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0 °C

Sodium hydride (12 g, 60% in oil, 297 mmol) was rinsed with hexane (4×100 mL), flushed with anhydrous nitrogen, suspended in N,N-dimethylformamide (3500 mL) and then treated with nitromethane (44 mL, 81 mmol). The resultant mixture was stirred at room temperature for 2.5 hours, cooled to 0° C. and then treated with a solution of phenyl 2,4,5-trifluorobenzoate (22.8 g, 9.0 mmol) in N,N-dimethylformamide (180 mL) over a period of two hours. The reaction mixture was kept at the same temperature overnight and stirring continued for an additional hour at room temperature. The mixture was poured into ice (400 g) with conc. hydrochloric acid (48 mL). The aqueous mixture was extracted with ethyl acetate (3×250 mL). The combined organic layers were washed with brine (40 mL), dried over anhydrous sodium sulfate, filtered, and evaporated under reduced pressure. The crude product was dissolved in ether-hexane (1:1, 240 mL) and water (200 mL). The organic layer was separated, and the crystals which formed upon standing and cooling in the freezer were recovered by filtration and dried to yield 2-nitro-1-(2,4,5-trifluorophenyl)ethanone as an off-white solid.

1. customflushed with anhydrous nitrogen
2. customwas kept at the same temperature overnight
3. waitcontinued for an additional hour at room temperature
4. extractionThe aqueous mixture was extracted with ethyl acetate (3×250 mL)
5. washThe combined organic layers were washed with brine (40 mL)
6. dry with materialdried over anhydrous sodium sulfate
7. filtrationfiltered
8. customevaporated under reduced pressure
9. dissolutionThe crude product was dissolved in ether-hexane (1:1, 240 mL)
10. customThe organic layer was separated
11. customthe crystals which formed
12. temperaturecooling in the freezer
13. filtrationwere recovered by filtration
14. customdried