Sodium hydride → Ethyl 2-(4-methoxybenzyl)-3-oxo-4,4,4-trifluorobutanoate

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Reaction Steps

A 1 L four neck round bottom flask, fitted with reflux condenser, dropping funnel, argon inlet, and magnetic stirrer was charged with 7.17 g (0.149 mol) of a 50% (w/v) oil dispersion of sodium hydride and 300 mL of dry ethyl ether. Absolute ethanol (9.0 mL) was slowly added to the stirred solution. After the evolution of hydrogen stopped, a mixture of 25 g (0.136 mol) of ethyl 4,4,4-trifluoroacetoacetate and 21.3 g (0.136 mol) of 4-methoxybenzyl chloride was added over a 1 hour period. The resulting mixture was refluxed overnight, cooled, extracted with water, 1 N hydrochloric acid, dried over anhydrous magnesium sulfate and rotary-evaporated under reduced pressure. The crude reaction mixture (33.5 g) was chromatographed on a 60 mm xx 300 mm silica gel column with ethyl acetate/hexane (25/75). Similar fractions were combined and gave 9.4 g (23%) of the (spectroscopically complex) product as an oil. NMR(CDC13): 1.26(m,3H), 3.77(s,3H), 4.12(m,2H), 7.08(m,2H).

Provenance & Evidence