Bis pentachlorophenyl methanol

A solution of pentachlorophenylmagnesium chloride is prepared from hexachlorobenzene (66 g, 0.23 mol) and magnesium (8.44 g, 0.35 mol) in a mixture of THF (150 ml) and benzene (150 ml) (HAZARD toluene would be preferable). The solution is heated to reflux, and ethyl formate (40 ml, excess) is added by syringe at such a rate that the exothermic reaction maintains refluxing. The mixture is stirred as it is allowed to cool to room temperature during 1 h. Methanol (20 ml) is added, and the solvents are evaporated. The resulting dark-brown residue is washed with hydrochloric acid, methanol and ethyl acetate, and then recrystallized from 4 1 toluene-pyridine, to give bis(pentachlorophenyl)methanol (35 g, 29%). 

Syntheses of tertiary alcohols by reactions of organomagnesium compounds with 

On the other hand, it is often desired to stop the reaction at the first stage, to synthesize a ketone. In this case, special conditions are required, in order to avoid the simultaneous presence of organomagnesium 

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