反应详情

To a solution of 4-fluoro-5-((2-fluorophenyl)amino)benzo[d]oxazole-6-carboxylic acid (7.22 g, 24.90 mmol) in DMF (50 mL) was added NIS (6.08 g, 26.37 mmol) followed by trifluoroacetic acid (3 mL). After stirring for 4 h at ambient temperature, the reaction was quenched with saturated NH4Cl (aq., 100 mL). The solution was extracted with ethyl acetate (150 mL×3). The combined organic extracts were washed with water (50 mL×3) and brine (100 mL) successively, dried over Na2SO4 and concentrated in vacuo. The crude product was purified by column chromatography on silica gel (petroleum ether/ethyl acetate, 3:1, v/v) and gave the desired product (brown solid, 6.339 g, 69% yield). 1H NMR (400 MHz, DMSO-d6): δ 8.97 (s, 1H), 8.18 (s, 1H), 8.08 (s, 1H), 7.58 (dd, J=11.0, 1.7 Hz, 1H), 7.34 (d, J=8.5 Hz, 1H), 6.55 (m, 1H).

1. customthe reaction was quenched with saturated NH4Cl (aq., 100 mL)
2. extractionThe solution was extracted with ethyl acetate (150 mL×3)
3. washThe combined organic extracts were washed with water (50 mL×3) and brine (100 mL) successively
4. dry with materialdried over Na2SO4
5. concentrationconcentrated in vacuo
6. customThe crude product was purified by column chromatography on silica gel (petroleum ether/ethyl acetate, 3:1