反应详情

A 5 L 3-neck round-bottom flask was charged with a solution of 3,5-bis(trifluoromethyl)benzothioamide (205.65 g) in DMF (1.03 L). Hydrazine hydrate (73.2 mL, 2.0 eq.) was added dropwise and the reaction mixture was stirred at RT for 1 h. HCOOH (1.03 L) was added dropwise and the reaction mixture was refluxed at 90° C. for 3 h. After being allowed to cool down to RT, the reaction mixture was poured into saturated aqueous sodium bicarbonate solution (7 L) and extracted with EtOAc (3×1 L). The combined organic layers were washed with aqueous saturated sodium chloride solution (3×500 mL), dried over anhydrous Na2SO4, filtered, and concentrated under reduced pressure (35° C., 20 mmHg) to afford 180 g of the crude product. The crude material was stirred with petroleum ether (3×500 mL), filtered, and dried to obtain 160 g of the desired 3-(3,5-bis(trifluoromethyl)phenyl)-1H-1,2,4-triazole obtained as a pale yellow solid (yield: 75%).

1. temperaturethe reaction mixture was refluxed at 90° C. for 3 h
2. temperatureto cool down to RT
3. extractionextracted with EtOAc (3×1 L)
4. washThe combined organic layers were washed with aqueous saturated sodium chloride solution (3×500 mL)
5. dry with materialdried over anhydrous Na2SO4
6. filtrationfiltered
7. concentrationconcentrated under reduced pressure (35° C., 20 mmHg)
8. customto afford 180 g of the crude product
9. filtrationfiltered
10. customdried