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

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

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).

Herkunft & Nachweise