Diisopropyl succinate and intermittent preparation method thereof

Abstract

The invention provides a diisopropyl succinate and an intermittent preparation method thereof. The molecular formula of the diisopropyl succinate is C10H18O4. The preparation method comprises the following steps: 1) adding succinic acid, isopropanol, a catalyst and a dehydrating agent into an esterification kettle for esterification, recovering the dehydrating agent and excessive isopropanol after no water is distributed from a water distributor, processing coarse ester, refining the coarse ester, and collecting a front fraction; 2) adding the recovered dehydrating agent, the recovered excessive isopropanol, new succinic acid, new isopropanol, new catalyst and new dehydrating agent into a reactor and dripping a front fraction; 3) performing esterification under reflux; 4) recovering the dehydrating agent and excessive isopropanol in the reactor; and 5) refining coarse ester to obtain diisopropyl succinate and the front fraction. In the invention, azeotropic esterification, azeotropic fractionation, reflux, water distribution and recovery are integrated, the recovery and recycling of the dehydrating agent and the excessive isopropanol are realized, energy consumption and material consumption are reduced, the process flow is short, less equipment is used, operation and control are easy, and product quality is stable.

Description

technical field [0001] The invention relates to a diisopropyl succinate and a batch preparation method thereof. Background technique [0002] Diisopropyl succinate is an organic synthesis intermediate, the main raw material for the synthesis of diketopyrrolopyrrole advanced organic pigments, and also used as a stationary liquid for gas chromatography, but the existing ones are used for the synthesis of Pigment Red 254 and 264 raw materials, there are quality problems, can not guarantee the quality of synthetic pigments. [0003] At present, there are few reports on the direct synthesis of diisopropyl succinate. EP844,231, EP728,731, U.SP4,795,824 reported that the catalysis of maleic anhydride and alkyl alcohols (such as methanol and ethanol) for many times Esterification generates dialkyl maleate, and then catalytic hydrogenation becomes diisopropyl succinate. [0004] For batch production, the traditional esterification process is mostly used, that is, succinic acid and ...

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Problems solved by technology

[0010] In the current production method, in order to improve the esterification rate, it is necessary to intermittently add anhydrous isopropanol to the esterification reactor, and generate more water-containing isopropanol at the same time, which must be recovered in a fractional distillation recovery system consisting of at least two towers. , to be able to fractionate hydrous isopropanol into anhydrous isopropanol, and then return to esterification, so that there are many equipments, large investment, large materials and energy consumption

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