5-Bromo-6-azauracil synthesis

Yield: 93%

Reaction Conditions:

with water;bromine at 60; for 10 h;

Steps:

2.i
1) 6-Bromo-2H-f 1, 2, 41tri azi ne-3, 5-d i one (2i); 2H- [1, 2,4] triazin-3,5-dione (50 g, 442 mmol) is placed in the presence of 60 ml of bromine in 800 ml of water at 60°C for 10 h. The reaction medium is then run slowly onto a solution of aqueous ammonia until pH = 5. It is then extracted with ethyl acetate and the organic phases are dried over MgS04. After filtration and concentration to dryness, 2i is isolated in the form of a white solid (79.2 g, yield = 93%). TLC Merck silica gel 60 F 254, CH2CI2-MeOH : 90-10, Rf = 0.32.

References:

PIERRE FABRE MEDICAMENT WO2005/80354, 2005, A1 Location in patent:Page/Page column 19