1-Benzyl-N-(tert-butoxycarbonyl)-L-histidine 20898-44-6 81018-79-3 EINECS 244-105-1 Histidine, 1-benzyl-N-carboxy-, N-tert-butyl ester, L- L-Histidine, N-((1,1-dimethylethoxy)carbonyl)-1-(phenylmethyl)- N-((1,1-Dimethylethoxy)carbonyl)-1-phenylmethyl-L-histidine NSC 164043