1-Ethyl-3-(3'-dimethylaminopropyl)carbodiimide → N-[(1-methylindole-2-carbonyl)valinyl]-3-amino-4-hydroxy-5-fluoropentanoic Acid T-Butyl Ester

Participants

Reaction Steps

DMAP (95 mg, 0.78 mmol) and EDAC (200 mg, 1.04 mmol) were added as solid to a solution of 1-methylindole-2-carboxylic acid (130 mg, 0.74 mmol) and N-(valinyl)-3-amino-4-hydroxy-5-fluoropentanoic acid, t-butyl ester (227 mg, 0.74 mmol) in methylene chloride (5 mL), and the resultant solution was stirred for 1 hour under a nitrogen atmosphere at 0° C. and then 4 hours at room temperature. The reaction mixture was partitioned between ethyl acetate and 5% KHSO4 solution and the aqueous solution was back-extracted with ethyl acetate. The combined ethyl acetate solutions were washed with 5% KHSO4 solution, saturated sodium bicarbonate solution (2×) and brine, dried over sodium sulfate, and concentrated to give a foam. The foam was triturated with ether to yield the title product as a slightly brown solid (224 mg, 65%/o). TLC: (methanol/methylene chloride, 1:9): Rf=0.46.

Provenance & Evidence