Efficient One-Pot, Two-Component Modular Synthesis of 3,5-Disubstituted Pyrazoles
Copyright © 2018 American Chemical Society. The pyrazole scaffold is one of the most prevalent and important tool in medicinal chemistry. Here, we report a method for preparing 3,5-diarylpyrazoles in good to excellent yield by reacting hydrazones of aryl aldehydes with substituted acetophenones in ethanol in the presence of dimethyl sulfoxide/cat. I2/cat. HCl. The reverse process, reacting hydrazones of substituted acetophenones with aryl aldehydes under the same conditions, also provides 3,5-diarylpyrazoles in good to excellent yields. Reaction of hydrazones of aldehydes with 2′-aryloxy ketones in the presence of cat. HCl in ethanol and the catalyst-free reaction of phenacyl bromides with hydrazones of aldehydes in ethanol also gave good to excellent yields of 3,5-diarylpyrazoles.
Mohamady, Samy; Kralt, Braden; Samwel, Shery K.; and Taylor, Scott D., "Efficient One-Pot, Two-Component Modular Synthesis of 3,5-Disubstituted Pyrazoles" (2018). Pharmacy. 87.