2-Chloro-3-nitrobenzoic acid → 1-Bromo-2-chloro-3-nitrobenzene

Temperatur

90 °C

To an oven dried round-bottom flask fitted with stir bar and an oven dried condenser under N2 at room temperature was added 2-chloro-3-nitrobenzoic acid (6.0 g, 29.8 mmol), mercuric oxide, red (9.67 g, 44.7 mmol) and carbon tetrachloride (200 mL). The reaction mixture heated to 90° C. for 30 minutes with irradiation from a 150 W TYPE A utility light bulb. The reaction mixture was then cooled to approximately 60° C. and bromine (2.30 mL, 44.7 mmol) added dropwise via syringe and the nitrogen inlet was replaced with an Ar balloon. The reaction mixture was heated again to 90° C. for 4 hours under constant irradiation from the light bulb. The reaction was allowed to cool to room temperature, quenched with saturated aqueous NaHCO3 solution and DCM and stirred for 30 minutes. The phases partitioned upon standing and then were separated. The aqueous portion was extracted with DCM. The combined organic phases were washed with water, brine, dried (Na2SO4), filtered and concentrated in vacuo to afford 7.04 g of 1-bromo-2-chloro-3-nitrobenzene: 1H NMR (400 MHz, CDCl3) δ 7.31 (t, J=8.0 Hz, 1H) 7.74 (dd, J=8.2, 1.2 Hz, 1H) 7.87 (dd, J=8.0, 1.4 Hz, 1H).

1. customTo an oven dried round-bottom flask fitted
2. customdried condenser under N2 at room temperature
3. temperatureThe reaction mixture was then cooled to approximately 60° C.
4. temperatureThe reaction mixture was heated again to 90° C. for 4 hours under constant irradiation from the light bulb
5. temperatureto cool to room temperature
6. customquenched with saturated aqueous NaHCO3 solution and DCM
7. stirringstirred for 30 minutes
8. customThe phases partitioned
9. customwere separated
10. extractionThe aqueous portion was extracted with DCM
11. washThe combined organic phases were washed with water, brine
12. dry with materialdried (Na2SO4)
13. filtrationfiltered
14. concentrationconcentrated in vacuo

ORD-Eintrag

ord-7d335e3d881f48dfb3a0abcfb6149fb9

Quelldatensatz

uspto-grants-2013_10

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08563553B2