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ChemicalBook CAS DataBase List Benzomn, 5-bromo-2-roethyl-
54965-04-7

Benzomn, 5-bromo-2-roethyl- synthesis

11synthesis methods
-

Yield:54965-04-7 71.1%

Reaction Conditions:

with potassium carbonate in acetonitrile at 20;

Steps:

20.20a Step 20a: Preparation of 5-bromo-2-methylbenzofuran (Compound 0301-68):

Ethyl 2-bromopropionate (2.7 g, 15 mmol, 1.5 eq),Added to 5-bromosalicylaldehyde (2 g, 10 mmol, 1.0 eq.)Potassium carbonate (2.8 g, 20 mmol, 2.0 equiv)In 70 ml acetonitrile solution,Stir overnight at room temperature.After the reaction solution was concentrated under reduced pressure to remove acetonitrile,Add 70 ml of methanol,The reaction was stirred at 70 °C for 4 hours.After cooling to room temperature, 100 ml of water was added, concentrated hydrochloric acid was added dropwise until the pH of the aqueous phase was 1, dichloromethane was added for extraction, the organic phase was dried over anhydrous sodium sulfate, and concentrated under reduced pressure to give a white solid.The white solid was dissolved in 50 ml of acetic anhydride and sodium acetate (2.5 g, 30 mmol, 3.0 equiv) was added.After stirring at 140° C. overnight, the reaction solution was cooled to room temperature, extracted with ethyl acetate, and the organic phase was dried over anhydrous sodium sulfate.Concentration under reduced pressure afforded the product 5-bromo-2-methylbenzofuran (1.5 g, 71.1% yield) as a colorless oil.

References:

CN107383024,2017,A Location in patent:Paragraph 0248

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