A kind of synthetic method of p-chlorophenyl alcohol

Abstract

The invention discloses a method for synthesizing p-chlorophenylethanol, which is to generate a Grignard reagent through the Grignard reaction of p-dichlorobenzene and magnesium chips in an ether solvent, and then add the Grignard reagent to ethylene oxide Reaction, after the reaction is completed and the ether solvent is recovered under reduced pressure, it is quenched with acid water, solvent extraction and liquid separation are added, the organic phase is washed with water, dried, filtered, the extraction solvent is recovered under reduced pressure, and finally the target product p-chloro Phenylethyl alcohol: p-dichlorobenzene is used in the present invention, and the chlorine atom is the 1, 4 positioning group, which is not easy to produce isomeric impurities of other substituent positions, and the product is easy to separate and purify, and has the advantages of low comprehensive raw material cost, high safety factor, and easy three wastes It has the advantages of less processing, less steps and high yield.

Description

technical field [0001] The invention relates to the technical field of organic synthesis, in particular to a synthesis method of p-chlorophenylethanol. Background technique [0002] p-Chlorophenylethanol is not only the key intermediate of the pesticide cyanoxenazole, which is often used as a fungicide to prevent and control the brown rot of peach trees and leaf spot of banana trees, but also the key ingredient for the synthesis of green caserin hydrochloride. Starting materials. [0003] At present, the methods for synthesizing p-chlorophenylethanol mainly include the following: (1) Xu Jianping et al. (Synthetic Chemistry, 2007, 15 (5): 595-596.) reported that p-chlorophenylacetic acid was first converted into p-chlorophenylacetic acid Ethyl phenylacetate is then reduced to p-chlorophenylethanol. This method needs to consume thionyl chloride, and a large amount of acid gases such as sulfur dioxide and hydrogen chloride will be produced in the production process. The enviro...

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Problems solved by technology

[0003] At present, the methods for synthesizing p-chlorophenylethanol mainly include the following: (1) Xu Jianping et al. (Synthetic Chemistry, 2007, 15 (5): 595-596.) reported that p-chlorophenylacetic acid was first converted into p-chlorophenylacetic acid Ethyl phenylacetate is then reduced to p-chlorophenylethanol. This method needs to consume thionyl chloride, and a large amount of acid gases such as sulfur dioxide and hydrogen chloride will be produced in the production process. The environmental pollution is serious, and the consumption of sodium borohydride in this method It is also relatively large, which is not conducive to controlling production costs

(2) Chinese Patent Publication No. CN 101250090A discloses that anhydrous chlorinated benzene can be catalyzed by Lewis acid anhydrous aluminum trichloride or boron trifluoride, etc., and p-chlorobenzene can be obtained after reacting with ethylene oxide Ethanol, although this method has fewer synthesis steps and is simple, ethylene oxide can also undergo Friedel-Crafts reactions with other positions of chlorobenzene to generate isomeric impurities or other impurities. Since the products are all homologous, their melting and boiling points are similar , making it difficult to separate and purify in the end; and the catalysts used in this process are anhydrous aluminum trichloride, anhydrous zinc chloride, and boron trifluoride, which are easy to absorb moisture and hydrolyze to produce a large amount of irritating smoke, which is easy to absorb moisture and deteriorate, which hinders the transportation of raw materials. It is inconvenient to store and store, and the large amount of irritating smoke produced by moisture absorption is not conducive to safety and environmental protection

(3) Zhang Liguang et al. (China Journal of Pharmaceutical Industry, 2011, 42 (3) 174-175) reported that 4-chloroacetophenone was used as raw material to prepare 4-chlorophenylacetic acid through the Willgerodt-Kindler method, and then in the presence of iodine 4-Chlorophenylethanol is obtained through sodium borohydride reduction, and the total yield is about 66%. This method not only easily produces hydrogen and borane inflammable and explosive gases, but also makes the reaction risk factor higher; this reaction uses sodium borohydride While reducing, equimolar iodine will be consumed, and the production cost of this method is high due to the high price of iodine

(4) The Chinese patent announcement number is CN 103058824A, which discloses that p-chlorophenylacetic acid uses tetrahydrofuran as the reaction solvent, under the action of sodium borohydride and boron trifluoride ether, stirs and reacts at room temperature, and TLC detects that the reaction is complete within minutes. After treatment, p-chlorophenylethanol can be produced. Since the reaction between p-chlorophenylacetic acid and sodium borohydride produces a large amount of flammable and explosive hydrogen, the subsequent reaction is prone to violent exothermic heat, resulting in loss of control and explosion hazards. The reaction risk factor High, in addition, sodium borohydride and boron trifluoride ether were used in the reaction, and a large amount of borate and fluoride-containing wastewater were produced after the reaction, which was difficult to treat

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