240 PRACTICAL ORGANIC CHEMISTRY add in turn 5 g. of anhydrous sodium carbonate, 10 g. of potassium permanganate, and finally 5 ml. (5-5 g.) of benzyl chloride. Fit the flask with a reflux water-condenser, and boil the mixture gently for i-i£ hours, i.e., until the reaction is com-plete and the liquid running down from the condenser contains no oily drops of unchanged benzyl chloride. During this boiling, the permanganate is slowly reduced, and manganese dioxide separates as a dark brown precipitate. Now cool the flask, and add concentrated hydrochloric acid (about 50 ml.) cautiously until the mixture is strongly acid, and all the benzoic acid has been precipitated. Then add a 20% aqueous solution of crystalline sodium sulphite (about ioo ml.) slowly with shaking until the manganese dioxide is completely dissolved* and only the white precipitate of benzoic acid remains. When the mixture is quite cold, filter off the benzoic acid at the pump, and wash well with water. Recrystallise from boiling water. The benzoic acid is
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This note was uploaded on 09/19/2011 for the course CHM 2211 taught by Professor Castalleano during the Fall '06 term at University of Florida.