Method for preparing 2-methyl-5, gamma-dioxotetrahydrofuran-2-pentanoic acid by catalysis of levulinic acid on basis of solvent process

Abstract

The invention provides a method for preparing 2-methyl-5, gamma-dioxotetrahydrofuran-2-pentanoic acid by catalysis of levulinic acid on the basis of a solvent process. The method comprises the following steps: mixing a solvent with levulinic acid as usual, then adding a catalyst, and performing heating to 70-200 DEG C for a reaction for 0.25-96 h; performing reduced-pressure distillation to removea reaction solvent and unreacted levulinic acid, then fully dissolving a distilled residue with an organic solvent, performing filtering, removing the catalyst, and distilling a filtrate to obtain anaddition product. The method has the advantages that the conversion rate of levulinic acid is higher than 34%, and the product yield is higher than 28 %.

Description

technical field [0001] The invention relates to a method for preparing 2-methyl-5,γ-dioxotetrahydrofuran-2-pentanoic acid by self-addition of levulinic acid. technical background [0002] Levulinic acid (4-pentanone acid) is an important biomass-based platform compound, which is listed as the 12 most important platform compounds for sugar conversion by the US National Energy Administration. In terms of chemical structure, levulinic acid is a five-carbon linear compound containing two functional groups, carbonyl and carboxyl. Currently, lignocellulose can be efficiently converted to levulinic acid through a biorefinery process in continuous industrial reactors. In view of the fact that lignocellulose is the largest biomass resource in the world, the generation of levulinic acid, a biomass-based platform compound, will have strong competitiveness (at present, it has reached 0.06-0.18 pounds), and it has the potential to become a bulk chemical. potential. [0003] The cataly...

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Problems solved by technology

However, levulinic acid contains a ketone carbonyl group. In theory, it can realize the formation of a new carbon-carbon bond through its own aldol condensation, thereby generating a C10 compound, and this compound often contains 1-2 carboxyl groups. After selective catalysis Hydrogenation can generate dicarboxylic acids / diols and branched alkanes. These compounds are important fine chemicals or polymer monomer raw materials, but there are still few studies on the self-condensation reaction of levulinic acid

Spanish scientists invented a reaction process that uses basic metals to catalyze the aldol condensation of levulinic acid. The reaction temperature of this process is low and the harmony is mild. However, since levulinic acid is an organic acid, it will react with the basic catalyst and the catalyst is stable. Because the acidity of the carboxyl group is stronger than that of α-H on levulinic acid, the basic catalyst is often more likely to interact with the carboxyl group, resulting in low activity of the catalytic system

Shell uses strong acids such as molecular sieves and acid resins as catalysts to catalyze the dimerization of levulinic acid, but there are many products, and the acid resin itself has poor stability in the organic phase, and the pores of molecular sieves are easy to block, which brings great restrictions to its industrial production.

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