Synthetic Route of 138526-69-9, In the next few decades, the world population will flourish. As the population grows rapidly and people all over the world use more and more resources, all industries must consider their environmental impact. 138526-69-9, name is 1-Bromo-3,4,5-trifluorobenzene belongs to bromides-buliding-blocks compound, it is a common compound, a new synthetic route is introduced below.
General procedure: The amount ratio of the charged material is 3,4,5-trifluorobromobenzene: trimethyl borate = 1:1; Precipitating 28.476 g (0.14 mol) of 3,4,5-trifluorobromobenzene in 70 mL of tetrahydrofuran,Formulation to form a 3,4,5-trifluorobromobenzene solution.In a 1000 mL dry three-necked flask equipped with a thermometer and a constant pressure dropping funnel, 3.8 g of magnesium dust was added.(0.16mol),Tetrahydrofuran (30 mL), 1 mL of 1,2-dibromoethane and 5 mL of the above-prepared 3,4,5-trifluorobromobenzene solution were added dropwise under N2 protection.When the reaction is initiated at 5 to 10 C, a large amount of bubble temperature rises rapidly, and the solution slowly turns grayish black.And controlling the temperature to drop the remaining 3,4,5-trifluorobromobenzene solution (80 mL) of the above configuration at 10 C,The solution slowly turned black-gray, and after the addition was completed, it was kept at 25 C for 2 h.The reaction solution is then cooled to below -30 C (ie, the temperature at which the format reagent reacts with trimethyl borate),Adding a solution of trimethyl borate (dissolving trimethyl borate (14.56 g, 0.14 mol) in 50 mL of tetrahydrofuran to prepare a solution),And keep the temperature stable at -30 ~ -27 C, after the addition of trimethyl borate solution, continue the insulation reaction for 2h.Then, 135 mL of dilute hydrochloric acid having a concentration of 12% was added dropwise to the reaction solution, and the mixture was hydrolyzed at room temperature for 4 hours.After the completion of the hydrolysis reaction, ethyl acetate was added to the reaction mixture to extract a layer (50 mL × 3), and the extract phase was combined.The extract phase was dried over anhydrous sodium sulfate, and the solvent was evaporated to concentrate.Suction filtration to give a small amount of white solid washed with dichloromethane, and dried to give 10.8 g of white powder,That is, 3,4,5-trifluorobenzeneboronic acid represented by the formula (II) was obtained in a yield of 44%.
The synthetic route of 1-Bromo-3,4,5-trifluorobenzene has been constantly updated, and we look forward to future research findings.
Reference:
Patent; Zhejiang University of Technology; Li Zhenhua; Zhang Xuchao; Tan Zhiyong; (11 pag.)CN109761820; (2019); A;,
Bromide – Wikipedia,
bromide – Wiktionary