Synthesis of Acetonitrile [75-05-8]

Acetonitrile from Acetamide [75-05-8-A]            C2H3N

In a 100-ml round-bottom flask, 20 g of phosphorus pentoxide is mixed with 12 g of acetamide by shaking. The flask and reagents must be completely dry. Fit a short Liebig condenser (jacket length 300 mm) and use a test tube as a receiver. Heat the flask with a small, fan-shaped, luminous flame. The reaction sets in with foaming. After a few minutes, distill the acetonitrile by slightly stronger heating.
Add the crude product to a small separatory funnel with half its volume of water and add potassium carbonate until no more dissolves in the lower aqueous layer. Separate this layer. Place the acetonitrile in a 50-ml round-bottom flask, add a spatula-tip of phosphorus pentoxide, and distill (boiling point 82 °C). The yield is about 6 g.

Source: G. Simon - Practical Organic Chemistry, Cologne: Aulis Verlag Deubner & Co 1975
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Last updated: 12/07/2006

Acetonitrile from Dimethyl Sulfate and Potassium Cyanide [75-05-8-B]            C2H3N

Warning! Dimethyl sulfate and potassium cyanide are strong poisons. When working with these substances, protective gloves must be worn (dimethyl sulfate is absorbed through the skin). The synthesis must be carried out in a well-ventilated fume hood.

Procedure: In a 250-ml two-neck round-bottom flask, dissolve 65 g of potassium cyanide in 60 ml of water. Equip the flask with a KPG stirrer and a dropping funnel filled with 95 ml of dimethyl sulfate. Place the flask in an ice water bath and begin adding the dimethyl sulfate. Add the dimethyl sulfate in 3 portions with vigorous stirring, with a 10-minute waiting period between each addition. After all the ester has been added, remove the stirrer and dropping funnel and fit the flask with a distillation apparatus. Seal the second neck of the flask with a hollow glass stopper. Distill the acetonitrile from a boiling water bath (boiling point 82 °C).

Source: Walden, Chem. Ber., 40 (1907), 3215
Delivered by: Mephisto
Last updated: 12/07/2006

Other names: Acetic acid nitrile; Methyl cyanide