Facile synthesis of Nε-(benzyl, methyl)-lysine as a building block for site-specifically lysine monomethylated peptides

Facile, mild and efficient one-pot preparation of Nα-Fmoc-Nε-(benzyl, methyl)-lysine, a building block for monomethylated peptide synthesis, was described. This building block was proved to be efficient for the synthesis of site-specifically monomethylated peptide. Benzyl group, which was incorporated by reductive benzylation and removed via catalytic hydrogenolysis, served as an excellent protecting group.