Tube type continuous flow reaction device and preparation method of isopropyl acetoacetate

Abstract

The invention provides a tube type continuous flow reaction device. The tube type continuous flow reaction device is characterized in that an isopropanol metering tank is connected with a catalyst mixing section through an isopropanol metering pump, and a catalyst metering tank is connected between the isopropanol metering tank and the catalyst mixing section; the other end of the catalyst mixingsection and a diketene metering tank are respectively connected with a tube type continuous flow reactor; the other end of the tube type continuous flow reactor is sequentially connected with a crudeester condenser, a crude ester buffer tank and a crude ester feeding pump; a pressure pump is arranged between the tube type continuous flow reactor and the crude ester condenser, and a hollow condenser is arranged on the crude ester buffer tank. The invention also provides a method using the tube type continuous flow reaction device to prepare the isopropyl acetoacetate. The tube type continuousflow reaction device has the advantages that a technology using the tube type continuous flow reactor to prepare the isopropyl acetoacetate is studied, so that the reaction staying time is greatly shortened, the side reaction is reduced, and the yield rate and content of the product are increased; furthermore, the difficulty in rectification separation is decreased, the production cost is reduced,and the safety risk in production is greatly decreased.

Description

technical field [0001] The invention relates to the field of chemical synthesis, in particular to a preparation device and a preparation method of isopropyl acetoacetate. Background technique [0002] Isopropyl acetoacetate [0003] Chinese name: isopropyl acetoacetate; [0004] English name: Isopropyl acetoacetate; [0005] Solubility: soluble in ethanol, chloroform, ether, toluene and other organic solvents; [0006] Molecular formula: C7H12O3; [0007] Molecular weight: 144.16; [0008] Melting point (℃): -27; [0009] Density (g / ml, 25 / 4°C): 0.993; [0010] Action and use: Isopropyl acetoacetate is an important pharmaceutical and pesticide intermediate, and it is mainly used in medicine as the intermediate of cardiovascular drug nimodipine and 2-(3-nitrobenzylidene) isopropyl acetoacetate Synthesis is also the basic raw material for the synthesis of organophosphorus insecticide-refenphos. [0011] Prior Art Synthetic Process: [0012] 1) is to adopt the transest...

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Problems solved by technology

[0012] 1) is to adopt the transesterification method to carry out synthesis, adopts ethyl acetoacetate or methyl acetoacetate to carry out transesterification reaction with isopropanol under reflux state as raw material, obtains finished product isopropyl acetoacetate, and this technology reaction time is long, and yield The yield is low, the highest yield is 87%, and involves the recovery of solvent toluene, the cost is high;

[0013] 2) It is the Claisen ester condensation route, which needs to use expensive metal sodium, and is used for synthesis with low yield, and there are no mature industrial reports;

[0014] 3) is to adopt diketene and isopropanol under acid catalysis, reflux reaction prepares isopropyl acetoacetate, the highest yield of this method is 86.5%, and because the existence of acid, produce isopropyl ether secondary plant in the reaction process, to reaction The yield is greatly affected

[0015] All of the above processes have either expensive raw materials or low yields, and they are all intermittent reactions, and the reaction time is too long, which leads to higher production and preparation costs.

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