1-Bromo-3-chloropropane → 2-cyano-7-(3-chloropropyloxy)-4-oxo-4H-1-benzopyran

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Reaction Steps

A mixture of 2.43 g (13 mmol) of 2-cyano-7- hydroxy-4-oxo-4H-1-benzopyran, 2.04 g (13 mmol) of 3-chlorobromopropane and 1.80 g (13 mmol) of potassium carbonate was refluxed in 250 ml dry acetone overnight with heating. After evaporating to dryness, the residue was extracted with chloroform (3×100 ml), and dried with sodium sulfate. The chloroform solution was evaporated to one-third of the original volume to which was added n-hexane. The white precipitate was collected by filtration, washed with n-hexane and dried in vacuum to obtain 2-cyano-7-(3-chloropropyloxy)-4-oxo-4H-1-benzopyran (yield 51%).

Provenance & Evidence