Dicyclohexylcarbodiimide → N-[1-Oxo-2-[5-[2-(2H-tetrazol-5-yl]phenyl]-1H-benzimidazol-1-yl]octyl]-lysine

Participants

Reaction Steps

N-carbobenzyloxy-L-Lysine methyl ester (1.0 mmoles, 0.295 g) and 2-[5-[2-(2H-tetrazol-5-yl)phenyl]-1H-benzimidazol-1-yl]octanoic acid (1.0 moles, 0.405 g) were reacted with 1.0 moles of hydroxybenzotriazole and dicyclohexylcarbodiimide as in Example 37. The stereoisomers were separated on silica gel eluted with 5% EtOH in chloroform with 1% acetic acid. Each was hydrolyzed with sodium hydroxide as in Example 37 and hydrogenated to remove the carbobenzyloxy group in ethanol over 5% Pd/C for 4 hours. The catalyst was removed by filtering through celite. The solvent was removed in vacuo to yield 74 mg of N-[1-Oxo-2-[5-[2-(2H-tetrazol-5-yl]phenyl]-1H-benzimidazol-1-yl]octyl]-lysine. Isomer A (MS)

Provenance & Evidence