Researchers who often do experiments know that organic synthesis is a process of preparing more complex target molecules from simple raw materials through one or more chemical reactions. Generally, it requires fewer steps, and cheap raw materials. 138526-69-9, name is 1-Bromo-3,4,5-trifluorobenzene, A new synthetic method of this compound is introduced below., SDS of cas: 138526-69-9
The format reagent is kept at a reaction temperature of 5 C.3,4,5-trifluorobromobenzene 28.476 g (0.14 mol) was previously dissolved in 70 mL of THF to prepare a 3,4,5-trifluorobromobenzene solution.Trimethyl borate (64.4 g, 0.28 mol) was previously dissolved in THF (50 mL) to form a trimethyl borate solution.In a 1000 mL dry three-necked flask equipped with a thermometer and a constant pressure dropping funnel,Add 3.8 g (0.16 mol) of magnesium, THF (30 mL),Under the protection of N2, 1 mL of 1,2-dibromoethane and 5 mL of the above-mentioned 3,4,5-trifluorobromobenzene solution were added dropwise, and the reaction was initiated at 5 to 10 C, and a large amount of bubble temperature rose rapidly. Slowly turned grayish black,And controlling the temperature to drop the remaining 3,4,5-trifluorobromobenzene solution of the above configuration at 10 C, the solution slowly turns black gray, after the addition is completed,The reaction was incubated at 5 C for 2 h (ie, the format reagent was kept at a reaction temperature of 5 C).Then the reaction solution is cooled to about -30~-27 C.The above-prepared trimethyl borate solution was slowly added dropwise dropwise.After the completion of the dropwise addition, the reaction was continued at -30 C for 2 h.After the reaction was completed, dilute hydrochloric acid (135 mL of 12% dilute hydrochloric acid) was added dropwise at room temperature, and the mixture was stirred at room temperature for 4 h.Ester extraction (50 mL × 3), the organic phase is combined, dried over anhydrous sodium sulfate, and the organic phase is distilled off under reduced pressure, and the residue is distilled.Add 20 mL of dichloromethane, stir for 5 min, filter with a white solid, wash with a small amount of dichloromethane, and dry to give a white powder3,4,5-trifluorobenzeneboronic acid 14.78 g, yield 60%.
The basis of chemical reaction formula synthesis, the synthesis route is composed of some specific reactions and combined according to certain logical thinking. We look forward to the emergence of more reaction modes in the future.
Reference:
Patent; Zhejiang University of Technology; Li Zhenhua; Zhang Xuchao; Tan Zhiyong; (11 pag.)CN109942433; (2019); A;,
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