Sulfuric Acid → 4-Bromo-3,5-dichlorophenol

Temperature

160 °C

100 g of 4-bromo-3,5-dichlorophenylamine are added with stirring at 5° C. to a mixture of 125 ml of water and 90 ml of concentrated sulphuric acid. 230 g of crushed ice are added to the reaction mixture, followed by 29 g of sodium nitrite in 70 ml of water, and the reaction mixture is left stirring for 15 minutes. The reaction mixture is added rapidly to a mixture composed of 280 ml of concentrated sulphuric acid and 200 ml of water raised to 160° C., and the reaction mixture is left stirring at 160° C. for 1 hour. The reaction mixture is poured onto a water/crushed ice mixture and extracted with dichloromethane. The organic phase is dried over magnesium sulphate and the solvents are evaporated off under reduced pressure. The residue obtained is purified by chromatography on a column of silica gel, eluting with a 4/6 (v/v) cyclohexane/dichloromethane mixture.

1. waitthe reaction mixture is left
2. additionThe reaction mixture is added rapidly to a mixture
3. waitthe reaction mixture is left
4. stirringstirring at 160° C. for 1 hour
5. customcrushed ice mixture
6. extractionextracted with dichloromethane
7. dry with materialThe organic phase is dried over magnesium sulphate
8. customthe solvents are evaporated off under reduced pressure
9. customThe residue obtained
10. customis purified by chromatography on a column of silica gel
11. washeluting with a 4/6 (v/v) cyclohexane/dichloromethane mixture

ORD record

ord-50b853a351064a8eafd8872a51767de1

Source dataset

uspto-grants-2002_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06482986B1