Method for synthesizing chloroacetamide compound with large steric hindrance by water phase reaction

The invention discloses a method for synthesizing a chloroacetamide compound with large steric hindrance by a water phase reaction, wherein the method comprises the following steps: taking inorganic alkali as an acid binding agent, enabling a secondary amine compound to react with chloroacetyl chloride in water to synthesize the corresponding chloroacetamide compound with large steric hindrance in the presence of an organic solvent. The method provided by the invention can be used for synthesizing pesticides s-metolachlor and metolachlor. The method provided by the invention has the advantages of simple operation, quick reaction, high product yield and good quality; the method provided by the invention is suitable for large-scale preparation.