Hydrogen Bromide → HCID 22909691, compound

HRID 1379096Notes

Reaction equation

HRID 1379096 reaction equation
N([O-])=O.[Na+].[CH3:5][O:6][C:7]1[CH:12]=[CH:11][C:10]([N:13]2[C:17]([C:18]3[CH:23]=[CH:22][C:21]([S:24][CH3:25])=[CH:20][CH:19]=3)=[CH:16][C:15](N)=[N:14]2)=[CH:9][CH:8]=1.S(=O)(=O)(O)O.[Br-:32].[Na+].Br>O.C(#N)C>[Br:32][C:15]1[CH:16]=[C:17]([C:18]2[CH:23]=[CH:22][C:21]([S:24][CH3:25])=[CH:20][CH:19]=2)[N:13]([C:10]2[CH:11]=[CH:12][C:7]([O:6][CH3:5])=[CH:8][CH:9]=2)[N:14]=1

Participants

8

Reactant 5

HCID 260Hydrogen BromideHCID 1118Sulfuric AcidHCID 253881Sodium BromideHCID 22909674HCID 22909674, compoundHCID 23668193Sodium Nitrite

Product 1

HCID 22909691HCID 22909691, compoundYield 25.7%

Reagents, catalysts & solvents 2

HCID 962WaterSolvent3×HCID 6342AcetonitrileSolvent

Procedure

A solution of sodium nitrite (492 mg) in water (0.6 ml) was added dropwise to a mixture of 1-(4-methoxyphenyl)-5-[4-(methylthio)phenyl]pyrazol-3-amine (2 g) and sulfuric acid (1.2 ml) in water (3 ml) and acetonitrile (6 ml) at 5° C., and the mixture was stirred at the same temperature for 1 hour. The mixture was added portionwise to a mixture of cuprous bromide (1.25 g), sodium bromide (1.2 g) and hydrobromic acid (3.3 ml) in water (6 ml) at 70° to 80° C. during a period of 15 minutes, and the resulting mixture was stirred at 80° C. for 30 minutes. The aqueous layer was removed by decantation and the oily residue was extracted with toluene. The extract was washed with water, dried, and concentrated in vacuo. The residue (1.1 g) was purified by column chromatography on silica gel (20 g) eluting with a mixture of chloroform and n-hexane (2:1) to give crystals of 3-bromo-1-(4-methoxyphenyl)-5-[4-(methylthio)phenyl]pyrazole (0.62 g).

Workup

  1. stirringthe resulting mixture was stirred at 80° C. for 30 minutes
  2. customThe aqueous layer was removed by decantation
  3. extractionthe oily residue was extracted with toluene
  4. washThe extract was washed with water
  5. customdried
  6. concentrationconcentrated in vacuo
  7. customThe residue (1.1 g) was purified by column chromatography on silica gel (20 g)
  8. washeluting with a mixture of chloroform and n-hexane (2:1)

Sources & evidence

ORD record
ord-6d6ecee805a84cfe8961a3dedc86da49
Source dataset
uspto-grants-1997_09
Patent number
US05670533

Reaction notes

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