2-Bromothiazole → HCID 66657144, compound

Participants

Reaction Steps

To a 150 ml of toluene solution containing 20.0 g of 3(S)-(3,4-dichlorophenylamino)pyrrolidine-1-carboxylic acid tert-butyl ester (60.4 mmol) and 15.0 g of 2-bromothiazole (91.5 mmol) were added 1.86 g. of tri-tert-butylphosphine•tetrafluoroborate (6.4 mmol), 2.88 g of tris(dibenzylideneacetone)dipalladium (3.15 mmol) and 11.6 g of sodium tert-butoxide (120 mmol). The mixture was heated under reflux under a nitrogen atmosphere for 9 hours. The reaction solution was cooled to room temperature and filtered using Celite. Water was added to the filtrate, and extraction with ethyl acetate was conducted. After drying over sodium sulfate and concentration under reduced pressure, the residue was then purified by silica gel column chromatography (n-hexane:ethyl acetate=4:1). The purified product was concentrated to dryness under reduced pressure to thereby obtain 7.94 g of yellow powdery 3(S)-[(3,4-dichlorophenyl)-thiazol-2-ylamino]pyrrolidine-1-carboxylic acid tert-butyl ester.

Provenance & Evidence