Study On Synthesis Process Of β–isophrone And Oxo-isophorone

Isophorone is a highly processed product of acetone and widely used in pharmaceutical industry, spices, coatings and adhesives etc..Isophorone has two isomers: the α- and the β- type. Industrial isophorone usually contains 98.8% α- and 0.58% β-isophorone. As α-isophorone(3,5,5-trimethylcyclohex-2-en-l-one) owns a π-π conjugation structure, it cannot be oxidized easily. On the other hand, β-isophorone(3,5,5-trimethylcyclohex-3-en-l-one) is an important intermediate in synthesis of edible perfume and vitamin E, also synthesize the smoke spices – oxoisophorone or keto-isophorone( 3,5,5-trimethylcyclohex-2-ene-l, 4-dione, KIP). Isophorone as raw materials by catalytic oxidation to synthesize oxo-isophorone is an important intermediate for the synthesis of many kinds of carotene, vitamin, spices and other compounds, in the preparation of food and cosmetics as a flavoring agent or spices are used widely. In addition, oxo-isophorone is a natural product,can be extracted directly from plants, but it requires not only a large number of raw materials, and the yield is very low. Since 1970, the synthesis of oxo-isophorone has been widespread concerned all around the world. By using the industrial isophorone as a raw material, the synthesis of β-isophorone by catalytic reaction distillation, and then bycatalytic oxidation to synthesize oxo-isophorone. This thesis is divided into three chapters, the main contents and research results are as follows:The chapter 1. Firstly, the definition and classification of isomerization, the present research progress of the isomerization ofα-isophorone have been introduced. Then, we introduced the application process definition, catalytic oxidation, and the research progress of catalytic oxidation of β-isophorone. At the end, we developed the synthesis process of β-isophorone and oxo-isophorone: by usingα-isophorone as a starting material, followed with a catalytic reaction distillation operation to β-isophorone, and finally oxo-isophorone by a catalytic process.The chapter 2. The reactive distillation and isomerization betweenα-isophorone and β-isophorone have been mainly studied; the thermal isomerization of catalytic and non- catalytic conditions of α-isophorone;the effects of different types and amounts of catalysts; and the operation conditions of the isomerization reaction. Also, we studied the effects of column packing, reflux ratio and other factors to the distillation reaction of β-isophorone. Emphatically, we discussed the influences of the distillation temperature on the purity of β-isophorone. The packing height on the isomerization of thermodynamic and distillation of α-isophorone isomerization reaction is carried out in the relevant research. The results showed that, the balance of the isomerization reaction of β-isophorone isonly 1.6% at 210℃. Using the technology of catalytic reaction distillation,under the optimized conditions the purity of β-isophorone is higher than98%.The chapter 3. We studied the reaction rules of catalytic oxidation ofβ-isophorone, the effects of the reaction temperature, the amount of pyridine, catalyst, and oxidant(oxygen or air) on the oxidation reaction w.Experimental results show that using Vanadium(IV)oxy acetylacetonate as the catalyst along with airoxidation of 48 h at 60 ℃, can get a high content of liquid oxo-isophorone(92%) and a high yield of oxo-isophorone(higher than 85%).