Nitric Acid → 2-Bromo-3-methoxy-6-nitropyridine

Temperature

60 °C

To a solution of 2-bromo-3-methoxypyridine (7.0 g, 37 mmol) in H2SO4 (70 mL) was added fuming HNO3 (2.4 ml, 37 mmol) dropwise at 0° C. under N2 atmosphere. The mixture was stirred at 60° C. for 2 hours. After cooling to room temperature, the mixture was quenched with water (100 mL). The insoluble solid was collected by filtration and washed with water (100 mL). The solid was dissolved in ethyl acetate (100 mL) and basified to pH to 8 with saturated aqueous NaHCO3. The aqueous layer was extracted with ethyl acetate (150×3 mL). The combined organics layers were washed with brine, dried over anhydrous Na2SO4, evaporated in vacuo and purified by chromatography on silica gel (10% ethyl acetate in petroleum ether) to give 2-bromo-3-methoxy-6-nitropyridine (5.0 g, 55%). 1H-NMR (300 MHz, CDCl3) δ 8.27 (d, J=8.7, 1H), 7.32 (d, J=8.7, 1H), 4.06 (s, 3H).

1. temperatureAfter cooling to room temperature
2. customthe mixture was quenched with water (100 mL)
3. filtrationThe insoluble solid was collected by filtration
4. washwashed with water (100 mL)
5. dissolutionThe solid was dissolved in ethyl acetate (100 mL)
6. extractionThe aqueous layer was extracted with ethyl acetate (150×3 mL)
7. washThe combined organics layers were washed with brine
8. dry with materialdried over anhydrous Na2SO4
9. customevaporated in vacuo
10. custompurified by chromatography on silica gel (10% ethyl acetate in petroleum ether)

ORD record

ord-44aeb062b70b454bad755f0debf7d511

Source dataset

uspto-grants-2011_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07956052B2