Carbon Dioxide → 7-BROMO-2,3-DIMETHYL-1-BENZOFURAN

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Reaction Steps

25 ml of concentrated sulphuric acid are introduced into a 100 ml three-necked flask equipped with a thermometer and a 10 ml dropping funnel and cooling is carried out to between -15 and 0° C. with a bath of solid carbon dioxide in acetone. 3-(2-Bromophenoxy)-2-butanone (5 g, 20.6 mmol) is added dropwise and stirring is continued for 5 min. The mixture is poured onto crushed ice and then extraction is carried out with ethyl acetate (3×80 ml). The organic phases are combined, dried over magnesium sulphate and concentrated. The residue is purified by silica column chromatography (elution solvent: cyclohexane). 4.24 g (Yield: 91%) of 2,3-dimethyl-7-bromobenzofuran are obtained--M.p.: 33° C.

Provenance & Evidence