الفهرس 
Chemistry of hydrazidesOnly 14 pages are availabe for public view
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Abstract
This work aimed to the synthesis of some new hydrazide-hydrazone derivatives of expected biological activity. The present work divided into three parts: Part 1: Synthesis of Novel Hydrazide-Hydrazones Incorporating Piperidine and Piperazine Moieties and Related Mannich Bases The chemistry of hydrazide-hydrazones and related compounds is of particular interest because of their potential application as synthetic intermediates and in medicinal chemistry. Therefore, this study has focused on the synthesis and reaction of some new hydrazides and hydrazide-hydrazones incorporating piperidine and piperazine moieties. the reaction of the hydrazide 2 with the appropriate aromatic aldehyde led to the formation of a series of N’-arylidene-2-oxo-2-(piperidin-1-yl)acetohydrazides. The hydrazide-hydrazones were treated with formaldehyde and piperidine in a molar ratio (1:2:2) to afford the phenolic bis(Mannich bases); N’-(4-hydroxy-3,5-bis(piperidin-1-ylmethyl)benzylidene)-2-oxo-2-(piperidin-1-yl)acetohydrazide and the N’-(2-hydroxy-3,5-bis(piperidin-1-ylmethyl)benzylidene) analogue, respectively, Otherwise, reaction of the bis(hydrazide); 2,2’-(Piperazine-1,4-diyl)bis(2-oxoacetohydrazide) with the appropriate aromatic aldehyde afforded a series of 2,2’-(Piperazine-1,4-diyl)bis(N’-(arylidene)-2-oxo-acetohydrazides).Part 2: Synthesis of Novel Formazans and Bis(formazans) Incorporating Piperidine and Piperazine Moieties There has been considerable interest in the chemistry and biological activities of formazans and related compounds, and a variety of biologically active formazans have been described. Accordingly, coupling of phenyl diazonium chloride with the piperidinyl hyrazide-hydrazones 3a-d afforded a series of 1-(2-oxo-2-(piperidin-1-yl) acetyl)-3,5-diarylformazans, and the coupling reaction of phenyl diazonium chloride with the piperazinyl-bis(hyrazide-hydrazones) 9a-d, in a molar ratio (2:1), offers an attractive and convenient route to the synthesis of 1,1’-(2,2’-(piperazine-1,4-diyl)bis(2-oxoacetyl))bis(3,5-diarylformazans).The new phenylhydrazone / hydrazide-hydrazone hybrids 16 and 19, prepared by treating pyruvaldehyde-1-phenylhydrazone with the hydrazide and isonicotinic acid hydrazide, respectively. The coupling reaction of phenyl diazonium chloride with compounds 16 and 19 afforded the formazan / hyrazide-hydrazone hybrids, respectively. In line with this, coupling of phenyl diazonium chloride with phenylhydrazone / hydrazide-hydrazone in a molar ratio (2:1), led to the formation of bis formazan. Part 3: Biological Evaluation The Antioxidant Activity The synthesized hydrazide-hydrazone derivatives were evaluated for their antioxidant activity by using ABTS method and L-Ascorbic acid as a reference antioxidant. Almost of these compounds showed variety of antioxidant activity. The Antimicrobial Activity The prepared compounds were also screened for their antimicrobial activity against Escherichia coli (Gram –ve) and Staphylococcus aureus (Gram +ve) as well as against Candida albicans to evaluate their antifungal activity. Almost of these compounds showed variety of antimicrobial activity.