Potassium Iodide → N-Benzyl-6,6-dimethyl-1H-pyrano[2,3-f]indole-2,3-dione

Participants

Reaction Conditions

Reaction Steps

Under nitrogen stream, a solution of N-benzyl-5-hydroxyisatin (4.74 g, 18.7 mmol), potassium iodide (5.09 g, 31.8 mmol), potassium carbonate (5.17 g, 37.4 mmol), copper iodide (71 mg, 0.37 mmol) and 3-chloro-3-methyl-1-butyne (4.83 mL, 43.0 mmol) in DMF (47 mL) was stirred at 70° C. for 2 hours. Upon the completion of the reaction, saturated ammonium chloride aqueous solution was added thereto, the resulting solution was extracted with ethyl acetate. The resulting organic phase was washed with saturated sodium chloride solution, dried over anhydrous sodium sulfate, concentrated and purified by silica gel short column (chloroform). 1,2-Dichlorobenzene (9 mL) was added and the resulting mixture was stirred at 200° C. for 30 minutes. After concentrating the reaction solution, the residue was purified by silica gel column (hexane/ethyl acetate=5/1) to obtain the aimed product (yield: 8%).

Provenance & Evidence