55 research outputs found

    An Efficient Synthesis of Tetrahydrobenzo[ b

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    Tetrahydrobenzo[b]pyran derivatives were efficiently synthesized by the reaction of appropriated aromatic aldehydes, malononitrile and dimedone in the presence of SiO2-Pr-SO3H as a nanoporous and recoverable solid acid catalyst, in good to excellent yields. Single crystal x-ray analysis conclusively confirmed the structure of the 2-amino-3-cyano-7,7-dimethyl-4-(4-methylphenyl)-5-oxo-4H-5,6,7,8-tetrahydro-benzopyran

    Knoevenagel condensation of isatins with malononitrile/ethyl cyanoacetate in the presence of sulfonic acid functionalized silica (SBA-Pr-SO3H) as a new nano-reactor

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    The Knoevenagel condensation between isatins and active methylene compounds like malononitrile and ethyl cyanoacetate to prepare 2-oxoindolin-3-ylidene malononitrile/ cyanoacetates is described. The reactions occur in the presence of sulfonic acid functionalized silica SBA-15 (SBA-Pr-SO3H) in an aqueous medium giving excellent yields of the products in short reaction times. SBA-Pr-SO3H with a pore size of 6 nm is found to be an efficient and environmentally benign catalyst for this reaction

    Modification of mesoporous silica SBA-15 with different organic molecules to gain chemical sensors: a review

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    The recognition of the biologically and environmentally important ions is of great interest in the field of chemical sensors in recent years. The fluorescent sensors as a powerful optical analytical technique for the detection of low level of various analytes such as anions and metal cations have been progressively developed due to the simplicity, cost effective, and selectivity for monitoring specific analytes in various systems. Organic-inorganic hybrid nanomaterials have important advantages as solid chemosensors and various innovative hybrid materials modified by fluorescence molecules were recently prepared. On the other hand, the homogeneous porosity and large surface area of mesoporous silica make it a promising inorganic support. SBA-15 as a two-dimensional hexagonal mesoporous silica material with stable structure, thick walls, tunable pore size, and high specific surface area is a valuable substrate for modification with different organic chelating groups. This review highlights the fluorescent chemosensors for ionic species based on modification of the mesoporous silica SBA-15 with different organic molecules, which have been recently developed from our laboratory

    Application of SBA-Pr-SO3H in the synthesis of benzoxazole derivatives

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    Propylsulfonic acid functionalized SBA-15 (SBA-Pr-SO3H) catalyzed the synthesis of 2-aryl benzoxazoles from 2-aminophenol and benzoyl chloride derivatives in good yields under reflux condition in acetic acid. In solvent free condition, hydroxybenzanilide derivatives were obtained

    Synthesis of 3,4-Dihydropyrano[c]Chromene Derivatives Using Sulfonic Acid Functionalized Silica (SiO 2 PrSO 3 H)

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    ABSTRACT: 3,4-Dihydropyrano[c]chromene derivatives were synthesized using sulfonic acid functionalized silica (SiO 2 -Pr-SO 3 H) as a highly efficient heterogenous solid acid catalyst via one-pot three-component condensation of aromatic aldehydes with malononitrile and 4-hydroxycoumarin in excellent yields

    (3-Nitro­phen­yl)methanediyl diacetate

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    In the title compound, C11H11NO6, only weak van der Waals inter­actions are found in the mol­ecular packing. The compound is an efficient catalyst for the acetalization of the carbonyl group of aldehydes in nearly quantative yield

    1-Benzyl-2-(4-chloro­phen­yl)-4,5-di­phenyl-1H-imidazole

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    The mol­ecular conformation of the title compound, C28H21ClN2, is stabilized by an intra­molecular C—H⋯N hydrogen bond. It has many pharmacological properties, such as being an inhibitor of P38 MAP Kinase, and can play an important role in biochemical processes

    9-(2,3-Dichloro­phen­yl)-4a-hydr­oxy-3,3,6,6-tetra­methyl-4,4a,5,6,9,9a-hexa­hydro-3H-xanthene-1,8(2H,7H)-dione

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    Mol­ecules of the title compound, C23H26Cl2O4, are linked by hydrogen bonds between the hydroxyl O atom and the carbonyl O atom of a neighboring mol­ecule. The central hydropyran and fused cyclohexanone rings adopt half-chair conformations, while the fused hydroxycyclohexanone ring adopts a chair conformation
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