Acetic Acid → 2-Fluoro-4-nitrobenzoic acid

Temperature

95 °C

Concentrated sulfuric acid (32 ml) was added carefully with stirring to a solution of 2-fluoro-4-nitrotoluene (16.5 g, 0.106 mol) in acetic acid (200 ml). The mixture was warmed up to 95° C., and solution of chromium trioxide (37.1 g, 0.371 mol) in water (32 ml) was added dropwise with stirring over 2 h. The mixture was heated with stirring for another 30 minutes, allowed to cool down to r.t., and poured into water (1000 ml). The product was extracted with diethyl ether (3×200 ml). Combined ether layers were washed with water and evaporated to dryness. The residue was dissolved in 10% aqueous potassium carbonate and washed with ether. The aqueous layer was acidified with con. HCl, and the resulting white precipitate filtered and dried (16.3 g, 83%), m.p. 174-177° C. 1H NMR.

1. temperatureThe mixture was heated
2. stirringwith stirring for another 30 minutes
3. temperatureto cool down to r.t.
4. extractionThe product was extracted with diethyl ether (3×200 ml)
5. washCombined ether layers were washed with water
6. customevaporated to dryness
7. dissolutionThe residue was dissolved in 10% aqueous potassium carbonate
8. washwashed with ether
9. filtrationHCl, and the resulting white precipitate filtered
10. customdried (16.3 g, 83%), m.p. 174-177° C

ORD record

ord-aba5fa1ed27a4a0887a1d9223a774fbb

Source dataset

uspto-grants-2003_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06562844B2