Sulfuric Acid → HCID 20328055, compound

HRID 372196Notes

Reaction equation

HRID 372196 reaction equation
[Br:1][C:2]1[C:6]([Br:7])=[CH:5][N:4]([CH:8]([CH3:11])[CH2:9][OH:10])[N:3]=1.[OH-].[Na+].[Mn]([O-])(=O)(=O)=[O:15].[K+].S(=O)(=O)(O)O.S(=O)(O)[O-].[Na+]>O.[O-2].[O-2].[Mn+4]>[Br:1][C:2]1[C:6]([Br:7])=[CH:5][N:4]([CH:8]([CH3:11])[C:9]([OH:15])=[O:10])[N:3]=1

Participants

8

Reactant 5

HCID 1118Sulfuric AcidHCID 14798Sodium HydroxideHCID 516875Potassium PermanganateHCID 20327982HCID 20327982, compoundHCID 23665763Sodium Bisulfite

Product 1

HCID 20328055HCID 20328055, compound

Reagents, catalysts & solvents 2

HCID 178418406HCID 178418406, compoundCatalystHCID 962WaterSolvent3×

Conditions

Temperature
25 °C

Procedure

To a suspension of 3,4-dibromo-β-methylpyrazole-1-ethanol (2.8 g., 0.01 mole) prepared in Example 38, above, in sodium hydroxide (0.3 g., 0.0075 mole) and water (3.0 ml.), a solution of potassium permanganate (3.4 g., 0.0215 mole) in water (30 ml.) was added over a period of 20 minutes. A further 30 ml. of water was added and the reaction mixture was stirred at about 25° C. for 4 hours, followed by acidification with 6N sulfuric acid and addition of sodium bisulfite until all the precipitated manganese dioxide went into solution. The aqueous solution was extracted with three 50-ml. portions of ether and the combined ether extracts were washed with water and dried over anhydrous sodium sulfate. Evaporation of the ether under reduced pressure followed by chromatography on silica gel using the solvent system benzene, 85:chloroform, 5:glacial acetic acid, 10 (by volume) gave a solid which on recrystallization from acetone-hexane gave 3,4-dibromo-α-methylpyrazole-1-acetic acid having a melting point at 124.5° to 126.5° C.

Workup

  1. customprepared in Example 38
  2. extractionThe aqueous solution was extracted with three 50-ml
  3. washportions of ether and the combined ether extracts were washed with water
  4. dry with materialdried over anhydrous sodium sulfate
  5. customEvaporation of the ether under reduced pressure
  6. customchloroform, 5:glacial acetic acid, 10 (by volume) gave a solid which
  7. customon recrystallization from acetone-hexane

Sources & evidence

ORD record
ord-bd420ac86d72459e95f95fcda323f6ff
Source dataset
uspto-grants-1978_05
Patent number
US04089672

Reaction notes

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