Hydrogen Bromide → 1-Bromo-2,3-dichlorobenzene

Temperature

35 °C

32.7 g 2,3-Dichloroaniline (0.20 mole) is added to a mixture of 168.5 g of 48% aqueous HBr (1.0 mole, 5.0 equivalents) and 40 ml water at 30-40° C. The mixture is stirred for 15 minutes at 30-40° C. and then heated to 45° C. Then 2.9 g Cu(I)Br (0.02 mole, 0.10 equivalent) is added and the mixture is stirred for 15 minutes at 45° C. After this, an aqueous solution of NaNO2 (40% solution in water, 35.6 g, 0.21 mole, 1.0 equivalents) is added via subsurface feeding over a period of 2 hours at 45° C. The reaction mixture is stirred for 30 minutes at 45° C. After this, the reaction mixture is heated to 60-65° C. The organic phase containing the reaction product is separated from the aqueous phase and is cooled to ambient temperature, leading to solidification of the reaction product. The remaining liquid is discarded and the crude product is washed twice with 10 ml water and dried under vacuum. 40.0 g (80% of theory) of 1-bromo-2,3-dichlorobenzene is obtained in the form of a light brown solid (purity: 90%).

1. temperatureheated to 45° C
2. stirringthe mixture is stirred for 15 minutes at 45° C
3. waitfeeding over a period of 2 hours at 45° C
4. stirringThe reaction mixture is stirred for 30 minutes at 45° C
5. temperatureAfter this, the reaction mixture is heated to 60-65° C
6. additionThe organic phase containing the reaction product
7. customis separated from the aqueous phase
8. temperatureis cooled to ambient temperature
9. washthe crude product is washed twice with 10 ml water
10. customdried under vacuum

ORD record

ord-d4270dbc6daf4f9b9f5c89c53375c8a2

Source dataset

uspto-grants-2012_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08088960B2