American Chemical Society
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One-Pot, Three-Component Approach to the Synthesis of 3,4,5-Trisubstituted Pyrazoles

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journal contribution
posted on 2015-05-01, 00:00 authored by Ahmed Kamal, K. N. Visweswara Sastry, D. Chandrasekhar, Geeta Sai Mani, Praveen Reddy Adiyala, Jagadeesh Babu Nanubolu, Kiran Kumar Singarapu, Ram Awatar Maurya
An operationally simple and high yielding protocol for the synthesis of polyfunctional pyrazoles has been developed through one-pot, three-component coupling of aldehydes, 1,3-dicarbonyls, and diazo compounds as well as tosyl hydrazones. The reaction proceeds through a tandem Knoevenagel condensation, 1,3-dipolar cycloaddition, and transition metal-free oxidative aromatization reaction sequence utilizing molecular oxygen as a green oxidant. The scope of the reaction was studied by varying the aldehyde, 1,3-dicarbonyl, and diazo component individually.