Dimethylformamide → Ethyl 5-bromo-4-formyl-1-phenyl-1H-pyrazole-3-carboxylate

HRID 1521847Notes

Reaction equation

HRID 1521847 reaction equation
O[C:2]1[N:6]([C:7]2[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=2)[N:5]=[C:4]([C:13]([O:15][CH2:16][CH3:17])=[O:14])[CH:3]=1.O(Br)[Br:19].[P].CN([CH:25]=[O:26])C>ClCCCl>[Br:19][C:2]1[N:6]([C:7]2[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=2)[N:5]=[C:4]([C:13]([O:15][CH2:16][CH3:17])=[O:14])[C:3]=1[CH:25]=[O:26]

Participants

5

Reactant 3

HCID 6228DimethylformamideHCID 57353534CID 573535342×HCID 178469352HCID 178469352, compound

Product 1

HCID 86670903Ethyl 5-bromo-4-formyl-1-phenyl-1H-pyrazole-3-carboxylate

Reagents, catalysts & solvents 1

HCID 111,2-DichloroethaneSolvent

Conditions

Temperature
90 °C

Procedure

To a solution of ethyl 5-hydroxy-1-phenyl-1H-pyrazole-3-carboxylate (6.47 g, 27.52 mmol) in DCE (70 mL) is added phosphorus oxy bromide (13.86 g, 48.16 mmol) and DMF (4 mL, 51.46 mmol). The reaction mixture is refluxed at 90° C. for 3 h. Phosphorus oxy bromide (34.8 g, 121.38 mmol) is added again and the reaction mixture is refluxed at 90° C. for 20 h. The reaction mixture is poured over ice and extracted with DCM twice. The organic layer is dried over Na2SO4 and concentrated. The crude is purified by column chromatography to afford the title compound. 1H NMR (DMSO-d6, 400 MHz): δ 10.30 (s, 1H), 7.63-7.61 (m, 5H), 4.38 (q, J=3.6 Hz, 2H), 1.32 (t, J=7.1 Hz, 3H). MS (ESI+): 325.0, HPLC (max plot) 97.37%, Rt 4.42 min.

Workup

  1. temperaturethe reaction mixture is refluxed at 90° C. for 20 h
  2. additionThe reaction mixture is poured over ice
  3. extractionextracted with DCM twice
  4. dry with materialThe organic layer is dried over Na2SO4
  5. concentrationconcentrated
  6. customThe crude is purified by column chromatography

Sources & evidence

ORD record
ord-34cdddfa1f21477aa6e6e992323bdd19
Source dataset
uspto-grants-2015_07
Patent number
US09073940B2

Reaction notes

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