Sulfolane → 2-Nitro-4-(trifluoromethoxy)phenol

Temperatur

-50 °C

To a mixture of 4-(trifluoromethoxy)phenol (4 g, 0.0225 mol) in ethylene glycol dimethyl ether (90 mL) was added a 0.5 M solution of nitronium tetrafluoroborate in sulfolane (46 mL, 0.0229 mol) at −50° C. The mixture was stirred at −50° C. under an atmosphere of nitrogen for 6 hours. The mixture was filtered through silica gel pad, and the pad was washed with 25% ethyl acetate/n-heptane. The solvent was removed under reduced pressure, and the residue was partitioned between ethyl acetate and water. The aqueous layer was extracted with ethyl acetate. The organic layer was washed with water and brine. The solvent was removed under reduced pressure, and the residue was purified by flash column chromatography on silica using 0%-50% ethyl acetate/n-heptane as a mobile phase to give 2-nitro-4-(trifluoromethoxy)phenol (2.5 g, 0.011 mol). TLC (ethyl acetate/n-heptane=25:75) Rf 0.50 MS: MH−: 222.

1. filtrationThe mixture was filtered through silica gel pad
2. washthe pad was washed with 25% ethyl acetate/n-heptane
3. customThe solvent was removed under reduced pressure
4. customthe residue was partitioned between ethyl acetate and water
5. extractionThe aqueous layer was extracted with ethyl acetate
6. washThe organic layer was washed with water and brine
7. customThe solvent was removed under reduced pressure
8. customthe residue was purified by flash column chromatography on silica using 0%-50% ethyl acetate/n-heptane as a mobile phase

ORD-Eintrag

ord-73ada632aa944814b4b43447f3394808

Quelldatensatz

uspto-grants-2005_07

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US06921763B2