Hydrazine hydrate (1:1) → 5-Phenyl-4H-pyrazol-3-ol

HRID 1471851Notes

Reaction equation

HRID 1471851 reaction equation
O=[C:2]([C:10]1[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=1)[CH2:3][C:4](OCCC)=[O:5].O.[NH2:17][NH2:18]>C(O)C>[C:10]1([C:2]2[CH2:3][C:4](=[O:5])[NH:18][N:17]=2)[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=1

Participants

4

Reactant 2

HCID 24654Hydrazine hydrate (1:1)HCID 10512459HCID 10512459, compound

Product 1

HCID 785775-Phenyl-4H-pyrazol-3-olYield 84.7%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Conditions

Temperature
80 °C

Procedure

To a solution of propyl 3-oxo-3-phenylpropanoate (10 g, 48.5 mmol) in ethanol (100 mL) was added hydrazine hydrate (9.71 g, 194 mmol) at room temperature. The reaction was heated to 80° C. for 2 h, cooled to room temperature and concentrated. The residue was crystallized from 20% ethyl acetate/hexane to give the title compound (6.58 g). LCMS m/z=161.08 [M+H]+; 1H NMR (400 MHz, DMSO-d6) δ ppm, 2.32 (br, 2H), 7.32-7.78 (m, 5H), 12.1 (s, 1H).

Workup

  1. temperaturecooled to room temperature
  2. concentrationconcentrated
  3. customThe residue was crystallized from 20% ethyl acetate/hexane

Sources & evidence

ORD record
ord-8e188294a750428a93b68ce8c0516460
Source dataset
uspto-grants-2015_04
Patent number
US09012478B2

Reaction notes

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