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

Participants

Reaction Conditions

Reaction Steps

120 parts (1 mol) of acetophenone and 106 parts (0.5 mol) of benzaldehyde were simultaneously added dropwise at 25° C. to 980 parts (6 mol) of initially introduced 60% strength by weight sulfuric acid. The mixture was stirred at 25° C. for 30 minutes and the phases were then separated. The sulfuric acid phase was initially introduced with 2 parts (0.013 mol) of sodium iodide and the organic phase was simultaneously metered in in the course of 10 minutes with 62.5 parts (1 mol) of 80% strength by weight hydrazine hydrate. The mixture was stirred under refluxfor 4.5 hours, during the course of which the temperature fell from 123° C. to 119° C. After diluting with 500 parts of water, the mixture was cooled to room temperature and the solid was filtered off.The filter residue was washed with water until neutral and dried. 210.4 parts of 3,5-diphenylpyrazole having a purity of 97.5% (HPLC) were obtained, which corresponds to a yield of 93.2% of theory. M.p.: 198° C.

Provenance & Evidence