Sc(OTf)3-catalyzed, solvent-free domino synthesis of functionalized pyrazoles under controlled microwave irradiation

An efficient, rapid, and green synthesis of functionalized pyrazoles has been accomplished under solvent-free conditions by the reaction of phenyl hydrazine, aldehydes and ethyl acetoacetate. This approach exploits the synthetic potential of microwave irradiation and scandium triflate combination and offers many advantages such as excellent product yields, shorter reaction time, easy isolation of products, and environmentally benign reaction conditions.