tailieunhanh - Synthesis of thiophene-pyrazole conjugates as potent antimicrobial and radical scavengers

The current study presents the synthesis of thiophene-appended pyrazoles through 3+2 annulations of chalcones 3(a-g) with aryl hydrazine hydrochlorides 4(a-d) in acetic acid (30%) under reflux conditions produced the thiophene-pyrazole hybrids 5(a-g) in good yields. | Synthesis of thiophene-pyrazole conjugates as potent antimicrobial and radical scavengers Current Chemistry Letters 7 2018 73 80 Contents lists available at GrowingScience Current Chemistry Letters homepage Synthesis of thiophene-pyrazole conjugates as potent antimicrobial and radical scavengers Malledevarapura Gurumurthy Prabhudevaa Nagamallu Renukab and Kariyappa Ajay Kumara a Department of Chemistry Yuvaraja College University of Mysore Mysuru-570005 India b Department of Chemistry GSSS Institute of Engineering and Technology For Women Mysuru 570 016 India CHRONICLE ABSTRACT Article history The current study presents the synthesis of thiophene-appended pyrazoles through 3 2 Received April 28 2018 annulations of chalcones 3 a-g with aryl hydrazine hydrochlorides 4 a-d in acetic acid 30 Received in revised form under reflux conditions produced the thiophene-pyrazole hybrids 5 a-g in good yields. June 29 2018 Structures of synthesized new pyrazoles were confirmed by spectral studies and elemental Accepted August 2 2018 analysis. Further preliminary biological evaluation studies show that compounds 5b and 5f Available online having chloro substitution only in the thiophene ring exhibited excellent inhibition August 2 2018 µg mL against all the tested organisms in comparison with that of the standard. Compounds Keywords 5a 5c and 5g having electronegative chloro substitutions each in the aromatic and thiophene Antimicrobial Antioxidant rings showed excellent µg mL-1 DPPH radical scavenging potencies. The Chalcone synthesis of pyrazoline derivatives and the efficacy of some of the synthesized molecules as Cyclocondensation antimicrobial and antioxidant agents validate the significance of this study. Radical scavengers 2018 Growing Science Ltd. All rights reserved. 1. Introduction An interest in discovery design and synthesis of novel small-molecules with antimicrobial and radical scavenging effects is propelling .