143489-45-6

13418-77-4

143489-45-6

Boron tribromide (2.6 mL, 50 mmol) was slowly added dropwise to a benzene solution (60 mL) containing 5-methoxy-2-aminopyrimidine (1.25 g, 10 mmol) under argon protection. The reaction mixture was stirred under reflux conditions for 6 hours. After completion of the reaction, the mixture was allowed to stand at room temperature overnight. Subsequently, the solvent was removed by rotary evaporator and the residue was carefully treated with ice-cold deionized water (10 mL). The solution pH was adjusted to 6-7 using 6N hydrochloric acid and subsequently extracted with ethyl acetate. The organic phase was washed with saturated saline, dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated to give a yellow solid, which was purified by column chromatography (eluent ratio of 20:1 dichloromethane to methanol) to give 840 mg (75% yield) of 2-aminopyrimidin-5-ol as a white solid. The structure of the product was confirmed by 1H-NMR and electron bombardment mass spectrometry (EI-MS).1H NMR (DMSO-d6) δ 8.90 (s, 1H), 7.86 (s, 2H), 5.91 (s, 2H); EI-MS (m/z) 111 (M+).