Trifluoroacetic acid → HDTrp-Leu-MeMetNH2 trifluoroacetate

Participants

Reaction Steps

Condensation of BocLeuOH (5.00 g.) and HMeMetNH2 (4.00 g.) using dicyclohexylcarbodiimide and 1-hydroxybenzotriazole gave BocLeu-MeMetNH2 in 81% yield. De-t-butoxycarbonylation of BocLeu-MeMetNH2 (5.96 g.) using hydrogen chloride in ethyl acetate gave HLeu-MeMetNH2 hydrochloride salt in 98% yield. Condensation of BocDTrpOPFP (7.56 g.) and HLeu-MeMetNH2 hydrochloride salt (5.00 g.) by the activated ester method gave BocDTrp-Leu-MeMetNH2 in 56% yield. De-t-butoxycarbonylation of BocDTrp-Leu-MeMetNH2 (2.0 g.) using trifluoroacetic acid in dimethyl sulfide and ethanedithiol gave HDTrp-Leu-MeMetNH2 trifluoroacetate salt in 79% yield.

Provenance & Evidence