A Highly Efficient Method for Synthesis of Bisarylmethylidenes of Cyclic Ketones in [BMIm]Cl/NaOH System as New and Recyclable Catalyst

An ionic liquid 1-Butyl-3-methylimidazoliumchloride[BMIm]Cl/sodium hydroxide system, was employed as a catalyst for the fast and one-pot crossed aldol-condensation of various aromatic aldehydes and cyclic ketones, to produce a variety of substituted α,α'-bis(benzylidene)-cycloalkanones under neat conditions. This process is simple, efficient and environmentally benign and proceeds in high yield and short reaction times. The ionic liquid can be recycled for subsequent reactions without any appreciable loss of efficiency

Silica-based sulfonic acid (MCM-41-SO3H): a practical and efficient catalyst for the synthesis of highly substituted quinolines under solvent-free conditions at ambient temperature

In this work, a variety of highly substituted quinolines were readily synthesized via Friedlander annulation using Brönsted acid silica-based sulfonic acid as a modified catalyst under solvent-free conditions at room temperature. This efficient procedure has the advantages of giving the target compounds in high yields, short reaction times, simple workup procedure, reusability of the catalyst, and environmentally benign conditions

Eco Friendly Composites Prepared from Lactic Acid Based Resin and Natural Fiber

Lactic acid based thermoset were synthesised by reacting lactic acid with glycerol andfunctionalizing lactic acid branches by methacrylic anhydride. Resins with different chainlength were prepared and their thermo mechanical properties were examined through DMAanalysis and their molecular structures were analyzed by NMR method and their viscositywere investigated through rheometry analysis and three monomers were selected as the bestchain length. Degree of reaction in different reaction times was evaluated by a modifiedtitration method and bulk preparation of resin was performed by optimal process condition.DSC analysis was conducted in order to evaluate curing behaviour of resin with benzoylperoxide as cross-linking initiator. TGA analysis was performed to check thermo stability ofthe resin. Bio composites by viscose unidirectional and bidirectional knitted fabrics and alsonon woven viscose fiber with different fiber loads were prepared by ordinary hand layupimpregnation followed by compress moulding and their mechanical and thermo mechanicalproperties were characterized by tensile, flexural, charpy and DMA analysis and optimumfiber loads were identified for each fiber type. Ageing properties of prepared composites wereexamined by placing samples in climate chamber to simulate long time ageing and ageingexperiment was followed by tensile and flexural test to evaluate mechanical properties afterageing simulation. Composite`s swelling properties for water and some other solvents wereinvestigated and also their chemical resistance were evaluated by immersing them in 1M HCland KOH. The resin was also compared with a commercial oil based thermoset by preparingglass fiber reinforced composites and also effect of adding styrene to the resin were evaluated.Results of this work demonstrated that the novel synthesised have very high mechanical andthermo mechanical properties surpassing commercial oil based poly esters but ageingbehaviour is not very good however adding styrene can improve ageing properties. Also theresin is compatible with cellulosic natural fibers and forms strong composites.Program: Masterutbildning i energi- och materia

Preparation, characterization and use of new lignocellulose-based bio nanocomposite as a heterogeneous catalyst for sustainable synthesis of pyrimido benzazoles

A sustainable combinatorial synthesis of densely substituted pyrimido [1,2-b] benzazole derivatives in water under microwave irradiation was performed using a new lignocellulose-based bio nanocomposite (BNC) as heterogeneous catalyst. The lignocellulosic waste peanut shells (LCWPS) were turned into a value-added product, a new BNC PS/ZnO, which was prepared via in situ hydrothermal synthesis. The as-prepared BNC was characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction spectrum. PS/ZnO has been successfully used in a sustainable catalytic method for the synthesis of pyrimido [1, 2-b] benzazole derivatives in water under microwave irradiation. The time of this reaction was significantly reduced. This catalytic system has a very high turnover number (TON ∼ 103) and turnover frequency (TOF ∼ 105 h−1). This paper presents the benefit of sustainable management of LCWPS, a bio-sourced polymeric carbohydrate for production of new nanocatalyst

Synthesis of Functionalized Thiopyrano [2,3-b]quinolines via Cascade Reactions Catalyzed by Magnetic Arginine/Alginate Biocomposite

An effective synthesis of functionalized thiopyrano [2,3-b]quinolines has been described via cascade reactions using super paramagnetic iron oxide nanoparticles (SPIONs) coated with l-arginine (Arg) grafted alginate (Alg), called Fe3O4@Alg@CPTMS@Arg. The reaction was performed between commercially available CH acid compounds such as dimedone or malononitrile, and 2-mercapto-quinoline-3-carbaldehydes under green conditions. This efficient method provides a new route for the formation of functionalized three or four fused rings

γ-aminobutyric acid and collagen peptides as recyclable bifunctional biocatalysts for the solvent-free one-pot synthesis of 2-aminobenzothiazolomethyl-2-naphthols

γ-aminobutyric acid (GABA) and Isinglass a collagen peptide have been utilized as highly efficient bifunctional biocatalysts for the efficient and convenient synthesis of 2-aminobenzothiazolomethyl-2-naphthols through a one-pot three-component Mannich reaction between diverse aldehydes, 2-naphthol and 2-aminobenzothiazole under solvent-free condition in high yields. Moreover, GABA could be recycled and reused at least four times without noticeable loss of its activity

Preparation, characterization and use of new lignocellulose-based bio nanocomposite as a heterogeneous catalyst for sustainable synthesis of pyrimido benzazoles

<p>A sustainable combinatorial synthesis of densely substituted pyrimido [1,2-b] benzazole derivatives in water under microwave irradiation was performed using a new lignocellulose-based bio nanocomposite (BNC) as heterogeneous catalyst. The lignocellulosic waste peanut shells (LCWPS) were turned into a value-added product, a new BNC PS/ZnO, which was prepared <i>via in situ</i> hydrothermal synthesis. The as-prepared BNC was characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction spectrum. PS/ZnO has been successfully used in a sustainable catalytic method for the synthesis of pyrimido [1, 2-b] benzazole derivatives in water under microwave irradiation. The time of this reaction was significantly reduced. This catalytic system has a very high turnover number (TON ∼ 10³) and turnover frequency (TOF ∼ 10⁵h⁻¹). This paper presents the benefit of sustainable management of LCWPS, a bio-sourced polymeric carbohydrate for production of new nanocatalyst.</p

Organocatalytic clean synthesis of densely functionalized 4H-pyrans by bifunctional tetraethylammonium 2-(carbamoyl)benzoate using ball milling technique under mild conditions

A green and simple method has been developed for efficient preparation of diverse annulated 2-amino-3-cyano-4H-pyran derivatives in the presence of a low loading of tetraethylammonium 2-(carbamoyl)benzoate (TEACB), as a bifunctional organocatalyst, under solvent-free conditions using the ball milling technique. This procedure is a clean, transition-metal-free, and environmentally friendly approach that offers many advantages including short reaction times, high to quantitative yields, low cost, and straightforward work-up

An improved solvent-free synthesis of flunixin and 2-(arylamino) nicotinic acid derivatives using boric acid as catalyst

Abstract A simple solvent-free protocol for the preparation of flunixin, a potent non-narcotic, non-steroidal anti-inflammatory drugs is reported using boric acid as catalyst. Its salt, flunixin meglumine are then prepared under reflux in EtOH. This sustainable method are then extended for the synthesis of a series of 2-(arylamino) nicotinic acid derivatives. The present protocol combines non-hazardous neat conditions with associated benefits like excellent yield, straightforward workup, and use of readily available and safe catalyst in the absence of any solvent, which are important factors in the pharmaceutical industry. The pathway for catalytic activation of 2-chloronicotic acid with boric acid was also investigated using Gaussian 03 program package