Isoamyl Nitrite → Ethyl 5-bromo-1-phenyl-1H-pyrazole-4-carboxylate

HRID 1731254Notes

Reaction equation

HRID 1731254 reaction equation
N[C:2]1[N:6]([C:7]2[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=2)[N:5]=[CH:4][C:3]=1[C:13]([O:15][CH2:16][CH3:17])=[O:14].[Br:18]Br.N(OCCC(C)C)=O>C(Cl)(Cl)Cl>[Br:18][C:2]1[N:6]([C:7]2[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=2)[N:5]=[CH:4][C:3]=1[C:13]([O:15][CH2:16][CH3:17])=[O:14]

Participants

5

Reactant 3

HCID 8053Isoamyl NitriteHCID 24408BromineHCID 85270Ethyl 5-amino-1-phenyl-1H-pyrazole-4-carboxylate

Product 1

HCID 13802165Ethyl 5-bromo-1-phenyl-1H-pyrazole-4-carboxylateYield 38%

Reagents, catalysts & solvents 1

HCID 6212ChloroformSolvent

Procedure

To a solution of 20.0 g of 5-amino-1-phenyl-1H-pyrazole-4-carboxylic acid, ethyl ester and 10 ml of bromine in 200 ml of chloroform was added 15.8 g of isoamyl nitrite dropwise. The reaction mixture was allowed to stir at room temperature for about 24 hours and the volatiles were removed under reduced pressure. The residue was recrystallized from ethanol/water to provide 10.0 g of 5-bromo-1-phenyl-1H-pyrazole-4-carboxylic acid, ethyl ester. Yield 38%. mp=86°-89° C.

Workup

  1. customthe volatiles were removed under reduced pressure
  2. customThe residue was recrystallized from ethanol/water

Sources & evidence

ORD record
ord-118c0bca525843a6b756d8040708fa0c
Source dataset
uspto-grants-1986_11
Patent number
US04620865

Reaction notes

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