Malononitrile

Malononitrile, also propanedinitrile, is a nitrile, with formula CH2(CN)2. Malononitrile is relatively acidic, with an pKa of 11 in water. This allows it to be used in the Knoevenagel condensation, for example in the preparation of CS gas:



In related chemistry, malononitrile is a suitable starting material for the Gewald reaction, where the nitrile condenses with a ketone or aldehyde in the presence of elemental sulfur and a base to produce a 2-aminothiophene.