Trifluoroacetic acid → Bis-boc-l-ornithyl-d-homophenylalanine quinoline-3-amide

Participants

Reaction Conditions

Reaction Steps

A solution of NaNd-bis-Boc-L-Ornithine (2.79 g, 8.4 mmol), triethylamine (1.29 mL, 9.2 mmol) and methylene chloride (90 mL) was stirred at 25° C. for 10 min, cooled to −10° C. and treated with ethyl chloroformate (0.80 mL, 8.4 mmol). The mixture was stirred at −10° C. for 2 hrs. During this time N-Boc-D-Homophenylalanine Quinoline-3-amide (2.27 g, 5.6 mmol) was treated with trifluoroacetic acid (15 mL) at 25° C. for 1 hr. The solution was concentrated to dryness and treated with diethyl ether (10 mL). The solid was filtered and dried. It was suspended in methylene chloride (40 mL) and neutralized with triethylamine (1.6 mL, 11.2 mmol). The resultant solution was added dropwise to the mixed anhydride and the mixture was allowed to warm up to 25° C. and stirred for an additional 1 hr. Saturated sodium bicarbonate (30 mL) was added, the organic layer was washed with water (30 mL), dried over anhydrous sodium sulfate, filtered and concentrated to dryness to afford crude product. It was purified by column chromatography on silica gel (ethyl acetate:hexane=2:1) to give the title compound (2.55 g) as white solid.

Provenance & Evidence