Preparation method of isopropyl acetoacetate

Abstract

The invention relates to a preparation method of isopropyl acetoacetate. The preparation method comprises the following steps of using diketene and islpropanol as starting materials, performing esterification to synthesize coarse isopropyl acetoacetate under catalysis action of a self-made catalyst with graphene as a carrier, then rectifying to obtain the finished product. Due to use of the self-made catalyst with graphene as the carrier, the reaction is thorough and is easy to control; generated byproduct isopropyl ether in the coarse isopropyl acetoacetate is controlled less than 1%, so thatthe reaction yield and product quality are improved, the yield and product purity of isopropyl acetoacetate are 93% or more and 98% or more respectively, up by 10% and 15% respectively in comparisonwith the method using sulfuric acid as the catalyst; the use ratio of the raw materials is improved, waste materials are reduced, environment protection investment is reduced, and the product cost islowered.

Description

technical field [0001] The present invention relates to a kind of preparation method of pesticide and medicine synthesis raw material, more specifically relate to a kind of preparation method of isopropyl acetoacetate. Background technique [0002] Isopropyl acetoacetate is a colorless, transparent, oily liquid with an aromatic odor. It is mainly used in the fields of synthetic medicine and synthetic pesticides, and has broad market prospects. [0003] After searching relevant information and comparative analysis, there are mainly two processing routes for synthesizing isopropyl acetoacetate both at home and abroad at present, as follows: [0004] 1: tert-butyl acetate method: using benzene as a solvent, two molecules of tert-butyl acetate are condensed in the presence of metal sodium to obtain isopropyl acetoacetate and isopropanol in one step, although the conversion rate of this route is relatively high (70%- 85%), but use highly toxic compound solvent benzene and strong...

AI Technical Summary

Problems solved by technology

[0007] 2: Diketene method: Diketene and isopropanol are used as starting materials to synthesize isopropyl acetoacetate through esterification under the action of sulfuric acid. The raw materials are cheap and easy to obtain and become the mainstream production method, but it also has its own inherent The disadvantage is that the product yield is low, only 75%-88%, which causes the cost to be high, and the reason for the low yield is that a certain amount of isopropyl ether (about 10%) will be generated in the reaction process. Distillation is usually repeated during the process, resulting in a large amount of decomposition of the product, resulting in a low yield

Images