Room-Temperature, Catalyst-Free, One-Pot Pseudo-Five-Component Synthesis of 4,4-(Arylmethylene)bis(3-methyl-1-phenyl-1H-pyrazol-5-ol)s under Ultrasonic Irradiation

A green and convenient approach for the synthesis of 4,4-(arylmethylene)bis (3-methyl-1-phenyl-1H-pyrazol-5-ols) by the reaction of aromatic aldehydes, phenylhydrazine derivatives, and ethyl acetoacetate in water/ethanol (1/1) under ultrasound irradiation is described. This method provides several advantages such as environmental friendliness, shorter reaction time, excellent yields, and simple workup procedure.