Aluminium lithium hydride → 2-(4-Chlorophenyl)-2,2-difluoroethanol

Participants

Reaction Conditions

Reaction Steps

Lithium aluminum hydride, 2.4 grams (0.063 mole), is placed in a reaction vessel, and 200 mL of diethyl ether is added dropwise with stirring. To this is added dropwise a solution of 22.8 grams (0.097 mole) of ethyl 4-chlorophenyldifluoroacetate (prepared by methods taught by W. J. Middleton et al., J. Org. Chem., (1980), 45, 2883-2887) in 100 mL of diethyl ether, while maintaining the reaction mixture temperature at about 25° C. Upon completion of addition, the reaction mixture is stirred at ambient temperature for about 36 hours. The reaction is then quenched by the careful dropwise addition of an aqueous solution of 10% sodium hydroxide. The reaction mixture is slowly made acidic with aqueous 2N hydrochloric acid and then is diluted with 200 mL of water. The organic layer is separated, and the aqueous layer is washed with two 300 mL portions of diethyl ether. The organic layer and the diethyl ether washes are combined and washed with one 250 mL portion of an aqueous solution saturated with sodium chloride. The organic layer is dried with magnesium sulfate and filtered. The filtrate is concentrated under reduced pressure, yielding 2,2-difluoro-2-(4-chlorophenyl)ethanol.

Provenance & Evidence