反应详情

温度

50 °C

Gaseous hydrogen bromide (1.05 equiv.) is fed into a mixture of 2,6-diethyl-4-methylaniline (1.00 equiv.) and sodium bromide (0.10 equiv.) in o-dichlorobenzene. The resulting salt suspension is cooled to 50° C. Isoamyl nitrite (1.05 equiv.) and additional gaseous hydrogen bromide (0.3 equiv.) are fed subsurface simultaneously at 50-55° C. over a 2-hour period to afford 1-bromo-2,6-diethyl-4-methylbenzene as a yellow to light brown solution. The reaction mass is neutralized with 25% caustic solution (ca. 0.3 equiv.). The bottom aqueous phase is separated off. Isoamyl alcohol and o-dichlorobenzene are sequentially stripped off to produce the crude 2,6-diethyl-4-methylbromobenzene material with an assay of 90% and an isolated yield of 87-90%. The product can be further purified by vacuum distillation at 95° C./5 mmHg to give an assay of 97-99%.

1. customsimultaneously at 50-55° C.
2. customover a 2-hour