Trimethyl borate → 1,3-Dichloro-2-fluoro-5-(3,3,3-trifluoroprop-1-en-2-yl)benzene

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Reaction Steps

In a solution of 2.00 g of 3,5-dichloro-4-fluoro-iodobenzene and 0.61 g of tert-butylmethyl ether in 18 mL of hexane, 5.3 mL of n-butyl lithium (1.54M hexane solution) was added dropwise at −10° C. with stirring, and stirred at the same temperature for 30 minutes. Then, a solution of 0.57 g of trimethoxyborane in 7 mL of tetrahydrofuran was added dropwise. After the completion of the addition dropwise, it was stirred at the same temperature further for 30 minutes and then the temperature was raised to room temperature. Then, in the reaction mixture, 1.80 g of 2-bromo-3,3,3-trifluoropropene, 1.90 g of potassium carbonate, 10 mL of water and 0.005 g of 1,3-bis(2,6-diisopropylphenyl)imidazole-2-ilidene (1,4-naphthoquinone) palladium (0) dimmer were added, and stirred under nitrogen atmosphere at 60° C. for 15 hours. After the completion of the reaction, the reaction mixture was left and cooled to room temperature, insoluble material was filtered off, and the organic phase was collected and the aqueous phase was extracted with 30 mL of ethyl acetate twice. The combined organic phases were washed with water, and dehydrated with and dried over saturated sodium chloride aqueous solution and then anhydrous sodium sulfate, and the solvent was distilled off under reduced pressure. The residue was purified with silica gel column chromatography that was eluated with hexane to obtain 1.20 g of the aimed product as yellow oily substance.

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