Trifluoroacetic acid → Ethyl 1-benzyl-4-(1-tert-butoxycarbonylaminocyclopropyl)-3-pyrroline-3-carboxylate

Participants

Reaction Steps

N-Benzyl-N-(n-butoxymethyl)trimethylsilylmethylamine (2.006 g, 7.176 mmol) and ethyl 3-(1-tert-butoxycarbonylaminocyclopropyl)propiolate (1.136 g, 4.485 mmol) were dissolved in dry dichloromethane (9 ml) and, while stirring at room temperature, the solution was mixed with dichloromethane solution of 1.0 M trifluoroacetic acid (0.72 ml, 0.72 mmol). After 3 hours of stirring, the reaction solution was mixed with a saturated sodium bicarbonate aqueous solution (20 ml) and extracted with dichloromethane (20 ml×3). The organic layers were combined, washed with saturated brine (30 ml) and then dried over anhydrous magnesium sulfate. After filtration, the filtrate was concentrated under reduced pressure, and the resulting residue was applied to a flash silica gel chromatography column and eluted with chloroform, to thereby obtain 1.449 g (83.6%) of the title compound as a colorless oil.

Provenance & Evidence