Process for preparing an N-(1(S)-ethoxy-carbonyl-3-phenylpropyl)-L-alanine

摘要

Preparation of a 1-alkoxycarbonyl- 3-phenylpropyl derivative of formula (II) comprises catalytic reduction of an 1-alkoxy-carbonyl-3-oxo- 3-phenylpropyl derivatives of formula (I) in the presence of 3 equivalents of a strong acid, optionally in a solvent comprising an alcohol or 0.4-0.5 N acid in alcohol. The production of 1-alkoxycarbonyl- 3-phenylpropyl by-products of formula (III) is suppressed. R = alkyl; X = Ala, Gly, Leu, Ile, Val or Hly (sic), Orn (sic) or Lys optionally protected on the omega -amino by acyl; Y = OH, Ala, Gly, Leu, Ile, Val, Pro or a group of formulae (i)-(iv); or X+Y = a group of formula (xi) or (xii).