Dimethylformamide → 5-chloro-1,3-diphenyl-1H-pyrazole-4-carbaldehyde

HRID 441857Notes

Reaction equation

HRID 441857 reaction equation
O=P(Cl)(Cl)[Cl:3].[C:6]1([N:12]2[C:16](=O)[CH2:15][C:14]([C:18]3[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=3)=[N:13]2)[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=1.[OH-].[Na+].CN(C)[CH:28]=[O:29]>>[Cl:3][C:16]1[N:12]([C:6]2[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=2)[N:13]=[C:14]([C:18]2[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=2)[C:15]=1[CH:28]=[O:29]

Participants

5

Reactant 4

HCID 6228DimethylformamideHCID 14798Sodium HydroxideHCID 24813Phosphorus oxychlorideHCID 785593H-Pyrazol-3-one, 2,4-dihydro-2,5-diphenyl-

Product 1

HCID 7366595-chloro-1,3-diphenyl-1H-pyrazole-4-carbaldehydeYield 93%

Procedure

At 5° to 10° 97.3 g of phosphorus oxytrichloride are added dropwise to 92.7 g of dimethylformamide and the mixture is stirred for completion of the complex formation for 30 minutes at room temperature. Following this 30 g of 1,3-diphenyl-2-pyrazoline-5-one are added and while stirring heating is carried out for 1 hour at 55° C. and for 20 hours at 70°. The product is poured on to approximately 600 g of ice neutralised with concentrated sodium hydroxide solution to pH 3-4, vacuum filtered and washed with water. 5-Chloro-1,3-diphenyl-pyrazole-4-carboxaldehyde is obtained with a yield of 93 %; F 109°-110° (from petroleum ether).

Workup

  1. additionare added
  2. stirringwhile stirring
  3. temperatureheating
  4. waitis carried out for 1 hour at 55° C. and for 20 hours at 70°
  5. filtrationfiltered
  6. washwashed with water

Sources & evidence

ORD record
ord-0d269c04e50b498c91c45e3723e38bbf
Source dataset
uspto-grants-1977_08
Patent number
US04042702

Reaction notes

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