Synthesis and Antibacterial Activity of Nitroaryl Thiadiazole‐Levofloxacin Hybrids

Abstract

Novel levofloxacin-containing hybrids carrying a 5-(nitroaryl)-1,3,4-thiadiazol-2-yl group were synthesized and evaluated in vitro against Gram-positive and Gram-negative bacteria. Preliminary data indicated that levofloxacin-nitrofuran and levofloxacin-nitroimidazole hybrids have a potent activity against Gram-positive organisms with enhanced anti-staphylococcal activity compared with the parent quinolone (N-desmethyl levofloxacin).

Synthesis, in vitro‐Antimycobacterial Activity and Cytotoxicity of Some Alkyl α‐(5‐aryl‐1, 3, 4‐thiadiazole‐2‐ylthio)acetates

“…IR (KBr): ν cm Ϫ1 3128 (furan), 1728 (CϭO), 1537, 1363 (NO 2 ). The synthesis of compound 6g was reported previously [13]. …”

“…Water was added and the separated solid was filtered off, washed with water, and crystallized from ethanol. The synthesis of compound 6b was reported previously [13].…”

“…Also, nifurtimox, a 2-substituted-5-nitrofuran drug ( Figure 1) is currently available for treatment of Chagas' disease, a chronic illness affecting many people in Latin America [8]. In addition, the 1,3,4-thiadiazole ring system is known to have several biological and antibacterial properties [10Ϫ12].Based on these findings, we have previously reported the synthesis and antituberculosis activity of some new hybrid compounds (I and II, Figure 1) in which the 1,3,4-thiadiazole ring is combined with 5-nitroheterocycles [13,14].In continuing our efforts to establish the structure activity relationships of 2-aryl-1,3,4-thiadiazoles, herein we report …”

“…Diazotiazation of 2 in hydrochloric acid in the presence of copper powder gave 2-aryl-5-chloro-1,3,4-thiadiazoles 3aϪb [15]. The reaction of 3 with thiourea in refluxing ethanol afforded the 2-aryl-5-mercapto-1,3,4-thiadiazoles 4aϪb [13]. Treatment of the latter with alkyl chloroacetates (5aϪe) gave alkyl α-(5-aryl-1,3,4-thiadiazole-2-ylthio) acetates 6aϪj (Figure 2).…”

Synthesis and antiviral activity of novel [1,2,4]triazolo[3,4-b][1,3,4]thiadiazoles, [1,2,4]triazolo[3,4-b] [1,3,4]thiadiazines and [1,2,4]triazolo[3,4-b][1,3,4] thiadiazepines

“…2 The [1,2,4]triazoles and [1,3,4]thiadiazoles are known for their broad-spectrum of biological activities and many other uses. [3][4][5][6][7] Moreover, the triazolothiadiazoles substituted in the 3 and 6…”