A Study On Synthesis Of Pinacolone

Pinacolone,because of its unique structure,is an important pesticide intermediates,thus it has very important significance to develop a new,suitable for industrial production of green technology,the following research is carried out in this paper:In the old process,reaction products are more complex,analysized more difficult,in this paper,for the first time to use the more economical high efficiency HPLC method for pinacolone reaction monitoring,make our products are well separated;then based on this analysis method,the key factors influencing the yield were optimized which further improves the yield,the optimum conditions were obtained:hydrochloric acid and isoamylene mole ratio is 2.6:1,isoamylene dropping rate is 5mL/min,The molar ratio of formaldehyde and pentene is 1.1:1 and its dropping time is 40 min,The final reaction time is 2 h;The overall yield was 69.3%.A green process route suitable for the industrialization is designed in this paper,this route not only overcome the shortcomings of original technology product separation difficulties,but also effectively improve the overall yield and the quality of the products;New process using tetramethyl ethylene as raw material is divided into two steps,which include the use of epoxidizing agents potassium peroxodisulfate complex salt and solid acid catalyst perfluorosulfonic acid resin;in this paper,the conditions of this technology were optimized,the process conditions of the first step:the ratio of potassium persulfate compound salt to olefin is 1.3:1,The reaction time was 1 h,and the rotational speed of the magnet 1800 rpm,and the pH of the solution 6.7,experiment is conducted at room temperature,The best yield was 96.1%;The process conditions of second step of the process conditions:The ratio of catalyst to tetramethyloxirane was 20:1(mg/mmol),reaction at 10-15℃,The yield was 90.3%,The overall yield was 86.8%.The results show that the new route has high reaction yield,raw materials for green,lower energy consumption,easy operation and low requirements for equipment,and is a green,suitable for industrial production process.