Synthesis Method for Candesartan Cilexetil Intermediate

A method for synthesizing candesartan cilexetil intermediate represented by formula (II),

• comprising:
• (1) dissolving a compound represented by formula (IV) in an aprotic solvent to obtain a first mixed solution;
• and dissolving a phase transfer catalyst and an azidation reagent in water to obtain a second mixed solution;
• (2) adding the first mixed solution dropwise to the second mixed solution to perform an azidation reaction;
• after the azidation reaction is completed, standing and layering to obtain an organic phase containing a compound represented by formula (V);
• and
• (3) adding the organic phase containing the compound represented by formula (V) dropwise to tertiary butyl alcohol to perform a rearrangement reaction;
• after the rearrangement reaction is completed, concentrating to obtain a solid or an oily material, then adding a crystallizing solvent to the solid or the oily material for recrystallization, and separating to obtain a crystal, i.e., the candesartan cilexetil intermediate represented by formula (II);
• wherein, R is methyl or ethyl.