FeCl 3 .nano SiO 2 : An Efficient Heterogeneous Nano Catalyst for the Synthesis of 14-Aryl-14H-dibenzo[a,j]xanthenes and 1,8-Dioxo-octahydro-xanthenes under Solvent-free Conditions

ABSTRACT A novel, efficient and eco-friendly procedure for the synthesis of 14-aryl-14H-dibenzo[a,j]xanthenes and 1,8-dioxo-octahydroxanthenes is described through one-pot condensation of 2-naphthol and dimedone with aryl aldehydes in the presence of nano silica-supported ferric chloride under solvent-free conditions. The present approach offers several advantages such as short reaction times, high yields, easy purification, recovery and reusability of the catalyst

MILD AND EFFICIENT METHOD FOR OXIDATION OF ALCOHOLS IN IONIC LIQUID MEDIA

In this study the strong oxidative agent, potassium permanganate, has been moderated with using under ionic liquid media for selective oxidation of some benzylic and aliphatic alcohols to their corresponding carbonyl compounds under mild and green conditions. 1-Butyl-3-methylimidazoliumbromide ([bmim]Br) (BMIM) associated with acetonitrile has been employed as modified media for oxidation of benzylic alcohols. This chemoselective and efficient process produced aldehydes and ketones with higher purity and yields and shorter reaction period in [bmim]Br as ionic liquid than conventional solvents

Aqua­(1,10-phenanthroline)(pyridine-2,6-dicarboxyl­ato)nickel(II) pyridine-2,6-di­carboxylic acid solvate tetra­hydrate

The title compound, [Ni(C7H3NO4)(C12H8N2)(H2O)]·C7H5NO4·4H2O or [Ni(pydc)(phen)(H2O)].pydcH2·4H2O, was obtained by the reaction of nickel(II) nitrate hexa­hydrate with the proton-transfer compound (phenH)2(pydc) (phen is 1,10-phenanothroline and pydcH2 is pyridine-2,6-dicarboxylic acid) in aqueous solution. Both the cationic and anionic portions of the starting proton-transfer compound are involved in the complexation. The NiII atom has a distorted octa­hedral geometry and is hexa­coordinated by three O atoms and three N atoms from one phen fragment (as a bidentate ligand), one (pydc)2− unit (as a tridentate ligand) and one water mol­ecule. In the crystal structure, extensive O—H⋯O, O—H⋯N and C—H⋯O hydrogen bonds with D⋯A distances ranging from 2.573 (2) to 3.385 (2) Å, π–π inter­actions between the phen ring systems [with centroid–centroid distances of 3.4694 (12), 3.4781 (11) and 3.8310 (11) Å] and inter­molecular C—O⋯π inter­actions [C⋯π distances of 3.4812 (17), 3.5784 (16) and 3.5926 (16) Å] connect the various components together

Hexaaqua­nickel(II) tetra­aqua­bis­(μ-pyridine-2,6-dicarboxyl­ato)bis­(pyridine-2,6-dicarboxyl­ato)trinickelate(II) octa­hydrate

The title compound, [Ni(H2O)6][Ni3(C7H3NO4)4(H2O)4]·8H2O, was obtained by the reaction of nickel(II) nitrate hexa­hydrate with pyridine-2,6-dicarb­oxy­lic acid (pydcH2) and 1,10-phenanothroline (phen) in an aqueous solution. The latter ligand is not involved in formation of the title complex. There are three different NiII atoms in the asymmetric unit, two of which are located on inversion centers, and thus the [Ni(H2O)6]2+ cation and the trinuclear {[Ni(pydc)2]2-μ-Ni(H2O)4}2− anion are centrosymmetric. All NiII atoms exhibit an octa­hedral coordination geometry. Various inter­actions, including numerous O—H⋯O and C—H⋯O hydrogen bonds and C—O⋯π stacking of the pyridine and carboxyl­ate groups [3.570 (1), 3.758 (1) and 3.609 (1) Å], are observed in the crystal structure

Modified Methods for the Synthesis of Triazinyl Fluorescent Brightener Intermediates

The production of triazinyl fluorescent brightener intermediates in high yields is described. The method involves a simplified work-up for the preparation of 4-nitro-toluene-2-sulfonic acid and the use of diethylene glycol instead of water in the preparation of 4,4\u27-dinitrostilbene-2,2\u27-disulfonic acid

Asymmetric synthesis of conformationally restricted amino acids

This thesis describes new approaches to the asymmetric synthesis of cyclic non-proteinogenic α-amino acids (NPAAs) and amino acid derivatives from (2R)-3-benzoyl-4-methylene-2-phenyloxazolidin-5-one. In the first Chapter, an overview of the strategies used for the synthesis of these compounds and also their biological activities was provided. It was found that for the preparation of cyclic α-amino acids in high enantiomeric purity, starting materials with a chiral auxiliary have generally been employed. In Chapter Two, the synthesis of cyclic NPAAs, through the thermally induced Diels-Alder reactions of (2R )-3-benzoyl-4-methylene-2- phenyloxazolidin-5-one (8) and substituted 1,3-butadienes and substituted 1,3-cyclohexadienes was explored. In general, the reactions were found to be highly regioselective and exo-diastereoselective. The exo selectivity of these reactions was explained by a secondary orbital interaction between the N-donor group of the oxazolidinone ring of (8) (a captodative alkene) and the diene. The NPAA, (2S,4S)-2-aminobicyclo[2.2.2]octane-2- carboxylic acid, was prepared in optically active form starting with (8) and cyclohexadiene. In Chapter Three, the 1,3-dipolar cycloaddition reactions of (2R)-3- benzoyl-4-methylene-2-phenyloxazolidin-5-one (14) with nitrones and nitrile oxides are reported. In general the nitrone reactions occur under equilibrating conditions to give the more stable adducts that result from addition to the exo -cyclic methylene of (14) from the sterically more hindered π-face. The major adducts from the reaction of (14) and nitrile oxides (2) and (37) had the expected stereochemistry, addition of the 1,3- dipole occurred from the least hindered π-face of the exo-cyclic methylene of (14). Hydrogenation / hydrolysis of the cycloadduct of (14) and C,Ndiphenylnitrone gave the novel compound, cw-(2/?,45)-l,4-diphenyl-2- benzoylazethane (58). In Chapter Four, a new method for the synthesis of polyfunctional prolines was established through exo-diastereoselective 1,3-dipolar cycloaddition reaction of (2/?)-3-benzoyl-4-methylene-2-phenyloxazolidin-5-one (22) and N-benzylidene α-amino acid eaters. The proline derivatives (49) and (50) were synthesised in high enantiomeric purity (92% e.e.) by methanolysis of the oxazolidinone moiety of their respective cycloadducts. In the case of ethyl N-benzylidene glycinate, a Michael addition product (35) and two novel tricyclic compounds (30a) and (30b) were also isolated and characterized. In each Chapter, the stereochemistry of the products was determined by a combination of single crystal X-ray structural analysis, ID and 2D NMR spectroscopy and molecular modelling

FeCl3/SiO2 NPs as a robust and efficient catalyst for the synthesis of 2-aryl-5-methyl-2,3-dihydro-1H-3-pyrazolones

A four-component reaction of phenylhydrazines, ethyl acetoacetate, aldehydes and β-naphthol has been achieved in the presence of FeCl3/SiO2 nanoparticles as a highly effective heterogeneous catalyst to produce 2-aryl-5-methyl-2,3-dihydro-1H-3-pyrazolones in good to excellent yields, short reaction times, mild reaction conditions and the employment of a cost-effective catalyst

Synthesis of some 3,5-diarylisoxazoline derivatives in ionic liquids media

Biologically active isoxazoline derivatives were efficiently synthesized in excellent yields and in less reaction time using mild, effective and environmentally friendly butylmethylimidazolium bromide as solvent and catalyst. By use of this catalyst isoxazoline derivatives are produced via cyclization reaction of chalcone and hydroxylamine hydrochloride in ionic liquids media. The separation of the product was facile and the catalyst could be separated and recycled. Our method is very quick, safe and avoids the use of hazardous and expensive reagents and solvents

Synthesis of pyrimidines by Fe3O4@SiO2-L-proline nanoparticles

Fe3O4@SiO2-L-proline nanoparticles have been used as an effective catalyst for the preparation of pyrimidines by three-component reactions of 1,3-dimethylbarbituric acid, aromatic aldehydes and 4-methyl aniline or 4-methoxy aniline under reflux condition in ethanol. Fe3O4@SiO2-L-proline nanoparticles have been characterized by scanning electronic microscopy (SEM), powder X-ray diffraction (XRD), vibrating sample magnetometer (VSM), thermal gravimetric analysis (TGA), energy dispersive X-ray (EDS), dynamic light scattering (DLS) and FT-IR spectroscopy. This method provides several advantages including, the reusability of the catalyst, low catalyst loading, atom economy, short reaction times and high yields of products

Sulfonated magnetic spirulina nanobiomaterial as a novel and environmentally friendly catalyst for the synthesis of dihydroquinazolin-4(1H)-ones in aqueous medium

Abstract Spirulina algae is an excellent candidate for catalyst preparation due to its reactive functional groups, cost-effectiveness, widespread commercial accessibility, and biodegradability. In this study, magnetized Spirulina was used for the synthesis of dihydroquinazolin-4(1H)-ones (DHQZs) as catalyst. Magnetized Spirulina was produced by CoFe2O4 and sulfonation method using chlorosulfonic acid to create the catalyst [CoFe2O4-Sp-SO3H]. It was affirmed by various techniques, including Fourier transform infrared (FT-IR), Vibrating sample magnetometry (VSM), Powder X-ray diffraction (XRD), Energy-dispersive X-ray spectroscopy (EDS), Thermogravimetric analysis (TGA), Transmission electron microscopy (TEM), Field emission scanning electron microscopy (FE-SEM), and elemental mapping techniques. DHQZs synthesis was accomplished through a concise one-pot, three-component reaction involving a range of diverse aldehydes, isatoic anhydride, and primary aromatic amine, within an aqueous medium. The method offers several advantages, including using green conditions, the generation of several new 2-furan-quinazolinone derivatives, chromatography-free purification, short reaction times, appropriate yield of product (75–96%), and catalyst recyclability. The proposed catalyst and water as solvent demonstrated a strong synergistic effect, leading to the prosperous synthesis of various novel dihydroquinazolinones at 60 °C. These numerous benefits make our approach highly attractive for academic research and industrial applications