The invention discloses a synthetic method method for
irbesartan. The method comprises the following steps of: hydrolyzing amino cyclopentyl
cyanogen serving as a
raw material in an alkaline solution to obtain amino cyclopentyl
formamide; undergoing a cyclization reaction on the obtained amino cyclopentyl
formamide and valeryl
chloride to obtain 2-butyl-1,3-diazaspiro[4,4]
nonane-1-
alkene-4-
ketone serving as an intermediate (I); undergoing a C-N
coupling reaction on the intermediate (I) and 4-bromomethyl-2'-cyanobiphenyl to obtain 2-butyl-3-[(2'-cyanobiphenyl-4-radical)methyl]-1, 3-diazaspiro[4,4]nona-1-
alkene-4-
ketone serving as an intermediate (II); undergoing a
sodium nitride cyclization reaction to obtain
irbesartan serving as a target product. Due to the adoption of the synthetic method, the total yield of the
irbesartan product is increased from below 45 percent to over 75 percent, the
tonnage consumption the product is greatly lowered, and cost is greatly lowered. An operation process is simplified, so that the yield is increased, three-waste
pollution is lowered, treatment is easy, and a novel process with high competitiveness is realized.