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US4443631A Expired / Lapsed US ⏱️ 0.0 years remaining

Selective halogenation of 2-fluoroaniline

Assignee: Pharmacia and Upjohn Co
•
Filing: 1982-01-18
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Granted: 1984-04-17
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Expires: 2002-01-18
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Abstract

Abstract Novel processes for making arylpropionic acids are described. One process comprises carboxylating particular Grignard compounds which are the products of a catalyzed reaction between corresponding arylmagnesium bromides and ethylene. Furthermore, the reaction making the particular Grignard compounds is itself novel. Also, an improved method is disclosed for making coupled aryl compounds useful as intermediates for making compounds having a pharmaceutical use. For example, particular biaryls may be used to make some of the Grignard compounds herein from which the arylpropionic acids are made. Finally, an improved bromination is disclosed giving high yields of 4-bromo-2-fluoroaniline, which is thereafter coupled with benzene, then used to make the arylmagnesium bromide reacted with ethylene to obtain the particular Grignard compound and subsequent desired arylpropionic acid, i.e. 2-(2-fluoro-4-biphenylyl)propionic acid.

Inventors

  • 👤 Amphlett G. Padilla

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-06 12:19
CPC Classifications
C; C07; C07C; C07C211/00; C07C211/43; C07C211/44; C07C211/52; C07C205/00; C07C205/07; C07C205/11; C07C205/12; C07C209/00; C07C209/68; C07C209/74

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 30 words
In a process comprising the bromination of 2-fluoroaniline, whereby high yields of 4-bromo-2-fluoroaniline are selectively obtained an improvement which comprises bromination in a solvent consisting essentially of dimethylformamide or dimethylacetamide.
Claim 2
Dependent Claim 30 words
In a process comprising the bromination of 2-fluoroaniline, whereby high yields of 4-bromo-2-fluoroaniline are selectively obtained an improvement which comprises bromination in a solvent consisting essentially of dimethylformamide or dimethylacetamide.
Claim 3
Dependent Claim 29 words
In a process comprising the chlorination of 2-fluoroaniline, whereby high yields of 4-chloro-2-fluoroaniline are obtained an improvement which comprises chlorination in a solvent consisting essentially of dimethylformamide or dimethylacetamide.
Claim 4
Dependent Claim 29 words
In a process comprising the chlorination of 2-fluoroaniline, whereby high yields of 4-chloro-2-fluoroaniline are obtained an improvement which comprises chlorination in a solvent consisting essentially of dimethylformamide or dimethylacetamide.
Claim 5
Dependent Claim 17 words
In a process according to claim 1 the brominating agent is dibromantin and the solvent is dimethylformamide.
Claim 6
Dependent Claim 19 words
In a process according to claims 1, 2 or 3 the bromination temperatures are from 0° to 50° C.

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) 1987-04-17 1987-10-17 1988-04-17 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1991-04-17 1991-10-17 1992-04-17 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1995-04-17 1995-10-17 1996-04-17 $7700.00 Window Closed / Lapsed

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