Dimethylformamide → 4-Chloro-6,7-dimethoxyquinazoline

Participants

Reaction Steps

Dimethylformamide (0.2 ml) was added dropwise to a solution of 6,7-dimethoxy-3,4-dihydroquinazolin-4-one (10.0 g, 48.5 mmol) in thionyl chloride (200 ml) and the reaction was heated at reflux for 6 hours. The reaction was cooled, excess thionyl chloride was removed in vacuo and the residue was azeotroped with toluene (2×50 ml) to remove the last of the thionyl chloride. The residue was taken up in dichloromethane (550 ml), the solution was washed with saturated aqueous sodium hydrogen carbonate solution (2×250 ml) and the organic phase was dried over magnesium sulphate. Solvent evaporation in vacuo yielded 4-chloro-6,7-dimethoxyquinazoline (10.7 g, 98% yield) as a white solid:

Provenance & Evidence