| 摘要 |
Prodn. of N-acylphenylalanines of formula (I) is effected by (a) subjecting a 4-benzylidene-5-oxazolone deriv. of formula (II) to alkaline hydrolysis, (b) adjusting the reaction mixt. to pH 5-9 with acid, and (c) hydrogenating the reaction mixt. in the presence of a Pd or Pt catalyst. In the formulae, R1 and R2 = H, 1-4C alkyl, 1-4C alkoxy, halogen, acyloxy or aryloxy, or R1+R2 = methylenedioxy; R3 = Me or Ph; R4 and R5 = H, 1-4C alkyl, 1-4C alkoxy, halogen, OH or aryloxy, or R4+R5 = methylenedioxy.
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