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

Participants

Reaction Steps

A solution of methyl 2-(6-aminopyridin-3-yl)-2-methyl-propanoate (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 celitei 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 (x3). 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 a solid (10.3 g).

Provenance & Evidence