Method for preparing benzalacetone

Abstract

The invention provides a method for preparing benzalacetone. According to the method, acetone and benzaldehyde are used as raw materials, CaO-MgO loaded with potassium carbonate is used as a catalyst,butylated hydroxytoluene is used as a polymerization inhibitor, and aldol condensation is conducted to obtain benzalacetone; product yield and product purity reach 91% or above and 99% or above respectively; and in the preparation process, the molar ratio of benzaldehyde to acetone is 1: (1.7-2.1), the usage amount of CaO-MgO loaded with potassium carbonate accounts for 5%-10% of the mass of acetone, the usage amount of the polymerization inhibitor butylated hydroxytoluene accounts for 0.1%-0.3% of the mass of benzaldehyde, and a molar ratio of magnesium chloride to calcium chloride is (6-8):1. The preparation method is simple, has the characteristics of mild reaction conditions, easy separation and recovery of the catalyst, high product yield, few byproducts and the like, and can easilyrealize industrial production.

Description

technical field [0001] The invention relates to a method for preparing benzylidene acetone, which specifically belongs to the technical field of organic synthesis. Background technique [0002] The molecular structure of benzylidene acetone contains functional groups such as phenyl, alkenyl, and carbonyl, and has active reactivity. It is an important intermediate for the synthesis of medicines, pesticides, and spices. The method for synthesizing benzylidene acetone in industry is generally to produce the target product through the Claisen condensation of benzaldehyde and acetone under the action of dilute alkali. Although this method has a mature process and stable yield, it has a large amount of wastewater discharge, serious pollution, and the catalyst cannot be reused. At present, most of the preparation methods of benzylidene acetone focus on the development and research of new catalysts, such as some potassium fluoride / alumina catalysts, polyvinyl chloride polyvinyl pol...

AI Technical Summary

Problems solved by technology

Although the process is mature and the yield is stable, this method has a large amount of wastewater discharge, serious pollution, and the catalyst cannot be reused.

At present, most of the preparation methods of benzylidene acetone focus on the development and research of new catalysts, such as some potassium fluoride / alumina catalysts, polyvinyl chloride polyvinyl polyamine resin catalysts, tributylamine aminated strong basic anion exchange Resin catalysts, etc., have also developed new phase transfer catalysts such as cetyltrimethylammonium bromide catalysts, cetyltrimethylammonium bromide catalysts, etc., and even supercritical and near-critical synthesis methods, etc. However, in the above-mentioned new synthetic methods, some have higher production costs, some catalysts are difficult to recycle, some have high requirements for reaction facilities, and some have more by-products, so it is difficult to popularize and apply in industry