67640-39-5Relevant articles and documents
Halex reactions of aromatic compounds catalysed by 2-azaallenium, carbophosphazenium, aminophosphonium and diphosphazenium salts: A comparative study
Pleschke, Axel,Marhold,Schneider,Kolomeitsev,R?schenthaler
, p. 1031 - 1038 (2007/10/03)
An increasing number of biologically active compounds in the pharma and agro-chemical sector contain carbon fluorine bonds. One of the most common methods to introduce fluorine into intermediates is the well-investigated halogen-exchange reaction, in which chloro- and bromoaromatics activated towards nucleophilic substitution, react with a fluoride source to yield the corresponding fluoroarenes. In general, the reaction is supported by phase-transfer catalysts. The use of a new class of very active phase-transfer catalysts gives the possibility of substituting even halogens with weak activation giving a convenient access to interesting compounds that are not available so far and opening up new synthetic routes in Halex chemistry. Our new classes of catalysts, CNC+ (1a), PNC+ (2a) and several different approaches presented by other groups are described and experimental results discussed.
Process for the preparation of difluorobenzenes
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, (2008/06/13)
Difluorobenzene is prepared by a multistep process involving fluorination of dichlorobenzoyl chloride to provide difluorobenzoyl fluoride, conversion thereof to difluorobenzoyl chloride, hydrogenation of this to difluorobenzaldehyde and decarbonylation of the aldehyde to difluorobenzene.
