Ethanol → HCID 178419588, compound

HRID 2260281Notes

Reaction equation

HRID 2260281 reaction equation
C[O:2][C:3]1[CH:4]=[C:5]([C:14]2[CH:18]=[C:17]([OH:19])[N:16]([CH3:20])[N:15]=2)[CH:6]=[C:7]([N+:11]([O-:13])=[O:12])[C:8]=1[O:9]C.B(Br)(Br)[Br:22].C(O)C>C(Cl)Cl>[BrH:22].[OH:19][C:17]1[N:16]([CH3:20])[N:15]=[C:14]([C:5]2[CH:4]=[C:3]([OH:2])[C:8]([OH:9])=[C:7]([N+:11]([O-:13])=[O:12])[CH:6]=2)[CH:18]=1

Participants

5

Reactant 3

HCID 702EthanolHCID 25134Boron tribromideHCID 178487583HCID 178487583, compound

Product 1

HCID 178419588HCID 178419588, compound

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

2.0 g of 3-(3,4-dimethoxy-5-nitrophenyl)-1-methylpyrazol-5-ol are suspended in 100 ml of methylene chloride. After cooling to -40° a solution of 4.9 ml of boron tribromide in 60 ml of methylene chloride is added dropwise thereto within 1 hour. The mixture is subsequently stirred at room temperature for 16 hours, cooled to -20° and treated within 30 minutes with 100 ml of ethanol. After stirring at room temperature for 1 hour, the solvent is removed by distillation in a water-jet vacuum at 40°. The residue is treated three times with a mixture of 100 ml of ethanol/toluene each time, with the solvent being distilled each time. The residue is recrystallized from ethanol. There is obtained 5-(5-hydroxy-1-methylpyrazol-3-yl)-3-nitropyrocatechol hydrobromide in the form of yellow crystals of m.p.>250°.

Workup

  1. additionis added dropwise
  2. temperaturecooled to -20°
  3. stirringAfter stirring at room temperature for 1 hour
  4. customthe solvent is removed by distillation in a water-jet vacuum at 40°
  5. additionThe residue is treated three times
  6. additionwith a mixture of 100 ml of ethanol/toluene each time
  7. distillationwith the solvent being distilled each time
  8. customThe residue is recrystallized from ethanol

Sources & evidence

ORD record
ord-ba4c72880b164308a21b87df5f9b7d09
Source dataset
uspto-grants-1995_12
Patent number
US05476875

Reaction notes

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