Acetic Acid → 3-(5-Nitrofuran-2-yl)-1-phenyl-1H-pyrazole-4-carbaldehyde

HRID 839203Notes

Reaction equation

HRID 839203 reaction equation
[C:1]([OH:4])(=O)[CH3:2].[C:5]1([NH:11][NH2:12])[CH:10]=[CH:9][CH:8]=[CH:7][CH:6]=1.[N+:13]([C:16]1[O:20][C:19]([C:21](=O)C)=[CH:18][CH:17]=1)([O-:15])=[O:14].[CH3:24]N(C)C=O>>[N+:13]([C:16]1[O:20][C:19]([C:21]2[C:2]([CH:1]=[O:4])=[CH:24][N:11]([C:5]3[CH:10]=[CH:9][CH:8]=[CH:7][CH:6]=3)[N:12]=2)=[CH:18][CH:17]=1)([O-:15])=[O:14]

Participants

5

Reactant 4

HCID 176Acetic AcidHCID 6228DimethylformamideHCID 7516PhenylhydrazineHCID 213482-Acetyl-5-nitrofuran

Product 1

HCID 203262553-(5-Nitrofuran-2-yl)-1-phenyl-1H-pyrazole-4-carbaldehydeYield 85%

Conditions

Temperature
40 °C

Procedure

Add 0.1 g of glacial acetic acid and 4.0 g of phenylhydrazine to a solution of 5.0 g of 5-nitro-2-acetylfuran in 27 ml of dimethylformamide, the temperature rising slightly. Stir the resulting admixture for 1 hour without heating before clarifying with degased active charcoal and then adding 16.3 g of phosphorus oxychloride to the thus-prepared solution of 5-nitro-2-acetylfuran-phenylhydrazone while cooling with ice at from 10° to 15° C. Stir for a further hour at this temperature and then for 24 hours at room temperature. Pour the solution (containing 4-pyrazolylmethylenedimethylammonium salt) onto ice and water and then heat for 1.5 hours at 40° C before cooling in ice to obtain an 85% yield of 3-(5-nitro-2-furyl)-1-phenylpyrazole-4-carboxaldehyde [m.p. 208° to 209° C (dimethylformamide/water)].

Workup

  1. temperaturewithout heating
  2. customwith degased active charcoal
  3. additionadding 16.3 g of phosphorus oxychloride to the thus-prepared solution of 5-nitro-2-acetylfuran-phenylhydrazone
  4. temperaturewhile cooling with ice at from 10° to 15° C
  5. stirringStir for a further hour at this temperature
  6. waitfor 24 hours at room temperature
  7. additionPour
  8. additionthe solution (containing 4-pyrazolylmethylenedimethylammonium salt) onto ice and water
  9. temperaturebefore cooling in ice

Sources & evidence

ORD record
ord-7407b2c520d34b5daeebc57802df7785
Source dataset
uspto-grants-1978_06
Patent number
US04093812

Reaction notes

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