2-Chloro-5-methoxypyrimidine (0.46 g, 3.18 mmol) in methylene chloride (10 mL) was treated with 1.0 N boron tribromide (16 mL, 16 mmol) at room temperature. The solution was stirred overnight. After that, the reaction was partitioned between saturated NaHCO3 and DCM. The aqueous layer was extracted with additional DCM. Combined the organic layers and dried (MgSO4), filtered, and concentrated to obtain the crude product. The residue was purified by flash column chromatography on silica gel to give 2-Chloro-5-hydroxypyrimidine.
