4'-Bromo-2,2,2-trifluoroacetophenone → 2-(4-Bromophenyl)-1,1,1-trifluoropropan-2-ol

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Reaction Conditions

Reaction Steps

A suspension of dichloro(dimethyl)titanium in a heptane/dichloromethane mixture was first prepared as follows: 100 ml (100 mmol) of a 1 M solution of titanium tetrachloride in dichloromethane were cooled to −30° C., 100 ml (100 mmol) of a 1 M solution of dimethylzinc in heptane were added dropwise and the mixture was stirred at −30° C. for a further 30 min. Subsequently, this suspension was cooled to −40° C. and a solution of 10 g (39.5 mmol) of 1-(4-bromophenyl)-2,2,2-trifluoroethanone in 50 ml of dichloromethane was added. The mixture was stirred at −40° C. for a further 5 min, then the temperature was allowed to come to RT and the mixture was stirred at RT for a further 2 h. While cooling with ice, 50 ml of water were slowly added dropwise and then the mixture was diluted with a further 300 ml of water. The mixture was extracted twice with dichloromethane, the combined dichloromethane phases were washed once with water, dried over anhydrous magnesium sulphate and filtered, and the solvent was removed on a rotary evaporator. The residue was purified by column chromatography on silica gel (eluent: 85:15 cyclohexane/ethyl acetate). 10.5 g (100% of theory) of the title compound were obtained, which, according to 1H NMR, still contained residues of solvent.

Provenance & Evidence