Three-component reaction for an efficient synthesis of 5-hydroxy-1-phenyl-1H-pyrazoles containing a stable phosphorus ylide moiety

A concise synthesis of new polysubstituted pyrazoles containing a phosphorane is achieved from readily available organic compounds. This C–H bond functionalization is an efficient means of selectively substituting 4-position of pyrazole to produce a five-membered aromatic ring with a chain containing ylide moiety. This protocol requires no additional catalyst and can be used for other pyrazoles including different substituents.