PRODUCTION OF MALONONITRILE

PROBLEM TO BE SOLVED: To produce malononitrile useful as a starting substance and an intermediate for producing an ingredient active as medicines and agrochemicals according to a method practicable on an industrial scale by converting a specific acetimidoyl halide at a temperature within a specific range. SOLUTION: A (2-cyano-N-alkoxy)acetimidoyl halide represented by formula I (R and R are each H or an alkyl; R is an alkyl, a cycloalkyl, an aryl or the like; X is a halogen) [e.g. (2-cyano-N-methoxy)acetimidoyl chloride] is converted at 500-1,000 deg.C, preferably 700-1,000 deg.C preferably in the presence of a hydrogen donor such as toluene usually in a tubular reactor generally for several s conversion time to produce the objective compound. The compound represented by formula I is obtained by halogenating a compound represented by formula II.