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Preparation of aromatic fluoro compounds
T993005 Preparation of aromatic fluoro compounds
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Inventor: Staniland
Date Issued: April 1, 1980
Application: 06/022,597
Filed: March 19, 1979
Inventors: Staniland; Philip A. (Tewin Wood, GB2)
Assignee: Imperial Chemical Industries Limited (London, GB2)
Primary Examiner:
Assistant Examiner:
Attorney Or Agent:
U.S. Class: 1/1
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Abstract: The present invention relates to a process for the preparation of 4,4'-difluorobenzophenone. 4,4-difluorobenzophenone may be prepared by diazotization of 4,4'-diamino-diphenylmethane in anhydrous or concentrated aqueous hydrogen fluoride, decomposition of the diazonium fluoride thus produced to yield 4,4'-difluoro-diphenylmethane and oxidation of 4,4'-difluoro-diphenylmethane to yield 4,4'-difluorobenzophonone.Thus, according to the present invention, there is provided a process for the preparation of 4,4'-difluorobenzophenone which comprises the following steps:(1) diazotization of 4,4'-diamino-diphenylmethane in anhydrous or concentrated aqueous hydrogen fluoride to yield a solution of a corresponding diazonium fluoride; and(2) (i) thermally decomposing the diazonium fluoride in the solution thus produced to yield 4,4'-difluoro-diphenylmethane and (ii) subsequently oxidizing the 4,4'-difluoro-diphenylmethane to yield 4,4'-difluorobenzophenone.
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