N([O-])=O.[Na+].[C:5]([C:9]1[CH:22]=[CH:21][CH:20]=[CH:19][C:10]=1[O:11][C:12]1[C:17](N)=[CH:16][CH:15]=[CH:14][N:13]=1)([CH3:8])([CH3:7])[CH3:6].[I-:23].[K+].S(=O)(O)[O-].[Na+]>O.Cl>[C:5]([C:9]1[CH:22]=[CH:21][CH:20]=[CH:19][C:10]=1[O:11][C:12]1[C:17]([I:23])=[CH:16][CH:15]=[CH:14][N:13]=1)([CH3:8])([CH3:7])[CH3:6]A solution of sodium nitrite (157 mg, 2.28 mmol) in water (1 mL) was added to a mixture of 2-(2-tert-butylphenoxy)-3-aminopyridine (prepared above according to 1b) (500 mg, 2.07 mmol) in (1:1) conc. HCl: water (14 mL) at 0° C. The mixture was stirred at 0° C. for 15 min and a solution of potassium iodide (1.0 g, 6.22 mmol) in water (2 mL) was added. The mixture was stirred at 60° C. for 1.5 h and allowed to cool down to rt. A solution of sodium bisulfite was added and the mixture was extracted with ethyl acetate (3×50 mL). The combined organic layers were dried (anhydrous sodium sulfate), filtered and evaporated. The residue was purified by flash-chromatography (dichloromethane:hexanes/20:100) to afford 394 mg (56%) of 2-(2-tert-butylphenoxy)-3-iodopyridine. (M+H)+=354.
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