Method for synthesizing oxime ether

Abstract

The invention discloses a method for synthesizing oxime ether. The method includes the steps of: adding 1 mol portion of ketoxime in 1- butyl-3- methylimidazole tetrafluoroborate of which the adding amount is 2-20 times of the weight of the ketoxime; then adding 1.05-2.6 mol portions of alkali, dripping 1-1.3 mol portions of alkylating agent at the temperature of 0-50 DEG C within 0.5-2h; after dripping, reacting for 0.5-2h with the temperature preserved; then filtering, adding ether which is 5-20 times of the weight of the 1-butyl-3- methylimidazole tetrafluoroborate in the filtrate and extracting respectively for 4-8 times; combining the upper layer of extraction liquid, recovering ether solvent through distillation and finally conducting rectification separation to obtain the product. The method adopts ion liquid as reaction solvent, which is not volatile, does not generate harmful gas and wastewater, and improves the operation environment. The process is simple, the post treatment investment is low, and the cost is saved; as the ion liquid can be recycled, the method is a green technology; and the product is high in yield and good in quality.

Description

technical field [0001] The invention relates to a method for synthesizing an organic intermediate, in particular to a method for synthesizing an oxime ether. Background technique [0002] Oxime ethers and their derivatives not only play an important role in pesticides and medicines, but also are important intermediates for the preparation of important pesticides and pharmaceutical intermediates alkoxyamines. Currently, there are several commonly used methods for synthesizing oxime ethers: [0003] Liu Aiping (Journal of Central China Normal University (Natural Science Edition), 2004, 38(1), 66~68) introduced α-(,2,4-triazolyl)-pinaconone oxime in water as a phase transfer catalyst The reaction is carried out under the presence of tetrabutylammonium iodide and NaOH, and the yield is about 50%; Pan Zhongwen et al. Diethyl ester reaction obtains 87.6% oxime ether product; Shao Juan et al. Allyl chloride is reacted to obtain oxime ether with a yield of 71%. The above-mentioned...

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Problems solved by technology

[0003] Liu Aiping (Journal of Central China Normal University (Natural Science Edition), 2004, 38(1), 66~68) introduced α-(,2,4-triazolyl)-pinaconone oxime in water as a phase transfer catalyst The reaction is carried out under the presence of tetrabutylammonium iodide and NaOH, and the yield is about 50%; Pan Zhongwen et al. Diethyl ester reaction obtains 87.6% oxime ether product; Shao Juan et al. Chloropropene reaction, obtains the oxime ether that yield is 71%; Above-mentioned these processes all are to react in water phase, and technical process can produce relatively large amount of waste water, causes environmental pollution

[0004] U.S. Patent No. 5,488,162 introduces such a synthetic route: taking sodium hydride as an acid-binding agent, dimethyl sulfoxide as a solvent, and acetone oxime reacting with trans 1,3-dichloropropene to generate O-(3-chloro-2-E -propenyl) 2-acetone oxime; after washing, extraction, etc., about 70% of the product is obtained; this process emits more hydrogen during the preparation process, and because hydrogen is flammable and explosive, there is a potential safety hazard; while the preparation process has considerable A large amount of waste water is generated, which is not environmentally friendly

[0005] Han Shidong et al. (Zhejiang Chemical Industry, 2005, 36 (9), 14-16) introduced the process route of first reacting sodium metal with ketoxime to form sodium salt and then reacting with alkylating agent to generate oxime ether. During the preparation of sodium salt The release of a large amount of hydrogen and the use of metal sodium are unsafe factors, and the safe operability of the process route is poor

[0006] EP0158159 introduces the reaction of ketoxime with NaOH, azeotropic dehydration with toluene to form sodium oxime and then O-alkylation reaction with alkylating agent, followed by acid precipitation, salt precipitation, extraction, vacuum distillation, decolorization, The product obtained after rectification and other post-treatments has a yield of about 71-72% depending on the product; the process of this method is relatively complicated, the operation is cumbersome, and the preparation process produces difficult-to-handle sewage waste, etc., resulting in high post-processing costs

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