2,4-Dichloro-6,7-dimethoxyquinazoline

28888-44-0

27631-29-4

The general procedure for the synthesis of 2,4-dichloro-6,7-dimethoxyquinazoline from 6,7-dimethoxy-2,4-quinazolinedione was as follows: in a 100 mL three-necked flask equipped with a reflux condenser, 6,7-dimethoxy-2,4-quinazolinedione (1.00 g) and phosphorus triclosan (15 mL; 24.77 g; 161.53 mmol) were added, the reaction mixture was refluxed at 100 °C in an oil bath with stirring for 24 hours. Upon completion of the reaction, the reaction solution was cooled to room temperature and the reaction was quenched by slowly pouring it into an ice-water mixture under vigorous stirring. The precipitated solid was collected by vacuum filtration and the crude product was purified by silica gel column chromatography using dichloromethane as eluent.