Hydrogen Bromide → 2-Bromo-4-chloro-1-methylbenzene

Temperatur

0 °C

5-Chloro-2-methylbenzenamine (50 g, 0.355 mol) was dissolved in HBr solution (1.5 M, 100 mL) and cooled to 0° C., a solution of NaNO2 (27.6 g, 0.4 mol) in water (200 mL) was added dropwise. After addition, the mixture was stirred for 1 hr. In another flask CuBr (30 g, 0.21 mol) was added to HBr solution (1.5 M, 30 mL) and heated to 60° C., then the mixture was added to the above solution. The mixture was heated to reflux for 1 hr then cooled to rt. The reaction was quenched with water (500 mL), the aqueous layer was extracted 3 times with CH2Cl2, dried over Na2SO4, solvent removal and purification by column chromatography afforded 2-bromo-4-chloro-1-methylbenzene (53 g, 0.26 mol). 1H NMR (CDCl3, 400 MHz) δ 7.53 (s, 1H), 7.20-7.10 (m, 2H), 2.36 (s, 3H).

1. additionAfter addition
2. temperatureheated to 60° C.
3. additionthe mixture was added to the above solution
4. temperatureThe mixture was heated
5. temperatureto reflux for 1 hr
6. temperaturethen cooled to rt
7. customThe reaction was quenched with water (500 mL)
8. extractionthe aqueous layer was extracted 3 times with CH2Cl2
9. dry with materialdried over Na2SO4, solvent removal and purification by column chromatography

ORD-Eintrag

ord-cec3c3eda06e42c3a6e79cd5df03a267

Quelldatensatz

uspto-grants-2013_07

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08487108B2