Trifluoroacetic acid → Nalpha,Ndelta-Bis-Boc-D-ornithyl-N-(phenethyl)glycine 2-Naphthylamide

Participants

Reaction Conditions

Reaction Steps

A solution (0° C.) of Nα,Nδ-bis-Boc-D-ornithine (130 mg, 0.39 mmol), diisopropylethylamine (1.6 mmol) and methylene chloride (10 mL) was treated with PyBroP (275 mg, 0.59 mmol) and kept at 0° C. for 30 min. In another reaction, a solution of Boc-N-(phenethyl)glycine 2-naphthylamide (240 mg, 0.59 mmol) (made by coupling of N-Boc-N-(phenethyl)glycine and 2-naphthylamine) and trifluoroacetic acid (3 mL) was stored at 24° C. for 1 hr and then concentrated in vacuo. The residue was coevaporated twice with methylene chloride and the resultant solid resuspended in methylene chloride (10 mL) and treated with diisopropylethylamine (1.2 mmol). The two solutions were mixed and stirred at 25° C. for 1 hr at which time the mixture was washed with 1M hydrochloric acid (2×25 mL), sat. sodium bicarbonate (25 mL), and brine (25 mL). The organic layer was dried over anhydrous sodium sulfate and adsorbed onto silica gel (500 mg) and applied to a column prepacked with silica gel. The column was eluted with ethyl acetate:hexane (50:50, v:v) to afford the titled compound.

Provenance & Evidence