1190360-23-6

3-Bromo-9,9-dimethylfluorene is an aromatic hydrocarbon derivative and can be used as an intermediate in organic synthesis.

The general procedure for the synthesis of 3-bromo-9,9-dimethyl-9H-fluorene from 3-bromo-9H-fluorene and iodomethane was as follows: 37 g (152 mmol) of 3-bromo-9H-fluorene was dissolved in 600 ml of anhydrous DMSO in a dry flask and heated to a dry state. At room temperature, 43.9 g (457 mmol) of sodium tert-butanolate (NaOtBu) was added to the reaction system. At this point, the reaction mixture showed a blue suspension and the reaction temperature was adjusted so that the internal temperature reached 80°C. At this temperature, 64.8 g (457 mmol) of iodomethane was slowly added dropwise to the reaction system, and the rate of dropwise acceleration was controlled to ensure that the internal temperature did not exceed 90 °C (the dropwise acceleration time was about 30 min). After the dropwise addition, the reaction mixture was continued to be stirred for 30 min at an internal temperature of 80-90 °C. Subsequently, the reaction solution was poured into 1500 ml of ice water and stirred for about 20 minutes. The precipitated solid product was collected by diafiltration and washed sequentially with about 200 ml of water and methanol. Finally, 39 g (144 mmol) of the target product 3-bromo-9,9-dimethyl-9H-fluorene was obtained in 96% yield of the theoretical value; the purity of the product was 95% as analyzed by 1H-NMR.

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