A Large Scale Synthesis of Mono- and Di-urethane Derivatives of Lysine

Abstract

In the search for a practical route to lysine diurethane derivatives useful for peptide synthesis, we elaborated the synthesis of N^ε-tert-butoxycarbonyl-L-lysine copper(II) complex (1). This served as substrate for obtaining N^ε-tert-butoxycarbonyl-L-lysine (2), N^α-benzyloxycarbonyl-N^ε-tert-butoxycarbonyl-L-lysine dicyclohexylamine salt (3) and N^α-(9-fluorenyl)methoxycarbonyl-N^ε-tert-butoxycarbonyl-L-lysine (4).