Ultrasonic Cavitation Facilitates Rapid Synthesis of Trisubstituted Pyrazole Scaffolds through Michael Addition/Domino Cyclization. Issue 33 (5th September 2019)

• Record Type: Journal Article
• Authors: Kannan, Damodharan; Naveen, Shivalingegowda; Jagadeesan, Ganapathy; Lokanath, Nerattur Krishnappagowda; Thennarasu, Sathiah
• Is Part Of: ChemistrySelect. Volume 4:Issue 33(2019)
• Page Start: 9807
• Page End: 9810
• Publication Date: 2019-09-05
• Subjects: Carbohydrazide -- Chalcone -- Domino cyclization -- Indolylpyrazole -- Isoniazid -- Michael addition -- Witting reaction; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/slct.201902126
• Languages: English
• ISSNs: 2365-6549

Abstract

Abstract: A series of aryl/indolyl substituted 4, 5‐dihydro‐1H‐pyrazole derivatives were synthesized via a domino method based on Michael addition mediated cyclization of appropriate chalcones. The chalcones were prepared by Witting reaction in which substituted aromatic aldehydes were treated with stable ylides under eco‐friendly ultrasonic cavitation. The pyrazole scaffolds were obtained in excellent yields within a short span of time. Abstract : Ultrasonic cavitation promotes Michael addition mediated domino cyclization of chalcones with hydrazides, yielding aryl/indolyl substituted pyrazole scaffolds. The two‐step procedure generates three new C−C, C−N, and C=N bonds with high atom efficiency and regioselectivity in excellent yields