Adiponitrile: Adipic Acid and Ammonia over Silica Gel, Lazier 1939

Adipic acid vapour, carried in a large excess of ammonia over silica gel at 325–350 °C, loses water and becomes adiponitrile (Lazier, du Pont, US 2,144,340, 1939). In his Example I, 617 g of acid gave 337.5 g of nitrile. Adiponitrile is the step between adipic acid and the diamine for nylon. The picture: our diagram of vaporiser, catalyst tube and separator.