a(i) 1-methylimidazole, MsCl, DCM, 45 °C, (ii) [1-13C] glycine, Ni(NO3)2·6H2O, KOH, MeOH, 60 °C, (iii) (2-(benzyloxy)phenyl)methanol, cyanomethylenetributylphosphorane (CMBP), toluene, 120 °C, (iv) 8-quinolinol, MeCN/H2O, 40 °C, (v) Et3N, Boc anhydride, dioxane/H2O, (vi) N,O-dimethylhydroxylamine, DIPEA, T3P, DCM, (vii) TFA, DCM; NMePip-Phe-OH, DIPEA, T3P, DCM, (viii) LAH, THF, 0 °C, and (ix) Pd/C, H2, MeOH.