IN a 5-l. flask are placed 1 kg. of crystallized (hydrated) oxalic
acid, 1.66 kg. of 95 per cent ethyl alcohol, and 1.33 kg.
of carbon tetrachloride. The flask is then fitted with a fractionating
column, I meter long, to which is attached a condenser and an automatic
separator so arranged that the lighter liquid flows off to a receiver
(Fig. 1). The heavier liquid flows through a tower of anhydrous
potassium carbonate, and then returns to the reaction flask.
The bottom of the tower is connected with a small separatory funnel
through which any potassium carbonate solution, which flows from
the solid in the tower, may be withdrawn from time to time.
The mixture in the flask is slowly distilled. As soon as about 500 cc.
of the lighter liquid has collected, it is placed in a fractionating
apparatus and distilled, the material which boils up to 79'0 being
collected separately. This fraction, which consists principally
of alcohol, with a little carbon tetrachloride and moisture, is dried
with potassium carbonate and returned to the reaction mixture.
The higher fractions are redistilled.
The above process is continued until the distillate no longer separates
into two phases (about twenty-seven hours). The liquid in the flask
is then distilled with the use of a column until the temperature
of the vapor reaches 85'0; the residue is then distilled under
reduced pressure, and the fraction which boils at 106-107/25 mm.
is collected. The yield is 920-960 g. of a colorless liquid
(80-84 per cent of the theoretical amount).