Synthetic method for isobutyl succinonitrile

The invention discloses a synthetic method for isobutyl succinonitrile and relates to the technical field of preparation of carboxylic nitrile compounds. The synthetic method comprises the following steps: A, synthesis of 5-methyl-2-cyano-2-hexenate IV: adding isovaleraldehyde II, cyano acetate III and a catalyst into acetic acid and carrying out stirring reaction at the reaction temperature of 0-30 DEG C to obtain the 5-methyl-2-cyano-2-hexenate IV; and B, synthesis of isobutyl succinonitrile I: adding the 5-methyl-2-cyano-2-hexenate IV and the catalyst into an ROH alcohol solvent, then adding HCN, controlling the temperature at 20-80 DEG C, and carrying out stirring reaction to obtain a product isobutyl succinonitrile I, wherein R is methyl or ethyl. The synthetic method disclosed by the invention is mild in reaction condition and high in yield, and the byproduct alcohol can be applied to a reaction solvent; the synthetic method is low in cost, meets the environmental requirements and is suitable for industrial production.