benzyl (2S)-2-amino-3-methylbutanoate → HCID 11285398, compound

Participants

Reaction Steps

According to U.S. Pat. No. 5,399,578, Valsartan can also be prepared by reaction of 4-bromomethyl-2′-(1-triphenylmethyltetrazol-5-yl)biphenyl (VI) with L-valine benzyl ester to produce N-[[2′-(1-triphenylmethyltetrazol-5-yl)biphenyl-4-yl]-methyl]-L-valine benzyl ester (VII), followed by treatment with valeryl chloride to produce N-(1-oxopentyl)-N-[[2′-(1-triphenylmethyltetrazol-5-yl)[1,1′-biphenyl]-4-yl]-methyl]-L-valine benzyl ester (VIII). Compound (VIII) is deprotected under acidic conditions to produce N-(1-oxopentyl)-N-[[2′-(1H-tetrazol-5-yl)[1,1′-biphenyl]-4-yl]-methyl]-L-valine benzyl ester (IX), which is then hydrogenated in presence of Pd/C catalyst to give finally Valsartan. The process is shown in scheme II, below:

Provenance & Evidence