Method for synthesizing 4-chloro-2-cyano-N,N-dimethyl-5-p-methylphenylimidazole-1-sulfamide

The invention discloses a method for synthesizing 4-chloro-2-cyano-N,N-dimethyl-5-p-methylphenylimidazole-1-sulfamide. The method is characterized in that 2-carbonyl-2-P-benzyl acetaldehyde is used as a raw material and reacted with glyoxylic acid to synthesize an imidazole ring, and then ammoniation, dehydration, chlorination and sulfonylation are performed, so that 4-chloro-2-cyano-N,N-dimethyl-5-p-methylphenylimidazole-1-sulfamide is finally synthesized. The purity of 4-chloro-2-cyano-N,N-dimethyl-5-p-methylphenylimidazole-1-sulfamide prepared by adopting the synthesizing method reaches over 98.0%, and the total yield reaches over 44.5%. The method is cheap and readily available in raw materials, simple, mild in reaction conditions and low in environmental pollution, and produces little wastewater. The method is mainly applied to synthesis of 4-chloro-2-cyano-N,N-dimethyl-5-p-methylphenylimidazole-1-sulfamide serving as a pesticide bactericide.