Ethylene Glycol → 3(S)-(3-chloro-4-fluorophenylamino)pyrrolidine-1-carboxylic acid tert-butyl ester

Participants

Reaction Steps

To a 50 ml of isopropyl alcohol solution containing 15.0 g of 3(S)-aminopyrrolidine-1-carboxylic acid tert-butyl ester (80.5 mmol) and 24.8 g of 2-chloro-1-fluoro-4-iodobenzene (96.7 mmol) were added 1.54 g of copper (I) iodide (8.1 mmol), 9.0 ml of ethylene glycol (10.1 mmol) and 34.2 g of potassium phosphate (161 mmol), and heated under reflux under a nitrogen atmosphere for 46 hours. The reaction solution was cooled to room temperature and filtered using Celite. The substance remained in the filter was washed with ethyl acetate and the filtrate was concentrated under reduced pressure together with the washings, and the residue was purified by silica gel column chromatography (n-hexane:ethyl acetate=4:1). The solvent was distilled off under reduced pressure, and the residue was recrystallized from diethyl ether to thereby obtain 15.9 g of white powdery 3(S)-(3-chloro-4-fluorophenylamino)pyrrolidine-1-carboxylic acid tert-butyl ester.

Provenance & Evidence