反应详情

温度

50 °C

1,3-Dihydroxybenzene (2.20 g, 20 mmoles) was added to a 200 ml flask equipped with a nitrogen inlet, magnetic stirrer and thermometer and containing 1.90 g of a 57 percent dispersion of sodium hydride in 100 ml of dry pyridine. After the initial evolution of hydrogen subsided, the resulting suspension of sodium recorcinate was heated at 50°C for 1 hour, and then chilled to -5°C with a salt-ice bath. Solid 4-fluoro-1,2-dinitrobenzene (9.16 g, 60 mmoles) was added all at once to the flask in the salt-ice bath which was allowed to warm overnight to room temperature. The reaction mixture was poured into 2N HCl (400 ml), and the aqueous phase was decanted from the resulting red tar. The tar was taken up in chloroform (300 ml), washed 5 times with 100 ml of 2N HCl, followed by washing with saturated NaHCO3 solution (100 ml) and water, and dried over MgSO4. Evaporation of solvent yielded 11.98 g of red oil which was chromatographed on silica gel (180 g) by elution with hexane-benzene mixtures. The yield of the desired product in the form of a yellow solid was 6.50 g (57 percent). Two recrystallizations from ethanol provided an analytical sample (melting point 107°-108.5°C).

1. customequipped with a nitrogen inlet, magnetic stirrer
2. temperaturechilled to -5°C with a salt-ice bath
3. temperatureto warm overnight to room temperature
4. customthe aqueous phase was decanted from the resulting red tar
5. washwashed 5 times with 100 ml of 2N HCl
6. washby washing with saturated NaHCO3 solution (100 ml) and water
7. dry with materialdried over MgSO4
8. customEvaporation of solvent