Triethylamine → 4-(4'-Chloro-4-methylbiphenyl-3-yl)-2,2-dimethylpyran-3,5-dione

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Reaction Steps

To a suspension of 6-[1-(4′-chloro-4-methylbiphenyl-3-yl)methylidene]-5,5-dimethyl-[1,4]dioxan-2-one (1.5 g, 4.38 mmol) in anhydrous acetonitrile (22 ml) is added triethylamine (0.67 ml, 4.81 mmol) and potassium cyanide (30 mg, 0.46 mmol). The reaction mixture is stirred under reflux for two hours. The cooled mixture is diluted with ethyl acetate, and 0.5N aqueous hydrochloric acid is added at 0° C. The organic layer is separated and the aqueous phase extracted twice with ethyl acetate. The combined organic extracts are dried over anhydrous sodium sulfate, filtered and the filtrate evaporated in vacuo. The residue is purified by flash chromatography (heptane/ethyl acetate 1:1 ratio) to afford 4-(4′-chloro-4-methylbiphenyl-3-yl)-2,2-dimethylpyran-3,5-dione (1.35 g) as a foam. A sample of the product is stirred in hexane/diisopropyl ether (4:1 ratio) and filtered to give a white solid with a melting point of 186-188° C.

Provenance & Evidence