New p-Substituted Salicylaldehyde Phenylhydrazone Derivatives: Synthesis, Characterization, and Antioxidant Activities

Abstract

A series of new p-nitrophenylhydrazone derivatives 3a–f were synthesized, characterized, and investigated for their antioxidant activities. These compounds have been synthesized by refluxing (p-nitrophenyl)hydrazine with 4-sub-stituted salicylaldehydes. The structures of the compounds were established by IR, 1H- and 13C-NMR, and MS data. The antioxidant activities (free radical-scavenging activity, reducing power, metal chelating activity, and total anti-oxidant activity) of the hydrazone compounds were evaluated. All of the compounds exhibited significant activities, while compound 3a, with the shortest chain, showed the highest antioxidant activity in all of the tests.

A Green and Efficient Protocol for the Synthesis of Phenylhydrazone Derivatives Catalyzed by Nanostructured Diphosphate Na2CaP2O7 and Screening of Their Antibacterial Activity

“…[1] Many researchers focused their efforts to synthesize these compounds and to evaluate their biological activities. [2] Several catalytic systems have been developed and used for the synthesis of hydrazone derivatives including polystyrene sulfonic acid, [3] choline chloride-oxalic acid, [4] glacial acetic acid, [5] SiO 2 /H 2 SO 4 , [6] Mg(ClO 4 ) 2 , [7] meglumine [8] and zeolites. [9] Nano-structured diphosphate Na 2 CaP 2 O 7 was recently used as a green and effective catalyst for the Knoevnagel reaction, [10] synthesis of unsaturated aryl sulfones, [11] α-amino phosphonates, [12] 2-amino-2-chromenes, [13] 1,2-disubstituted benzimidazoles, [14] pyranic heterocyclic nucleus [15] and tetraketones.…”

“…Some natural hydrazone derivatives are known for their anticonvulsant, analgesic, anti‐inflammatory, antihypertensive, antimicrobial, anti‐tubercular, antitumor, antimalarial, and antiproliferative activities [1] . Many researchers focused their efforts to synthesize these compounds and to evaluate their biological activities [2] . Several catalytic systems have been developed and used for the synthesis of hydrazone derivatives including polystyrene sulfonic acid, [3] choline chloride‐oxalic acid, [4] glacial acetic acid, [5] SiO 2 /H 2 SO 4 , [6] Mg(ClO 4 ) 2 , [7] meglumine [8] and zeolites [9] .…”

Synthesis, experimental and theoretical antiradical activity assessment of some azomethines and phenylhydrazones

“…Phenylhydrazones are compounds that contain a Ph-NH-N = CH-Ph group in their structures. Antiradical activity of phenylhydrazones and their derivatives was established in various studies [17,31]. Other applications of these compounds have been cited in some articles in a wide range of fields.…”

Effects of the Exchange Coupling on Dynamic Properties in a Series of CoGdCo Complexes

“…Working with manganese in place of cobalt ions yields the corresponding [L 1 MnGdMnL 1 ]­(ClO 4 ) complex involving Mn II ions, as nicely confirmed by magnetic measurements. The stabilization of the II oxidation state for the cobalt or manganese ions may be related to the reducing character of the deprotonated hydrazone L 1 H 3 ligand or perhaps to a greater rigidity of the L 1 H 3 ligand that would not be able to evolve to a regular octahedral environment, as in the case of the LH 3 ligand.…”

“…Working in presence or absence of oxygen, with use of gadolinium ion or gadolinium complex in different ratios, trinuclear [L 1 CoGdCoL 1 ]­X (X = NO 3 – ,ClO 4 – , hfa – ) complexes are isolated. Here the reducing character of the hydrazone functions plays a prominent role . We must remark that mononuclear L 1 M complexes (M = Mn II , Co II , Ni II , Zn II ) are unknown, neutral trinuclear [L 1 MMML 1 ] complexes being always characterized with use of transition-metal ions only. , Here again, the reducing character of the hydrazone functions impedes formation of neutral L 1 M III species and only yields anionic [L 1 M] − species, prone to coordinate M II ions in order to give neutral [L 1 MMML 1 ] complexes.…”