Polycondensation

  • Miklos Bodanszky
  • Agnes Bodanszky
Part of the Springer Lab Manual book series (SLM)

Abstract

A solution of l-lysine dihydrochloride (22 g, 100 mmol) in 2 N NaOH (150 ml) is cooled in an ice-water bath and vigorously stirred. Benzyl chlorocarbonate [3] (53 g = 44 ml, ca. 300 mmol) and 4 N NaOH (125 ml) are added, each in four portions. These additions require about 30 min. Stirring is continued for an additional 30 min then the mixture [4] is acidified to congo with 6 N hydrochloric acid (about 55–60 ml). Di-benzyloxycarbonyl-l-lysine separates as an oil which is extracted into ether (twice, 200 ml each time). The organic layers are combined and extracted with a 5% solution of KHCO3 in water (three times, 200 ml each time) [5]. Acidification of the combined bicarbonate solutions with 6 N HC1 (60 ml) and reextraction with ether (twice, 150 ml each time), drying the ether extracts over anhydrous Na2SO4 and evaporation of the solvent under reduced pressure leaves di-benzyloxycarbonyl-l-lysine (40 g) as a syrup, which is used without further purification [6].

Keywords

Foam Recrystallization Anhydride Charcoal Benzyl 

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Copyright information

© Springer-Verlag Berlin Heidelberg 1994

Authors and Affiliations

  • Miklos Bodanszky
    • 1
  • Agnes Bodanszky
    • 2
  1. 1.PrincetonUSA
  2. 2.ClevelandUSA

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