Acetic Acid → 3-Cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)-5-methylamino-4-trifluoromethylsulfonylpyrazole

HRID 987073Notes

Reaction equation

[C:1]([C:3]1[C:7]([S:8]([C:10]([F:13])([F:12])[F:11])=[O:9])=[C:6]([N:14]=[CH:15]OCC)[N:5]([C:19]2[C:24]([Cl:25])=[CH:23][C:22]([C:26]([F:29])([F:28])[F:27])=[CH:21][C:20]=2[Cl:30])[N:4]=1)#[N:2].[BH4-].[Na+].C(O)(=[O:35])C>C(O)C>[C:1]([C:3]1[C:7]([S:8]([C:10]([F:12])([F:13])[F:11])(=[O:35])=[O:9])=[C:6]([NH:14][CH3:15])[N:5]([C:19]2[C:24]([Cl:25])=[CH:23][C:22]([C:26]([F:29])([F:28])[F:27])=[CH:21][C:20]=2[Cl:30])[N:4]=1)#[N:2]

Participants

Conditions

Temperature: 10 °C

Procedure

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.).

Workup

customremained generally below 35° C
waitwas continued overnight
customto quench
filtrationThe resulting precipitate was collected by filtration
washwashed with water
customair-dried
customRecrystallization from methanol

Sources & evidence

ORD record: ord-0c0a6119baaf48b08780ade78c6993a1
Source dataset: uspto-grants-2003_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06630499B1

Reaction notes

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