Preparation technology of isopropyl acetoacetate

Abstract

The invention discloses a preparation technology of isopropyl acetoacetate. The preparation technology comprises the following steps: adding isopropanol and a catalyst into a reaction vessel, whereinthe catalyst is selected from aliphatic amine catalysts or tertiary amine catalysts; or the catalyst is prepared by mixing one or more of the aliphatic amine catalysts and the tertiary amine catalysts; raising the temperature to 20 to 100 DEG C, dropwise adding diketene, controlling the reaction temperature in the reaction process at 20 to 150 DEG C; after dropwise adding is finished, controllingthe temperature at 20 to 150 DEG C and carrying out thermal insulation for 0.5 to 6 hours, thus obtaining raw isopropyl acetoacetate, wherein the molar ratio of the isopropanol to the diketene is (1 to 1.8) to 1 and the adding amount of the catalyst is 0.1 to 1 weight percent of the total amount. By adopting a combined amine catalyst to carry out esterification reaction of the diketene and the isopropanol, the influence of steric hindrance of the isopropanol is reduced and the yield of esterification is improved; meanwhile, the difficulty of subsequent separation is reduced. After distillation, the yield of esterification liquid reaches 95 percent and the content of the esterification liquid reaches 99 percent or above.

Description

technical field [0001] The invention relates to the technical field of preparation of isopropyl acetoacetate, and relates to a preparation process of isopropyl acetoacetate. Background technique [0002] Isopropyl acetoacetate [0003] Alias: 3-butanuate isopropyl ester; Acetoacetate isopropyl ester; [0004] English name: Isopropyl acetoacetate [0005] Appearance properties: colorless, transparent liquid. [0006] Solubility: soluble in ethanol, chloroform, ether, toluene and other organic solvents; [0007] CAS No.: 542-08-5 [0008] Molecular formula: C 7 h 12 o 3 [0009] Structural formula: [0010] Molecular weight: 144.168 [0011] Melting point (°C): -27 [0012] Boiling point (°C): 95 (52hpa) [0013] Relative density (water=1): 0.989 [0014] Flash point (℃): 73 [0015] Function and use: [0016] Isopropyl acetoacetate is an important intermediate of medicine and pesticide. Organophosphorus insecticide - the basic raw material of difenphos. [...

AI Technical Summary

Problems solved by technology

[0018] 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;

[0019] 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;

[0020] 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 Yield is greatly affected

[0021] All of the above processes have either expensive raw materials or low yields, which lead to high production and preparation costs.

Images