20279-49-6Relevant articles and documents
Inexpensive and tuneable protic ionic liquids based on sulfuric acid for the biphasic synthesis of alkyl levulinates
Chrobok, Anna,Gillner, Danuta,Matuszek, Karolina,Przypis, Marta,Swad?ba-Kwa?ny, Ma?gorzata
, (2020)
Alkyl levulinates are bio-derived chemicals, increasingly popular for their uses as solvents, additives and intermediates. However, efficient and recyclable catalysts for their synthesis are still the subject of intensive research. In this study, a wide range of alkyl levulinates was synthesized under mild conditions (room temperature, atmospheric pressure), using inexpensive and efficient Br?nsted acidic ionic liquids (ILs) based on sulfuric acid and off-the-shelf bases. Acidity of the ILs was closely related to their activity. The ILs could be easy separated and recycled, without significant changes in conversion or selectivity over 10 cycles (yields ca. 90–95%). Under optimized conditions, a 99% yield of pentyl levulinate (model reaction) was achieved. The method was demonstrated to be efficient in the synthesis of levulinates of C1-C16 linear, branched and cyclic alcohols. This innovative, green route to alkyl levulinates fits well within the sustainable development strategy.
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Schuette,Cowley
, p. 3487 (1931)
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Acidic ion functionalized N-doped hollow carbon for esterification of levulinic acid
Zhang, Qifang,Jiang, Pingping,Nie, Zhixin,Zhang, Pingbo
, p. 1588 - 1593 (2020)
Acidic ion functionalized N-doped hollow carbon (NHC-[C4N][SO3CF3]) has been successfully synthesized by quaternization of N-doped hollow carbon (NHC) with 1,4-butanesultone, followed by ion exchange with trifluoromethanesulfonic acid. The catalyst was characterized by Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), acid-base titration techniques and other methods. A hollow spherical catalyst with regular morphology, high acid density (2.72 mmol g-1) and good stability was obtained. Various characterizations showed that NHC-[C4N][SO3CF3] possesses abundant nanopores (3.41 nm), large Brunauer-Emmett-Teller (BET) surface area (154 m2 g-1) and strong and controllable Br?nsted acid sites. The as-prepared NHC-[C4N][SO3CF3] was then used for the acid-catalyzed esterification of levulinic acid with ethanol. At the optimum conditions, the highest conversion of levulinic acid reached 94.17% and high conversion was maintained after recycling four times. Further investigation of the catalytic activity in the esterification of different aliphatic and aromatic alcohols with levulinate was carried out, showing good results.
Method for preparing alkyl levulinate by regulating water content
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Paragraph 0060; 0061, (2020/04/17)
The invention discloses a method for preparing alkyl levulinate by regulating water content. The method comprises the following steps: at least mixing furfuryl alcohol, alkyl alcohol and an acidic catalyst to form a reaction system, carrying out a reaction under the conditions of continuous stirring and reflux condensation, regulating the content of water in the reaction system to enable a mol ratio of the furfuryl alcohol to the water to be 1: (0.1-5), and carrying out aftertreatment to obtain alkyl levulinate. The structural formula of the alkyl levulinate is as shown in the specification. In the structural formula, R is any one selected from the group consisting of -CH3, -C2H5, -C3H7, -C4H9 and -C5H11. Compared with the prior art, the method provided by the invention has the advantagesthat the alkyl levulinate is prepared by regulating the water content; process is simple and feasible; conditions are mild; cost is low; few byproducts are produced; maximum yield reaches 99.8%; and the problem of low yield of alkyl levulinate in conventional synthesis methods is solved.