Hydrogen Bromide → Benzene, 1-bromo-3-ethyl-

Temperature

0 °C

To a solution of 3-ethylaniline (10.0 g, 82.5 mmol) in 50% sulfanic acid (43.6 g) was added dropwise an aqueous solution (16.5 mL) of sodium nitrite (6.83 g, 99.0 mmol) over 30 minutes at 0° C. The resulting reaction mixture was stirred for 45 minutes at 0° C. This diazonium salt solution was added dropwise to a solution of copper (I) bromide (12.4 g, 86.6 mmol) in a 48% hydrobromic acid (82.5 mL) while heating gently under reflux. After the addition, the reaction mixture was heated to reflux for 30 minutes. The reaction mixture was cooled to room temperature, and extracted with ether. The extracts were sequentially washed with a 1N-aqueous sodium hydroxide solution and brine, and filtrated, dried, and concentrated. The residue was purified by silica gel column chromatography (hexane-ethyl acetate=20:1) to obtain a title compound (6.13 g, yield 40%).

1. customThe resulting reaction mixture
2. temperaturewhile heating gently
3. temperatureunder reflux
4. additionAfter the addition
5. temperaturethe reaction mixture was heated
6. temperatureto reflux for 30 minutes
7. temperatureThe reaction mixture was cooled to room temperature
8. extractionextracted with ether
9. washThe extracts were sequentially washed with a 1N-aqueous sodium hydroxide solution and brine
10. filtrationfiltrated
11. customdried
12. concentrationconcentrated
13. customThe residue was purified by silica gel column chromatography (hexane-ethyl acetate=20:1)

ORD record

ord-ea2e14a1de50471bb3fdb50fa2708a93

Source dataset

uspto-grants-2009_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07495018B2