反应详情

温度

50 °C

A stirred solution of 2,5-difluorobenzonitrile (25 g, 180 mmol) in pyridine (90 mL) was treated with 20 wt % ammonium sulfide in water (67.4 mL, 198 mmol) and triethylamine (27.4 mL, 198 mmol). The reaction mixture was stirred at 50° C. for 5 hr until the reaction was complete. After cooling to room temperature, the mixture was diluted with cold water and extracted with EtOAc. The organic layer was separated, then washed with H2O (×3), brine (×3), then dried over anhydrous Na2SO4, filtered, and evaporated under reduced pressure to give the crude product. Purification on silica gel column (20% EtOAc in hexanes) to afford 2,5-difluorobenzothioamide as yellow solid (31.0 g, 99%). 1H NMR (CDCl3, 300 MHz): δ 7.12 (m, 2H), 7.90 (br, 2H), 8.08 (m, 1H). LC/MS (uplc): MH+174.0, 0.64 min.

1. temperatureAfter cooling to room temperature
2. extractionextracted with EtOAc
3. customThe organic layer was separated
4. washwashed with H2O (×3), brine (×3)
5. dry with materialdried over anhydrous Na2SO4
6. filtrationfiltered
7. customevaporated under reduced pressure
8. customto give the crude product
9. customPurification on silica gel column (20% EtOAc in hexanes)