Reaction Of Salicylaldehyde Research Articles

ChemInform Abstract: ZnO Nanoparticles as an Efficient Catalyst for the Selective Synthesis of 4‐Hydroxychromenes via the Reaction of Salicylaldehydes with Dimethyl or Diethyl Acetylenedicarboxylate in [bmim]BF4.

ZnO nanoparticles as a highly effective heterogeneous base catalyst selectively catalyzes the reaction between salicylaldehydes and dialkyl acetylenedicarboxylates in ionic liquid [bmim]BF4 to obtain 4-hydroxy-4H-chromenes in high to excellent yields. The advantages of this method include the selectivity of reaction, one-pot procedure, mild reaction conditions, operational simplicity, and use of inexpensive and non-toxic catalyst. .

Bismuth triflate: A highly efficient catalyst for the synthesis of bio-active coumarin compounds via one-pot multi-component reaction

A series of coumarin-chalcone hybrid compounds and coumarins linked to pyrazoline was synthesized in good yield and short time using a simple and efficient method. This method involved the one-pot reaction of salicylaldehyde, an α-ketoester and an aromatic aldehyde (in the case of the coumarin-chalcone derivatives) in addition to hydrazine hydrate (in the case of the pyrazolyl coumarins) in the presence of a catalytic amount of bismuth triflate [Bi(OTf)3, 5 mol%]. The synthesized compounds showed scavenging activity towards the free radical 2,2-diphenyl-1-picrylhydrazyl. All compounds were characterized using IR, 1H NMR and 13C NMR spectroscopy.

Non-catalytic multicomponent rapid and efficient approach to 10-(2,4,6-trioxohexahydropyrimidin-5-yl)-3,3-dimethyl-2,3,4,9-tetrahydro-1H-xanthen-1-ones from salicylaldehydes, dimedone, and barbituric acids

Non-catalytic multicomponent reaction of salicylaldehydes, dimedone, and barbituric acids initiated by reflux in ethanol results in the fast (5 min) and efficient formation of substituted tetrahydro-1H-xanthen-1-ones in 90–95 % yields. The developed fast multicomponent approach to the substituted tetrahydro-1H-xanthen-1-ones, which are known as medicinally relevant substances such as antibiotics, enzyme inhibitors, and anticancer drugs, is beneficial from the viewpoint of diversity-oriented multi-gram-scale processes and represents fast, efficient, and environmentally benign synthetic concept for multicomponent reaction strategy.

ChemInform Abstract: Synthesis of Coumarin‐3‐carboxylic Esters via FeCl3‐Catalyzed Multicomponent Reaction of Salicylaldehydes, Meldrum′s Acid and Alcohols.

AbstractTitle compounds [(IV) and (VI)] are synthesized using an environmentally friendly and highly atom‐economic procedure and readily available educts.

An Efficient Synthesis of Chromeno[2,3‐d]pyrimidine‐2,4‐diones with a Nitroketene‐Aminal Moiety at C(5) by a One‐Pot Four‐Component Reaction

AbstractAn efficient and novel synthesis of chromeno[2,3‐d]pyrimidine‐2,4‐dione derivatives with a nitroketene‐aminal moiety at C(5) via four‐component reaction of salicylaldehydes, barbituric acid, diamines, and 1,1‐bis(methylsulfanyl)‐2‐nitroethene in EtOH and in the presence of AcOH is reported. Easy performance, good yields, and easy purification are the main advantages of this method. All structures were confirmed by IR, MS, and 1H‐ and 13C‐NMR, and by X‐ray crystal‐structure analyses. A plausible mechanism for this type of reaction is proposed (Scheme).

Cobalt(II), copper(II), zinc(II) and palladium(II) Schiff base complexes: Synthesis, characterization and catalytic performance in selective oxidation of sulfides using hydrogen peroxide under solvent-free conditions

An asymmetric bidentate Schiff-base ligand (HL: 2-tert-butyliminomethyl-phenol) was prepared from the reaction of salicylaldehyde and tert-butylamine. Cobalt(II), copper(II), zinc(II) and Pd(II) complexes, CoL2, CuL2, ZnL2 and PdL2, were synthesized from the reaction of CoCl2·6H2O, CuCl2·2H2O, Zn(NO3)2·6H2O and PdCl2 with the bidentate Schiff base ligand HL in methanol. The ligand and its metal complexes were characterized by elemental analysis (CHN), FT-IR and UV-Vis spectroscopy. In addition, 1H and 13C NMR techniques were employed for characterization of the ligand (HL) and the diamagnetic complexes (ZnL2 and PdL2). The molecular structures of all the complexes were determined by the single crystal X-ray diffraction technique. The crystallographic data reveal that in all the complexes the metal centers are four-coordinated by two phenolate oxygen and two imine nitrogen atoms of two Schiff base ligands. The geometry around the metal center in the CoL2, CuL2 and ZnL2 complexes is a distorted tetrahedral and for PdL2 it is square-planar.The catalytic activity of these complexes has been evaluated for the selective oxidation of sulfides with the green oxidant 35% aqueous H2O2 under solvent free conditions. For all the catalysts, using optimized reaction conditions, different sulfides were converted to the corresponding sulfones. ZnL2 showed a higher catalytic performance for the oxidation of the different sulfides to the corresponding sulfones.

A metal-free tandem C-C/C-O bond formation approach to densely functionalized indolyl 4H-chromenes catalyzed by polystyrene-supported p-toluenesulfonic acid under solvent-free conditions.

A new environmentally benign and highly convergent protocol for the synthesis of indolyl 4H-chromene derivatives has been developed. This one-pot three-component condensation reaction of salicylaldehyde, cyclic 1,3-diketones, and indole is promoted by PS-PTSA as a reusable heterogeneous acid catalyst under solvent-free conditions. This protocol demonstrates several notable advantages such as that the catalyst is readily available and can be recovered and reused for at least five runs without any significant impact on product yields, high atom economy, excellent yields, and efficiency of producing three new bonds (two C-C and one C-O) and one stereo center in a single operation.

Multicomponent assembling of salicylaldehydes, malononitrile and cyanoacetamides: A simple and efficient approach to medicinally relevant 2-amino-4H-chromene scaffold

Sodium hydroxide catalyzed a new multicomponent reaction of salicylaldehydes, malononitrile and cyanoacetamides under ‘on-water’ conditions, which results in the facile and efficient formation of the corresponding substituted 2-amino-4 H -chromenes in 80–95% yields. The convenient approach to the substituted 2-amino-4 H -chromenes developed here — the promising small-molecule ligands for different biomedical applications with known spasmolitic, diuretic and antianaphylactic activities — is beneficial from the viewpoint of diversity-oriented large-scale processes and represents a fast, efficient and environmentally benign ‘on-water’ synthetic concept for multicomponent reactions strategy.

ChemInform Abstract: Efficient Synthesis of Chromenopyridine and Chromene via MCRs.

AbstractThe temperature dependence of the three‐component reaction of salicylaldehydes, malononitrile and thiols is demonstrated.

Regioselective and diastereoselective borono-Mannich reactions with pinacol allenylboronate.

The first documented study of the borono-Mannich (Petasis) reactions of pinacol allenylboronate is described. The reactions of salicylaldehyde and primary and secondary amines are highly regioselective and give homopropargylamine and α-allenylamine products, respectively. In contrast, glycoaldehyde and chiral α-hydroxyaldehydes give exclusively anti-β-amino-β-allenyl alcohol products, irrespective of the nature of the amine component. These reactions are highly regio- and diastereoselective and can be employed using an enantiomerically enriched α-hydroxyaldehyde without detectable racemization.

ChemInform Abstract: Reactions of Salicylaldehydes with Activated Terminal Alkynes in Aqueous Media: Synthesis of 3‐Substituted 4‐Hydroxy Chromenes as Potential Cytotoxic Agents.

AbstractDerivatives (IIIc) and (IIId) show interesting inhibitory activity against MDA‐MB231 (breast cancer) cells.

ChemInform Abstract: Base‐Promoted Synthesis of Coumarins from Salicylaldehydes and Aryl‐Substituted 1,1‐Dibromo‐1‐alkenes under Transition‐Metal‐Free Conditions.

Facile synthesis of coumarin via the tandem reaction of salicylaldehyde with aryl-substituted 1,1-dibromo-1-alkene was developed. This new protocol proceeds smoothly under mild and transition-metal-free conditions, it allows rapid access to coumarins containing various heteroatoms that are more difficult to prepare by traditional methods. Based on the isolated intermediate of 4-(diethylamino)-3-phenylchroman-2-one and detailed mechanistic studies, a credible tandem pathway was proposed.

Meglumine catalyzed one-pot, three-component combinatorial synthesis of pyrazoles bearing a coumarin unit

Meglumine has been found to be an efficient catalyst for the synthesis of pyrazolylcoumarins by one-pot three-component reaction of salicylaldehyde, 4-hydroxy-6-methyl-2H-pyran-2-one, and hydrazine.

Coordination Polymers: Preparation, Physicochemical Characterization, Thermal and Biological Evaluation of Thiosemicarbazide Polychelates

Coordination polymers were prepared by the condensation reaction of salicylaldehyde and thiosemicarbazide with formaldehyde, transition metal acetates Mn(II), Co(II), Ni(II), Cu(II) and Zn(II). Structural and spectral properties have been studied by elemental, spectral (FT-IR, 1H NMR, and UV–Vis), and thermogravimetric analysis. The geometry of the chelated coordination polymers was confirmed by magnetic susceptibility measurements and UV–Visible spectroscopy. Antimicrobial screening was done against microbes such as Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, Staphylococcus aureus, Staphylococcus typhi, Candida albicans, Microsporum canis, Aspergillus niger. In vitro antimicrobial activity was determined by the Agar Well Diffusion method and result show that all the coordination polymers exhibited better antimicrobial activity than their parent polymeric Schiff base. Coordination polymers were found to be more stable than their corresponding ligand as deduced by on thermogravimetric analysis. Because of antimicrobial and thermal behavior, these coordination polymers have broad range of applications as thermally resistant as well as antimicrobial-biocidal and antifouling coating materials.

Synthesis and characterization of a novel Schiff-base/SBA-15 nanoadsorbent for removal of methylene blue from aqueous solutions

A novel Schiff-base/SBA-15 nanoadsorbent was successfully synthesized by the reaction of salicylaldehyde and (3-aminopropyl) trimethoxysilane in methanol and subsequent grafting with SBA-15. The morphology and structures of the as-synthesized Schiff-base/SBA-15 nanoadsorbent were characterized by powder X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy, thermo-gravimetric analysis, and N2 adsorption/desorption isotherms. The obtained Schiff-base/SBA-15 nanoadsorbent was used for the removal of methylene blue (MB) from aqueous solutions. The effects of various parameters such as temperature, concentration, pH, and contact time were examined, and optimal experimental conditions were determined. The equilibrium isotherms were conducted using Freundlich and Langmuir models. The pseudo-first-order, pseudo-second-order, and intraparticle diffusion models were used to fit adsorption data in the kinetic studies. The thermodynamic parameters such as the standard enthalpy, standard entropy, and standard free energy were evaluated. The obtained results indicated that the Schiff-base/SBA-15 nanoadsorbent is an efficient adsorbent for removing MB.

Synthesis of coumarin-3-carboxylic esters via FeCl3-catalyzed multicomponent reaction of salicylaldehydes, Meldrum's acid and alcohols

A FeCl3-catalyzed multicomponent reaction was developed for the facile synthesis of coumarin-3-carboxylic ester derivatives in a highly atom-economic and environmentally friendly way. Using simple and cheaply available salicylaldehydes, Meldrum's acid and alcohols as the starting materials, the method needs no extra additives and features wide substrate scope, good functional group tolerance and mild reaction conditions.

A detailed investigation of the multicomponent reaction of salicylaldehyde, ethyl acetoacetate and isocyanides under microwave heating

New insights into the cyclocondensation reaction of salicylaldehyde, ethyl acetoacetate and isocyanides are reported. Depending on the reaction conditions either the previously reported 5-hydroxy-N-substituted-2H-dihydrochromeno[3,4-c]pyrrol-2-ones or the novel 2-imino-5-hydroperoxy-5-methyl-2H-dihydrochromeno[3,4-c]furans were obtained. Although suggested as intermediates in previously proposed reaction mechanisms, these hydroperoxides are not obtained when the reaction is performed under open vessel reflux conditions, but are the main product when conducted in a closed vessel using either microwave or conventional heating. Thorough NMR studies and X-ray crystallography confirm the structure of the generated hydroperoxy products.

Syntheses and Redox Properties of Complexes with Mo3S4 Cores and Tridentate Schiff Base Ligands

Abstract A series of potentially tridentate Schiff base ligands, {HOPhC=N-(CH2)3-XMe: X = S (HLSMe), Se (HLSeMe)}, was prepared by condensation reactions of salicylaldehyde and the corresponding functionalized propylamines. These ligands were used to form the monocationic complexes, [Mo3S4(LXMe)3]+ (X = S (1+), Se (2+)), through treatment of [Mo3S4(H2O)9]4+ with the appropriate Schiff base ligand in methanol. Single-crystal X-ray structural analysis of 1-PF6 revealed that one Schiff base ligand coordinates to each Mo via the O, N, and SMe donor atoms, and then the mono cationic cluster [Mo3S4(LSMe)3]+ has a pseudo C3 symmetry if the chirality around the coordinated sulfur atoms is not taken into account. Because of the arrangements of the asymmetric Schiff base ligand, this monocationic cluster possibly adopts one of two axial chiralities. Furthermore, each sulfur atom of the three coordinated SMe groups in the complex cation is also chiral affording the two enantiomers observed in the unit cell. Dynamic behaviors of complexes 1-PF6 and 2-PF6 in solution were examined using line shape analyses of variable temperature NMR spectra revealing that the rate constant of the chiral inversion at the S atoms in 1-PF6 is greater than that at the Se atoms in 2-PF6 and the difference in the ΔH‡ values of 1-PF6 (47.1 kJ mol−1) and 2-PF6 (56.7 kJ mol−1) and the negative ΔS‡ values (−39.9 and −57.5 J mol−1 K−1 for 1-PF6 and 2-PF6, respectively) suggest that the inversion processes involve bond cleavage between the metal centers and S or Se atoms followed by coordination of solvent molecules. The electrochemical properties of 1-PF6 and 2-PF6 were evaluated using cyclic voltammetry and this revealed that both 1+ and 2+ exhibit two consecutive, reversible one-electron reduction waves that are assigned to formal Mo(IV IV IV)/Mo(III IV IV) and Mo(III IV IV)/Mo(III III IV) couples, respectively. The ability of 1-PF6 and 2-PF6 to catalyze the electroreduction of H+ was also examined using CH3CO2H or CF3CO2H as a proton source. Noteworthy, the redox potentials for the catalytic wave depend on the acidity of the added acids. Thus, the catalytic current around the first reduction wave is observed in the presence of the stronger trifluoroacetic acid as a proton source, while the current around the second reduction wave appears when the weaker acetic acid is used.

ChemInform Abstract: Studies on the Biginelli Reactions of Salicylaldehyde and 2‐Hydroxy‐1‐naphthaldehyde.

AbstractChemoselectivity of the Biginelli Reactions depends on the reaction conditions used, tricyclic bridged pyrimidine derivatives are formed upon refluxing whereas, at lower temperatures pyrimidine derivatives of type (IV) are formed.

Synthesis, characterization and X-ray crystal structures of Vanadium(IV), Cobalt(III), Copper(II) and Zinc(II) complexes derived from an asymmetric bidentate Schiff-base ligand at ambient temperature

An asymmetric bidentate Schiff-base ligand (HL: 2-((allylimino)methyl)phenol) was prepared from reaction of salicylaldehyde and Allylamine. Vanadium(IV), Cobalt(III), Copper(II) and Zinc(II) complexes, VOL2, CoL3, CuL2 and ZnL2 were synthesized from the reaction of VO(acac)2, CoCl2·6H2O, CuCl2·2H2O and Zn(NO3)2·6H2O with the bidentate Schiff base ligand (HL: 2-allyliminomethyl-phenol) in methanol at ambient temperature. The ligand and its metal complexes were characterized by elemental analysis (CHN), FT-IR spectroscopy. In addition, 1H and 13C NMR techniques were employed for characterization of the ligand (HL) and diamagnetic complex ZnL2. The molecular structures of all complexes were determined by single crystal X-ray diffraction technique. In the ZnL2 and CuL2 complexes, the metal ion is coordinated by two nitrogen and two oxygen atoms from two Schiff base ligands in an approximately square planar trans-[MN2O2] coordination geometry. In the Vanadium(IV) complex, VOL2, the vanadium center in this structure has a distorted tetragonal pyramidal N2O3 coordination sphere and for Cobalt(III) complex, CoL3, the CoIII ion is six coordinated by three bidentate Schiff base ligands in a distorted octahedral environment.