Hydrogen Peroxide → 1-Bromo-4-methoxy-2-methylbenzene

Temperature

0 °C

36.65 g (0.3 mol) of m-cresol methyl ether and 39.8 g (0.35 mol) of 30% hydrogen peroxide in 40 ml of acetic acid (98%) are initially introduced into a flask which has a volume of 250 ml and ground-glass joints and is fitted with an internal thermometer, stirrer and dropping funnel. The mixture is stirred vigorously and cooled to 0° C. Subsequently, bromine dissolved in 40 ml of 98% acetic acid is slowly added dropwise over 3 hours. The reaction is highly exothermic. During the period of dropwise addition, the reaction temperature is held constant at about 0° to 5° C. Following the end of dropwise addition, the temperature is raised to 20° C. and stirring is continued for one hour. The stirrer is then switched off and the mixture is left to stand at 20° C. Two phases immediately form. The lower organic, halogenated phase is separated off from the upper acetic acid phase and concentrated, to give 2-bromo-5-methoxytoluene of the formula ##STR11## as a yellow oil.

1. customis fitted with an internal thermometer, stirrer
2. additionis slowly added dropwise over 3 hours
3. additionDuring the period of dropwise addition
4. customis held constant at about 0° to 5° C
5. additionthe end of dropwise addition
6. temperaturethe temperature is raised to 20° C.
7. stirringstirring
8. waitthe mixture is left
9. customto stand at 20° C
10. customTwo phases immediately form
11. customThe lower organic, halogenated phase is separated off from the upper acetic acid phase
12. concentrationconcentrated

ORD record

ord-a3db497f60f247e9b221dad86859ac5a

Source dataset

uspto-grants-1997_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05679856