Synthesis and antibacterial activity of new derivatives of 1,4-di-N-oxides of quinoxaline

Synthesis of 7-amino-6-halogeno-3-phenylquinoxaline-2-carbonitrile 1,4-dioxides: a way forward for targeting hypoxia and drug resistance of cancer cells

“…The synthesis of compounds 9b, 10b based on the nucleophilic substitution of halogen atom in the nitroanilines 8a-b and subsequent oxidation of 9b, 10b into benzofuroxans 9b and 10b respectively, have been described previously. [39][40][41][42][43][44][45] 5-(tert-Butyl-piperazine-1-yl-carboxylate)-2-nitroaniline (6). To a stirring mixture of 5-uoro-2-nitroaniline (5, 1.0 g, 6.4 mmol) in N,N-dimethylformamide (10 mL) the 1-Boc-piperazine (3.0 g, 16.0 mmol) and Et 3 N (1 mL) were added at 50 C. The mixture was stirred for 4 h at 50 C. The mixture was poured in water (20 mL) and stirred for 1 h when cooling.…”

“…This compound was prepared from 8b and N-methylpiperazine as described in. 43 5-(4-tert-Butyl-aminopiperidine-1-yl-carboxilate)-4-chloro-2nitroaniline (10g). This compound was prepared from 8b and 4-N-Boc-aminopiperidine as described for 6.…”

“…This compound was prepared from 10b as described in. 43 Yield 0.9 g (3.3 mmol, 89%), yellow powder, mp 110-113 C (lit., 43 6-(4-tert-Butyl-aminopiperidine-1-yl-carboxilate)-5chlorobenzofuroxan (12g). This compound was prepared from 10g as described for 7.…”

“…Yield 0.9 g (3.3 mmol, 83%), yellow powder, mp 204-205 C (lit.,43 202 C). 1 H NMR (400 MHz; DMSO-d 6 ; Me 4 Si) d 7.95 (1H, s, H Ar ), 7.53 (2H, s, NH 2 ), 7.52 (1H, s, H Ar ), 3.13-3.05 (4H, br m, CH 2 ), 2.55-2.52 (4H, br m, CH 2 ), 2.26 (3H, s, CH 3 ); 13 C NMR (100 MHz; DMSO-d 6 ) d 154.9 (C-N), 146.6 (C-NH 2 ),…”

Synthesis, Characterization, Anti-Bacterial and Anti-Fungal Activities of New Quinoxaline 1,4-di-N-Oxide Derivatives

“…Quinoxaline 1,4-di-Noxide is a nucleus that displays a wide range of activities. Quinoxaline 1,4-di-N-oxides and their derivatives demonstrated excellent activities as antibacterial [1][2][3][4][5], antiplasmodial [2,6,7], antifungal [8] and as antimycobacterial [9][10][11][12][13]. Encouraged by these reported activities and with the aim of searching for new, broad spectrum and more potent antimicrobial compounds which can improve the current chemotherapeutic treatments, 20 new quinoxaline 1,4-di-Noxide derivatives were synthesized and evaluated.…”