Ammonia → 5-(5-nitrofuran-2-yl)-1H-pyrazole-4-carbaldehyde

HRID 839195Notes

Reaction equation

HRID 839195 reaction equation
N.C1O[CH:5]([C:6]2[C:7]([C:15]3[O:16][C:17]([N+:20]([O-:22])=[O:21])=[CH:18][CH:19]=3)=[N:8][N:9](C(OC)=O)[CH:10]=2)[O:4]C1.Cl>CN(C)C=O.O>[N+:20]([C:17]1[O:16][C:15]([C:7]2[C:6]([CH:5]=[O:4])=[CH:10][NH:9][N:8]=2)=[CH:19][CH:18]=1)([O-:22])=[O:21]

Participants

6

Reactant 3

HCID 222AmmoniaHCID 313Hydrochloric AcidHCID 203260461-Methoxycarbonyl-3-(5-nitro-2-furyl)pyrazole-4-carboxaldehyde-ethyleneacetal

Product 1

HCID 1785198815-(5-nitrofuran-2-yl)-1H-pyrazole-4-carbaldehydeYield 96%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6228DimethylformamideSolvent

Procedure

Add dropwise 292 ml of a 25% ammonia solution to a suspension of 513 g of 1-methoxycarbonyl-3-(5-nitro-2-furyl)pyrazole-4-carboxaldehyde-ethyleneacetal in 2000 ml of dimethylformamide and 250 ml water at 20° to 25° C within a period of approximately 20 minutes, whereupon the precipitate is dissolved. Then stir for a further 30 minutes. While cooling to a moderate extent, add approximately 1000 ml of 2N hydrochloric acid; a strongly acidic reaction is obtained. Stir for 2 hours at 30° C and add 1.7 kg of ice. Draw off the thrown-down precipitate under cold conditions and wash with water until neutral to obtain 3-(5-nitro-2-furyl)-1H-pyrazole-4-carboxaldehyde [m.p. 187° to 187.5° C]with a yield of 96%.

Workup

  1. dissolutionwhereupon the precipitate is dissolved
  2. temperatureWhile cooling to a moderate extent
  3. customa strongly acidic reaction
  4. customis obtained
  5. stirringStir for 2 hours at 30° C
  6. washwash with water until neutral

Sources & evidence

ORD record
ord-74241f7000044d39bf80bd8c32dabc47
Source dataset
uspto-grants-1978_06
Patent number
US04093812

Reaction notes

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