Hydrochloric Acid → 1-phenyl-1H-pyrazol-5-ol

HRID 485680

Reaction equation

HRID 485680 reaction equation
C(OC([C:6]1[C:10](=[O:11])[N:9]([C:12]2[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=2)[NH:8][CH:7]=1)=O)C.Cl>[OH-].[Na+]>[C:12]1([N:9]2[C:10](=[O:11])[CH:6]=[CH:7][NH:8]2)[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1

Participants

4

Reactant 2

HCID 313Hydrochloric AcidHCID 223722Ethyl 3-oxo-2-phenyl-2,3-dihydro-1h-pyrazole-4-carboxylate

Product 1

HCID 27487101-phenyl-1H-pyrazol-5-olYield 72.7%

Reagents, catalysts & solvents 1

HCID 14798Sodium HydroxideSolvent

Procedure

4-Ethoxycarbonyl-1-phenyl-3-pyrazolin-5-one (2.139 g, 9.2 mmol) in 1N sodium hydroxide (50 ml) was stirred under nitrogen at vigorous reflux for three hours. The reaction mixture was allowed to cool and acidified (HCl) to pH 3.5, whereupon ethyl acetate extraction, followed by drying (MgSO4) and evaporation produced the desired product (1.072 g, 72%) δ max(CHCl3) 1705, 1595, 1495 cm-1 δ(D6 -DMSO) 5.60 (1H,d,J2 Hz, C4 proton), 7.60 (6H, m, phenyl protons and C3 proton) Found; M+ ; 160.0641. C9H8N2O6 requires M; 160.0637.

Workup

  1. temperatureat vigorous reflux for three hours
  2. temperatureto cool
  3. extractionwhereupon ethyl acetate extraction
  4. customby drying
  5. custom(MgSO4) and evaporation

Sources & evidence

ORD record
ord-e552ae1ab9a741ab8e60d2c0b06aecd9
Source dataset
uspto-grants-1985_08
Patent number
US04537886

Linked notes

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