2,6-Diethyl-4-methylbromobenzene synthesis

Yield:314084-61-2 95%

Reaction Conditions:

Stage #1:2,6-diethyl-4-methylaniline with hydrogen bromide at 10; for 0.5 h;
Stage #2: with sodium nitrite at -5 - 0; for 2.5 h;
Stage #3: with ferrous(II) sulfate heptahydrate;hydrogen bromide;sodium bromide in water at 65 - 75; for 0.5 h;Reagent/catalyst;

Steps:

1-4
1 Add 168.5 g (1.0 mol) of 48 wt% hydrobromic acid to a 1 L four-necked flask, cool to 10 ° C, and add 23.0-diethyl-4-methylaniline 163.0 g (1.0 mol) dropwise. Stir for 30min, then cool to -5 ° C, slowly add 25wt% sodium nitrite aqueous solution 303.5g (1.1mol), control the temperature during the addition process -5 ~ 0 ° C, the addition time is about 2h, the reaction is completed for 30min, A diazo solution is obtained.2 Immediately add the diazonium droplet obtained in the step 1 to 27.8 g (0.1 mol) of ferrous sulfate heptahydrate and 10.3 g (0.1 mol) of sodium bromide.48 wt% hydrobromic acid 168.5 g (1.0 mol) and 200 g water in a 2 L four-necked flask,During the dropwise addition process, the temperature is controlled from 65 ° C to 75 ° C, and the reaction is carried out at this temperature for 30 min.Stop the reaction. Add 100 g of dichloromethane to the reacted system and stir for 30 min.The layers were allowed to stand, and the aqueous layer was further extracted with 100 g of dichloromethane, and the organic layers were combined.After evaporating the solvent under reduced pressure, 214.0 g of product was obtained in a yield of 94.3%.The purity was 97.5% (HPLC).

References:

Jiangsu Nongyong Hormone Engineering Technology Research Center Co., Ltd.;Nanjing Gaoheng Biological Technology Co., Ltd.;Zou Peipei;Jiang Xuming;Yang Chuanpeng;Liu Xiaojia;Sun Yonghui CN110105164, 2019, A Location in patent:Paragraph 0022-0028

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