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

Participants

Reaction Conditions

Reaction Steps

60 parts (0.5 mol) of acetophenone and 53 parts (0.5 mol) of benzaldehyde were simultaneously added dropwise at 25° C. to 140 parts (1 mol) of initially introduced 70% strength by weight sulfuric acid. The mixture was stirred at 25° C. for 60 minutes and the reaction solution obtained was simultaneously added dropwise with 25 parts (0.5 mol) of hydrazine hydrate at 135° C. to 140 parts (1 mol) of initially introduced 70% strength by weight sulfuric acid and 0.5 parts (0.0033 mol)of sodium iodide in the course of 25 minutes. The mixture was stirred at 125° C. for 60 minutes. In order to keep the temperature at 135° C., 38 parts of water were distilled off. The mixture was diluted with 500 parts of water and neutralized with 247.8 parts (3.1 mol)of 50% strength by weight sodium hydroxide solution. After filtering off the solid it was washed until sulfate-free and dried. 109.7 parts of 3,5-diphenylpyrazole having a purity of 96.8% (HPLC) were obtained, which corresponds to a yield of 96.5% of theory. M.p.: 197° C.

Provenance & Evidence