Ethyl Acetate → 2-{3-[1-(4-Chloro-phenyl)-cyclopropyl]-ureido}-3-methyl-butyric acid methyl ester

Participants

Reaction Conditions

Reaction Steps

To a suspension of 1-(4-Chlorophenyl)-1-cyclopropane carboxylic acid (400 mg) in benzene (8 mL) was added triethylamine (0.23 mL) and diphenylphosphoryl azide (0.44 mL) over 5 minutes under argon. The mixture was the allowed to stir at 90° C. for 2 hours. D,L-valine methyl ester hydrochloride was added in one portion and stirring was continued at 90° C. for 20 hours. The mixture was cooled and added to ethyl acetate and 1 M NaOH. The layers were separated and the organic phase was washed with brine, dried over Na2SO4 and evaporated. The residue was purified by flash chromatography using methanol/ethyl acetate 9:1 as an eluent. Fractions containing the desired material were combined and evaporated to give 2-{3-[1-(4-chloro-phenyl)-cyclopropyl]-ureido}-3-methyl-butyric acid methyl ester as colorless solid (500 mg). MS (ESI): 325.2 (MH+).

Provenance & Evidence