Halomethyl-metal compounds LV. The synthesis of phenyl(trifluoromethyl)mercury by fluorination of phenyl(tribromomethyl)mercury

Abstract

The reaction of phenylmercuric hydroxide with aqueous hydrofluoric acid gives a material which appears to be an HF adduct of phenylmercuric fluoride (“PhHgF·HF”). This material has been found to fluorine phenyl(tribromomethyl)-mercury in benzene or toluene medium at room temperature to give phenyl(trifluoromethyl)mercury in yields avaraging 60–65% when the reaction is carried out in the presence of 48% HF. Phenyl(trichloromethyl)mercury can be fluorinated to PhHgCF 3 in this manner, but a reaction temperature of 90° is required. Partial fluorination in good yield of phenyl(bromodichloromethyl)mercury to phenyl-(fluorodichloromethyl)mercury could be achieved at room temperature, but attempted partial fluorination of PhHgCBr 3, PhHgCClBr 2 and PhHgCFBr 2 was unsuccessful, PhHgCF 3 being the major product obtained. The possible mechanism of this novel fluorination process is discussed.