compounds of the formula ##STR1## where R is CN or CF 3 , comprises the steps of (A) reacting an alkali metal fluoride with 4-chloro-3,5-dinitrobenzonitrile or 4-chloro-3,5-dinitrobenzotrifluoride to form the corresponding 4-fluoro-3,5-dinitrobenzonitrile or 4-fluoro-3,5-dinitrobenzotrifluoride product. (B) chlorodenitrating the 4-fluoro product of step (A) to form the corresponding 3,5-dichloro-4-fluorobenzonitrile or 3,5-dichloro-4-fluorobenzotrifluoride compound. (C) reacting the 3,5-dichloro-4-fluorobenzonitrile or 3,5-dichloro-4-fluorobenzotrifluoride compound prepared in step (B) with an alkali metal fluoride to form the corresponding 3-chloro-4,5-difluorobenzonitrile or 3-chloro-4,5-difluorobenzotrifluoride compound.
Inventors
- 👤 James J. Maul
- 👤 David Y. Tang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 08:18
CPC Classifications
C; C07; C07C; C07C255/00; C07C17/00; C07C17/093; C07C17/20; C07C17/202; C07C17/208
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
52 words
A process for the preparation of 3-chloro-4,5-difluorobenzotrifluoride which comprises the steps of (A) reacting an alkali metal fluoride with 4-chloro-3,5-dinitrobenzotrifluoride to form 4-fluoro-3,5-dinitrobenzotrifluoride; (B) chlorodenitrating the 4-fluoro product of step (A) to form 3,5-dichloro-4-fluorobenzotrifluoride; and (C) reacting the 3,5-dichloro-4-fluorobenzotrifluoride compound prepared in step (B) with an alkali metal fluoride to form 3-chloro-4,5-difluorobenzotrifluoride.
Claim 2
Dependent Claim
52 words
A process for the preparation of 3-chloro-4,5-difluorobenzotrifluoride which comprises the steps of (A) reacting an alkali metal fluoride with 4-chloro-3,5-dinitrobenzotrifluoride to form 4-fluoro-3,5-dinitrobenzotrifluoride; (B) chlorodenitrating the 4-fluoro product of step (A) to form 3,5-dichloro-4-fluorobenzotrifluoride; and (C) reacting the 3,5-dichloro-4-fluorobenzotrifluoride compound prepared in step (B) with an alkali metal fluoride to form 3-chloro-4,5-difluorobenzotrifluoride.
Claim 3
Dependent Claim
19 words
A process according to claim 1 wherein the alkali metal fluoride of steps (A) and (C) is potassium fluoride.
Claim 4
Dependent Claim
21 words
A process according to claim 1 wherein the reactions of steps (A) and (C) are carried out in the liquid phase.
Claim 5
Dependent Claim
18 words
A process according to claim 3 wherein the reactions of steps (A) and (C) are carried out neat.
Claim 6
Dependent Claim
23 words
A process according to claim 3 wherein the reactions of steps (A) and (C) are carried out in the presence of a solvent.
Claim 7
Dependent Claim
31 words
A process according to claim 3 wherein the reaction of step (A) is carried out in the presence of a solvent and the reaction of step (C) is carried out neat.
Claim 8
Dependent Claim
31 words
A process according to claim 3 wherein the reaction of step (A) is carried out neat and the reaction of step (C) is carried out in the presence of a solvent.
Claim 9
Dependent Claim
26 words
A process according to claim 7 wherein the chlorodenitration reaction of step (B) is carried out in the vapor phase by reacting Cl 2 with 4-fluoro-3,5-dinitrobenzotrifluoride.
Claim 10
Dependent Claim
20 words
A process according to claim 1 wherein the chlorodenitration reaction of step (B) is carried out in the vapor phase.
Claim 11
Dependent Claim
92 words
A process for the preparation of 3-chloro-4,5-difluorobenzotrifluoride which comprises the steps of (A) reacting potassium fluoride with 4-chloro-3,5-dinitrobenzotrifluoride in the liquid phase, at a temperature of about 75° to about 160° Celsius to form 4-fluoro-3,5-dinitrobenzotrifluoride; and (B) reacting the 4-fluoro-3,5-dinitrobenzotrifluoride product of step (A) with chlorine in the vapor phase at a temperature of about 290° to about 410° Celsius to form 3,5-dichloro-4-fluorobenzotrifluoride; and (C) reacting the 3,5-dichloro-4-fluorobenzotrifluoride product of step (B) with potassium fluoride in the liquid phase at a temperature of about 170° to about 270° Celsius to form 3-chloro-4,5-difluorobenzotrifluoride.
Claim 12
Dependent Claim
92 words
A process for the preparation of 3-chloro-4,5-difluorobenzotrifluoride which comprises the steps of (A) reacting potassium fluoride with 4-chloro-3,5-dinitrobenzotrifluoride in the liquid phase, at a temperature of about 75° to about 160° Celsius to form 4-fluoro-3,5-dinitrobenzotrifluoride; and (B) reacting the 4-fluoro-3,5-dinitrobenzotrifluoride product of step (A) with chlorine in the vapor phase at a temperature of about 290° to about 410° Celsius to form 3,5-dichloro-4-fluorobenzotrifluoride; and (C) reacting the 3,5-dichloro-4-fluorobenzotrifluoride product of step (B) with potassium fluoride in the liquid phase at a temperature of about 170° to about 270° Celsius to form 3-chloro-4,5-difluorobenzotrifluoride.
Claim 13
Dependent Claim
18 words
A process according to claim 10 wherein step (C) is carried out in the presence of a solvent.
Claim 14
Dependent Claim
11 words
A process according to claim 11 wherein the solvent is sulfolane.
Claim 15
Dependent Claim
20 words
A process according to claim 10 wherein step (A) is carried out in the presence of a phase transfer catalyst.
Claim 16
Dependent Claim
12 words
A process according to claim 13 wherein the catalyst is tetraphenylphosphonium chloride.
References Cited (Backward Citations)
US4388472A
Cited
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1989-05-19 | 1989-11-18 | 1990-05-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-05-19 | 1993-11-18 | 1994-05-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-05-19 | 1997-11-18 | 1998-05-20 | $7700.00 | Window Closed / Lapsed |