Study On The Synthesis Of Farnesylacetone Through Carroll Reaction With Multi-reactor Connection In Series Countinous Technology

Farnesylacetone is an important perfume, and also an important raw material in chemical and medical, The main synthesized method is describes as follow:nerolidol and methyl acetoacetate as the raw materials take Carroll reaction under the action of catalyst to achieve product. In order to solve the problems such as low productive efficiency, labor intensive and high production cost, that is widespread in the synthesis process of farnesylacetone at present in my working company. According to the study of Carroll reaction’s mechanism, we designed a novel technology with multi-reaction kettles, it can keep solution dropping and temperature separately. Through experiments and trial production, it shows that the novel technology described in this paper has reached expected aims.First, in order to verify effect of the novel Carroll reaction technology, which have three sections and five reaction kettles. A small amount of isopropyl alcohol aluminum is added proactively, then nerolidol and acylating agent methyl acetoacetate were dripped into in sequence. Raw material ratio, temperature and other process conditions are studied, the optimum reaction conditions are determined as follows:the feeding molar ratio of nerolidol and methyl acetoacetate and aluminum isopropanol is 1:1.20:0.020, the best temperature range of reaction stage A is 96-101℃, the best temperature range of second stage B is 120-128 ℃, the best temperature range of reaction stage C is 155-170 ℃, the best reaction time range of warm keeping stage D is 2-3 h, the vacuum of stage E is keeped-8～-12 kPa. The sample of farnesyl acetone before and after the new technology put into effect was tested by Gas Chromatography, the test results illustrates that after the new technology of Carroll reaction worked, the finished product farnesyl acetone have less impurity and more yield. In combination with the results on the investigation of variable changing, the new technology of Carroll reaction with three sections and five reaction kettles proved to be effected.According the experiment result in lab, pilot scale production is put into effect. From the perspective of the process of pilot scale experiment, the new technology of carroll reaction with three sections and five reaction kettles can’t meet the demand of Large-scale production, then a thermal insulation kettle added behind the final thermal insulation kettle to continuing production. The main reason is amplification effect makes the vacuum degree of reduced pressure kettle is less than bench experiment, the secondary stress added after thermal insulation kettle, the reaction yield can reach the level test. The yield reach 95.76% for nerolidol, the yield reach 95.76% for methyl acetoacetate.The large scale shows that the novel technology, which have multi-reaction kettles and can keep solution dropping and temperature separately, has the advantages of mild reaction conditions, short producing time, low energy consumption, non-polluting, high purity, and also has good prospects for industrial application.