314084-61-2

light yellow liquid

General procedure for the synthesis of 2-bromo-1,3-diethyl-5-methylbenzene from 2,6-diethyl-4-methylaniline: 5.2 g (0.4 mol) of 2,6-diethyl-4-methylaniline was dissolved in 280 g of hydrobromic acid (40% by mass) and cooled down to 0°C. Slowly, an aqueous sodium nitrite solution was added dropwise (prepared by dissolving 33.1 g of 0.48 mol sodium nitrite in 100 mL of water). dissolved in 100 mL of water), and after the dropwise addition, stirring was continued for 30 minutes. Subsequently, 26.2 g (0.2 mol) of cuprous bromide was added and the reaction mixture was heated to 60 °C and maintained at this temperature for 4 hours. The progress of the reaction was monitored by thin layer chromatography (TLC). Upon completion of the reaction, the mixture was poured into 250 mL of ice water and extracted three times with dichloromethane. The organic phases were combined, dried with anhydrous sodium sulfate, filtered and the solvent was evaporated to give 92.36 g of crude product. Fractions with boiling points of 102-106 °C/5 mmHg were collected by distillation under reduced pressure, resulting in 81.07 g of the target product 2-bromo-1,3-diethyl-5-methylbenzene in 89.2% yield.

[1] Patent: CN106928253, 2017, A. Location in patent: Paragraph 0039-0043
[2] Patent: WO2006/84663, 2006, A1. Location in patent: Page/Page column 11
[3] Patent: WO2006/84663, 2006, A1. Location in patent: Page/Page column 11
[4] Patent: US2010/234652, 2010, A1. Location in patent: Page/Page column 4-5