Reaction Of Benzil Research Articles

Synthesis and crystal structural analysis of bismuth phosphovanadate compounds: An eco-friendly and recyclable catalyst for green synthesis of imidazole derivatives

In this investigation, our primary objective is to synthesize and characterize a bismuth phosphovanadate compound Bi13V0.8-xBa0.1PxO21.55 isotype to γ-Bi2O3 of sillenite type and space group is I23. This compound serves as a catalyst for the environmentally friendly synthesis of imidazole derivatives. These derivatives are produced via the reaction of benzil, ammonium acetate, and aromatic aldehydes, yielding satisfactory yields ranging from 87 % to 96 %. The composite catalyst underwent thorough characterization using a variety of analytical techniques, including Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction analysis (XRD). The investigations revealed the excellent performance of this catalyst system. The findings revealed that this catalyst system exhibited excellent performance, offering advantages such as quick reaction time, high product yields, and a simple workup procedure. Moreover, the catalyst demonstrated high stability and could be recovered for at least five repeated runs, providing cost-effective benefits and aligning with principles of green chemistry. This method has the potential to serve as an environmentally friendly protocol for synthesizing other heterocyclic compounds.

Synthesis, Crystal Structure, DFT, and Anticancer Activity of Some Imine-Type Compounds via Routine Schiff Base Reaction: An Example of Unexpected Cyclization to Oxazine Derivative.

The synthesis, characterization, and anticancer properties of three imine-type compounds 1-3 and an unexpected oxazine derivative 4 are presented. The reaction of p-dimethylaminobenzaldehyde or m-nitrobenzaldehyde with hydroxylamine hydrochloride afforded the corresponding oximes 1-2 in good yields. Additionally, the treatment of benzil with 4-aminoantipyrine or o-aminophenol was investigated. Routinely, the Schiff base (4E)-4-(2-oxo-1,2-diphenylethylideneamino)-1,2-dihydro-1,5-dimethyl-2-phenylpyrazol-3-one 3 was obtained in the case of 4-aminoantipyrine. Unexpectedly, the reaction of benzil with o-aminophenol proceeded with cyclization to produce the 2,3-diphenyl-2H-benzo[b][1,4]oxazin-2-ol 4. The structures of compounds 3 and 4 were unambiguously determined by single crystal X-ray diffraction. Hirshfeld analysis of molecular packing revealed the importance of the O…H (11.1%), N…H (3.4%), C…H (29.4%), and C…C (1.6) interactions in the crystal stability of 3. In the case of 4, the O…H (8.8%), N…H (5.7%), and C…H (30.3%) interactions are the most important. DFT calculations predicted that both compounds have a polar nature, and 3 (3.4489 Debye) has higher polarity than 4 (2.1554 Debye). Different reactivity descriptors were calculated for both systems based on the HOMO and LUMO energies. The NMR chemical shifts were calculated and were found well correlated with the experimental data. HepG2 growth was suppressed by the four compounds more than MCF-7. The IC50 values of 1 against HepG2 and MCF-7 cell lines were the lowest, and it is considered the most promising candidate as an anticancer agent.

Synthesis of 5-Metalla-Spiro[4.5]Heterodecenes by [1,4]-Cycloaddition Reaction of Group 13 Diyls with 1,2-Diketones

Monovalent group 13 diyls are versatile reagents in oxidative addition reactions. We report here [1,4]-cycloaddition reactions of β-diketiminate-substituted diyls LM (M = Al, Ga, In, Tl; L = HC[C(Me)NDipp]2, Dipp = 2,6-iPr2C6H3) with various 1,2-diketones to give 5-metalla-spiro[4.5]heterodecenes 1, 4–6, and 8–10, respectively. In contrast, the reaction of LTl with acenaphthenequinone gave the [2,3]-cycloaddition product 7, with Tl remaining in the +1 oxidation state. Compound 1 also reacted with a second equivalent of butanedione as well as with benzaldehyde in aldol-type addition reactions to the corresponding α,β-hydroxyketones 2 and 3, while a reductive activation of a benzene ring was observed in the reaction of benzil with two equivalents of LAl to give the 1,4-aluminacyclohex-2,4-dien 12. In addition, the reaction of L’BCl2 (L = HC[C(Me)NC6F5]2) with one equivalent of benzil in the presence of KC8 gave the corresponding 5-bora-spiro[4.5]heterodecene 13, whereas the hydroboration reaction of butanedione with L’BH2 (14), which was obtained from the reaction of L’BCl2 with L-selectride, failed to give the saturated 5-bora-spiro[4.5]heterodecane.

Synthesis, antioxidant activity, antimicrobial efficacy and molecular docking studies of 4-chloro-2-(1-(4-methoxyphenyl)-4,5-diphenyl-1H-imidazol-2-yl)phenol and its transition metal complexes.

Herein, a one-pot synthesis of tetra-substituted imidazole, 4-chloro-2-(1-(4-methoxyphenyl)-4,5-diphenyl-1H-imidazol-2-yl)phenol (HL), is reported by the reaction of benzil, 5-bromosalicylaldehyde, ammonium acetate and anisidine. The synthesized imidazole was reacted with salts of 1st row transition metals (Co(ii), Ni(ii), Cu(ii), Mn(ii) and Zn(ii)) to obtain metal complexes. The structure of the compounds was confirmed using various spectroscopic and analytical techniques. HL, which is crystalline, was characterized by SC-XRD. Subsequently, the synthesized compounds were evaluated for their antioxidant and antimicrobial activities. Antimicrobial studies revealed the more noxious nature of metal complexes compared to ligand against various strains of bacteria and fungi. Molecular docking results based on the binding energy values also supported the experimental results of the antioxidant activities of the compounds. HL was found to be a better antioxidant than metal complexes. For a better insight into the structure, computational studies of the compounds were also carried out. A clear intra-molecular charge transfer was perceived in the ligand and its metal complexes. The transfer integral values for holes (36.48 meV) were found to be higher than the electron transfer integrals (24.76 meV), which indicated that the ligand would be a better hole transporter. According to the frontier molecular orbitals of the dimer, the charge transfer within the molecule is found from monomer 1 to 2.

Experimental and Theoretical Investigation on Imidazole Derivatives Using Magnetic Nanocatalyst: Green Synthesis, Characterization, and Mechanism Study

The green synthesis of 4,5-diphenyl-1H-imidazole derivatives was studied experimentally and theoretically through a one-pot, three-component reaction of diverse aldehydes, ammonium acetate, and benzil using Fe3O4@C@PrNHSO3H nanoparticles under solvent-free conditions. The core-shell magnetic nanoparticles of Fe3O4@C@PrNHSO3H were introduced as an effective, environmentally friendly, and magnetically removable catalyst in the reaction. The recovered catalyst could be used eight times with admirable catalytic activity. Before entering the laboratory, the synthesis of imidazoles was studied from a computational point of view to find the most plausible mechanism and select the appropriate raw materials. Three probable mechanistic paths were considered. Density functional theory (DFT) calculations confirmed the following mechanism: (1) reaction of benzil and ammonia to form iminoethanone, (2) reaction of aldehyde and ammonia to form imin, (3) reaction of imin with iminoethanone and ring formation, and (4) rearrangement to produce 4,5-triphenyl-1H-imidazole. The results were affirmed by the frontier molecular orbitals, natural bond orbital analyses, and molecular electrostatic potential calculations. HIGHLIGHTS The green synthesis of 4,5-diphenyl-1H-imidazole derivatives was studied experimentally and theoretically using Fe3O4@C@PrNHSO3H nanoparticles (NPs). Three proposal mechanisms were considered using M062X/6-311++G(d,p) to achieve the most plausible mechanism, The proposed mechanism was verified by the frontier molecular orbitals, natural bond orbital analyses, and molecular electrostatic potential calculations. The Fe3O4@C@PrNHSO3H NPs were introduced as an effective, eco-friendly and magnetically recoverable catalyst in the one-step synthesis of imidazoles. The recovered catalyst could be used eight times with admirable catalytic activity.

An Efficient and One Pot Synthesis of 2,4,5-Trisubstituted Imidazole Derivatives Catalyzed by Silver Nanoparticles

Silver nanoparticles (AgNPs) have been used as an excellent and highly efficient catalyst for one pot synthesis of 2,4,5-trisubstituted imidazole derivatives in presence of ethanol as a solvent. This synthetic route involves multicomponent reaction of benzil, substituted aromatic aldehydes and ammonium acetate under reflux. The synthesized silver nanoparticles were characterized by UV-visible spectroscopy (UV-visible), X-ray diffraction (XRD) pattern, scanning electronic microscope (SEM) analysis. The process was simple and environmentally benign with high to excellent yield. The methods provides several advantages such as simple operation, clean reaction profile, short reaction time and high yield of product. The synthesized silver nanoparticles as catalyst was non-toxic, eco-friendly, low cost and green synthetic method.

Synthesis of Tri- and Tetra- Phenyl Substituted 1H-imidazoles in the Presence of Chitin and Pectin as Natural Catalyst

Introduction: Chitin and pectin are important natural polymers which are used as a natural catalyst for the synthesis of tri- and tetra- phenyl substituted 1H-imidazoles. Material and Methods: The reaction of benzil and aromatic aldehydes with ammonium acetate in the presence of chitin produces 2,4,5-triphenyl-1H-imidazoles and the reaction of benzil, aromatic aldehydes and aniline derivatives with ammonium acetate in the presence of pectin produces 1,2,4,5- tetraphenyl-1H-imidazoles, respectively. Results: The results show that the synthesis of 2,4,5-triphenyl-1H-imidazoles and 1,2,4,5-tetraphenyl- 1H-imidazoles can be catalyzed by chitin and pectin in an effective route, respectively. All synthesized compounds are in good agreement with previously reported compounds. Conclusion: In conclusion, an efficient methodology has been carried out to generate 2,4,5-triphenyl- 1H-imidazoles and 1,2,4,5-tetraphenyl-1H-imidazoles, by using non-toxic, cheap and in available catalysis (chitin and pectin).

MOLECULAR IODINE CATALYZED SOLVENT FREE ONE POT SYNTHESIS, CHARACTERIZATION, INSILICO ADME, hERG ANALYSIS, MOLECULAR DOCKING STUDIES AND DFT ANALYSIS OF 2- SUBSTITUTED 4,5-DIPHENYL-1H-IMIDAZOLE DERIVATIVES

In the present investigation, a series of 2-substituted 4,5-Diphenyl-1H-imidazoles (3a-f) were prepared via one pot Debus-Radziszwski multicomponent condensation reaction using molecular iodine as a catalyst. Synthesis involves one pot reaction of benzil and substituted aromatic aldehydes (2a-e) in the presence of ammonium acetate and molecular iodine as catalyst under the solvent free grinding technique. The structures of the compounds were established based on multi nuclear NMR (1H 813C) spectral data and mass spectrometry. These compounds were subjected to in- silico ADMETox evaluation, hERG analysis, and molecular docking studies to evaluate their potency as antibacterial, antifungal, anti-inflammatory, and antimycobacterial. Molecular physicochemical properties were analyzed using density functional theory (DFT), molecular electrostatic potential (MEP) studies and reduced density gradient analysis.

Ultrasound‐Promoted Mild, and Efficient Protocol for Three‐Component Synthesis of 2,4,5‐Trisubstituted Imidazoles Using Urea and PPh3 as the Sources of Nitrogen and Organocatalyst

AbstractSubstituted imidazoles have wild applications in different area of sciences and industries. In this research, the catalytic activity of PPh3 as a cheap and efficient organocatalyst is reported for synthesis of 2,4,5‐trisubstituted imidazoles. In this method, ultrasonic assisted one‐pot, three‐component reaction of benzil, aldehydes, urea and PPh3 in ethylene glycol as a green solvent at room temperature has been achieved to afford the structurally diverse 2,4,5‐trisubstituted imidazoles in 80–95 %. The effect of different parameters on the reaction progress was also discussed. Utilizing ultrasonic irradiation dramatically improved the reaction in terms of yields and reaction times compared to conventional heating technique. The current protocol offers many advantages such as mild reaction conditions, short reaction time, the use of non‐metallic, harmless, and cheap catalyst, ease of separation and purification, simple work‐up procedure, and the reactivity to all types of aldehydes particularly the aliphatic aldehydes.

Bmim]HSO4-Catalyzed Synthesis of Tetrasubstituted Imidazoles as Potential Mutant Isocitrate Dehydrogenase 1 Inhibitors

An ecofriendly, simple, and efficient one-pot protocol has been developed for the synthesis of 1,2,4,5-tetrasubstituted imidazoles by the reaction of benzil, aryl aldehydes, aliphatic or aromatic amines, and ammonium acetate, catalyzed by the acidic halogen-free ionic liquid [bmim]HSO4 under solvent-free conditions. The advantages of the proposed protocol include high yields, short reaction time, operational simplicity, and recyclability of the catalyst. Eight previously unknown tetrasubstituted imidazoles were synthesized, among which those bearing a cyclopropyl substituent on N1 can be considered as potential mutant isocitrate dehydrogenase 1 (IDH1) inhibitors.

Synthesis and biological evaluation of triphenyl-imidazoles as a new class of antimicrobial agents

Newer triphenyl-imidazole derivatives (4a-h) were synthesized in good yields by the reaction of benzil and substituted benzaldehydes in equimolar quantities and refluxing the product with acetyl chloride thereafter. Structures were confirmed by using FT-IR, 1H NMR and 13C NMR spectroscopic methods. All the synthesized compounds were tested for their antimicrobial activity using agar diffusion technique against Gram positive (Staphhylococcus aureus and Bacillus subtilis), Gram negative (Escherichia coli and Pseudomonas aureginosa) as well as Fungal strain (Candida albicans). Interestingly compounds 4a, 4b, 4f and 4h showed significant antibacterial activity, whereas compound 4b was found to have remarkable activity against the fungal strain. The Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of most active compounds were determined by broth dilution method and compound 4b emerged to have potent activities against most of the strains having MIC in the range of 25-200 µg/mL. To check the possible toxicities of the most active compounds, they were orally administered in rats and the concentration of liver enzymes serum glutamic-oxaloacetic transaminase (SGOT), serum glutamic pyruvic transaminase (SGPT) and alkaline phosphatase (ALKP) were determined. Compound 4h showed significant increase in the enzymes level depicting the hepatotoxicity. The structure-activity relationship studies showed the importance of electron withdrawing groups at the distant phenyl ring at ortho and para positions as the compounds having chloro or nitro at these positions tend to be more active than the compounds with electron releasing groups such as methoxy. These compounds may act as lead compounds for further studies and appropriate modification in their structure may lead to agents having high efficacy with lesser toxicity.

One-pot synthesis, physicochemical and photophysical properties of deep blue light-emitting highly fluorescent pyrene-imidazole dye: A combined experimental and theoretical study

A one-pot multi-component synthesis of 4,5,-diphenyl-2-(pyren-1-yl)-1H-imidazole (DPI) chromophore was performed by the reaction of benzil, pyrene-1-carboxaldehyde and ammonium acetate in acetic acid. Structure elucidation of DPI chromophore was confirmed by spectroscopic techniques (FT-IR, 1H NMR, 13C NMR and mass spectra). The physicochemical and photophysical parameters of DPI chromophore such as extinction coefficient, oscillator strength, dipole moment, stokes shift and fluorescence quantum yield were calculated experimentally and theoretically on the basis of the different solvents polarity to see the effect of the solvents on DPI chromophore. DPI chromophore was also applicable for determination of critical micelle concentration (CMC) of cationic and anionic surfactant such as cetyl trimethyl ammonium bromide (CTAB) and sodium dodecyl sulfate (SDS).

Pyrazole nucleus fused tri-substituted imidazole derivatives as antioxidant and antibacterial agents

A novel series of tri-substituted imidazole derivatives were synthesized according to the well-known Radziszewski reaction. The desired molecules were obtained by a reaction of benzil, ammonium acetate and different derivatives of 1H-pyrazole-4-carbaldehyde. Structures of the synthesized entities were confirmed with the support of modern techniques like elemental analysis (CHN) and spectral analysis (FTIR, 1H and 13C NMR and LC–MS). All compounds were screened for their biological potency: antibacterial activity using a serial broth dilution method and antioxidant activity using the DPPH method. Antimicrobial activity was performed against Gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis) and Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa). The title compounds showed moderate to excellent antimicrobial and antioxidant potency against different bacterial strains and the DPPH radical.

Novel Three-Step Synthesis of Imidazo[1,2-c]quinazoline-5(6H)-thione Derivatives

A novel synthesis of Iimidazo[1,2-c]quinazoline-5(6H)-thione framework was developed through a three-step reaction starting from benzil. The resulting (2-nitrophenyl)-4,5-diphenyl-1H-imidazole from the reaction of benzil and different 2-nitrobenzaldehyde, reduction of nitro group and then cyclization reaction with carbon disulfide (CS2). All steps were carried out under easy and user-friendly conditions in short time without using expensive catalysts or reagents.

ChemInform Abstract: Microwave‐Assisted Nickel‐Catalyzed One‐Pot Synthesis of 2,4,5‐Trisubstituted Imidazoles.

AbstractA N‐(4‐Bromophenyl)salicylidenimine‐derived nickel catalyst is used in the novel microwave‐assisted 3‐component reaction of benzil, arylaldehydes, and ammonium acetate to furnish the title compounds in high yields.

ChemInform Abstract: Graphene Oxide—Chitosan Bionanocomposite: A Highly Efficient Nanocatalyst for the One‐Pot Three‐Component Synthesis of Trisubstituted Imidazoles under Solvent‐Free Conditions.

AbstractImidazoles (III) are rapidly, conveniently, and eco‐friendly obtained by reaction of benzil (I) or benzoin with various aromatic aldehydes and ammonium acetate.

Acid treated clays: preparation, characterization and catalytic activity for synthesis of quinoxaline derivatives

The preparation, characterization, and catalytic properties of acid treated clay (ATC) are reported. ATC has been characterized by XRD (basal spacing, 14.82 A), specific surface area (66 m2/g), pore volume and pore width using BET method, UV–Vis DRS, TGA, SEM, and surface acidity by TPD of NH3. The activity of was investigated by the reaction of benzil with o-phenylene diamine. Among the catalysts, ATC was found to be more active. The reaction of various substituted o-phenylenediamines with benzil was studied on ATC to obtain corresponding quinoxalines in good yields. The regeneration and reusability of ATC has also been investigated.

One-Pot Synthesis of Imidazolidine-2-Thiones, Hydantoins and Thiohydantoins under Solvent-Free and Grinding Conditions

A convenient, environmentally friendly and mild green synthesis of imidazolidine-2-thiones, hy-dantoin and thiohydantoin derivatives was developed by the one-pot reaction of benzils, urea or thiourea derivatives, and strong base at with grinding. The key advantages are the short reaction times, excellent yields, simple workup, and easy purification in the solvent-free condition. The present method aimed to overcome the limitations and drawbacks of the reported methods such as hard work-up, low yield, hazardous solvent and long reaction time.

9,11,12,14‐Tetraaryldibenzo[f,h]imidazo[1,2‐b]isoquinolines and Their Emission Responses to Solvent Polarity, Acidity, and Nitroarenes

Abstract9,11,12,14‐Tetraaryldibenzo[f,h]imidazo[1,2‐b]isoquinolines 3a–h were synthesized in moderate yields through the reaction of benzils with 1,3‐diphenyl‐2H‐cyclopenta[l]phenanthren‐2‐ones and ammonium acetate. The photophysical properties of the products in solutions and in thin films were investigated, and strong emissions ranging from 492 to 516 nm were observed in cyclohexane solutions. Moreover, 3h exhibited potential as a versatile fluorescent chemosensor for the detection of solvent polarity, acidity, or trace amounts of nitroaromatics.

Synthesis and Evaluation of 2, 4, 5 - Trisubstituted and 1, 2, 4, 5 Tetrasubstituted Imidazole as Antimicrobial Agents

A series of 2,4,5-trisubstituted (A1-A15) and 1,2,4,5-tetrasubstituted (B1-B7) imidazole derivatives were synthesized by the reaction of Benzil, aldehyde, ammonium acetate, aromatic primary amines using catalyst tetrabutylammoniumbromide in isopropanol. Structures of these compounds were elucidated by spectral (IR, 1 H NMR) analysis. The newly synthesized compounds were screened for antifungal and antibacterial activities. The activity was measured in terms of zone of inhibition and compared with standard drug. Compounds A4,A7,A8,A10,A12,A14,A15,B1,B3,B5 and B6 have shown good antibacterial activity against std. Norfloxacin and Compound A2,A3,A6,A7,A9,A10,A14,A15,B2,B3,B4,B6 and B7 exhibited good antifungal activities against std. Clotrimazole, and other compound shows moderate activity.