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ChemicalBook CAS DataBase List 4-Bromobenzo[b]thiophene
5118-13-8

4-Bromobenzo[b]thiophene synthesis

14synthesis methods
-

Yield:5118-13-8 98.8%

Reaction Conditions:

Stage #1:Benzo[b]thiophene with dihydrogen peroxide;acetic acid at 78; for 0.5 h;Inert atmosphere;
Stage #2: with tetrabutylammomium bromide;sodium bromide in water at 120; under 7220.48 Torr; for 20 h;

Steps:

1.1; 1.2 4 - Bromophenylacetic and [B] thiophene synthetic method, comprises the following steps
1) The benzothiophene, acetic acid and catalyst mixing, and the argon gas, control pressure is 3 atmospheric pressure, to control the temperature of 78 °C, uniform dropwise 30% hydrogen peroxide, and control of the hydrogen peroxide solution dropping time is 30 min, when the dropping of the hydrogen peroxide reaches its total volume of 15% when, the beginning of the uniform drop control interface sodium bromide, water and tetrabutyl ammonium bromide mixture A, control mixture A dropping time of 40 min, after the end of the dropping operation, increasing the reaction temperature to 120 °C, raise the pressure to the 9.5 atmospheric pressure, then continue to reaction 20 h the reaction is finished;Catalyst preparation method is: will be 10 Z-type molecular sieve triturated, over 600 mesh, for 530 °C activation obtained.Benzo thiophene with acetic acid in a molar ratio of 1:20, benzothiophene with sodium bromide in a molar ratio of 1: 1.22, benzothiophene with hydrogen peroxide in the weight ratio of 1: 1.12, benzothiophene and catalyst weight ratio of 1: 0.076; the weight ratio of sodium bromide and water 1:6.2) A system is cooled added to 3 times of the volume of water, then extracted with toluene, the extracting solution by anhydrous magnesium sulfate after drying, concentrating and evaporate the solvent to obtain the product. The molar yield 98.8%, GC purity 99.1%.

References:

Shenzhen The Second People Hospital;Tan Hui;Li Weiping;Huang Xianjian;Liu Wenlan;Tang Aifa;Zhao Huafu CN109574985, 2019, A Location in patent:Paragraph 0032-0061

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