反应详情

To a solution of the title compound from Step 4 (3 g, 16 mmol) in a mixture of THF (20 mL) and H2O (20 mL) was added KI (662 mg, 4 mmol) and iodine (6.1 g, 24 mmol). The reaction was stirred at rt for 1 hour and then heated to 60° C. for another 17 hours. The reaction mixture was then cooled to room temperature and concentrated under reduced pressure to remove the THF. The mixture was diluted with water (100 mL) and extracted with DCM (10 mL×3). The combined organic layers were washed with brine, dried over Na2SO4, filtered and concentrated. The residue was purified by prep-HPLC to afford 6-ethylsulfonyl-2-iodopyridin-3-ol and 6-ethylsulfonyl-4-iodopyridin-3-ol as white solids. 6-ethylsulfonyl-2-iodopyridin-3-ol: 1H NMR (DMSO-d6, 400 MHz) δ 7.85 (d, J=8.4 Hz, 1H), 7.31 (d, J=8.4 Hz, 1H), 3.30 (q, J=7.2 Hz, 2H), 1.11 (t, J=7.2 Hz 3H). LCMS: 313.8 (M+1)+; 6-ethylsulfonyl-4-iodopyridin-3-ol: 1H NMR (DMSO-d6, 400 MHz) δ 8.23 (s, 1H), 8.18 (s, 1H), 3.31 (q, J=7.2 Hz, 2H, overlapped with solvent peak), 1.10 (t, J=7.2 Hz 3H). LCMS: 313.8 (M+1)+

1. temperatureheated to 60° C. for another 17 hours
2. temperatureThe reaction mixture was then cooled to room temperature
3. concentrationconcentrated under reduced pressure
4. customto remove the THF
5. additionThe mixture was diluted with water (100 mL)
6. extractionextracted with DCM (10 mL×3)
7. washThe combined organic layers were washed with brine
8. dry with materialdried over Na2SO4
9. filtrationfiltered
10. concentrationconcentrated
11. customThe residue was purified by prep-HPLC