Synthesis of <i>N</i>-Methylpyrrole and <i>N</i>-Methylimidazole Amino Acids Suitable for Solid-Phase Synthesis

Abstract

New and higher yielding synthetic routes to N-protected N-methylpyrrole and N-methylimidazole amino acids are introduced to circumvent difficulties associated with established schemes. Key steps in each synthesis include copper-mediated cross-coupling reaction to directly install a carbamate-protected 4-amine in the N-methylpyrrole derivative and effective nitration followed by a one-pot reduction/Boc protection of the amine in the synthesis of the N-Me-imidazole amino acid.