Hydrogen Bromide → 2-Bromo-4-methyl-5-nitroanisole

Temperature

0 °C

a mixture of 2-methoxy-5-methyl-4-nitroaniline (20 g, 110 mmol) in 140 mL of water was heated under reflux and 48% hydrobromic acid (56 mL) was added dropwise and the mixture was heated for 20 minutes. The resulting suspension was cooled to 0° C. and treated with 40 mL of aqueous sodium nitrite (7.6 g, 110 mmol) dropwise keeping the temperature at 0° C. The suspension was added carefully dropwise to a 0° C. solution of cuprous bromide (18.1 g, 126 mmol) in 96 mL of water and 38 mL of 48% HBr. The mixture was stirred at 0° C. for 30 minutes and at room temperature for 1 hour and finally on a steam bath for 20 minutes to complete the reaction. The solid precipitate was suction filtered and dissolved in methylene chloride, washed with 400 mL of 10% sodium hydroxide, 5% sodium bisulfite, and water. The organic layer was dried, filtered, and evaporated in vacuo to give 24.9 g of dark brown solid. This was recrystallized from hexane to give 13.4 g of bromo compound.

1. temperaturewas heated
2. temperatureunder reflux
3. temperaturethe mixture was heated for 20 minutes
4. customat 0° C
5. customthe reaction
6. filtrationfiltered
7. dissolutiondissolved in methylene chloride
8. washwashed with 400 mL of 10% sodium hydroxide, 5% sodium bisulfite, and water
9. customThe organic layer was dried
10. filtrationfiltered
11. customevaporated in vacuo

ORD record

ord-5461b0259273488db663aef9c7548965

Source dataset

uspto-grants-1995_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05444038