What is "malononitrile"

n. (context chemistry English) A nitrile with the chemical formula CH₂(CN)₂.

Malononitrile, also propanedinitrile, is a nitrile with the formula CH(CN). Malononitrile is relatively acidic, with a pK 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-amino thiophene.