Sodium Acetate → 4'-hydroxymethyl-biphenyl-2-carbonitrile

Participants

Reaction Steps

According to U.S. Pat. No. 5,399,578, the process for the preparation of Valsartan (I) involves the reaction of 4′-bromomethyl-2-cyanobiphenyl (II) with sodium acetate and glacial acetic acid to produce 2′-cyano-4-hydroxymethylbiphenyl (III), which is reacted with oxalyl chloride in dichloromethane and dimethyl sulfoxide to produce 2′-cyano-4-formylbiphenyl (IV), which is further reacted with (L)-valine methyl ester hydrochloride (V) and sodium cyanoborohydride to produce N-[(2′-cyanobiphenyl-4-yl)methyl]-(L)-valine methyl ester (VI), followed by treatment with valeryl chloride to produce N-valeryl-N-[(2′-cyanobiphenyl-4-yl)methyl]-(L)-valine methyl ester (VII), which is treated with tri-n-butyltin azide followed by flash chromatography to produce Valsartan of formula (I).

Provenance & Evidence