Synthetic method for sartan drug intermediate and application of intermediate

The invention relates to a synthetic method for a sartan drug intermediate. The method includes: dissolving N-[(2'-cyanobiphenyl-4-base) methyl]-N-amyl acyl-(L)-valine methyl ester and sodium azide in an organic solvent, reacting under the catalytic action of catalyst, and obtaining the drug intermediate N-[(2'-tetra-nitrogen imidazolyl biphenyl-4-base]-N-amyl acyl-(L)-valine methyl ester. Rare-earth metal organic chloride is applied to the preparation process of the sartan drug intermediate, the fact that tributyl tin chloride can be substituted, better effect is obtained, product yield and quality are improved to some extent, reaction time is short, toxicity does not exist, a new assistant catalyst which is economical and environment-friendly is provided for synthesis of the sartan drug intermediate, and the sartan drug intermediate has quite high application value and economic value.