Hydrochloric Acid → 1-(3-Chloro-2-hydroxyphenyl)propan-1-one

Participants

Reaction Conditions

Reaction Steps

Anhydrous aluminum trichloride (130 g, 0.974 mol) in 150 ml of dry o-dichlorobenzene is cooled to 10° C. and 2-chlorophenyl propionate (100 g, 0.543 mol) is added slowly dropwise to this reaction mixture (15 minutes). The flask with the mixture is heated slowly in an oil bath to 110-120° C. At this temperature, HCl begins to evolve. The temperature is then raised slowly to 130-140° C. and the reaction mixture is held within this temperature range for three hours. After the oil bath has been removed and the batch has cooled, the excess aluminum chloride is broken down by addition of 350 g of crushed ice, followed by the addition of 50 ml of concentrated hydrochloric acid. After the reaction mixture has cooled, ethyl acetate (500 ml) is added. The organic phase is separated off and washed with saturated sodium hydrogen carbonate solution (500 ml) and brine (500 ml). After the organic phase has been dried and the solvent has been removed on a rotary evaporator, the residue is purified by chromatography on silica gel (eluent: toluene). This isolates 10 g (10%) of the desired compound and also 40 g (40%) of the corresponding regioisomer, 5′-chloro-3′-hydroxy propiophenone.

Provenance & Evidence