Facile one-step synthesis of N-α-Boc-1-alkyl-l-histidines

N-α-Boc-l-Histidine upon direct τ(N-1) ring alkylation with various alkyl halides in the presence of sodium hydride in DMF or CH3CN easily afforded N-α-Boc-1-alkyl-l-histidines 2a–f. The reaction works equally well in either DMF or CH3CN as solvent, however, CH3CN is preferred due to ease of reaction work-up.