m-Chloroperbenzoic acid → Fipronil

HRID 2253764Notes

Reaction equation

HRID 2253764 reaction equation
[NH2:1][C:2]1[N:6]([C:7]2[C:12]([Cl:13])=[CH:11][C:10]([C:14]([F:17])([F:16])[F:15])=[CH:9][C:8]=2[Cl:18])[N:5]=[C:4]([C:19]#[N:20])[C:3]=1[S:21][C:22]([F:25])([F:24])[F:23].ClC1C=CC=C(C(OO)=[O:34])C=1>ClCCl.C(OCC)(=O)C>[NH2:1][C:2]1[N:6]([C:7]2[C:12]([Cl:13])=[CH:11][C:10]([C:14]([F:15])([F:16])[F:17])=[CH:9][C:8]=2[Cl:18])[N:5]=[C:4]([C:19]#[N:20])[C:3]=1[S:21]([C:22]([F:25])([F:24])[F:23])=[O:34]

Participants

5

Reactant 2

HCID 70297m-Chloroperbenzoic acid2×HCID 9953940Fipronil sulfide

Product 1

HCID 3352FipronilYield 57.8%

Reagents, catalysts & solvents 2

HCID 6344DichloromethaneSolventHCID 8857Ethyl AcetateSolvent

Procedure

A stirred solution of 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)-4-trifluoromethylthiopyrazole (10.0 g) in dichloromethane (100 ml) was treated with m-chloroperbenzoic acid (4.5 g). After stirring overnight additional m-chloroperbenzoic acid (1.6 g) was added in 2 portions, and left for 2 days. The reaction product was diluted with ethyl acetate (30 ml) and then washed in turn with sodium sulphite solution (50 ml), sodium carbonate solution (50 ml) and with water (50 ml). After drying over magnesium sulphate, this was filtered and evaporated in vacuo. Purification by chromatography on silica eluting with dichloromethane gave 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)-4-trifluoromethylsulphinylpyrazole as a white solid (6.0 g), m.p. 200.5°-201° C.

Workup

  1. additionwas added in 2 portions
  2. washwashed in turn with sodium sulphite solution (50 ml), sodium carbonate solution (50 ml) and with water (50 ml)
  3. dry with materialAfter drying over magnesium sulphate
  4. filtrationthis was filtered
  5. customevaporated in vacuo
  6. customPurification by chromatography on silica eluting with dichloromethane

Sources & evidence

ORD record
ord-59ec3b05d5f4441b8411a3632590d677
Source dataset
uspto-grants-1993_08
Patent number
US05232940

Reaction notes

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