Acetone → 1-(3-Bromo-phenyl)-pentane-1,4-dione

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Reaction Steps

A round bottom flask containing zinc chloride (71.95 mmol, 2.0 eq.) was heated under vacuum until the solid melted (˜300° C.) and the molten solid was kept under vacuum for 5 min. The molten solid was then allowed to cool to room temperature resulting in solidification. The flask was then filled with nitrogen and benzene (36 mL) was added followed by diethylamine (53.97 mmol, 1.5 eq.) and tert-butanol (53.97 mmol, 1.5 eq.). This mixture was stirred until the solid zinc chloride dissolved and then 3-bromophenacylbromide (35.98 mmol, 1.0 eq.) was added followed by acetone (53.97 mmol, 1.5 eq.). The resulting solution was stirred 4 d and quenched by the addition of 0.1N HCl (100 mL) and diluted with brine solution (25 mL) and extracted with ethyl acetate (3×75 mL). The combined organic layers were dried (MgSO4), filtered and concentrated to give an orange oil that was purified by column chromatography using 5% acetone/dichloromethane to give the final product as an orange solid (18.93 mmol, 53%). HRMS: calcd for C11H11BrO2+H+, 255.00152; found (ESI, [M+H]+ Obs'd), 255.0020.

Provenance & Evidence