Hydrogen Bromide → 5-Bromo-2-methylbenzonitrile

Temperatur

50 °C

Water (13.5 mL), HBr (74%, 14.4 mL) and 5-amino-2-methylbenzonitrile (2.0 g, 15.1 mmol) dissolved in water (24 mL) was added to a flask and heated to 50° C. for 20 min. Then the mixture was cooled to 0˜5° C., and a solution of NaNO2 (1.2 g, 17.4 mmol) in water was added. The reaction mixture was stirred for 10 min at 0˜5° C., then was warmed to 40° C. A solution of CuBr (6.5 g, 45.1 mmol) in water (36 mL) and HBr (7.2 mL) was added to the mixture, and refluxed for 2 h. The mixture was extracted with AcOEt, and the organic layer was washed by saturated NaHCO3 solution and brine, and dried over Na2SO4. The crude product was purified by flask chomatograph (PE:EA=50:1), obtaining 2.3 g of 5-bromo-2-methylbenzonitrile as a white solid (yield: 77%). 1H NMR (400 MHz, CDCl3) δ 7.72 (s, 1H), 7.59 (d, J=8.0 Hz, 1H), 7.19 (d, J=8.0 Hz, 1H), 2.51 (s, 3H).

1. additionwas added to a flask
2. temperatureThen the mixture was cooled to 0˜5° C.
3. temperaturewas warmed to 40° C
4. temperaturerefluxed for 2 h
5. extractionThe mixture was extracted with AcOEt
6. washthe organic layer was washed by saturated NaHCO3 solution and brine
7. dry with materialdried over Na2SO4
8. customThe crude product was purified by flask chomatograph (PE:EA=50:1)

ORD-Eintrag

ord-721830c618f34be2bb58f9864f44935f

Quelldatensatz

uspto-grants-2011_12

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08071588B2