Synthesis
The synthesis of 4-amino-5-bromopyrimidine was carried out using the compound (CAS: 163133-86-6) as starting material according to a modified scheme of the literature method 7: 4-aminopyrimidine (1.00 g, 10.5 mmol, 1.0 eq.) was dissolved in water (20 mL) with CaCO3 (263 mg, 2.63 mmol, 0.25 eq.) followed by slow addition of bromine (Br2, 1.06 mL, 20.5 mmol, 2.0 eq.). The reaction mixture was stirred at 60 °C for 45 min, then cooled to room temperature and poured into dichloromethane (CH2Cl2, 20 mL) for layering. After separation of the organic layer, the aqueous layer was further extracted with dichloromethane (2 x 20 mL). All organic layers were combined and stored temporarily. The aqueous layer was adjusted to pH 9-10 with 20% aqueous K2CO3 to induce precipitation of the product. The precipitate was collected by filtration and dried to afford the target product 4-amino-5-bromopyrimidine (1.08 g, 6.22 mmol, 59% yield) as a light tan solid.
References
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