Potassium Iodide → Methyl (2S)-3-(3-bromo-4-iodophenyl)-2-[(tert-butoxycarbonyl)amino]-propanoate

Participants

Reaction Conditions

Reaction Steps

Methyl (2S)-3-(4-amino-3-bromophenyl)-2-[(tert-butoxycarbonyl)amino]-propanoate (19.8 g, 53.0 mmol) suspended in 1 N aqueous hydrogen chloride (500 mL) was treated sequentially at 0° C. with sodium nitrite (3.66 g, 53.0 mmol) in water (75 mL) dropwise. After 15 minutes at 0° C., potassium iodide (8.81 g, 53.1 mmol) in water (75 mL) was added and the solution was heated at 40° C. for 15 minutes. The solution was quenched with saturated aqueous sodium thiosulfate solution (100 mL), and extracted with ethyl acetate (500 mL). The organic phase was washed with 0.1 N Hydrochloric acid solution (500 mL), saturated aqueous sodium bicarbonate solution (500 mL), and dried over sodium sulfate. Purification by silica gel chromatography (10–40% ethyl acetate/hexanes) afforded product as slightly yellow solid (18.7 g, 73%). 1H NMR (400 MHz, CD3OD): δ 7.80 (d, J=8.0 Hz, 1H), 7.55 (d, J=1.8 Hz, 1H), 6.92 (dd, J=8.0, 1.9 Hz), 4.36–4.29 (m, 1H), 3.71 (s, 3H), 3.10–2.79 (m, 1H), 1.37 (s, 9H); LCMS found for C15H19BrINO4Na (M+Na)+: m/z=506.

Provenance & Evidence