| 摘要 |
Aromatic carboxylic acid halides are made by reacting an aromatic carbocyclic compound having at least one unsubstituted hydrogen atom on the aromatic ring with a halocarbon or halohydrocarbon and carbon monoxide, in the presence of a catalyst comprising a metal which is capable of forming a carbonyl or carbonyl halide compound, particularly a metal of Group 8 of the periodic table, especially palladium, rhodium, osmium, platinum, ruthenium or iridium, or a compound of such a metal. Other suitable catalyst metals are copper, nickel, cobalt and iron. The halogen-substituted reactant is preferably a paraffin in which at least half of the hydrogen atoms have been replaced by halogen atoms, e.g., carbon tetrachloride, dichlorodibromomethane and tetrabromoethane. A pressure of CO in the range 1 to 3000 atm. and a temperature in the range 150-350 DEG C. may be used. A starting material containing a carboxylic acid or halide group may be used to give a di- or poly-acid halide.
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