- Synthesis of a new heterocyclic dye compound as an indicator in acid and base reactions
-
In the present research, the use of 2-(3-hydroxyamino-2,3-dihydroimidazo[1,2-a]pyridine-2-ylidene)-2-(2-tienyl)acetonitrile as a new acid and base indicator in aquatic environments has been investigated. This compound has been synthesized by the reaction of 3-nitroimidazo [1,2-a] pyridine and 2-(2-thienyl) acetonitrile in a methanol solution by the hydrogen nucleophilic substitution. The aqueous-ethanol solution of this compound shows a change in color by adding acid and an base. For the potential function of this reagent as an indicator, the spectral properties of UV-Vis and the equilibrium of acid and base source have been examined. The results show that the reagent is an amphoteric with two stable ionization factors Ka and Kb with poor acid and base properties. Indicator dissociation constants in aqueous solutions specified by spectrophotometric method are pKa = 9.73 and pKb = 11.57. The types of base that can be titrated with this index have been reported. This index has been compared with effective acid and base indexes with similar pH range.
- Chenarboo, Mahdi Khorsandi,Ebrahimi, Mahmoud,Pordel, Mehdi,Razmi, Mina
-
p. 287 - 290
(2021/09/28)
-
- 3-(Hydroxyimino)imidazo[1,2-a]pyridin-2(3H)-ylidene)-1-arylethanones as new red heterocyclic dyes: Synthesis, spectral studies, quantum-chemical investigations, and antibacterial activities
-
The synthesis, optical properties, theoretical calculations, and antibacterial activities of a series of new red heterocyclic dyes derived from imidazo[1,2-a]pyridine are presented. 3-(Hydroxyimino)imidazo[1,2-a]pyridin-2(3H)-ylidene)-1-arylethanones are obtained from the reaction of 3-nitroimidazo[1,2-a]pyridine with substituted acetophenone derivatives in good yields (65%–72%). The structures are confirmed by spectral and analytical data, and the optical properties of the dyes are characterized by spectrophotometry. Density functional theory calculations are performed to provide the optimized geometries and relevant frontier orbitals. Calculated electronic absorption spectra are also obtained by the time-dependent density functional theory method. Moreover, the antibacterial activities (minimum inhibitory concentration) of the new dyes against Gram-positive and Gram-negative bacterial species are determined (minimum inhibitory concentration: 5–200 μg mL?1).
- Poormirzaei, Nazanin,Pordel, Mehdi,Yaghoobi, Elnaz,Shojaee, Saeed,Aminiyanfar, Masoud,Gonabadi, Atoosa
-
p. 167 - 173
(2020/01/03)
-
- Synthesis, Spectral Studies, and Quantum Chemical Investigations of a New Violet Dye and a Fluorescent Heterocyclic System
-
The new violet dye 3-(hydroxyimino)imidazo[1,2-a]pyridin-2(3H)-ylidene)-2-(naphthalen-1-yl) acetonitrile was synthesized by reaction of 3-nitro-imidazo[1,2-a]pyridine with 1-naphthylacetonitrile. Cyclization of the latter compound in pyridine led to the formation of new fluorescent heterocyclic system benzo[f]pyrido[2’,1’:2,3] imidazo[4,5-b]quinoline. The structural assignments of the new compounds were based on their spectral and microanalytical data. The optical and solvatochromic properties of the compounds were investigated, and the results showed that they display interesting photophysical properties such as high values of extinction coefficient and fluorescence quantum yield. Moreover, the density functional theory (DFT) calculations were employed to gain a deeper insight into the geometry and relevant frontier orbitals of the compounds. Calculated electronic absorption spectra were also obtained by the time-dependent DFT method.
- Alipoor, Hamideh,Pordel, Mehdi,Morsali, Ali
-
p. 313 - 319
(2018/09/26)
-
- New fluorescent heterocyclic systems from imidazo[1,2-a]pyridine: Design, synthesis, spectral studies and quantum-chemical investigations
-
Two new fluorescent heterocyclic systems dipyrido[1′,2′:1,2]imidazo[4,5-b:4,5-e]pyridine-13-carbonitrile and pyrido[1′,2′:1,2]imidazo[4,5-b]pyrido[2′,1′:2,3]imidazo[4,5-e]pyridine-13-carbonitrile were synthesized by one-pot reaction of imidazo[1,2-a]pyridine with 2-(imidazo[1,2-a]pyridin-3-yl)acetonitrile and 2-(imidazo[1,2-a]pyridin-2-yl)acetonitrile, respectively, in MeOH/KOH solution via the nucleophilic substitution of hydrogen in high yields. Spectral and analytical data have confirmed the structures of the synthesized dyes. The optical and solvatochromic properties of the compounds were investigated and the results showed that they exhibited interesting photophysical properties. Density functional theory (DFT) calculations of fluorescent dyes were performed to provide the optimized geometries and relevant frontier orbitals by using the B3LYP hybrid functional and the 6–311?++ G(d,p) basis set. Calculated electronic absorption spectra were also obtained by time-dependent density functional theory (TD-DFT) method. In addition, electron density iso-surface map, intra- and intermolecular interactions of these fluorescent heterocyclic systems were evaluated by AIM (Atoms in Molecules) analysis.
- Pordel, Mehdi,Chegini, Hamed,Ramezani, Shirin,Daee, Mohammadreza
-
p. 105 - 112
(2016/10/04)
-
- Synthesis of new dyes from imidazo[1,2-a]pyridine: Tautomerism, spectroscopic characterisation, DFT/TD-DFT calculations, atoms in molecules analyses and antibacterial activities
-
The synthesis, optical properties, theoretical calculations and antibacterial activity of a series of new heterocyclic dyes from imidazo[1,2-a] pyridine are described. The key intermediate 2-[3-(hydroxyimino)imidazo[1,2-a]pyridin-2(3H)-ylidene]malononitrile was obtained via the nucleophilic substitution of hydrogen in 3-nitroimidazo[1,2-a]pyridine with malononitrile in basic methanol solution. Tautomerism, oxidation and alkylation studies on the dye led to the synthesis of new heterocyclic indigo-coloured, purple, and orange dyes in good yields. The structures of all newly synthesised compounds were confirmed by spectral and analytical data. The optical properties of the dyes were spectrally characterised and shown to exhibit interesting photophysical properties including high extinction coefficients. Density functional theory calculations of the dyes were performed to provide the optimised geometries and relevant frontier orbitals. Calculated electronic absorption spectra were also obtained by the time-dependent density functional theory method. In addition, electrostatic potential maps and electron density maps of the dyes were evaluated by AIM (atoms in molecules) analysis. Moreover, the new dyes exhibited potent antibacterial activity and their antibacterial activities (MIC) against Gram-positive and Gram-negative bacterial species were determined.
- Mohammadi, Samaneh,Pordel, Mehdi,Allameh, Sadegh,Chegini, Hamed
-
p. 143 - 148
(2017/03/27)
-
- Synthesis, DFT calculations, cyclic voltammetry and antibacterial activities of a new blue-violet dye and a new blue-green fluorescent heterocyclic system
-
The new blue-violet dye 2-(3-hydroxyimino-2,3-dihydroimidazo[1,2-a]pyridin-2-yliden)-2-(2-thienyl)acetonitrile was prepared in high yield from the reaction of 3-nitroimidazo[1,2-a]pyridine with 2-(2-thienyl)acetonitrile by nucleophilic substitution of hydrogen. Acylation of the hydroxyl group led to a new heterocyclic system, (pyrido[2′,1′:2,3] imidazo[4,5-b]thieno[2,3-e]pyridine-11-carbonitrile) with very strong blue-green fluorescent properties. Physical, spectral and analytical data have confirmed the structures of the synthesized dyes. The optical and solvatochromic properties of these compounds were investigated and showed interesting photophysical properties. Density functional theory calculations of blue-violet and fluorescent dyes were performed to provide the optimized geometries, Mulliken atomic charges, relevant frontier orbitals and the prediction of 1H NMR chemical shifts. The electrochemical properties of these dyes were investigated by cyclic voltammetry and an oxidation wave was observed at a half-wave potential of -0.143 V versus SCE for the blue-violet dye. Also, these new compounds exhibited potent antibacterial activity against Gram positive and negative bacterial species.
- Baf, Mozhgan Mazloum Farsi,Pordel, Mehdi,Daghigh, Leila Rezaei
-
p. 6925 - 6930
(2015/01/09)
-
- Targeting the human parasite Leishmania donovani: Discovery of a new promising anti-infectious pharmacophore in 3-nitroimidazo[1,2-a]pyridine series
-
We report herein the discovery of antileishmanial molecules based on the imidazo[1,2-a]pyridine ring. In vitro screenings of imidazopyridines belonging to our chemical library, toward the promastigotes stage of Leishmania donovani, J774A.1 murine and HepG2 human cells, permitted to identify three selective hit-compounds (12, 20 and 28). New derivatives were then synthesized to allow structure-activity and -toxicity relationships analyses, enabling to characterize a lead-compound (44) displaying both a high potency (IC 50 = 1.8 μM) and a good selectivity index, in comparison with three antileishmanial reference drug-compounds (amphotericin B, miltefosine and pentamidine). Moreover, lead-compound 44 also exhibits good in vitro activity against the intracellular amastigote stage of L. donovani. Thus, the 6-halo-3-nitro-2-(phenylsulfonylmethyl)imidazo[1,2-a]pyridine scaffold appears as a new promising selective antileishmanial pharmacophore, especially when substituted at position 8 by a bromine atom.
- Castera-Ducros, Caroline,Paloque, Lucie,Verhaeghe, Pierre,Casanova, Magali,Cantelli, Christophe,Hutter, Sébastien,Tanguy, Floriane,Laget, Michèle,Remusat, Vincent,Cohen, Anita,Crozet, Maxime D.,Rathelot, Pascal,Azas, Nadine,Vanelle, Patrice
-
p. 7155 - 7164
(2013/11/06)
-
- Effect of the lipophilic parameter (log P) on the anti-parasitic activity of imidazo[1,2-a]pyridine derivatives
-
A number of imidazo[1,2-a]pyridine derivatives were selected and investigated in relation to antiparasitic (Trichomonas vaginalis) activity. After treatment with derivatives, biological activity was assessed by determination of the in vitro viability of c
- Lopez-Martinez, Margarita,Salgado-Zamora, Hector,Campos-Aldrete, Ma. Elena,Trujillo-Ferrara, Jose G.,Correa-Basurto, Jose,Mexica-Ochoa, Carlos
-
scheme or table
p. 415 - 420
(2012/10/07)
-
- Synthesis of polyfused heterocycle derivatives containing the dipyridoimidazole core by Friedlaender's reaction: Access to analogs of ellipticine
-
Reaction of 3-amino-2-formylimidazo[1,2-a]pyridine with various aldehydes and ketones by Friedlaender's methodology afforded an entry to dipyridoimidazole, tri(tetra)azacyclopenta[b]fluorene, tri(tetra)azabenzo[b]- fluorene and triazaindeno[2,1-b]phenanth
- Desbois, Nicolas,Chezal, Jean-Michel,Fauvelle, Florence,Debouzy, Jean-Claude,Lartigue, Claire,Gueiffier, Alain,Blache, Yves,Moreau, Emmanuel,Madelmont, Jean-Claude,Chavignon, Olivier,Teulade, Jean-Claude
-
p. 1121 - 1137
(2007/10/03)
-
- Chemotherapeutically effective nitro compounds. III. Nitropyridines, nitroimidazopyridines and related compounds
-
New 2 nitropyridines and 3 nitropyridines, and 3 nitroimidazo [1,2 a] pyridines and related compounds (together 106) were synthesized and tested for their chemotherapeutic efficacy against trichomonads, amoebas and other organisms, such as Eimeria tenella, bacteria, fungi and helminths. Several 2 nitropyridines revealed a detectable systemic effect against Entamoeba histolytica (extraintestinal amoebiasis of the golden hamster) and also a weak activity against Trichomonas fetus in the NMRI mouse. Only a few 3 nitropyridines showed a marked systemic effect against trichomonads. Of the 3 nitroimidazo [1,2 a] pyridines, only the electroneutral carboxylic acid amide group exhibited a pronounced activity, exclusively against trichomonads; however, the activity was nullified by electronegative, electropositive and other electroneutral substituents. As they were not superior in chemotherapeutic respect compared to the known standard preparations (metronidazole), no further tests were carried out with the most effective compounds.
- Winkelmann,Raether,Hartung,Wagner
-
-