Method for aqueous-phase catalytic synthesis of methyl succinic acid

Abstract

The invention discloses a method for aqueous-phase catalytic synthesis of methyl succinic acid. The methyl succinic acid is an important organic synthesis intermediate and is wide in application. According to the method disclosed by the invention, a Ru-based catalyst is adopted to make itaconic acid have a catalytic hydrogenation reaction to prepare the methyl succinic acid under an aqueous-phase neutral and moderate reaction condition, the conversion rate and the selectivity can both be as high as 99%, and the catalyst can be used repeatedly.

Description

technical field [0001] The invention relates to the field of chemistry and chemical engineering, in particular to a method for synthesizing methylsuccinic acid by aqueous catalysis. Background technique [0002] Itaconic acid is an unsaturated organic dibasic acid, which is mainly obtained through the biological fermentation of sugar compounds; in addition, itaconic acid is also prepared from citric acid or maleic anhydride as raw materials. At present, my country is the fourth itaconic acid producer and the main itaconic acid exporter in the world after the United States, Japan, and Russia. It is estimated that the annual demand growth rate of itaconic acid will be about 10% in the next few years, and the domestic and foreign markets have broad prospects. Itaconic acid is mainly used as a synthetic monomer for unsaturated polyesters and resins. It is of great research significance to use catalytic conversion technology to develop downstream products of itaconic acid, impr...

AI Technical Summary

Problems solved by technology

Oxidation method is adopted to prepare methylsuccinic acid, but the method yield is not higher than 59%, and the reaction requires a long reaction time (60h) (JP 08-081410); the process of ester hydrolysis is complicated and the yield is low (JP07- 258149); esterification hydrogenation is another method, but the operation steps are more complicated, the cost is high, and the yield is low (CN10171169A)

Hydrogenation is a method with relatively high atom economy. At present, most reports use homogeneous catalysis methods, such as using metal complexes such as Rh, Ru, and Pd as catalysts. However, in homogeneous reactions, catalysts Difficult to separate and easier to lose active metals (J.Mol.Catal.A, 1996, 109(1), 45–50); Tetrahedron: Asymmetry 1995, 6(10) 2535-2546)

In addition, heterogeneous catalysts such as Pd / C catalyst and Ni catalyst also have reports, but all adopt organic solvents such as ethanol or tetrahydrofuran; Pd / C catalyst price is comparatively expensive, and production cost is high; Reaction pressure is higher when using Ni base catalyst (CN102617326A ; CN100412840C)

[0004] In view of the limitations in the prior art of hydrogenation of itaconic acid to methylsuccinic acid mentioned in the above documents, the present invention provides a method for the catalytic synthesis of methylsuccinic acid in aqueous phase