Yield:-

Reaction Conditions:

Stage #1:7-aminoquinazolin-4-one with hydrogenchloride;sodium nitrite in water at 0; for 0.416667 h;
Stage #2: with potassium iodide in water at 0 - 20; for 3 h;

Steps:

7-Iodoguinazolin-4-one
7-Iodoguinazolin-4-one 7-Amino-quinazolin-4-one (R. Dempsy and E. Skito, Biochemistry, 30, 1991, 8480) (1.61 g) was suspended in 6N HCl (20 ml) and cooled in an ice bath. A solution of sodium nitrite (0.75 g) in water (10 ml) was added dropwise over 15 minutes. After a further 10 minutes, a solution of potassium iodide (1.66 g) in water (5 ml) was added dropwise. The mixture was warmed to 20° C. and after 3 hours partitioned between ethyl acetate and sodium thiosulphate. The organic phase was dried and concentrated in vacuo to give the title compound (0.485 g); m/z (M+1+) 271.

References:

SmithKline Beecham Corporation US6933299, 2005, B1 Location in patent:Page/Page column 75