Used to convert aromatic chlorides to the corresponding aromatic fluorides.
In chemistry, the Halex process is used to convert aromatic chlorides to the corresponding aromatic fluorides. The process entails Halide exchange, hence the name.[1] The reaction conditions call for hot (150-250 °C) solution of the aryl chloride and anhydrous potassium fluoride. Typical solvents are dimethylsulfoxide, dimethylformamide, and sulfolane. Potassium chloride is generated in the process. The reaction is mainly applied to nitro-substituted aryl chlorides. Sometimes more soluble fluorides, such as caesium fluoride and TBAF are used.[2]
The following reactions are practiced commercially in this manner:[3]
The nitro groups in the above compounds can be reduced to give the corresponding aniline. For example, selective hydrogenation of 4-fluoronitrobenzene gives 4-fluoroaniline. Thus, the Halex method provides access to a host of fluoroanilines.
For producing aryl fluorides, the Halex process is complementary to the Balz-Schiemann reaction and its variants.
^Furuya, Takeru; Klein, Johannes E. M. N.; Ritter, Tobias (2010). "C–F Bond Formation for the Synthesis of Aryl Fluorides". Synthesis: 1804–1821. doi:10.1055/s-0029-1218742. PMC 2953275.
In chemistry, the Halexprocess is used to convert aromatic chlorides to the corresponding aromatic fluorides. The process entails Halide exchange, hence...
Halex may refer to: The Halexprocess in chemistry Halex, a brand of electrical fitting from the Scott Fetzer Company Halex, a subsidiary of the British...
tri-n-butylphosphine have been found to be suitable catalysts as well. Halexprocess, also a salt metathesis, but for conversion of aryl chlorides to aryl...
Many commercial aryl fluorides are produced from aryl chlorides by the Halexprocess. The method is often used for aryl chlorides also bearing electron-withdrawing...
Finkelstein reaction, while for aromatic compounds it is known as the Halexprocess. R 3CCl + MF → R 3CF + MCl (M = Na, K, Cs) Alkyl monofluorides can be...
It will convert electron-deficient aryl chlorides to aryl fluorides (Halexprocess), although potassium fluoride is more commonly used. Due to the strength...
known as Hale End, as evidenced by the name of Hale End Library, and the Halex factory. Although postcode areas are not intended to define districts, it...
British Xylonite had established three subsidiaries - BX Plastics, Halex and Cascelloid. Halex was based in Highams Park, Hale End, in North London and made...
ceasefires and since 1997, demilitarisation has been part of the peace process and the military presence has been reduced. On 25 June 2007 the 2nd Battalion...
diversified by acquiring companies including PLM Products, the Adalet Co., the Halex Die Casting Co., and the Cleveland Wood Products Co. In 1964, Quikut, a...
the tins. This round drum-shaped design was developed in clear plastic by Halex Ltd., toothbrush manufacturers, after Hutton asked Sir. Laurence Merriam...