Benzaldehyde → 1H-Pyrazole, 3,5-diphenyl-

HRID 1600366Notes

Reaction equation

HRID 1600366 reaction equation
S(=O)(=O)(O)O.[I-].[Na+].O.[NH2:9][NH2:10].[C:11]([C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1)(=O)[CH3:12].[CH:20](=O)[C:21]1[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=1.[OH-].[Na+]>O>[C:21]1([C:20]2[CH:12]=[C:11]([C:14]3[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=3)[NH:10][N:9]=2)[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=1

Participants

8

Reactant 6

HCID 240BenzaldehydeHCID 1118Sulfuric AcidHCID 5238Sodium IodideHCID 7410AcetophenoneHCID 14798Sodium HydroxideHCID 24654Hydrazine hydrate (1:1)

Product 1

HCID 708401H-Pyrazole, 3,5-diphenyl-Yield 94.8%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

490 parts (3 mol) of 60% strength by weight sulfuric acid and 1.5 parts (0.01 mol) of sodium iodide 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 and 79.5 parts (0.75 mol) of benzaldehyde were simultaneously added dropwise at 120° C. in the course of 2 hours. By distilling off 120 parts of water the temperature was kept at 120° C. for 2 hours. The reaction mixture obtained was diluted with the distilled-off water and neutralized with 936 parts (4.7 mol) of 20% strength by weight sodium hydroxide solution. The precipitate was filtered off at room temperature, and the filter residue was washed with water and dried. 162.7 parts of 3,5-diphenylpyrazole having a purity of 96.1% (HPLC) were obtained, which corresponds to a yield of 94.8% of theory. M.p.: 196° C.

Workup

  1. distillationBy distilling off 120 parts of water the temperature
  2. customThe reaction mixture obtained
  3. filtrationThe precipitate was filtered off at room temperature
  4. washthe filter residue was washed with water
  5. customdried

Sources & evidence

ORD record
ord-d5e787144bad4aa4bd2517dc04f035a2
Source dataset
uspto-grants-1998_04
Patent number
US05744614

Reaction notes

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