protected N-α,N-1(τ)-dialkyl-Lhistidine derivatives. Synthesis of suitably protected N-α,N-1(τ)-dialkyl-L-histidines 7-9 containing different alkyl groups at the N-α and N-1(τ) positions was achieved in four steps starting from L-histidine methyl ester. Whereas, in the one-step alternate route N-α-Boc-L-histidine methyl ester upon direct and simultaneous N-α and N-1(τ) alkylation with various alkyl