Method for preparing (E)-2-methyl-alpha-methoxyimino methyl phenylacetate

The invention relates to the technical field of pesticide synthesis, in particular to a method for preparing (E)-2-methyl-alpha-methoxyimino methyl phenylacetate, which comprises the following steps of: by taking DMF (Dimethyl Formamide) as a solvent, reacting a compound in a formula (II) with dimethyl sulfate under the action of alkali to prepare a dialkylate containing oxime hydroxyl and carboxyl, the reaction product is (E)-2-methyl-alpha-methoxyimino methyl phenylacetate. The method is short in reaction route and high in reaction efficiency. After a compound shown in the formula (II) is obtained from an initial raw material through a simple shrinkage process, a one-step methylation reaction is carried out, and a target product (I) compound which is obtained through simultaneous methylation of oxime hydroxyl and carboxyl can be obtained. The reaction stereospecificity is high. After the compound of the formula (II) is subjected to in-situ acid regulation and transposition, the purity gt is obtained; and 98