The present invention provides a method for the preparation of N-(1-oxopentyl)-N-[[2′-(1H-tetra-zol-5-yl)[1,1′-biphenyl]-4-yl]methyl]-L-valine (Valsartan) which comprises; treating N-[[2′-(1-triphenylmethyl-tetra-zol-5-yl)biphenyl-4-yl]methyl]-L-valine methyl ester (X) with oxalic acid or its hydrates in a solvent to produce N-[[2′-(1-triph-enylmethyl-tetrazol-5-yl)biphenyl-4-yl]methy]-L-valine methyl ester oxalate (Xa) and treating the compound (Xa) with a base in a solvent followed by reacting with valeryl chloride in presence of base in a solvent to produce N-[[2′-(1-triphenylmethyl-tetra-=zol-5-yl)[1,1′biphenyl]-4-yl]methyl]-N-valeryl-L-valine methyl ester (XI), de-protecting the compound (XI) using anhydrous acidic conditions to produce N-(1-oxopentyl)-N-[[2′-(1-H-tetrazol-5-yl)[1,1′biphenyl]-4-yl]methyl-L-valine methyl ester (V) followed by <="" div="">
本发明提供了一种制备缬沙坦(Valsartan)的方法,包括以下步骤:将N-[[2'-(1-三苯甲基-四唑-5-基)[1,1'-联苯]-4-基]甲基]-L-缬氨酸甲酯(X)与草酸或其水合物在溶剂中反应,生成N-[[2'-(1-三苯甲基-四唑-5-基)联苯-4-基]甲基]-L-缬氨酸甲酯草酸酯(Xa),然后将化合物(Xa)与溶剂中的碱反应,随后在溶剂中的碱存在下与戊酰氯反应,生成N-[[2'-(1-三苯甲基-四唑-5-基)[1,1'联苯]-4-基]甲基]-N-戊酰-L-缬氨酸甲酯(XI),用无水酸性条件去保护化合物(XI),生成N-(1-氧代戊基)-N-[[2'-(1-H-四唑-5-基)[1,1'联苯]-4-基]甲基]-L-缬氨酸甲酯(V),最后在溶剂中用碱处理,生成缬沙坦。