Hydrochloric Acid → ethyl (S)-2-(trifluoromethylsulfonylamino)-3-(4-nitrophenyl)propionate

Participants

Reaction Steps

Acetonitrile (100 ml) was added to hydrochloride (4.00 g, 14.6 mmol) of ethyl (S)-2-amino-3-(4-nitrophenyl)propionate and trifluoromethylsulfonyl chloride (2.5 ml, 23.5 mmol) and then N-methylmorpholine (3.2 ml, 29.1 mmol) were added. The mixture was stirred at room temperature for 2 hours. Water (100 ml) was poured into the reaction mixture and the mixture was extracted with ethyl acetate. The extract was washed with water and dried over anhydrous magnesium sulfate. After filtration, low boiling matters were distilled away from the filtrate under reduced pressure and the residue was purified by silica gel column chromatography (chloroform/n-hexane=2/1) to give 2.25 g of ethyl (S)-2-(trifluoromethylsulfonylamino)-3-(4-nitrophenyl)propionate as a yellow solid (42%). This solid (1.97 g, 5.32 mmol) was dissolved in acetic acid. (100 ml) and 10% palladium-carbon (750 mg) was added. The mixture was stirred at room temperature for 66 hours under a hydrogen atmosphere. The reaction mixture was filtered through Celite and acetic acid was distilled away from the filtrate under reduced pressure. The residue was washed with water to quantitatively give 1.81 g of ethyl (S)-3-(4-aminophenyl)-2-(trifluoromethylsulfonylamino)propionate as a yellow solid.

Provenance & Evidence