Preparation method of losartan metabolite EXP-3174

The invention discloses a preparation method of a losartan metabolite EXP-3174. The chemical name of the EXP-3174 is 2-butyl-4-chloro-5-carboxy-1-{[2'-(1H-tetrazolyl-5-yl)-biphenyl-4]-methyl}imidazole. The preparation method is realized in a way that: 2-butyl-4-chloro-5-formacyl-1-{[2'-(1H-tetrazolyl-5-yl)-biphenyl-4]-methyl}imidazole is used as the raw material, a polar solvent is used as the solvent, and the pH value is regulated and controlled at 1-7 with a buffer solution; and in the presence of hydrogen peroxide, a sodium chlorite-antichlor system is used for oxidizing aldehyde to generate the corresponding carboxylic acid, and finally, the 2-butyl-4-chloro-5-carboxy-1-{[2'-(1H-tetrazolyl-5-yl)-biphenyl-4]-methyl}imidazole is generated. The preparation method has the advantages of mild reaction conditions, environment friendliness, high yield and purity, low cost for after-treatment and production, and the like, is simple to operate, and is applicable to industrial large-scale production.