Sulfuric Acid → 1H-Pyrazole, 3,5-diphenyl-

HRID 1600367Notes

Reaction equation

HRID 1600367 reaction equation
S(=O)(=O)(O)O.O.[NH2:7][NH2:8].[C:9]([C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1)(=O)[CH3:10].[Na]>>[C:12]1([C:9]2[CH:10]=[C:9]([C:12]3[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=3)[NH:8][N:7]=2)[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1

Participants

5

Reactant 4

HCID 1118Sulfuric AcidHCID 7410AcetophenoneHCID 24654Hydrazine hydrate (1:1)HCID 5360545Sodium

Product 1

HCID 708401H-Pyrazole, 3,5-diphenyl-Yield 91.9%

Procedure

490 parts (3 mol) of 60% strength by weight sulfuric acid were initially introduced into the stirring flask. 46.9 parts (0.75 mol) of 80% strength by weight hydrazine hydrate, 90 parts (0.75 mol) of acetophenone, 79.5 parts (0.75 mol) of benzladehyde and 1.5 parts (0.01 mol) of sodium iodidewere metered in in succession at room temperature. The reaction mixture wasbrought to 120° C. by distilling off water and kept at 120° C. for 2.5 hours. 110 parts of water were distilled off. The mixture was diluted with the distilled-off water and neutralized with 717 parts (4.5 mol) of 25% strength by weight sodium hydroxide solution. The precipitate was filtered off at room temperature, and the filter residue was washed with water and dried. 160.6 parts of 3,5-diphenylpyrazole having a purity of 94.4% (HPLC) were obtained, which corresponds to a yield of 91.9% of theory. M.p.: 194° C.

Workup

  1. customiodidewere metered in in succession at room temperature
  2. customwasbrought to 120° C.
  3. distillationby distilling off water
  4. distillation110 parts of water were distilled off
  5. additionThe mixture was diluted with the distilled-off water
  6. filtrationThe precipitate was filtered off at room temperature
  7. washthe filter residue was washed with water
  8. customdried

Sources & evidence

ORD record
ord-ae8aff72413741bc90708320f47c3194
Source dataset
uspto-grants-1998_04
Patent number
US05744614

Reaction notes

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