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Optimization of the Ugi Reaction Using Parallel Synthesis and Automated Liquid Handling
Published on: November 11, 2008
Improved scalable syntheses of mono- and bis-urethane derivatives of ornithine
S Wiejak1, E Masiukiewicz, B Rzeszotarsk
1Laboratory of Chemistry, Technical University of Opole, Poland.
Abstract:
In the search for a practical route to ornithine bisurethane derivatives useful for peptide synthesis, we elaborated the simple and efficient (86% yield) synthesis of N(epsilon)-tert-butoxycarbonyl-L-ornithine copper(II) complex (1). This served as substrate for obtaining N(epsilon)-tert-butoxycarbonyl-L-ornithine (2), N(alpha)-benzyloxycarbonyl-N(epsilon)-tert-butoxycarbonyl-L-ornithine (3) and N(alpha)-(9-fluorenyl)methoxycarbonyl-N(epsilon)-tert-butoxycarbonyl-L-ornithine (4). These were synthesized in 94-95% yields and with a purity above 99%.
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