Chloroform → 5-(2,2-dichlorovinyl)-2,2,8-trimethyl-4H-1,3-dioxino[4,5-c]pyridine

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Reaction Steps

To a well stirred ice-cooled mixture of 0.1 mole of triphenylphosphine and 0.1 mole of potassium t-butoxide in 250 ml. of heptane is added over thirty minutes a mixture of 0.1 mole of chloroform in 200 ml. of heptane. The resulting mixture is concentrated in vacuo at 15°-20° to a volume of about 100 ml. and a solution of 0.1 mole of 2,2,8-trimethyl-4H-1,3-dioxino[4,5-c]-pyridine-5-carboxaldehyde in 250 ml. of heptane is added. The reaction mixture was heated at 40°-50° for 5 hours, then cooled, filtered, and concentrated in vacuo to give crude product. Chromatography on silica gel and elution with ether-petroleum ether (10-50%) gives pure 5-(2,2-dichlorovinyl)-2,2,8-trimethyl-4H-1,3-dioxino[4,5-c]pyridine.

Provenance & Evidence