Method for preparing terpinyl acetate

Abstract

The invention relates to a method for preparing terpinyl acetate, comprising: terpilenol and acetic anhydride are respectively added into a reaction kettle to be stirred, the mixture is added with phosphoric acid to be evenly stirred and then added with SnCl4.5H2O at the room temperature until the SnCl4.5H2O is completely dissolved, and the reaction is carried out under agitation while the temperature gradually raises; the reaction liquid is cooled to be room temperature and added with Na2CO3 to neutralize H3PO4 and SnCl4, and is directly distilled after being neutralized by carbonic acid, so that most acetic acid is evaporated; reaction product is washed by 10% of NaOH solution and saturated saline solution to remove the residual acetic acid until neutrality and then processed by fractionation, so that the terpinyl acetate is obtained. The method has the advantages of providing a novel composite catalyst system and a new technique for synthesizing the terpinyl acetate, being low in cost and simple in post treatment and having higher catalytic activity and reaction selectivity. The method also can ensure the yield of terpinyl acetate, shorten the reaction time, reduce the wastewater in the production and improve the recovery rate of acetic acid byproduct and the concentration of acetic acid.

Description

Technical field: [0001] What the present invention relates to is a kind of method for preparing terpineyl acetate. The invention relates to a method for preparing terpineol acetate by reacting terpineol as a raw material with acetic anhydride under the action of a composite catalyst, which belongs to the technical field of preparation of flavors and fragrances. Background technique: [0002] Terpinyl acetate is a general-purpose fragrance with a sweet and delicate taste and a unique aroma of lavender and lemon. It is widely used as a main fragrance and modifier in the food, cosmetic and pharmaceutical industries. It is often used in flavors such as lavender, cologne, vanilla, pine needles, and citrus. It can also be used in food flavors such as berry, white lemon, orange, cherry, spicy, and meat. It can also be used in cardamom, ganache, etc. Oregano, thyme and other flavoring essential oils to enhance the spicy aroma. [0003] Terpine acetate is an ester compound synthesi...

AI Technical Summary

Problems solved by technology

SnCl 4 and Ce(SO 4 ) 2 4H 2 O catalysis (Zhao Qianrong et al. Synthetic Chemistry, 2006, 14(3): 190-292; Applied Chemical Industry, 2005, 34(12): 731-733) Although the reaction temperature and reaction time have been shortened, the reaction selectivity Low, the content of olefin by-products such as terpinene is as high as 18%, and the product yield is low, and its effect is similar to that of solid super acid

Activated carbon-immobilized heteropolyacid catalytic method (Xie Hui et al. Journal of Nanjing Forestry University (Natural Science Edition), 2005, 29(6): 65-68) on the one hand heteropolyacid is expensive, the preparation process is complicated, and the cost is high. At the same time, there is still the disadvantage of high impurity content

Phosphoric acid / ionic liquid composite system catalytic method (Liu Shiwei et al. Forestry Chemistry and Industry, 2006, 26(3): 9-12; Industrial Catalysis, 2008, 16(10): 157-160; Forestry Chemistry and Industry, 2007, 27 (Supplement), 33-36) there is a large amount of ionic liquid, which exceeds the amount of terpineol, and the reaction time is as long as 12h. More importantly, the preparation of ionic liquid is difficult and has no production value.

There is also a research report (Wu Chunhua et al. Forest Products Chemistry and Industry, 2007, 27 (4): 123-1262) that adopts the microwave radiation method to synthesize terpineol acetate, but the microwave radiation equipment is complicated, and industrialized production cannot be carried out equally, and pine oil acetate The yield of ester is lower, only about 75%

There are also reports on the preparation of terpineyl acetate by composite solid superacid catalysis, such as using SO 4 2- / SnO 2 -TiO 2 Catalytic method (Zhao Qianrong et al. Chemical Research and Application, 2006, 18(5): 510-514), SO 4 2- / SnO 2 -CeO 2 Catalytic method (Guo Haifu et al. Petrochemical Industry, 2007, 36 (6): 565-569), etc., but the preparation process of solid superacid with multi-component carrier is complicated, the cost is high, the regeneration of solid superacid is difficult, and sulfuric acid, etc. Re-impregnated with strong acid and roasted at high temperature to activate and regenerate

And the polyaniline solid acid catalysis method (Jia Qingming etc.. Chinese patent, CN101270047A, September 24th, 2008) that adopts acid doping has catalytic effect, but there is the problem that catalyst preparation is complicated equally

[0005] Looking at the existing literature reports, although most of the synthetic processes can shorten the reaction time, they all have fatal shortcomings such as high content of by-products and low product quality, and the amount of catalyst is relatively high. Although various solid superacid catalysts are easy to realize and react with Separation of materials, but the recycling process and regeneration process are very complicated, which greatly increases the operating cost

The traditional phosphoric acid method has stable product quality, and the catalyst phosphoric acid consumption is low, only about 0.6%. The only disadvantage is that the reaction time is long, generally 18-20h

How to overcome the long reaction time while ensuring the product quality and the yield of terpineol acetate, the production process is simple, the cost is low, and the co-product acetic acid can be reclaimed simultaneously, which is the main problem to be overcome in the existing terpineol acetate production process, It is also one of the research directions for the synthesis of terpineol acetate