Bromine → 5-Bromopyrimidine-2,4-diamine

Participants

Reaction Conditions

Reaction Steps

To a stirring mixture of 2,4-diaminopyrimidine (25 g, 0.23 mol, 1.0 eq) in acetic acid (375 ml) was added Br2 (36.3 g, 0.23 mol, 1.0 eq) at room temperature. The resulting mixture was stirred at room temperature (about 25° C.) for 2 hours and then filtered. The yellow solid was mixed with water (250 ml) and the pH of the resulting mixture was adjusted to 8-9 using 50% NaOH solution. Stirring was continued at room temperature for 30 min and the mixture was filtered, washed with water, and then dried under vacuum to give 38 g (87%) of 2,4-diamino-5-bromo-pyrimidine as a white solid. 1H NMR (400 MHz, d6-DMSO) δ 6.06 (s, 2H, ex. D2O), 6.50 (br, 2H, ex. D2O), 7.76 (s, 1H); MS (+)-ES [M+H]+ m/z 191.

Provenance & Evidence