吲哚3位上氰基

General procedure:

To a solution of the appropriate indoles 3a-d (6.8 mmol) in anhydrous acetonitrile (6.0 mL),chlorosulfonyl isocyanate (CSI) (0.63 mL, 7.25 mmol) was added dropwise at 0 °C and the reactionmixture was stirred at 0 °C for 2 h. Anhydrous dimethylformamide (DMF) (1.3 mL, 170.0 mmol)was added dropwise and the mixture was stirred at 0 °C for 2 h. The mixture was poured intoice-water and the obtained precipitate was filtered off, dried (anhydrous Na2SO4) and purified bycolumn chromatography using petroleum ether/ethyl acetate as eluent.