Quinazolone-4 was chlorinated with chlorine in glacial acetic acid,with ferric chloride as catalyst.The reaction was carried out at different temperatures (39-100Å),and with different amount of chlorine (molar ratio of chlorine to quinazolone varying from 0.92 to 1.81).The chlorinated products were separated and purified by recrystallization from benzene,ethanol,aqueous ethanol,butanol and acetone,and were found to be 6-chloroquinazolone (m.p.268-269Å),8-chloroquinazolone (m.p.300-302Å)and 6,8 dichloroquinazolone (m.p.347-349Å) respectively.Their identities were established by elementary analysis and mixed melting point tests with known synthetic compounds.