Boron trifluoride etherate → 4-(3,4-Dimethoxy-5-nitrophenyl)-2-(2-(trifluoromethyl)pyridin-3-yl)oxazole

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Reaction Steps

To a solution of 2-(3,4-dimethoxy-5-nitrophenyl)-2-oxoethyl acetate (4.24 g, 15 mmol) in xylene (30 mL) were added 2-(trifluoromethyl)nicotinamide (3.135 g, 16.5 mmol) and boron trifluoride etherate (0.18 mL, 15 mmol). The resulting yellow solution was heated to reflux for 18 hours and then cooled to room temperature. After evaporation of the solvent, the residue was partitioned between ethyl acetate and saturated aqueous sodium bicarbonate. The organic phase was separated, washed with brine and the dried over anhydrous magnesium sulphate, filtered and evaporated. The pure 4-(3,4-dimethoxy-5-nitrophenyl)-2-(2-(trifluoromethyl)pyridin-3-yl)oxazole was obtained by column chromatography over silica gel (petroleum ether/ethylacetate 2:1) as a pale yellow solid, 2.488 g (42%).

Provenance & Evidence