One-pot synthesis of novel substituted quinoxaline piperazine derivatives and their antimicrobial activities

The present investigation reports the preparation of 1-(4-(tolyl quinoxaline-2-yl) piperazine-1-yl) derivatives catalyzed via polymer supported reagents. We have developed novel quinoxaline piperazine derivatives from 2,3-dichloroquinoxaline, wherein one chloro group is substituted with an aryl group, and the other is substituted by alkyl and aryl piperazine derivatives, through aromatic nucleophilic substitution reaction, and Suzuki coupling reactions to substituted quinoxaline-piperazine derivatives (5a-5g) compounds. The synthesized compounds were identified using FTIR, H-1 NMR, C-13 NMR and LC-MS. The synthesized compounds were examined for their antimicrobial activity. The results indicated that 5d, 5f and 5 g compounds have exhibited well to moderate antibacterial activity with the zone of inhibition of 18, 22 and 21 mm for Escherichia coli (40 mu g/mL), and 17, 19 and 17 mm for Staphylococcus aureus (40 mu g/mL). Besides, 5f compound showed respectable results to moderate antifungal activity with the zone of inhibition of 21 mm for Aspergillus niger (40 mu g/mL) and 19 mm for Candida albicans (40 mu g/mL). The established synthetic route is beneficial to develop various key intermediates as well as active pharmaceutical ingredients for pharmaceutical applications. (C) 2021 Elsevier B.V. All rights reserved.