نتایج جستجو برای: reusable acidic ionic liquid
تعداد نتایج: 294619 فیلتر نتایج به سال:
a variety of alcohols readily add to 3,4-dihydro-2h-pyran under solvent free conditions in the presence of catalytic amount of acidic ionic liquid [et3n(ch2)4so3h][ots] to afford the corresponding tetrahydropyranyl ethers in good to excellent yields at room temperature. the use of this procedure allows easy separation of the desired products from ionic liquid and recycling the ionic liquid. som...
a mild and efficient method has been developed for the preparation of substituted coumarins from reaction of various phenols with different β-ketoesters via pechmann condensation in the presence of brønsted acidic ionic liquid (n-(4-sulfonic acid) butyl triethylammonium hydrogen sulfate) as an effective catalyst under solvent-free conditions. different phenols reacted with ethyl acetoacetate to...
an efficient and chemoselective procedure for the preparation of 1, 1-diacatates (acylals) from various aldehydes with acetic anhydride in the presence of brønsted acidic ionic liquid [msei]cl as a reusable catalytic system under solvent-free condition at room temperature and short periods of times with excellent yields will be described. the catalyst was easily separated in simple work-up and ...
A mild and efficient method has been developed for the preparation of substituted coumarins from reaction of various phenols with different β-ketoesters via Pechmann condensation in the presence of Brønsted acidic ionic liquid (N-(4-sulfonic acid) butyl triethylammonium hydrogen sulfate) as an effective catalyst under solvent-free conditions. Different phenols reacted with ethyl acetoacetate to...
A mild and efficient method has been developed for the preparation of substituted coumarins from reaction of various phenols with different β-ketoesters via Pechmann condensation in the presence of Brønsted acidic ionic liquid (N-(4-sulfonic acid) butyl triethylammonium hydrogen sulfate) as an effective catalyst under solvent-free conditions. Different phenols reacted with ethyl acetoacetate to...
the ionic liquid li(ohch2ch2nh2)(cf3oac) was found to efficiently catalyze the three-component reaction between different enols, aldehydes, and malononitrile , leading to rapid synthesis of 2-amino-4h-chromene derivatives in fairly high yields. the catalyst is easily prepared, highly stable, simple to handle and recycled for several times without significant loss of activity. the method is simp...
abstract in first part of this project, the use of a new and biguanid-like catalyst supported on silica as a recyclable catalyst provides a new route for the synthesis of a variety of arylalkylidene rhodanine derivatives through knoevenagle reaction in at present of solvent at room temperature. rhodanine derivatives and especially arylalkylidene rhodanines have proven to be attractive compound...
abstract-a novel and efficient method has been developed for the synthesis of pyrano[3,2-c]quinoline-2,5-dione derivatives by the convenient ultrasound-mediated condensation of 4-hydroxyquinolin-2-one with meldrum’s acid and aldehydes in the presence of a catalytic amount of [hmim]hso4 as a green, efficient and reusable acidic ionic liquid medium. the stability of the ionic liquid during the re...
the brønsted acidic ionic liquid ([bmim]hso4) catalyzed three-component synthesis of 2h-indazolo[2,1-b]phthalazine-trione derivatives at room temperature. the integrity of the ionic liquid remains reasonably unchanged when it is separated from the reaction mixture by water extraction, as it can be recycled several times without any loss of activity in each of the title syntheses. the products a...
In this protocol, 3-(2-carboxybenzoyl)-1-methyl-1H-imidazol-3-ium chloride [Cbmim]Cl and sulfonic acid functionalized pyridinium chloride [pyridine-SO3H]Cl as a new, reusable, and green Brønsted acidic ionic liquid (BAIL) catalyst were synthesized and successfully used for the one-pot ring opening of epoxide with sodium azide (NaN3) in water at room temperature. Epoxides under ring-opening easi...
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