Synthesis, biological activities and SAR studies of novel 1‐Ethyl‐7‐methyl‐4‐oxo‐1,4‐dihydro‐[1,8]naphthyridine‐3‐carboxylic acid based diacyl and sulfonyl acyl hydrazines

Abstract

The study revealed that a few compounds possessed good activity against three different pests namely certain fungus, soil bacteria and insect, among which, compound 37 (R' = 4-chlorophenyl) behaved the best.

Synthesis and in vitroAntimicrobial Activity of Nalidixic Acid Hydrazones

“…In the 1 H NMR spectra of hydrazones (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16), one typical proton singlet signal for the N¼CH group was observed in the range of δ 8.67-9.14 ppm and for the CONH group at δ 12.42-13.32 ppm. Whereas in the 13 C NMR of compounds 3-16, three signals for N¼CH group [17] and two C¼O groups were observed at δ 145.1-155.1 ppm and δ 161.1-180.2 ppm, respectively, which successfully confirmed the formation of expected products.…”

“…Then in the second step, the obtained ester (1) was converted to appropriate hydrazide by the reaction with hydrazine hydrate. Finally in the third step of synthesis, the desired hydrazones of nalidixic acid (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16) were synthesized by a condensation reaction of nalidixic acid hydrazide (2) with various substituted (hetero)aromatic aldehydes. Using the aforementioned reactions, 12 new nalidixic acid-based hydrazones were obtained (3,4 and 7-16).…”

“…It acts against bacteria by selectively inhibiting the type II topoisomerase DNA gyrase and topoisomerase IV, enzymes that play a critical role in bacterial cell growth and division [2]. Structure activity relationship of compounds based on nalidixic acid [3][4][5] has led to a large group of synthetic antibacterial agents collectively known as the quinolones [6].…”

Synthesis and Anticancer Activity of Novel Thiazole-5-Carboxamide Derivatives

“…In past decades, amide containing heterocycles are reported as a class of compounds displaying extensive biological activities, which consist of a large number of natural and synthetic products and are extremely versatile building blocks for the manufacture of bioactive compounds in pharmaceutical drug design and agrochemical industry [12][13][14][15][16][17][18]. We noticed that most optimizations focused on the pyridine [19], pyrazole [20], piperazine [21] and oxadiazole [22] heterocycles, but the thiazole ring, as an active moiety widely used in pesticides and medicine, has not been fully reported.…”

Microwave-Assisted Synthesis and Antifungal Activity of Some Novel Thioethers Containing 1,2,4-Triazole Moiety

“…In recent years, heterocycles had been attracted in medicinal or pesticidal importance due to its wide and spectrum activity [1][2][3][4][5][6]. The 1,2,4-triazole compounds represent an important nitro-containing heterocycles with extensively bioactivities [7][8][9][10], such as anti-inflammatory activity [11], anticancer OPEN ACCESS activity [12], anti-oxidation activity [13,14], herbicidal activity [15],antifungal activity [16,17], antiurease activity [18], antidepressant activity [19] and so on.…”