Patent US5053542A successfully refreshed from Google Patents.
US5053542A
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Catalytic bromination of 2-fluoroaniline
Assignee: Mallinckrodt Chemical Inc
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Filing: 1990-01-31
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Granted: 1991-10-01
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Expires: 2010-01-31
Abstract
Abstract A process for the production of 2,4-dihaloaniline, especially 4-bromo-2-fluoroaniline, via the halogenation (bromination) of 2-haloaniline (2-fluoroaniline) in the presence of quaternary ammonium halide (bromide) catalyst in an inert solvent. The yield and selectivity are very high and the inventive method includes continuous processing with recycle of the catalyst/solvent mixture.
Inventors
- 👤 Jerry R. Patton
- 👤 Narayanasamy Gurusamy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 12:02
CPC Classifications
C; C07; C07C; C07C209/00; C07C209/68; C07C209/74; Y; Y02; Y02P; Y02P20/00; Y02P20/50; Y02P20/582; Y02P20/584
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
29 words
A process for the production of 2,4-dihaloaniline comprising halogenating 2-haloaniline with a halogenating agent in the presence of a quaternary ammonium halide and neutralizing the resulting 2,4-dihaloaniline hydrohalide salt.
Claim 2
Dependent Claim
29 words
A process for the production of 2,4-dihaloaniline comprising halogenating 2-haloaniline with a halogenating agent in the presence of a quaternary ammonium halide and neutralizing the resulting 2,4-dihaloaniline hydrohalide salt.
Claim 3
Dependent Claim
13 words
A process according to claim 1 wherein the halogenating agent is molecular halogen.
Claim 4
Dependent Claim
26 words
A process according to claim 2 wherein the halogen of the quaternary ammonium halide is the same as the halogen of the molecular halogen halogenating agent.
Claim 5
Dependent Claim
29 words
A process for the production of 4-halo-2-fluoroaniline comprising halogenating 2-fluoroaniline with a halogenating agent in the presence of a quaternary ammonium halide and neutralizing the resulting 4-halo-2-fluoroaniline hydrohalide salt.
Claim 6
Dependent Claim
29 words
A process for the production of 4-halo-2-fluoroaniline comprising halogenating 2-fluoroaniline with a halogenating agent in the presence of a quaternary ammonium halide and neutralizing the resulting 4-halo-2-fluoroaniline hydrohalide salt.
Claim 7
Dependent Claim
16 words
A process according to claim 4 wherein said halogenating step is conducted in an inert solvent.
Claim 8
Dependent Claim
13 words
A process according to claim 5 wherein said inert solvent is methylene chloride.
Claim 9
Dependent Claim
24 words
A process according to claim 4 wherein said halogenating step comprises adding molecular halogen to 2-fluoroaniline and quaternary ammonium halide in an inert solvent.
Claim 10
Dependent Claim
12 words
A process of claim 7 wherein said inert solvent comprises methylene chloride.
Claim 11
Dependent Claim
23 words
A process of claim 4 wherein said neutralizing step comprises adding the 4-halo-2-fluoroaniline hydrohalide salt to an aqueous solution having a basic pH.
Claim 12
Dependent Claim
14 words
A process of claim 9 wherein said pH is between about 7 and 8.
Claim 13
Dependent Claim
36 words
A process for the preparation of 4-bromo-2-fluoroaniline, comprising: (a) providing a mixture of bromine and quaternary ammonium bromide in an inert solvent; (b) adding 2-fluoroaniline to said mixture; and (c) precipitating 4-bromo-2-fluoroaniline as its hydrobromide salt.
Claim 14
Dependent Claim
36 words
A process for the preparation of 4-bromo-2-fluoroaniline, comprising: (a) providing a mixture of bromine and quaternary ammonium bromide in an inert solvent; (b) adding 2-fluoroaniline to said mixture; and (c) precipitating 4-bromo-2-fluoroaniline as its hydrobromide salt.
Claim 15
Dependent Claim
21 words
A process of claim 11 wherein said mixture of step (a) comprises substantially equimolar amounts of bromine and quaternary ammonium bromide.
Claim 16
Dependent Claim
12 words
A process of claim 11 wherein said inert solvent comprises methylene chloride.
Claim 17
Dependent Claim
16 words
A process of claim 11 wherein said precipitating step (c) is conducted at about 20° C.
Claim 18
Dependent Claim
15 words
A process of claim 11 further comprising: (d) neutralizing said hydrobromide salt to yield 4-bromo-2-fluoroaniline.
Claim 19
Dependent Claim
46 words
A continuous process for the production of 4-bromo-2-fluoroaniline comprising: (a) adding 2-fluoroaniline to a mixture of bromine and quaternary ammonium bromide in an inert solvent to produce 4-bromo-2-fluoroaniline hydrobromide salt as a precipitate in a mother liquor; (b) recovering said precipitate and recycling said mother liquor.
Claim 20
Dependent Claim
46 words
A continuous process for the production of 4-bromo-2-fluoroaniline comprising: (a) adding 2-fluoroaniline to a mixture of bromine and quaternary ammonium bromide in an inert solvent to produce 4-bromo-2-fluoroaniline hydrobromide salt as a precipitate in a mother liquor; (b) recovering said precipitate and recycling said mother liquor.
References Cited (Backward Citations)
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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) | 1994-09-30 | 1995-04-01 | 1995-10-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-09-30 | 1999-04-01 | 1999-10-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-09-30 | 2003-04-01 | 2003-10-01 | $7700.00 | Window Closed / Lapsed |