An efficient synthesis of some new bipyrazole derivatives by three-component reaction between 3-methyl-1 H -pyrazol-4(5 H )-one, aroylphenylhydrazones and arylglyoxals

A simple one-pot and catalyst-free method is reported for synthesis of some new bipyrazole derivatives by three-component reaction between arylglyoxals, 3-methyl-1H-pyrazol-4(5H)-one and aroylphenylhydrazone derivatives. The reactions were carried out in ethanol as a green solvent in neutral reaction conditions and products were simply isolated by filtering of the precipitated solids in high yields. All products were characterized by their 1H and 13C NMR and IR spectral and elemental analysis data.