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n the S104, the third intermediate (2.25 g, 5 mmol), <strong>[53965-69-8]4-bromo-2,3,5,6-tetramethylaniline</strong> (1.39 g, 6 mmol) in argon was added to a 250 mL two-necked flask. In a gas atmosphere, 100 mL of acetone with water and oxygen removed in advance was injected, and the reaction was performed at 60 C for 24 hours. The reaction solution was poured into 200 mL of ice water, and extracted with dichloromethane three times. The organic phases were combined, and the mixture was separated into silica gel by column chromatography (dichloromethane: n-hexane, v: v, 1: 1) to obtain 2.41 g of a white powder. The yield is 80%. MS (EI) m / z: [M] +: 604.13. The theoretical relative molecular mass of the first reactant is 604.25.