反应详情

温度

10 °C

A 50 L reactor was charged with 3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)-5-ethoxymethylideneamino-4-trifluoromethylsulfinylpyrazole (1.645 g, 3.335 moles) and absolute ethanol (16 L) under nitrogen. The solution was cooled to 10° C., and sodium borohydride (266 g, 7.03 moles) was added slowly such that the temperature remained generally below 35° C. After 6.75 h, some additional sodium borohydride (25 g, 0.66 mole) was added and stirring was continued overnight. Acetic acid (1.3 L, 22.7 moles) was added to quench, followed by 16 L of water. The resulting precipitate was collected by filtration, washed with water, and air-dried. Recrystallization from methanol afforded 3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)-5-methylamino-4-trifluoromethylsulfonylpyrazole (350 g) as an off-white solid (m.p. about 227° C.).

1. customremained generally below 35° C
2. waitwas continued overnight
3. customto quench
4. filtrationThe resulting precipitate was collected by filtration
5. washwashed with water
6. customair-dried
7. customRecrystallization from methanol