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75-36-5

64483-69-8

Example I Synthesis of 5-acetyl-2-indolomanone: 171 g (1.28 mol) of anhydrous aluminum chloride was suspended in 500 mL of 1,2-dichloroethane and cooled to 0-5°C under ice bath conditions. Subsequently, 78 g (1.1 mol) of acetyl chloride was slowly added dropwise, and the reaction temperature was controlled to not exceed 10 °C. After the dropwise addition, the reaction was continued with stirring for 1 hour. Then, 71.3 g (0.53 mol) of 2-indolone (1,3-dihydroindol-2-one) was added in four batches, ensuring that the reaction temperature was maintained between 10-12 °C after each batch. After the addition was completed, the reaction mixture was allowed to warm slowly to room temperature and stirred overnight. At the end of the reaction, the reaction solution was quenched by slowly pouring it into 1 kg of ice water under vigorous stirring. Subsequently, the slurry was diluted with 1 L of water and stirring was continued for 30 min. The precipitate was collected by diafiltration and dried to give the crude product. After purification, 80.9 g of the target compound 5-acetyl-2-indolomanone was obtained in 86.3% yield of the theoretical value. Thin layer chromatography (TLC) analysis showed Rf = 0.36 (silica gel plate, unfolding agent was ethyl acetate/cyclohexane/methanol = 9:9:2). The molecular formula of the product was C10H9NO2 (molecular weight = 175.19 g/mol) and mass spectrometry analysis showed m/z = 174 ([M-H]-).