| Ionone compounds with excellent aromatic flavor,active in the field of spices,widely used in the sweet atmosphere,food additives,and other areas of the daily chemical products,at the same time they can also be used for synthetic nutrition material category,such as vitamin A,carotenoids,and also could be used in medical in recent years,all of above mention makes ionone compounds very popular,the study of ionone compounds has never stopped.The conventional synthesis method of ionone compounds are describes like that:firstly get the pseudo ionone compounds,and then we can get the ionone compounds molecule through cyclization reaction.Synthesis of pseudo ionone compounds usually have two ways,one is through Carroll reaction from linalool as starting material;the second way is through aldol condensation from citral.In this paper,combined with the company’s own advantage,using citral as raw materials,synthetic pseudo ionone compounds,further we can get ionone compounds under the acid closed the loop of pseudo ionone compounds and heterogeneous.In second chapter,alpha ionone was synthesized from pseudo ionone:with 85%phosphoric acid as catalyst,the inventory is 0.24 mass time of the pseudo ionone,with toluene as solvent,the inventory is 2 mass time for pseudo ionone,under 60℃,add time is 120 min,heat preservation time is 60 min,after washing rectification,alpha ionone content>90%,the yield of Alpha ionone is about 80-82%,the alpha ketone content is 78%or higher,total ketone content is 94%or higher.Beta ionone was synthesized from pseudo ionone:with sulfuric acid as catalyst,the inventory is 2.3 mass time of the pseudo ionone,with petroleum ether toluene as solvent,the inventory is 5.7 mass time for pseudo ionone,without methanol as antifreeze,under-15℃,adjust pH 9-12 in washing step,when the final yield of 85%or higher,up to 90%,the alpha ketone content is 0.5%or less,beta ketone content is 98%or higher,total ketone content 99%or higher.The third chapter,We can get methyl ionone compounds through condensation reaction and cyclization reaction starts from citral.Pseudo methyl ionone was synthesis in optimum process conditions:citral:butanone =1:6(mole ratio),sodium 70%hydroxide:citral = 0.4(mass ratio),reaction temperature was 50℃,add time was 3 h,the yield of Pseudo methyl ionone was 87.0%,quality yield was 117.0%,foot feeding rate was 7.0%.Pseudo iso-methyl ionone was synthesis in optimum process conditions:using 90%potassium hydroxide as condensation catalyst,dissolved in methanol,addition amount was about 0.24 mass times of citral.The mole ratio of citral:butanone was 1:10,maintain add temperature at 40℃,add time was 2.5 h,after heating up to 40℃ and heat preservation was 2.5 h,after citral residue<5%by detected.At that condition,the foot material at a rate of around 10.0%,average molar yield was about 85.0%.Methyl ionone was synthesis in optimum process conditions:with 85%phosphoric acid as catalyst,catalyst was 20%mass of pseudo methyl ionone,toluene as solvent,the amount of solvent was 47%mass of pseudo methyl ionone.Up to 50℃,add time controlled in 2 hours,and then up the temperature to 55℃,with hourly testing samples,and stop the reaction when the raw material content was less than 1%.Under appropriate conditions,the citral condensation yield can reach 85.0%,methyl ionone can be got under the condition of phosphoric acid as concentrated catalyst,cyclization yield is about 85.0%,citral total mole yield is about 77.0%.Iso-methyl ionone was synthesis in optimum process conditions:with 85%phosphoric acid as catalyst,catalyst was 17%mass of pseudo iso-methyl ionone,up temperature to 50℃,keep dropping speed in control,add time was about 2 h,add finished,heat preservation continued in 55℃,when pseudo iso-methyl ionone was 1%or less,cooled to 30℃,hydrolysis in water.Foot feeding rate can be controlled at<5%,Mole yield is>85%. |
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