反应详情

温度

0 °C

A mixture of 6-amino-1,1-dioxobenzo[b]thiophene (253 mg, 1.39 mmol) and 30% aqueous HCl (1.53 mL) was cooled to 0° C. in an open flask, and then 40% aqueous sodium nitrite (754 μL) was added dropwise over 2.25 minutes. The mixture was stirred at 0° C. for 15 minutes, and then 30% aqueous HCl (768 μL) and solid CuSO4 (20.4 mg, 0.128 mmol) were added. To this mixture was added 40% aqueous NaHSO3 (2.39 mL) dropwise over 6 minutes, and the reaction was stirred at 0° C. for 2.5 hours. The reaction was diluted with water (50 mL) and extracted with dichloromethane (2×50 mL). The combined organic layers were washed with brine (75 mL), dried over Na2SO4, filtered and evaporated. The product was purified by flash column chromatography through 20 g of silica gel using CH2Cl2 to give the title compound (171 mg, 46%) as a pale yellow solid. 1H-NMR (300 MHz, CDCl3) δ8.35 (m, 1H), 8.26 (dd, 1H, J=8.0, 1.8 Hz), 7.65 (d, 1H, J=8.0 Hz), 7.34 (dd, 1H, J=7.0, 1.0 Hz), 7.02 (d, 1H, J=7.0 Hz).

1. stirringthe reaction was stirred at 0° C. for 2.5 hours
2. extractionextracted with dichloromethane (2×50 mL)
3. washThe combined organic layers were washed with brine (75 mL)
4. dry with materialdried over Na2SO4
5. filtrationfiltered
6. customevaporated
7. customThe product was purified by flash column chromatography through 20 g of silica gel