Dimethyl Sulfoxide → N-[(3-Chloro-1-Methylindole-2-Carbonyl)Valinyl]-3-Amino-4-Oxo-5-Fluoropentanoic Acid, t-Butyl Ester

Participants

Reaction Conditions

Reaction Steps

DMSO (0.06 mL, 0.9 mmol) was added to a solution of oxalyl chloride (0.14 mL, 2.0M, 0.28 mmol, in 4 mL of methylene chloride) and the solution was then stirred for 10 minutes under a nitrogen atmosphere at -78° C. A solution of N-[(1-methylindole-2-carbonyl)valinyl]-3-amino-4-hydroxy-5-fluoropentanoic acid, t-butyl ester (85 mg, 0.18 mmol) in dry methylene chloride (1 mL), was added dropwise to the reaction mixture and the mixture was stirred for 15 minutes at -78° C. Triethylamine (0.15 mL, 1.08 mmol) was added dropwise to the reaction mixture and the mixture was stirred for 10 minutes at -78° C. and then was allowed to warm to room temperature. The reaction mixture was partitioned between ethyl acetate and 5% KHSO4 solution and the aqueous layer was back-extracted with ethyl acetate. The combined ethyl acetate solutions were washed with 5% KHSO4 solution and brine, dried over sodium sulfate, and concentrated to give a brown foam. The foam was triturated with ether to afford the title product as a light brown powder (64 mg). MS for C24H31ClFN3O5 : (MH)- =494/496.

Provenance & Evidence