A common heterocyclic compound, 553-94-6, name is 2,5-Dimethylbromobenzene, molecular formula is C8H9Br, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route. 553-94-6.
1) Add 1 mol of 2-bromo-p-xylene or chloroacetyl chloride to the reaction kettle.The catalyst and DMSO were heated to 100 C under stirring for 5 h.Then a mixture of sodium sulfite and water was added dropwise to control the dropping time to 45 min.After the completion of the dropwise addition, the reaction temperature was raised to 135 C, and the reaction was continued for 7.5 h; The ratio of 2-bromo-p-xylene to chloroacetyl chloride is 1:1.14,The ratio of 2-bromo-p-xylene to catalyst is 1:0.07, and the ratio of 2-bromo-p-xylene to DMSO is 1g: 13ml.The ratio of 2-bromo-p-xylene to sodium sulfite was 1:1.18, and the ratio of sodium sulfite to water was 1:4.5. The preparation process of the catalyst is: Mix ruthenium oxide and 10% palladium carbon in a weight ratio of 1:20. Then soaked in 4% concentration of hydrochloric acid for 6 minutes,Then, a solid was obtained by filtration, and the solid was washed and then placed at 280 C for 2.5 h to obtain a catalyst. 2) cooling the system, filtering to remove insoluble matter to obtain a filtrate, and adding the filtrate to about 5 volumes of water.Then, the filtrate is added twice the volume of toluene, and the layer is allowed to stand, and the organic phase is washed with water.After drying with anhydrous sodium sulfate,Concentration gave the product in a molar yield of 98.1% and a HPLC purity of 97.5%.
The synthetic route of 2,5-Dimethylbromobenzene has been constantly updated, and we look forward to future research findings.
Reference:
Patent; Shandong Nong Pharmaceutical Xue Institute; Jinan Kehai Co., Ltd.; Fu Hongxin; Yang Chaohui; Wang Ling; (6 pag.)CN109369378; (2019); A;,
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