Ethyl oxalate, which is also known as , ethyl ester, could be produced through the following synthetic routes.

In a 5-l. flask are placed 1 kg. (7.9 moles) of crystallized (hydrated) oxalic acid, 1.66 kg. (2034 cc.) of 95 per cent ethyl alcohol, and 1.33 kg. (887 cc.) of carbon tetrachloride. The flask is then fitted with a fractionating column, 1 meter long, to which are attached a condenser and an automatic separator so arranged that the lighter liquid flows off to a receiver (Fig. 13). 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small separatory funnel through which any potassium carbonate solution, which flows from the solid in the tower, may be withdrawn from time to time.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° 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°; 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 (80–83 per cent of the theoretical amount).