Dimethylformamide → 1-Benzyl-3,5-dimethyl-1H-pyrazole-4-carbaldehyde

HRID 220465Notes

Reaction equation

HRID 220465 reaction equation
[CH2:1]([N:8]1[C:12]([CH3:13])=[CH:11][C:10]([CH3:14])=[N:9]1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.P(Cl)(Cl)(Cl)=O.[OH-].[Na+].CN(C)[CH:24]=[O:25]>>[CH2:1]([N:8]1[C:12]([CH3:13])=[C:11]([CH:24]=[O:25])[C:10]([CH3:14])=[N:9]1)[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1

Participants

5

Reactant 4

HCID 6228DimethylformamideHCID 14798Sodium HydroxideHCID 24813Phosphorus oxychlorideHCID 6037651-Benzyl-3,5-dimethyl-1H-pyrazole

Product 1

HCID 9689341-Benzyl-3,5-dimethyl-1H-pyrazole-4-carbaldehyde

Conditions

Temperature
95 °C

Procedure

Dissolve 1-benzyl-3,5-dimethyl-1H-pyrazole (3.088 g, 16.6 mmol) in N,N-dimethylformamide (12.8 mL) and heat the mixture to 95° C., then add phosphorus oxychloride (13.4 mL) dropwise. Stir the mixture for 3 hr. at 95° C. then cool and add ice water very slowly. Adjust the mixture to approximately pH=4 using 5 N sodium hydroxide, extract the black mixture with diethyl ether 3 times, dry (sodium sulfate) and filter to give the title preparation as a yellow solid (2.65 g, 75%). 1H-NMR (400 MHz, DMSO-d6) δ 2.282 (s, 3H); 2.433 (s, 3H); 5.233 (s, 2H); 7.13 (m, 2H); 7.21-7.34 (m, 3H); 9.800 (s, 1H).

Workup

  1. temperatureat 95° C. then cool
  2. extractionextract the black mixture with diethyl ether 3 times
  3. dry with materialdry (sodium sulfate)
  4. filtrationfilter
  5. customto give the title

Sources & evidence

ORD record
ord-1ee2ea9e902d49b389fd90ea7f4437e9
Source dataset
uspto-grants-2012_06
Patent number
US08202873B2

Reaction notes

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