Iodine → Methyl 2-(6-amino-5-iodopyridin-3-yl)-2-methylpropanoate

Participants

Reaction Steps

A solution of methyl 2-(6-aminopyridin-3-yl)-2-methylpropanoate (10.0 g, 51.5 mmol) in MeOH (50 mL) was added over approximately 0.5 h via pressure equalizing addition funnel to a vigorously stirred suspension of iodine (17.0 g, 67.0 mmol) and silver trifluoroacetate (14.8 g, 67.0 mmol) in MeOH (200 mL) at room temperature. After 3 h, the reaction was quenched sequentially with 1M Na2S2O3 followed by saturated aqueous NaHCO3. The resulting mixture was filtered through celite® washing copiously with ethyl acetate, the filtrate concentrated in vacuo and the residue partitioned between ethyl acetate and water. The organic phase was separated and the aqueous phase was re-extracted with ethyl acetate (×3). The combined organic extract was washed with brine, dried (MgSO4) and concentrated in vacuo. The residue was purified by flash chromatography on silica gel (gradient elution; 35-40% ethyl acetate/hexanes as eluent) to give the title compound as an off-white solid (10.3 g, 62%).

Provenance & Evidence