A New Method of Preparing Hydrazonyl Halides (original) (raw)
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This review provides detailed methods for the synthesis, structures and chemical properties of hydrazones bearing carboxamide, thioamide and amidine functions. The main accent was put on the cyclization reactions leading to pyrazoles, thiazoles, 1,2,3-triazoles, 1,2,3-thiadiazoles, 1,2,4triazines and other heterocyclic compounds. In addition, we have reviewed methods for the synthesis of substrates for pericyclic reactions from the hydrazones.
A new approach for the synthesis of N,N’-bis(phenoxyacetyl)hydrazines
Istanbul university journal of pharmacy, 2019
This report is about an unexpected formation of N,N'-bis(substituted phenoxyacetyl) hydrazine derivatives. The reaction between N'-(4-ethylcyclohexylidene)phenoxyacetohydrazide with sulfanyl acids to obtain 4-thiazolidinones s, gave an unexpected product, N,N'-bis(phenoxyacetyl)hydrazine, with high purity instead of the expected cyclocondensation product. When repeating the reaction with p-toluenesulfonic acid under the same conditions, the reaction resulted in the same compound. This indicates that two molecules of N'-(4-ethylcyclohexylidene)phenoxyacetohydrazide were involved in the reaction. The reaction can be applied as a different and new procedure for the synthesis of several N,N'-bis(substituted phenoxyacetyl) hydrazine derivatives.
The Synthesis and Diazotization of Some Ketone Hydrazones
1972
Hydrazones have been synthesized in this study both from a variety of bicyclic ketones and from ketones containing either the 1-naphthyl or 2-naphthyl group. Three of these hydrazones, those derived from 1-acetonaphthone, 2-acetonaphthone, and benzosuberone, have not been reported previously in the literature. All of the hydrazones were allowed to rearrange in a diazotizing medium to produce amide products. One of these, 4,5-benzoai-heptanolactarn, has never been reported in the literature. From the results of this research, it is possible to reaffirm some general conclusions concerning the utility and scope of the hydrazone diazotization-rearrangement. Among these are the facts that the reaction generally functions well only if at least one aromatic ring is present and that it is stereospecific with migration of the group anti to the NH2 group of the original hydrazone. Thus, the assignment of hydrazone isomer configuration appears to be possible on the basis of the identity of the...
Carbohydrate Research, 1990
1,2,4-Triazolo[3,4-alphthalazines have been shown to possess antihypertensive'-+, tuberculostatic3, antiinflammatory5, hypotensive6", and cardiovascular' activities. We have previously described the synthesis"", and conformational analysis',", as well as some of the biologicaP" activities and industrial""' applications of 3-(polyhydroxyalkyl)-1,2,4-triazolo[3,4-ulphthalazines. In this paper we describe new routes for the synthesis of these compounds. RESULTS AND DISCUSSION We have previously synthesized acyclic 1,2,4-triazolo[3,4-ulphthalazine C-nucleoside analogs by the dehydrogenative cyclization of hydrazones derived from monosaccharides and cyclic amidrazones, namely 1-hydrazinophtalazine~?lo. Some monosaccharide hydrazonesi3 derived from the other cyclic amidrazones such as 2-hydrazinoquinoline, 2-hydrazino4-methylquinoline (2_hydrazinolepidine), 2-hydrazinobenzothiazole, and 2_hydrazinopyridine, however, were resistant to such a dehydrogenative cyclization even under catalytic conditions13. We decided, therefore, to direct our attention to derivatives other than hydrazones which possess better leaving entities than hydrogen. Hydrazides derived from aldonic acids and cyclic amidrazones seemed to us to fulfil this requirement since their dehydrative cyclization is expected to be much more facile than the dehydrogenative cyclization of the hydrazone congeners. In this paper we describe two routes for the synthesis of these hydrazides and their cyclization to the title compounds. Reaction of l-hydrazino-4-phenyIphthalazine4,'4 (2) with o-glucono-1,5lactone (4) or of 1-chloro-4-phenylphthalazine'4 (6) with D-gluconic acid hydrazidei4*" (8) gave one and the same product. This product showed C=N and OH absorptions, its 'H-n.m.r. spectrum showed signals of nine aromatic protons in addition to the pentahydroxypentyl chain protons and hydroxyl protons, and it gave a satisfactory analysis * To whom correspondence should be addressed.
A three series of p-substituted aromatic hydrazones have been synthesized by condensation of benzhydrazide/p-substituted benzhydrazides (CH 3 , OCH 3 , Cl and OH) with benzaldehyde/p-substituted benzaldehydes ( OCH 3 and NO 2). Initially, p-substituted esters were prepared from benzoic acid, p-substituted benzoic acid and methanol. In the second step, p-substituted hydrazides were prepared from the previously synthesized esters and hydrazine hydrate. Finally, p-substituted aromatic hydrazones were obtained from hydrazides and benzaldehyde or p-substituted benzaldehyde. The identity of the synthesized hydrazones was confirmed by the following techniques: 1 H NMR, 13 C NMR, IR and UV spectroscopy and element analysis (CNH). The proposed method of synthesis resulted in excellent yield and purity of the prepared hydrazones. Using three conventional LFER models based on mono and the dual substituent parameters, quantitative assessment of the substituent effects on the substituent chemical shifts (SCS) was made. In order to obtain the correlation models for investigated series the IR (
Heliyon, 2020
There has been substantial interest over the past many years in the design of novel chemical compounds containing the azomethine group (-NH-N¼CH) and exhibiting various medicinal properties such as antibacterial, antiviral, antifungal, and anti-inflammatory activities. Herein, hydrazones were synthesized via the chemical reaction of substituted aromatic hydrazides with various aromatic aldehydes. The obtained products were confirmed using different physical and spectroscopic techniques, such as m.p., IR, 1 H-NMR and 13 C-NMR. The present study was designed to synthesize different aromatic hydrazones assembled by various combinations of aromatic hydrazides and aromatic benzaldehydes containing different substituents such as hydroxyl and polyhydroxyl groups as key structural features. Thus, incorporating such moieties and simultaneously creating highlyconjugated systems was expected to create novel species to mimic as much as possible natural phenolics, chalcones and stilbenes. Compounds of aromatic hydrazones synthesized in the present study were tested in vitro for their direct and indirect antioxidant activities using different methods such as DPPH, ABTS and FTC. The antioxidant activities of the new compounds ranged from very weak to very high activity. In addition, the inhibition of tyrosinase and cholinesterase by these compounds was tested. The new compounds containing two or three hydroxyl groups attached to aldehyde rings exhibited significantly greater inhibition effects on tyrosinase or cholinesterase activities in comparison to other compounds of the same series containing only one hydroxyl group.
Molbank, 2021
Here we describe the preparation of 2-(4-((1H-benzo[d]imidazol-2-yl)thio)-benzylidene)-hydrazine-1-carbothioamide in two steps. In the first step, 1,3-dihydro-2H-1,3-benzimidazole-2-thione was reacted with 4-fluorobenzaldehyde in DMSO to get 4-[(1H-benzimidazol-2-yl)sulfanyl]benzaldehyde in high yield. The reaction of the obtained aldehyde with thiosemicarbazide in ethanol at reflux temperature yielded 2-({4-[(1H-benzimidazol-2-yl)sulfanyl]phenyl}methylidene)hydrazine-1-carbothioamide. The structure of the synthesized compounds was established by NMR spectroscopy (1H, 13C), mass spectrometry, and infrared spectroscopy.
Synthesis and characterization of new p-substituted aromatic hydrazones
Organic Chemistry: An Indian Journal, 2012
A three series of p-substituted aromatic hydrazones have been synthesized by condensation of benzhydrazide/p-substituted benzhydrazides (CH3, OCH3, Cl and OH) with benzaldehyde/p-substituted benzaldehydes (OCH3 and NO2). Initially, p-substituted esters were prepared from benzoic acid, p-substituted benzoic acid and ethanol. In the second step, p-substituted hydrazides were prepared from the previously synthesized esters and hydrazine hydrate. Finally, p-substituted aromatic hydrazones were obtained from hydrazides and benzaldehyde or p-substituted benzaldehyde. The identity of the synthesized hydrazones was confirmed by the following techniques: 1H NMR, 13C NMR, IR and UV spectroscopy and element analysis (CNH). The proposed method of synthesis resulted in excellent yield and purity of the prepared hydrazones. Using three conventional LFER models based on mono and the dual substituent parameters, quantitative assessment of the substituent effects on the substituent chemical shifts (SCS) was made. In order to obtain the correlation models for investigated series the IR (C=O, C=N and NHC=O), 1HNH, 1H=CH, 13C=CH- and 13C C=O peaks were used.