One-Pot Microwave-Assisted Synthesis of Benzopyrano[2,3-c]pyrazol-3-one Derivatives

A convenient one-pot microwave-assisted synthesis of Benzopyrano[2,3- c ]pyrazol-3-one derivatives was developed, where Knoevenagel condensation and hydrazinolysis reactions were continuously performed under microwave irradiation without separation and purification of the intermediates until the last cyclocondensation reaction except the substrates addition. The one-pot procedure exhibited shorter reaction times and higher yields (25–55%) of the objects than the conventional heating method.