Thionyl Chloride → 4-Chloro-6,7-dimethoxyquinazoline

Participants

Reaction Steps

A mixture of 6,7-dimethoxy-3,4-dihydroquinazolin-4-one (2.06 g), thionyl chloride (20 ml) and DMF (1 drop) was stirred and heated to reflux for 2 hours. The mixture was evaporated and the residue was partitioned between ethyl acetate and a saturated aqueous sodium hydrogen carbonate solution. The organic phase was washed with water, dried over magnesium sulphate, filtered and evaporated to dryness. The residue was purified by column chromatography using increasingly polar mixtures of methylene chloride and ethyl acetate as the eluant to give 4-chloro-6,7-dimethoxyquinazoline (0.6 g, 27%).

Provenance & Evidence