Reaction Of Benzaldehyde Research Articles

Synthesis, crystal structure investigation and computational approach to discover potential hydrazide derivatives as a potent inhibitor of cyclooxygenase-2 enzyme.

This study reports the synthesis of two new hydrazide derivatives, namely, (E)-N'-(4- bromobenzylidene)-2-(4-isobutylphenyl)propanehydrazide (4a) and (E)-N'-benzylidene-2-(4-isobutylphenyl)propanehydrazide (4b), respectively. The compounds were synthesized by the reaction of benzaldehyde with Ibuprofen acid hydrazide. Their structures were confirmed by X-ray crystallography. To try to do a more detailed investigation, computational studies including Hirshfeld surface analyses, energy frameworks, density functional theory (DFT)optimizations, frontier orbital analyses, molecular electrostatic potential analyses, and natural bond orbital analyses of the studied compounds are performed. Moreover, molecular docking and dynamics simulations of complexes of the compounds with the cyclooxygenase-2 (COX-2) enzyme were performed to determine the anti-inflammatory potential of the compounds. These analyses predicted the compounds to show maximum chemical interactions and be dynamically stable during simulation time. Furthermore, estimation of binding free energies confirmed the high binding affinity of the compounds for the COX-2 enzyme.

Synthesis of Some New 1,3,4- Oxadiazole Derivatives and Thiazolidine Derived from Cysteine and Evaluation their Anticancer (MCF7) Activity

The study focused on the preparation of oxadiazole derivatives containing thiazolidine. Thiazolidine firstly was prepared from the reaction of benzaldehyde with L-cysteine with a good yield and then it was reacted with acetic anhydride to prepare acetyl thiazolidine, then with ethanol in the presence of H2SO4, then steps were taken to prepare a thiazolidine hydrazide (A3), which was reacted with aromatic carboxylic acid in presence POCl3 or carbon disulphide and base KOH to obtain oxadiazole derivatives A4-8. These compounds characterized using FT-IR, NMR and Mass (EI) were diagnosed and the synthesized compound were validated. The activity of oxadiazole derivatives were studied against breast cancer cells, the two compound A8, A4 showed good activity against the cells as for the compounds A5, A6, A7 it was showed little activity against these cells and the value IC50 was calculated.

Design and synthesis of iron(II) complexes with Schiff bases derived from 6-aminopenicillanic acid and heterocyclic aldehydes

The reaction of iron (II) acetate with Schiff bases derived from the condensation reaction of benzaldehyde or indole-3-carboxaldehyde with (2S,5R,6R)-6-Amino-3,3-dimethyl-7-oxo-4-thia-1azabi cyclo[3.2.0] hepta -ne-2-carboxylic acid (6- Aminopenicillanic Acid) in 1:1 molar ratio gave a new series of iron(II) complexes. The coordination bond formation behaviour of Schiff bases with iron atom has been characterised by elemental analysis, conductance measurements, molecular weight determinations, IR, UV and 1H NMR spectral studies.

Enantioselective Biginelli Reaction Catalyzed by (L)‐Prolinamide Containing Imidazolium Ionic Liquid

Abstract(L)‐Prolinamide containing imidazolium ionic liquids have been synthesized and evaluated as organocatalysts for the asymmetric Biginelli reaction of benzaldehydes, urea, and β‐keto esters. The synthesized chiral ionic liquids were characterized by various techniques such as FT‐NMR, FT‐IR, TGA, and HRMS. The chiral ionic liquid containing adamantyl (L)‐prolinamide having [BF4]‐ anion (5 mol %) and p‐toluenesulfonic acid (5 mol %) as an additive catalyzed the Biginelli reaction and afforded a variety of chiral 3,4‐dihydropyrimidin‐2‐(1H)‐ones (DHPMs) in 16–74 % yields and 7–85 % ee's after 48 h at room temperature and out of 30 chiral DHPMs products, 18 are new. A plausible reaction mechanism and transition states or intermediates have been proposed and supported by FT‐NMR spectroscopy and DFT calculations. The asymmetric induction was favored by the Re‐face attack on the imine bond and the Biginelli products were obtained with (R)‐absolute configuration. The DFT calculations (B3LYP/631‐G*) were performed to find the energy of the intermediates.

Core-shell magnetic microspheres as heterogeneous catalyst for synthesis of benzimidazole

γ-Fe2O3 was used to prepare γ-Fe2O3@SiO2, γ-Fe2O3@SiO2-NH2 and γ-Fe2O3@SiO2-NH2-COOH nanoparticles. Core-shell modification of IRMOF3 was used to obtain γ-Fe2O3@SiO2-NH2-COOH/IRMOF3 nanoparticles. γ-Fe2O3@SiO2-NH2-COOH/IRMOF3 nanoparticles were modified by activated arginine (Arg), glycine (Gly) and lysine (Lys) to synthesize γ-Fe2O3@SiO2-NH2-COOH/IRMOF3-Arg, γ-Fe2O3@SiO2-NH2-COOH/IRMOF3-Gly and γ-Fe2O3@SiO2-NH2-COOH/IRMOF3-Lys nanoparticles. The products were used as catalysts for condensation reactions of benzaldehyde and o-phenylenediamine. Infrared spectroscopy (IR), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) spectra were used for the characterization. γ-Fe2O3@SiO2-NH2-COOH/IRMOF3-Gly nanoparticles showed outstanding catalytic effects as determined by a fluorescence spectrophotometer. In RP-HPLC spectra, the retention time of the reaction products was 2.458 min and 3.392 min. The results of the 1H NMR (400 MHz, MeOH-d 6) spectra showed γ-Fe2O3@SiO2-NH2-COOH/IRMOF3-Gly nanoparticles to be more active.

A new finding in the old Knoevenagel condensation reaction

Reaction of benzaldehyde (5a) with defined quantities of ethyl cyanoacetate (6) in presence of piperidine was studied. In a neat condition, hexasubstituted cyclohexeneamine (7a) with three ester substituents was formed along with ethyl acrylate (9a); occasionally the triesters (7) were transformed to diesters (8). (7) and (8) had uniquely defined stereochemistry. Many substituted aromatic aldehydes and pyridine-3 and 4-aldehydes exhibited this reaction. Cyclohexenes were also formed in solutions. Mass spectral evidence showed the presence of small percentage of isomeric tri and diesters. Mechanistic and other aspects are discussed. Richly substituted cyclohexene amine esters are attractive substrates for medicinal chemistry.

Tuning selectivity among acetalization, pinacol coupling, and hydrogenation reactions of benzaldehyde by catalytic and photochemical pathways at room temperature

Benzaldehyde is one of the industrially most useful feedstocks, and its transformation to high-value chemicals is very attractive. Different transformations of benzaldehyde, such as acetalization, pinacol coupling, and hydrogenation, have been achieved herein by adjusting pH, light source, and selection of a catalyst. Consequently, the corresponding products have been obtained with excellent yields (e.g. 92% yield for acetalization, 96% yield for pinacol coupling, and 85% yield for hydrogenation). The mechanisms behind each transformation were studied, and it revealed that pinacol coupling reaction was achieved through a photochemical process under 365 nm irradiation at pH 12, where the introduction of the TiO2 (P25) catalyst would completely shift the selectivity toward benzyl alcohol through a photocatalytic pathway and to benzaldehyde dimethyl acetal via low-temperature thermal catalysis.

Upconverting Er3+-Yb3+ Inorganic/Covalent Organic Framework Core-Shell Nanoplatforms for Simultaneous Catalysis and Nanothermometry.

Lanthanide-based luminescent nanoparticles that are thermally responsive can be used to probe temperature changes at a nanoscale regime. However, materials that can work as both a nanothermometer and a catalyst are limited. Herein, we show that covalent organic frameworks (COFs), which is an emerging class of porous crystalline materials, can be grown around lanthanide nanoparticles to create unique core-shell nanostructures. In this way, the COF (shell) supports copper metal ions as catalytic sites and simultaneously lanthanide nanoparticles (β-NaLuF4:Gd,Er,Yb-core) locally measure the temperature during the catalytic reaction. Moreover, β-NaLuF4:Gd,Er,Yb nanoparticles are upconverting materials and hence can be excited at longer wavelengths (975 nm), which do not affect the catalysis substrates or the COF. As a proof-of-principle, a three-component addition reaction of benzaldehyde, indole, and malononitrile was studied. The local temperature was probed using luminescence nanothermometry during the catalytic reaction.

Valmet Chiral Schiff‐Base Ligands And Their Copper(II) Complexes as Organo, Homogeneous and Heterogeneous Catalysts for Henry, Cyanosilylation and Aldol Coupling Reactions

AbstractCyanosilylation, aldol coupling and asymmetric Henry reactions were carried out with L‐ and D‐valmet ligands in different configurations: i) coordinated to sodium ions, as organocatalysts, with week base properties, ii) complexes with copper(II), as homogeneous catalysts, and iii) immobilized copper(II) complexes onto graphene oxide (GO) as heterogeneous catalysts. For the reaction of benzaldehyde and nitromethane in water these afforded an asymmetric Henry reaction, with a spectacular increase of the conversion and ee (92.5 and 95.8 %, respectively) after the deposition on GO. Ligand complexed copper was also effective for cyanosilylation and Aldol coupling reaction.

Two Coexisting Forms of Simple Molecules for Directing Sesqui-Unit-Cell Zeolite Nanosheets

Feasible strategies are desirable for preparing zeolitic nanosheets with opener porosities and more accessible active sites. Highly delaminated FER nanosheets (ECNU-17) with unit-cell scale thickness were hydrothermally synthesized using a simple, small, and low-cost imidazole molecule as the sole organic structure-directing agent (OSDA). The single OSDA directed the formation of the FER framework, while the π–π stacked OSDAs terminated the growth perpendicular to the zeolite sheets. The ECNU-17 nanosheet is only 2.9 nm in thickness, corresponding to one and a half FER unit cells along a-axis. With open hierarchical porosity and an enhanced external surface area of 253 m2 g–1, ECNU-17 is endowed with improved mass transport and a significantly increased number of active acid sites accessible to bulky organic molecules. The ultrathin sheets of ECNU-17 aluminosilicate display excellent activity and selectivity for the protection reaction of benzaldehyde with pentaerythritol as well as the cracking of 1,3,5-triisopropylbenzene.

Offretite zeolite templated by amphiphile and its catalytic performance in microwave-assisted Knoevenagel condensation of benzaldehyde and ethyl cyanoacetate

A detailed investigation on the crystallization of offretite (OFF) zeolite templated by non-toxic cetyltrimethylammonium bromide (CTABr) is reported. Various hydrothermal synthesis conditions are prepared by systematically adjusting the synthesis variables, namely crystallization time, heating temperature and amount of reactants (SiO2, Al2O3, K2O, M2O (M = Na+, Cs+), CTABr and H2O) to investigate their effects on the crystal growth of OFF zeolite. It is shown that each variable has its profound influences on the crystallization process, which further affect the properties of final zeolite products (e.g. phase purity, morphology, crystal size). Unlike classical synthesis pathway using tetramethylammonium (TMA+) as organic template, the CTABr-templating approach successfully produces large OFF single crystals (framework Si/Al ratio = 4.11) with hexagonal prism shape (ca. 9.4 × 1.8 μm2) and smooth surface. Besides that, the OFF zeolite (81.9% conversion) also shows comparable or even higher catalytic performance than other zeolites reported in this work and other works in microwave assisted-Knoevenagel reaction of benzaldehyde and ethyl cyanoacetate, offering a sustainable and facile pathway for preparing zeolitic materials for advanced applications.

Alkoxo bridged heterobimetallic CoIIISnIV compounds with face shared coordination octahedra: Synthesis, crystal structure and cyanosilylation catalysis

The self-assembly reaction of the Schiff base N,N’-ethylenebis(2-hydroxyacetophenoneimine) (H2L), CoCl2··6H2O and [SnPh2Cl2] led to the alkoxo-bridged heteroorganometallic CoIIISnIV complex [{SnPhCl2}(1κO2:2κO2N2-μ-L)(μ-OMe){CoPh}]·CH3OH·H2O (1) or [{SnPhCl2}(1κO2:2κO2N2-μ-L)(μ-OEt){CoPh}] (2) in MeOH or EtOH, respectively. The structures of these complexes are authenticated by single crystal X-ray diffraction analyses. They are derived from an intermetallic (Sn to Co) phenyl shift, leading to face-shared distorted octahedral coordination geometries. The complexes were tested as homogeneous catalysts for the solvent-free cyanosilylation reaction of benzaldehyde with trimethylsilyl cyanide (TMSCN) under low power microwave irradiation at 50°C. They exhibited a high catalytic activity, yielding (for catalyst 1) up to 93% of the cyano-derivative from benzaldehyde in 90 minutes.

Cationic Aluminium Complexes as Catalysts for Imine Hydrogenation

Strongly Lewis acidic cationic aluminium complexes, stabilized by β–diketiminate (BDI) ligands and free of Lewis bases, have been prepared as their B(C6F5)4 − salts and were investigated for catalytic activity in imine hydrogenation. The backbone (R1) and N (R2) substituents on the R1,R2BDI ligand (R1,R2BDI=HC[C(R1)N(R2)]2) influence sterics and Lewis acidity. Ligand bulk increases along the row Me,DIPPBDI<Me,DIPePBDI≈tBu,DIPPBDI<tBu,DIPePBDI; DIPP=2,6‐C(H)Me2‐phenyl, DIPeP=2,6‐C(H)Et2‐phenyl. The Gutmann‐Beckett test showed acceptor numbers of: (tBu,DIPPBDI)AlMe+ 85.6, (tBu,DIPePBDI)AlMe+ 85.9, (Me,DIPPBDI)AlMe+ 89.7, (Me,DIPePBDI)AlMe+ 90.8, (Me,DIPPBDI)AlH+ 95.3. Steric and electronic factors need to be balanced for catalytic activity in imine hydrogenation. Open, highly Lewis acidic, cations strongly coordinate imine rendering it inactive as a Frustrated Lewis Pair (FLP). The bulkiest cations do not coordinate imine but its combination is also not an active catalyst. The cation (tBu,DIPPBDI)AlMe+ shows the best catalytic activity for various imines and is also an active catalyst for the Tishchenko reaction of benzaldehyde to benzylbenzoate. DFT calculations on the mechanism of imine hydrogenation catalysed by cationic Al complexes reveal two interconnected catalytic cycles operating in concert. Hydrogen is activated either by FLP reactivity of an Al⋅⋅⋅imine couple or, after formation of significant quantities of amine, by reaction with an Al⋅⋅⋅amine couple. The latter autocatalytic Al⋅⋅⋅amine cycle is energetically favoured.

Boron-carbon-nitrogen-containing heterogeneous catalysts for base-catalyzed reaction

To advance green chemistry, further development of heterogeneous base catalysts rather than homogeneous catalysts is essential. In this study, boron–carbon-nitrogen (BCN)-containing materials were prepared and used as heterogeneous catalysts for a base-catalyzed reaction. The BCN materials were prepared by heat treatment of polyacrylonitrile at various temperatures (600, 800, and 1000 °C) and BCl3 concentrations (0.1, 0.5, and 1.0%) to control the composition of the BCN materials. The prepared samples were characterized by X-ray diffractometry, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, and N2 adsorption–desorption measurement. We evaluated the catalytic activity of the samples using the Knoevenagel reaction of benzaldehyde with ethyl cyanoacetate to produce ethyl cyanocinnamate (ECC). Higher surface compositions of boron and nitrogen were obtained by introducing higher concentrations of BCl3 in the preparation process, which increased the ECC yield. Furthermore, the surface ratio of B-N-C-type nitrogen correlated with the ECC yield. The recycling test of the Knoevenagel reaction indicated that the BCN material gradually deactivated with increasing the number of runs, which is attributed to hydrolysis of the B–N site.

Acid-base bifunctional SBA-15 as an active and selective catalyst for synthesis of ethyl α-cyanocinnamate via Knoevenagel condensation

Alanine functionalized mesoporous SBA-15 (SBA-15-Alanine) as an active and selective catalyst for Knoevenagel condensation reaction of benzaldehyde and ethyl cyanoacetate is reported. The catalyst is prepared by 2-step grafting approach using (3-chloropropyl)triethoxysilane (CPTES) followed by dl-alanine. The XRD, TEM and N2 adsorption results reveal that the mesoporous characteristic of SBA-15-Alanine is retained upon modification. Furthermore, the IR, TG/DTG, CHN and TPD analyses indicate the successful functionalization of alanine, leading to the formation of bifunctional mesoporous catalyst bearing both acidic (-COOH) and basic (-NH) sites. This catalyst exhibits acid-base cooperative effect and good catalytic performance in the Knoevenagel condensation between benzaldehyde with ethyl cyanoacetate (96.7% conversion) with 100% selective to ethyl α-cyanocinnamate under novel non-microwave instant heating conditions. The SBA-15-Alanine also shows stable catalytic performance with high reusability where insignificant decline in catalytic reactivity is observed after five successive cycles, thus suggesting a promising replacement of base catalysts in condensation reactions.

Copper‐Catalyzed Three‐Component Cascade Reaction of Benzaldehyde with Benzylamine and Hydroxylamine or Aniline: Synthesis of 1,2,4‐Oxadiazoles and Quinazolines

AbstractThe analogous three‐component synthesis strategy for substituted 1,2,4‐oxadiazole and quinazoline derivatives from readily available benzaldehyde, benzylamine and hydroxylamine or aniline has been developed. Both the cascade reaction sequences involves nucleophilic addition of C−N bond, introduction a halogen donor, nucleophilic substitution and Cu(II)‐catalyzed aerobic oxidation. This synthesis methodology demonstrated good yields, broad substrate scope and oxygen as a green oxidant. Thus, this synthesis protocol provides strategies for the construction of substituted 1,2,4‐oxadiazole and quinazolines from readily and simple starting materials.magnified image

DFT Exploration on Molecular Characteristics of 6-Methyl-2-oxo-4-phenyl-1,2,3,4-tetrahydropyrimidine-5-carboxylate

Present investigation deals with the synthesis and density functional theory study (DFT) of a Biginelli adduct; 6-methyl-2-oxo-4-phenyl-1,2,3,4-tetrahydropyrimidine-5-carboxylate (MOPTHPC). The synthesis of a MOPTHPC has been carried out by the reaction of benzaldehyde, ethyl acetoacetate and urea in ethanol 70-80 ℃ under stirring condition in presence of catalytic amount of sulfamic acid. The structure of a synthesized chalcone is affirmed on the basis of 1H NMR and 13C NMR. The geometry of a MOPTHPC is optimized by using the density functional theory method at the B3LYP/6-311G(d,p) basis set. The optimized geometrical parameters like bond length and bond angles have been computed. Quantum chemical parameters have been determined and examined. Molecular electrostatic surface potential (MESP) surface plot analysis has been carried out at the same level of theory. Mulliken atomic charge study is also discussed in the present study.

Highly active solid oxide acid catalyst for the synthesis of benzaldehyde glycol acetal

A series of composite metal oxide catalysts, namely CeMnTiO, CeCoTiO, and CeFeTiO, were prepared by sol-gel method, and their physicochemical properties were characterized by various techniques, viz. SEM, XRD, XPS, and NH3-TPD. Their desirable acidity and surface area were suitable for the acid-catalyzed acetalization reaction of benzaldehyde (BzH) with ethylene glycol (EG). In particular, CeFeTiO catalyst exhibited superior activity and excellent durability, leading to an acetal yield of 96.8 %, which was in close agreement with the optimal yield (96.95 %) predicted by the response surface methodology (RSM) based on a Box-Behnken design (BBD). Moreover, a kinetic study under the optimal reaction conditions showed that the acetalization reaction was second-order with an active energy (Ea) of 46.65 kJ/mol. Results revealed that CeFeTiO catalyst had high efficiency to surpass conventional Amberlyst catalysts for acetalization reactions.

Synergistic surface basicity enhancement effect for doping of transition metals in nanocrystalline MgO as catalysts towards one pot Wittig reaction

The syntheses of Cu, Fe and Mn doped nanocrystalline MgO was carried out using alkali leached hydrothermal technique. The synergistic effect of transition metals (Cu, Fe and Mn) doping, particle size and nano-scale morphology on surface basicity enhancement was established in one pot Wittig reaction. The doped and undoped nanocrystalline MgO catalysts are characterized by XRD, UV-DRS, FT-IR, FESEM, EDS and XPS techniques. XRD study revealed formation of pure cubic phase of undoped and up to 1 wt% Cu, Fe and Mn doped MgO. The FESEM photographs of transition metal doped MgO indicated the formation of prismatic hexagonal nano plates and nanosheets with thickness in the range 20–70 nm. The catalytic activity of synthesized catalysts was investigated in one pot Wittig reaction of benzaldehyde, triphenylphosphine and ethyl bromoacetate at room temperature in DMF solvent. The Mn doped nanocrystalline MgO catalyst shows 98% yield under optimized reaction conditions. Enhancement of surface basicity due to doping of Mn in MgO was ascertained by UV-DRS and XPS study. The characterization of Wittig product ethyl cinnamate was carried out using HR-MS, 1H NMR, 13C NMR. The 1H NMR evaluates 95:5% E/Z ratio of ethyl cinnmate. Reported methodology is eco-friendly and easy to scale up.

Continuous production of benzylideneacetophenone via gas phase reaction of benzaldehyde and acetophenone: Mechanism and reaction kinetics

Up to 10 times greater chalcone productivity vs. standard batch-liquid systems. • Continuous and time invariant acetophenone + benzaldehyde → chalcone over MgO. • Increase in chalcone production with specific surface basicity. • Undesired formation of benzyl alcohol and benzoic acid over SiO 2 and CeO 2. • Condensation mechanism described by Langmuir-Hinshelwood model. The continuous gas phase condensation of acetophenone (A) with benzaldehyde (B) into valuable (chalcone) benzylideneacetophenone ( P = 1 atm, 498 K ≤ T ≤ 573 K; E app = 58 ± 4 kJ mol −1 ) has been performed over an array of commercial oxides ( i.e. SiO 2 , ZnO, ZrO 2 , CeO 2 and MgO) with modified crystal size (18–50 nm, from XRD), specific surface area (8–176 m 2 g −1 ) and total surface basicity (based on carbon dioxide temperature programmed desorption (CO 2 -TPD)). Reaction operation under chemical controlled regime has been expressly established by parameter estimation and experimental variation of contact time and catalyst/reactant ratio. Full selectivity to target benzylideneacetophenone was achieved over ZnO, ZrO 2 and MgO, while benzaldehyde disproportionation to benzyl alcohol and benzoic acid (Cannizzaro reaction) was promoted using SiO 2 and CeO 2 . A direct correlation between activity and specific (per m 2 ) Lewis catalyst basicity has been presented, where MgO delivered the highest chalcone production rate. The reaction orders with respect to acetophenone and benzaldehyde have been estimated, while the experimentally determined benzylideneacetophenone production rates/ P A / P B profiles were subjected to a Langmuir-Hinshelwood type kinetic modelling. The best fit was obtained with a model involving non -competitive adsorption of A and B with the surface -C–C- bond formation as rate-determining. Our results demonstrate, for the first time, the sole formation of benzylideneacetophenone over extended reaction time (28 days on-stream) through an alternative continuous gas phase route involving acetophenone + benzaldehyde condensation using MgO to deliver an order of magnitude greater productivity relative to conventional batch liquid systems.