Dimethylformamide → Ethyl 5-chloro-4-formyl-1-isopropyl-1H-pyrazole-3-carboxylate

HRID 1862462Notes

Reaction equation

HRID 1862462 reaction equation
[CH2:1]([O:3][C:4]([C:6]1[CH:10]=[C:9](O)[N:8]([CH:12]([CH3:14])[CH3:13])[N:7]=1)=[O:5])[CH3:2].P(Cl)(Cl)([Cl:17])=O.CN(C)[CH:22]=[O:23]>>[CH2:1]([O:3][C:4]([C:6]1[C:10]([CH:22]=[O:23])=[C:9]([Cl:17])[N:8]([CH:12]([CH3:14])[CH3:13])[N:7]=1)=[O:5])[CH3:2]

Participants

4

Reactant 3

HCID 6228DimethylformamideHCID 24813Phosphorus oxychlorideHCID 178469364HCID 178469364, compound

Product 1

HCID 58907109Ethyl 5-chloro-4-formyl-1-isopropyl-1H-pyrazole-3-carboxylate

Conditions

Temperature
100 °C

Procedure

8 g of 5-hydroxy-1-isopropyl-1H-pyrazole-3-carboxylic acid ethyl ester was added portionwise to a preformed mixture of 3.44 ml of dimethylformamide and 94 ml of phosphorus oxychloride at 0° C. under nitrogen. The mixture was then heated at 100° C. for 20 h. The mixture was evaporated under reduced pressure, the residue poured into ice-cold saturated sodium hydrogen carbonate and then extracted three times with dichloromethane. The combined extracts were washed with brine then dried over anhydrous magnesium sulphate, filtered and evaporated to give 9.1 g of 5-chloro-4-formyl-1-isopropyl-1H-pyrazole-3-carboxylic acid ethyl ester as a light brown solid which was used without further purification. Mass spectrum (ESI) m/z 245 [M+H]+.

Workup

  1. customThe mixture was evaporated under reduced pressure
  2. additionthe residue poured into ice-cold saturated sodium hydrogen carbonate
  3. extractionextracted three times with dichloromethane
  4. washThe combined extracts were washed with brine
  5. dry with materialthen dried over anhydrous magnesium sulphate
  6. filtrationfiltered
  7. customevaporated

Sources & evidence

ORD record
ord-593ba8ee9f354cbd8d5a1706e6d5263c
Source dataset
uspto-grants-2003_03
Patent number
US06538015B1

Reaction notes

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