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

Participants

Reaction Conditions

Reaction Steps

120 parts (1 mol) of acetophenone and 106 parts (1 mol) of benzaldehyde were simultaneously added dropwise at 70° C. to 490 parts (3 mol) of 60% strength by weight sulfuric acid. The mixture was stirred at 70° C. for 2 hours and the phases were then separated. The sulfuricacid phase was initially introduced with 2 parts (0.0133 mol) of sodium iodide and 62.5 parts (1 mol) of 80% strength by weight hydrazine hydrate were added dropwise. The reaction mixture was heated to reflux (116° C.) and the organic phase was added dropwise in the course of60 minutes. In order to keep the temperature at 116° C., water was distilled off. The mixture was stirred at 116° C. for 5 hours, 150 ml of water being distilled off in this process. The mixture was diluted with 500 ml of water, and the precipitate was filtered off at room 30 temperature and washed with water until neutral. After drying, 213.3 partsof 3,5-diphenylpyrazole having a purity of 96% (HPLC) were obtained, which corresponds to a yield of 93.1% of theory. M.p.: 196° C.

Provenance & Evidence