5. The submitters state that the
dimethyl ether of quinacetophenone is conveniently prepared by the following procedure: In a 1-l. round-bottomed flask fitted with a reflux condenser
60 g. (0.39 mole) of quinacetophenone2 is dissolved in
300 ml. of ethanol by heating. The source of heat is then removed, and to the hot solution are alternately added in five installments with shaking a solution of
sodium hydroxide (40 g. in 100 ml. of water) and
dimethyl sulfate (120 g.). The heat evolved during the reaction makes the solution boil. After the addition is complete (about 20 minutes), the reaction mixture is made alkaline by the further addition of
10 g. of sodium hydroxide in 20 ml. of water and is allowed to reflux on the water bath for 3 hours. The dark mixture is distilled to remove most of the
ethanol, and the residual liquid in the flask is steam-distilled. The distillate, which amounts to about 2.5 l., is cooled in an
ice bath and saturated with
sodium chloride, whereupon a thick oil settles to the bottom. Most of the aqueous layer is decanted, and the remaining oil is extracted with
ether and dried over
calcium chloride. The
ether is removed by distillation, and the residue is fractionated at reduced pressure to give
50–52 g. (
71–74% yield) of material boiling at
152–156°/15 mm., m.p.
20–22°.