PRODUCTION OF CYANOMETHYLENE-SUBSTITUTED HETEROCYCLIC COMPOUND

PROBLEM TO BE SOLVED: To obtain a compound useful as an intermediate for a medicine, an agrochemical, a dye, a resin, etc., without emitting an offensive substance as a by-product industrially and readily. SOLUTION: This cyanomethylene-substituted heterocyclic compound is shown by formula I (R is H, an alkyl, an alkenyl or an alkynyl) such as ethyl (E)-(1- ethyl-2-imidazolidinylidene)cyanoacetate. The compound of formula I is obtained by reacting a compound of formula II (A is ethylene or trimethylene; Z is an alkylsulfonyl, an alkylcarbonyl, etc.) such as ethyl (1,3-dioxolan-2-ylidene) cyanoacetate with an alkylenediamine of the formula R-NH-CH2 CH2 -NH2 such as ethylenediamine in an inert solvent such as hexane, etc., at -10 to 120 deg.C. The blending molar ratio of the reagents of the compound of formula II/the compound of formula III is preferably 0.2-1.2.