Unprecedented crystallization and X-ray crystal structure of racemic N(alpha)-(t-butyloxycarbonyl)-L-L-phenylalanine N-methoxy-N-methylamide

Chirality. 2000 Jan;12(1):2-6. doi: 10.1002/(SICI)1520-636X(2000)12:1<2::AID-CHIR2>3.0.CO;2-Y.

Abstract

Weinreb amide 3 was synthesized using isobutyl chloroformate, carbonyldiimidazole, or ethylcarbodiimide as the coupling agent in the reaction of Boc-phenylalanine with O,N-dimethylhydroxylamine hydrochloride. An optically active oil was isolated along with an optically inactive solid irrespective of the type of coupling agent used. Single crystal X-ray analysis of the solid revealed that it is a racemate. The molecular packing of the crystals reflect the stability of the racemate as opposed to an enantiomerically pure solid.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Calpain / antagonists & inhibitors
  • Carbodiimides / chemistry
  • Cross-Linking Reagents / chemistry
  • Crystallography, X-Ray
  • Cysteine Proteinase Inhibitors / chemical synthesis
  • Cysteine Proteinase Inhibitors / chemistry*
  • Formates / chemistry
  • Molecular Weight
  • Phenylalanine / analogs & derivatives*
  • Phenylalanine / chemical synthesis
  • Phenylalanine / chemistry
  • Stereoisomerism

Substances

  • Carbodiimides
  • Cross-Linking Reagents
  • Cysteine Proteinase Inhibitors
  • Formates
  • N-butyloxycarbonyl-phenylalanine N-methoxy-N-methylamide
  • Phenylalanine
  • isobutyl chloroformate
  • Calpain