Extracurricular laboratory: Synthetic route of 1,4-Dibromo-2,5-dimethoxybenzene

According to the analysis of related databases, 2674-34-2, the application of this compound in the production field has become more and more popular.

Reference of 2674-34-2, In the chemical reaction process, reaction time, type of solvent, can easily affect the result of the reaction, thereby determining the yield and properties of the reaction product. An updated downstream synthesis route of 2674-34-2 as follows.

Into a 200-mL three-neck flask were put 8.9 g (30 mmol) of 1,4-dibromo-2,5-dimethoxybenzene, 10 g (72 mmol) of 2-fluorophenylboronic acid, 15 mL of toluene, 15 mL of diethylene glycol dimethyl ether (diglyme), and 60 mL of a sodium carbonate aqueous solution (2.0 mol/L). This mixture was degassed by being stirred while the pressure in the flask was reduced. After the degassing, the atmosphere in the flask was replaced with nitrogen, and the mixture was heated to 80 C. To this mixture was added 0.69 g (0.60 mmol) of tetrakis(triphenylphosphine)palladium(0), and the mixture was stirred at the same temperature for 2 hours. The mixture was cooled down to room temperature and degassed again under reduced pressure. Then, the atmosphere in the flask was replaced with nitrogen, and the mixture was heated to 80 C. After the heating, 0.69 g (0.60 mmol) of tetrakis(triphenylphosphine)palladium(0) was added to this mixture, and the mixture was heated at the same temperature for 5 hours. After the heating, 2.0 g (14 mmol) of 2-fluorophenylboronic acid was added to this mixture, and the mixture was further stirred at the same temperature for 3 hours. After the heating, the mixture was cooled down to the room temperature and degassed under reduced pressure. Then, the atmosphere in the flask was replaced with nitrogen. This mixture was heated to 80 C., 0.64 g (0.55 mmol) of tetrakis(triphenylphosphine)palladium(0) and 3.0 g (21 mmol) of 2-fluorophenylboronic acid were added to the mixture, and the mixture was stirred at the same temperature for 2 hours. After the stirring, the mixture was cooled down to the room temperature, and the mixture was separated into an organic layer and an aqueous layer. The obtained aqueous layer was subjected to extraction with toluene three times, the extracted solution and the organic layer were combined, and this mixture was washed with saturated saline and dried with anhydrous magnesium sulfate. The obtained mixture was gravity-filtered, and then the obtained filtrate was concentrated to give a compound. The obtained compound was recrystallized with toluene to give 2.5 g of a target. The compound obtained by the concentration of the filtrate was purified by column chromatography (a developing solvent: a mixed solvent of hexane and ethyl acetate in a ratio of 30:1) to give 0.3 g of a target. The targets were 2.8 g in total, and the yield was 29%. A synthesis scheme of the above synthesis method is shown in (A-1) below.

According to the analysis of related databases, 2674-34-2, the application of this compound in the production field has become more and more popular.

Reference:
Patent; Semiconductor Energy Laboratory Co., Ltd.; Kawakami, Sachiko; Ishiguro, Yoshimi; Takahashi, Tatsuyoshi; Hamada, Takao; Seo, Hiromi; Seo, Satoshi; (113 pag.)US9997725; (2018); B2;,
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