1,2-Dimethoxyethane → 3,6-DI-Tert-butyl-2,7-diphenyl-9H-fluorene

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Reaction Steps

Under a nitrogen atmosphere, a 300-mL three-necked flask was charged with 8.15 g (18.7 mmol) of 2,7-dibromo-3,6-ditert-butyl-fluorene and 1.08 g (0.93 mmol) of Pd(PPh3), and further charged with 120 mL of dehydrated 1,2-dimethoxyethane. The mixture was stirred at room temperature for 20 minutes. To this solution, 20 mL of an ethanol solution in which 5.01 g (41.1 mmol) of phenylboric acid was dissolved was added, and the mixture was then stirred at room temperature for 20 minutes. Thereafter, 37.4 mL (74.8 mmol) of a 2.0 mol/L aqueous solution of sodium carbonate was added. Subsequently, the mixture was heated to reflux for 18 hours, left to be naturally cooled, and quenched with dilute hydrochloric acid in an ice bath. Thereafter, ether was added to extract the soluble fraction, and the organic layer was washed two times with a saturated aqueous solution of sodium hydrogen carbonate, two times with water, and two times with saturated brine, and then dried over magnesium sulfate. Subsequently, the solvent was distilled off, and the resulting solids were subjected to separation by column chromatography to obtain a target product (yield 4.36 g (54%)). The target product was identified by 1H-NMR and FD-MS spectroscopy.

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