Triethylamine → N-(1-{(3R)-3-[(tert-butoxycarbonyl)amino]piperidin-1-yl}-2,2-dicyanovinyl)glycine ethyl ester

Participants

Reaction Conditions

Reaction Steps

Glycine methyl ester hydrochloride (3.3 g) and triethylamine (3.7 ml) were added to a solution of tert-butyl {(3R)-1-[2,2-dicyano-1-(methylthio)vinyl]-piperidin-3-yl}carbamate (1.3 g) in ethanol (30 ml), and the resulting mixture was heated under reflux. After 4 hours, triethylamine (1.5 ml) was added thereto, followed by heating under reflux for another 7 hours. After the reaction solution was cooled to 25° C., a saturated aqueous sodium hydrogencarbonate solution was added thereto, followed by extraction with chloroform. The organic layer was washed with a saturated aqueous sodium chloride solution, dried over sodium sulfate and then filtered and the filtrate was concentrated under reduced pressure. The resulting residue was purified by a silica gel column chromatography (hexane/ethyl acetate=3/1 to 1/1) to obtain the title compound (360 mg) as a white amorphous substance.

Provenance & Evidence