To supply a derivative having a 2-acyliminopyridinestructure and being represented by the following formula(I) in an amount required as a pest control agent stablyand at a low cost, provided is a method comprising the stepsof: acylating an amino group at position 2 of a compoundrepresented by formula (A) by use of an acylating agent,to thereby produce a compound represented by formula (B)；and further alkylating a nitrogen atom at position 1 ofthe compound represented by formula (B):(see formula A) (see formula B) (see formula I)[where Ar represents a phenyl group or a 5-to 6-memberedheterocycle, R1 represents a C1-6 alkyl group, and Yrepresents a hydrogen atom； a halogen atom； a hydroxylgroup； a C1-6 alkyl group which may be substituted with ahalogen atom； a C1-6 alkyloxy group which may be substitutedwith a halogen atom； a cyano group； a formyl group； or anitro group].
