Reactions of enamines. X. The structure of 2-substituted 1-methyl-Δ1-pyrrolinium and Δ1-piperideinium salts

A series of novel 1, 3, 4-oxadiazole analogues was synthesized from cyclization of hydrazones of substituted 1-ethyl-1,4-dihydro-7-methyl-4-oxo-1,8-naphthyridine-3-carbohydrazides were prepared from nalidixic acid. The structures of synthesized oxadiazole derivatives and their copper complexes were elucidated on the basis of FTIR, elemental analyses, 1H-NMR and atomic absorption spectral analysis. It was observed from spectral data that metal ligand ratio was 1:1 in all copper complexes and they were bidentate, coordination was found to be done through oxygen of 4-oxo group and nitrogen of oxadiazole ring. The synthesized compounds were further evaluated with biological activities and compared with parent hydrazones. Copper complexes possess antibacterial and antifungal activities better than the oxadiazoles while they have better antioxidant activity then copper complexes. Parent hydrazones were better in all biological activities than synthesized oxadiazoles.

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Full Kinetics and a Mechanism Investigation for the Generation of 4- Substituted 1, 4-Dihydropyridine Derivatives in the Presence of Green Catalyst and Aqueous Medium: Experimental Procedure

Current Organic Synthesis ◽

10.2174/1570179417666201231105013 ◽

2020 ◽

Vol 17 ◽

Author(s):

Sayyed Mostafa Habibi-Khorassani ◽

Mehdi Shahraki ◽

Sadegh Talaiefar

Keyword(s):

Reaction Mechanism ◽

Reaction Centre ◽

Green Catalyst ◽

Experimental Procedure ◽

Dominant Mechanism ◽

Rate Determining Step ◽

12 Steps ◽

Reaction Constant ◽

Substituted 1 ◽

Dihydropyridine Derivatives

Aims and Objective: The main objective of the kinetic investigation of the reaction among ethyl acetoacetate 1, ammoniumacetat 2, dimedone 3 and diverse substitutions of benzaldehyde 4-X, (X= H, NO2, CN, CF3, Cl, CH (CH3)2, CH3, OCH3, OCH3, and OH) for the generation of 4-substituted 1, 4-dihydropyridine derivatives (product 5) was the recognition of the most realistic reaction mechanism. The layout of the reaction mechanism studied kinetically by means of the UV-visible spectrophotometry approach. Materials and Methods: Among the various mechanisms, only mechanism1 (path1) involving 12 steps was recognized as a dominant mechanism (path1). Herein, the reaction between reactants 1 and 2 (kobs= 814.04 M-1 .min-1 ) and also compound 3 and 4-H (kobs= 151.18 M-1 .min-1 ) were the logical possibilities for the first and second fast steps (step1 and step2, respectively). Amongst the remaining steps, only step9 of the dominant mechanism (path1) had substituent groups (X) near the reaction centre that could be directly resonated with it. Results and Discussion: Para electron-withdrawing or donating groups on the compound 4-X increases the rate of the reaction 4 times more or decreases 8.7 times less than the benzaldehyde alone. So, this step is sensitive for monitoring any small or huge changes in the reaction rate. For this reason, step9 is the rate-determining step of the reaction mechanism (path1). Conclusion: The recent result is the agreement with the Hammett description with an excellent dual substituent factor (r = 0.990) and positive value of reaction constant (ρ = +0.9502) which confirmed both the resonance and inductive effects “altogether” contributed on the reaction centre of step9 in the dominant mechanism (path1).

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Extraction of hafnium by means of some substituted 1-phenyl-3-methyl-4-benzoyl-pyrazol-5-ones

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19811901 ◽

1981 ◽

Vol 46 (8) ◽

pp. 1901-1905 ◽

Cited By ~ 3

Author(s):

Oldřich Navrátil ◽

Jiří Smola

Keyword(s):

Ionic Strength ◽

Aqueous Phase ◽

Dissociation Constants ◽

Parent Substance ◽

Benzoyl Group ◽

Extraction Constants ◽

Extraction Parameters ◽

Substituted 1

Distribution between aqueous phase and benzene or chloroform was studied for 1-phenyl-3-methyl-4-benzoylpyrazol-5-ones with 2-chloro, 4-methoxy, 3-nitro, and 4-nitro substitution in the benzoyl group (ionic strength of the aqueous phase 0.1) and for hafnium in their presence (ionic strength 2.0). The distribution and dissociation constants of the reagents and the extraction constants of their hafnium complexes were determined. Hafnium was found to be extracted as the HfA4 species. The extraction parameters of the derivatives in question do not differ substantially from those of the parent substance.

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Sterically Crowded Heterocycles. III. A General Approach to Imidazo[1,2-a]pyridines by Ferricyanide Oxidation of Quaternary Pyridinium Salts

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19960126 ◽

1996 ◽

Vol 61 (1) ◽

pp. 126-138 ◽

Cited By ~ 6

Author(s):

Richard Kubík ◽

Stanislav Böhm ◽

Iveta Ruppertová ◽

Josef Kuthan

Keyword(s):

Potassium Hydroxide ◽

Potassium Ferricyanide ◽

Pyridinium Salts ◽

Oxidizing Agents ◽

Quaternary Pyridinium Salts ◽

Substituted 1

Substituted 1-(pyridin-2-yl)-2,4,6-triphenylpyridinium perchlorates 1b-1e were converted with potassium ferricyanide and potassium hydroxide to sterically crowded 2-phenyl-3-[(Z)-1,3-diphenyl-3-oxopropenyl]imidazo[1,2-a]pyridines 2b-2e accompanied by minor isomeric 2-benzoyl-3,5-diphenyl-1-(pyridin-2-yl)pyrroles 3c-3e. 4-Phenyl-2,6-di(4-substituted phenyl)-1-(pyridin-2-yl)pyridinium salts 4a, 4b gave exclusively corresponding imidazo[1,2-a]pyridines 5a, 5b while the ferricyanide oxidation of 1-(5-iodo- and 5-cyanopyridin-2-yl)-2,4,6-triphenylpyridinium perchlorates 6a, 6b led to mixtures of major imidazo[1,2-a]pyridines 7a-7c and minor pyrroles 8a-8c. Some mechanistic aspects of the oxidation procedure are discussed in connection with a resistance of 2,6-diphenyl-1,3,5-trimethylpyridinium perchlorate (9c) towards the oxidizing agents.

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Synthesis of β-D-Glucopyranosides of 6-Substituted 2-(Indol-3-yl)benzothiazoles

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc20050072 ◽

2005 ◽

Vol 70 (1) ◽

pp. 72-84 ◽

Cited By ~ 8

Author(s):

Martin Humeník ◽

Peter Kutschy ◽

Katarína Valková ◽

Branislav Horváth ◽

Vladimír Kováčik ◽

...

Keyword(s):

Potassium Ferricyanide ◽

Substituted 1

A linear synthesis of substituted 1-(β-D-glucopyranosyl)benzocamalexins starting from indoline and penta-O-acetyl-β-D-glucopyranose was elaborated. Jacobson cyclization of corresponding 4-substituted peracetylated β-D-glucopyranosylindole-3-carbothioanilides employing potassium ferricyanide under basic conditions was a key synthetic step.

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2,6-Dibromogallates as a new building block for controlling π-stacking, network formation and mirror symmetry breaking

Chemical Communications ◽

10.1039/d1cc01922h ◽

2021 ◽

Author(s):

Ohjin Kwon ◽

Xiaoqian Cai ◽

Azhar Saeed ◽

Feng Liu ◽

Silvio Poppe ◽

...

Keyword(s):

Symmetry Breaking ◽

Building Block ◽

Mirror Symmetry ◽

Network Formation ◽

Network Structures ◽

Π Stacking ◽

Bicontinuous Cubic ◽

Substituted 1 ◽

End Group

Achiral multi-chain (polycatenar) compounds based on the 2,7-diphenyl substituted [1]benzothieno[3,2-b]benzothiophene (BTBT) unit and a 2,6-dibromo-3,4,5-trialkoxybenzoate end group lead to materials forming bicontinuous cubic liquid crystaline phases with helical network structures...

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