[CH3:1][O:2][C:3](=[O:11])[C:4]1[CH:9]=[C:8]([OH:10])[CH:7]=[N:6][CH:5]=1.O1CCCC1.O.C(=O)([O-])[O-].[Na+].[Na+].[I:24]I>>[OH:10][C:8]1[C:7]([I:24])=[N:6][CH:5]=[C:4]([CH:9]=1)[C:3]([O:2][CH3:1])=[O:11]To solution of 5-hydroxy-nicotinic acid methyl ester (2.50 g, 16.3 mmol) in tetrahydrofuran (50.0 mL, 616 mmol)/water (50.0 mL, 2780 mmol) was added sodium carbonate (5.19 g, 49.0 mmol) and iodine (10.4 g, 40.8 mmol). The reaction mixture was stirred at room temperature 4h. The aqueous layer containing product was separated and wash with hexane. The organic layer was neutralized to pH 7 with HCl, extracted EtOAc 4×. The combined organic layers was dried Na2SO4, concentrated. The crude product was purified by flash chromatography (EtOAc/DCM) (eluted at 40 EtOAc) to give methyl 5-hydroxy-6-iodonicotinate (81.2%) MS: (ESI+) 280.0
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