A method for producing a compound represented by formula (4) (Q, R1 and R2 being the same as those in formula (3)), comprises chemically reacting a compound represented by formula (3) with a hydroxylamine or a salt thereof, and subjecting a product of the chemical reaction to a dehydration reaction, (in which Q represents a substituted or unsubstituted 5- to 6-membered or 9- to 10-membered heteroaryl group, R1 represents a C1-6 alkyl group, and R2 represents a hydrogen atom, a substituted or an unsubstituted C1-6 alkyl group, a substituted or unsubstituted C3-6 cycloalkyl group, a substituted or unsubstituted phenyl group, or a substituted or unsubstituted 5- to 6-membered heteroaryl group), or chemically reacting a compound represented by formula (3) with an ammonia or an ammonium salt in the presence of an alcohol, and oxidizing a product of the chemical reaction in the presence of an organic oxidizing agent.