tert-Butyl (2S)-2-amino-3-(4-(3-ethoxycarbonylpropyloxy)phenyl)propionate → (1,1-dimethyl ethyl) O-(4-ethoxy-4-oxobutyl)-N-[1-(phenylmethyl)-1H-tetrazol-5-yl]-L-tyrosinate

Participants

Reaction Steps

A solution of aminoester 4-2 (325 mg, 0.92 mmole) and 5-fluoro-1-(phenylmethyl)-1H-tetrazole (170 mg, 0.95 mmole) in 15 ml of pyridine is heated at 100° C. for 2 hours. Evaporation is then carried out under reduced pressure until a dry extract is obtained which is purified by chromatography eluting with a heptane/AcOEt mixture 50/50. 270 mg of the expected product 5-1 is obtained.

Provenance & Evidence