Hydrochloric Acid → 1-(2,4-dihydroxyphenyl)-3-methylbutan-1-one

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Reaction Steps

Resorcinol, 5.506 g (50.00 mmol), was added to 45 ml of nitrobenzene and stirred cooling with cold water and 13.3 g (100 mmol, 2.00 equivalents) of aluminum chloride was added piecemeal and they were stirred, with a calcium chloride tube attached. Then, 6.03 g (50.0 mmol, 1.00 equivalent) of isovaleryl chloride was slowly added dropwise, stirred at room temperature for one hour, and further heated stirring at 90° C. for six hours. When the evolution of an acidic gas ceased, the resultant mixture was poured into dilute hydrochloric acid (prepared from 40 ml of concentrated hydrochloric acid and 160 ml of cold water) with stirring, and then extracted by ether. The ether layer was washed with saturated brine and removed by distillation under a reduced pressure. The residue, with water added piecemeal, was distilled under a reduced pressure and distilled off nitrobenzene by steam distillation method. The residue was extracted again by ether, washed with saturated brine, dried over sodium sulfate, and distilled to remove the solvent and obtain 8.952 g of a red viscous oily substance. This oily substance was purified by silica gel column chromatography (20 g of Wako Gel C-200, eluted with hexane:ether at varying ratios=8:2-7:3) to obtain 4.37 g of (2,4-dihydroxyphenyl) (2-methylpropyl) ketone (52) in the form of light yellow crystals.

Provenance & Evidence