Preparation of isobornyl acetate

Abstract

The invention discloses a preparation method of isobornyl acetate which is an intermediate needed for producing medical synthetic camphor. The preparation method of the invention takes camphene and acetic acid as raw materials and the isobornyl acetate is prepared under the existence of styrene sulfonic strong acid positive ion resin and according to a certain technological condition. Crude products prepared through the reaction are extracted in a way of liquid phase lateral line by the middle part of a distillation tower of finished ester products after continuous vacuum distillation by a series-wound distillation tower of refined ether and the distillation tower of finished ether products, so as to obtain the isobornyl acetate, namely, the intermediate meeting the requirements for producing the medical synthetic camphor. The preparation method of the invention has the advantages that the continuous distillation of esterified materials can lead the quality of various products within the tower to be stabilized at a quite high level, and the preparation method of the invention has stable operation, low energy consumption, good selectivity of products, little impurity, and high content of the isobornyl acetate.

Description

technical field [0001] The invention relates to a method for producing isobornyl acetate, an intermediate required for the production of medicinal synthetic camphor. High-purity isobornyl acetate is a precondition for synthesizing high-quality medicinal camphor. Background technique [0002] Isobornyl acetate, also known as isobornyl acetate, has a cool and pleasant pine leaf-like aroma, and it can undergo saponification reaction with sodium hydroxide to form isoborneol. [0003] [0004] Isoborneol is converted into camphor by catalytic dehydrogenation, so isobornyl acetate is an important intermediate product for the manufacture of synthetic camphor. [0005] [0006] At present, the production route of isobornyl acetate mainly includes the direct esterification process route of camphene and acetic acid in the presence of a catalyst. Sulfuric acid is usually used as the catalyst, and the reaction temperature is controlled at about 50°C. The initial stage of chemical...

AI Technical Summary

Problems solved by technology

When these esters are used for esterification with the camphor cycle, molecular rearrangement reactions are prone to occur, thereby reducing the selectivity of the total isobornyl acetate formation, which affects both the quality of camphor and the consumption of raw materials

The refined ester discharged from the bottom of the rectification distillation tower is intermittently and simply vacuum distilled in the finished ester distillation tower. The content of the distilled isobornyl acetate is low, usually only 90-92%, while the remaining light components reach 4-92%. 5%, these light components will further change in the production of camphor, and finally enter the product to cause quality decline

[0008] Visible, the shortcoming of above-mentioned traditional isobornyl acetate manufacturing process is: the selectivity of isobornyl acetate in the esterification reaction is low, and the harmful impurity that generates is many, and target ester selectivity is only 90 ± 2%

The content of isobornyl acetate is low, with more light components, which increases new impurities in camphor, and is difficult to meet the requirements of producing pharmaceutical synthetic camphor

Images