Water → 5-Amino-3-bromo-1-(2,6-dichloro-4-trifluoromethylphenyl)-4-methylsulphinylpyrazole

HRID 975502Notes

Reaction equation

HRID 975502 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]([Br:19])[C:3]=1[S:20][CH3:21].S(OOS([O-])(=O)=O)(O)(=O)=[O:23].[K+].O.S(=O)(O)[O-].[Na+]>CO>[NH2:1][C:2]1[N:6]([C:7]2[C:12]([Cl:13])=[CH:11][C:10]([C:14]([F:17])([F:15])[F:16])=[CH:9][C:8]=2[Cl:18])[N:5]=[C:4]([Br:19])[C:3]=1[S:20]([CH3:21])=[O:23]

Participants

6

Reactant 4

HCID 962WaterHCID 226184245-Amino-3-bromo-1-(2,6-dichloro-4-trifluoromethylphenyl)-4-methylthiopyrazoleHCID 23665763Sodium BisulfiteHCID 23690007Potassium hydrogen persulfate2×

Product 1

HCID 226183715-Amino-3-bromo-1-(2,6-dichloro-4-trifluoromethylphenyl)-4-methylsulphinylpyrazoleYield 43.4%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Conditions

Temperature
0 °C

Procedure

A solution of 5-amino-3-bromo-1-(2,6-dichloro-4-trifluoromethylphenyl)-4-methylthiopyrazole (2.0 g) [preparation described in Example 15] in methanol (45 ml) at -25° C. was treated with a rapidly added solution of potassium hydrogen persulphate (1.66 g), followed immediately by the addition of water (22 ml). The mixture was stirred for 30 minutes at 0° C., and potassium hydrogen persulphate (0.4 g) added. After 21/2 hours stirring at room temperature, the mixture was poured onto water (300 ml) and saturated sodium bisulphite solution (35 ml) added. This was extracted with dichloromethane (2×150 ml) and the extract washed with water (2×50 ml), dried over anhydrous magnesium sulphate, and evaporated in vacuo. The crude product was purified by chromatography eluting with dichloromethane/ethyl acetate (4:1) to give 5-amino-3-bromo-1-(2,6-dichloro-4-trifluoromethylphenyl)-4-methylsulphinylpyrazole (0.9 g) as a white solid, m.p. 135°-136° C.

Workup

  1. stirringAfter 21/2 hours stirring at room temperature
  2. additionadded
  3. extractionThis was extracted with dichloromethane (2×150 ml)
  4. washthe extract washed with water (2×50 ml)
  5. dry with materialdried over anhydrous magnesium sulphate
  6. customevaporated in vacuo
  7. customThe crude product was purified by chromatography
  8. washeluting with dichloromethane/ethyl acetate (4:1)

Sources & evidence

ORD record
ord-0f2bc94501f546e2b256102805556561
Source dataset
uspto-grants-1997_03
Patent number
US05608077

Reaction notes

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