ChemInform Abstract: One-Pot Synthesis of Functionalized 3-Aryl-1-phenyl-1H-pyrazoles from Hydrazonoyl Chlorides and Acetylenic Esters in the Presence of Ph3P.
Three-component reaction between acetylenic esters, aldehyde semicarbazones and tributyl- or triethyl phosphite leads to stable crystalline phosphite ylides at one step in nearly quantitative yields.