Dicyclohexylcarbodiimide → BocDPhe-Leu-NleNH2

Participants

Reaction Steps

Condensation of BocDPheOH (2.65 g.) and HLeuOBz hydrobromide salt (3.02 g.) by the mixed anhydride method using diphenylphosphinyl chloride gave BocDPhe-LeuOBz in 54% yield. Debenzylation of BocDPhe-LeuOBz (2.25 g.) by hydrogenation with palladium catalyst gave BocDPhe-LeuOH in 87% yield. Condensation of BocDPhe-LeuOH (1.50 g.) and HNleNH2 hydrochloride salt (0.667 g.) using dicyclohexylcarbodiimide and N-hydroxysuccinimide gave BocDPhe-Leu-NleNH2 in 60% yield. De-t-butoxycarbonylation of BocDPhe-Leu-NleNH2 (1.00 g.) using hydrogen chloride in acetic acid gave HDPhe-Leu-NleNH2 hydrochloride salt in 79% yield.

Provenance & Evidence