A 2-(N-methyl-N-methanesulfonylamino)pyrimidine compound of the formula (3): [R is a hydrocarbyl group], is prepared by the steps of: (I) reacting an isobutyrylacetate ester with 4-fluorobenzaldehyde and urea in the presence of a protonic compound and a metal salt; (II) oxidizing the reaction product of the step (I); (III) reacting the oxidation product of the step (II) with an organic sulfonyl halide or an organic sulfonyl anhydride; and (IV) reacting the reaction product of the step (III) with N-methyl-N-methanesulfonamide.