p-Bromoacetophenone → Ethyl 3-(4-bromophenyl)-3-oxopropanoate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

Into a 1000 mL 4-necked round-bottom flask purged and maintained with an inert atmosphere of nitrogen, was placed a solution of sodium hydride (10.1 g, 420.83 mmol, 2.10 equiv) in diethyl ether (400 mL). To the resulting mixture was then added diethyl carbonate (35.6 g, 301.69 mmol, 1.50 equiv) in 10 min at 0° C., followed by addition of a solution of 1-(4-bromophenyl)ethanone (40 g, 202.02 mmol, 1.00 equiv) in diethyl ether/EtOH (100 mL/1 mL) dropwise with stirring at 0° C. in 20 min. The resulting solution was heated to reflux for 3 hr. The reaction was then quenched by the addition of water/ice. The pH value of the solution was adjusted to about 5-6 with HCl (1 mol/L). The resulting solution was extracted with diethyl ether (3×200 mL), the organic layers combined and dried over anhydrous magnesium sulfate, then concentrated under vacuum. The residue was applied onto a silica gel column with ethyl acetate/petroleum ether (1:100) to yield ethyl 3-(4-bromophenyl)-3-oxopropanoate as yellow oil.

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