阅读说明：本技术 一种1-芳基-1,2-二溴乙烷的制备方法 (Preparation method of 1-aryl-1, 2-dibromoethane ) 是由 钱波 李伟鹤 于 2019-11-19 设计创作，主要内容包括：本发明涉及一种1-芳基-1,2-二溴乙烷的制备方法,该方法是指：在氮气保护下,将溶剂、芳基烷烃以及<I>N</I>-溴代丁二酰亚胺依次加入到反应管中,于80~120℃发生双溴化反应,12~48小时后反应结束,经蒸干溶剂、柱层析分离即得1-芳基-1,2-二溴乙烷类化合物。本发明合成工艺简单,反应条件温和,产率高,易于工业化。(The invention relates to a preparation method of 1-aryl-1, 2-dibromoethane, which comprises the following steps: under the protection of nitrogen, adding solvent, aryl alkane and N and (3) adding bromosuccinimide into a reaction tube in sequence, carrying out a double bromination reaction at 80-120 ℃, ending the reaction after 12-48 hours, evaporating the solvent to dryness, and carrying out column chromatography separation to obtain the 1-aryl-1, 2-dibromoethane compound. The invention has simple synthesis process, mild reaction condition, high yield and easy industrialization.)

1. A method for preparing 1-aryl-1, 2-dibromoethane is characterized in that: under the protection of nitrogen, adding solvent, aryl alkane andNbromosuccinimide is sequentially added into a reaction tube, a double bromination reaction is carried out at 80-120 ℃, the reaction is finished after 12-48 hours, and the 1-aryl-1, 2-dibromoethane compounds are obtained after solvent evaporation and column chromatography separation; said arylalkane with saidNThe mol ratio of bromosuccinimide is 1: 2-5; the ratio of the solvent to the arylalkane is 1L: 0.1 to 1.0 mol.

2. A process for producing 1-aryl-1, 2-dibromoethane as claimed in claim 1, characterized in that: the solvent is any one of acetonitrile, trifluoromethyl benzene, dichloromethane, trichloromethane, carbon tetrachloride, tetrachloroethane, 1, 2-dichloroethane and 1, 2-dibromoethane.

3. A process for producing 1-aryl-1, 2-dibromoethane as claimed in claim 1, characterized in that: the aryl alkane has a structural formula of

Technical Field

The invention relates to the technical field of organic chemical synthesis, in particular to a preparation method of 1-aryl-1, 2-dibromoethane.

Background

The 1-aryl-1, 2-dibromoethane compound can be used as an organic synthesis intermediate and is widely applied to synthesis of natural products, medicines, pesticides, bioactive molecules and functional materials. For example, 1-aryl-1, 2-dibromoethane, which is converted to 2-bromo-1-phenyl-1-hydroxyethane in an acetone-water system, is useful for the synthesis of antibiotics; reacting with sodium azide to generate 1-azido-1-phenylethene, wherein the compound can be used for synthesizing various natural products and medicines containing nitrogen heterocycles; under alkaline condition, the compound can be converted into 1-bromo-1-phenyl ethylene, and the compound is a precursor for synthesizing naproxen as an anti-inflammatory analgesic. Because of the wide range of applications of 1-aryl-1, 2-dibromoethane compounds, a large number of synthetic methods have been developed in recent years.

There are many conventional methods for synthesizing 1-aryl-1, 2-dibromoethane, such as ⑴ triphenylphosphine oxide catalyzed reaction of aryl alkene with oxalyl bromide, ⑵ excess tetrabutyl ammonium fluorohydride reaction of alkene with NBS, ⑶ oxidation of aryl alkene with potassium bromide, ⑷ palladium catalyzed reaction of oxygen oxidized alkene with copper bromide, ⑸ catalysis of thiourea molecule reaction of aryl alkene with dibromohydantoin, ⑹ excess lithium bromide reaction of alkene with NBS, ⑺ benzoyl peroxide initiation reaction of 1, 2-diarylethane with NBS.

At present, aryl ethane is directly used as a reactant to overcome the disadvantages of the above reactions, and a method for synthesizing 1, 2-diaryl-1, 2-dibromoethane by reacting 1, 2-diarylolefin with NBS under the initiation of Azobisisobutyronitrile (AIBN) is developed, wherein the synthetic route is shown as follows, and the specific references are as follows: t is. J. Groshens, et al.Organic Preparations and Procedures International,2011,43, 314.

Although this method is an improvement over previous methods, there are still some disadvantages: first, the reaction substrate adaptability is limited, there is only one reaction example, and only applies to 1, 2-diaryl compounds; secondly, AIBN is used as an initiator and cannot be recycled; thirdly, the raw materials need to be prefabricated, and the synthesis steps are increased.

Disclosure of Invention

The invention aims to solve the technical problem of providing a simple and efficient preparation method of 1-aryl-1, 2-dibromoethane.

In order to solve the above problems, the present invention provides a method for preparing 1-aryl-1, 2-dibromoethane, which is characterized in that: under the protection of nitrogen, adding solvent, aryl alkane andNadding bromosuccinimide (NBS) into a reaction tube in sequence, carrying out a double bromination reaction at 80-120 ℃, ending the reaction after 12-48 hours, evaporating the solvent to dryness, and carrying out column chromatography separation to obtain a 1-aryl-1, 2-dibromoethane compound; said arylalkane with saidNThe mol ratio of bromosuccinimide is 1: 2-5; the ratio of the solvent to the arylalkane is 1L: 0.1 to 1.0 mol.

The synthetic route is as follows:

orOr

The solvent is any one of acetonitrile, trifluoromethyl benzene, dichloromethane, trichloromethane, carbon tetrachloride, tetrachloroethane, 1, 2-Dichloroethane (DCE) and 1, 2-dibromoethane.

The aryl alkane has a structural formula of

Or

Or

Wherein R is selected from C₄~C₃₀An aromatic group of (a); r¹And R²Are independently selected from hydrogen or C₁~C₂₀An aliphatic group of (a); r³Is selected from C₀~C₂₀Fatty radical or C of₄~C₃₀An aromatic group of (a); r⁴Is selected from C₀~C₈The fatty group of (2).

Compared with the prior art, the invention has the following advantages:

1. the invention consists of arylalkanes andNthe-bromosuccinimide (NBS) is reacted, and the 1-aryl-1, 2-dibromoethane compound can be efficiently prepared by one step through an oxidation method, so that the synthesis process is greatly simplified, and the synthesis reaction range of the 1-aryl-1, 2-dibromoethane is expanded.

2. The invention has cheap and easily obtained reaction raw materials and solvents, and greatly reduces the synthesis cost.

3. The method has the advantages of mild reaction conditions, simple operation, high yield and wide substrate applicability range, and is easy for industrial production.

4. The reaction raw materials and the solvent are clean and nontoxic, the reaction process is clean, the environmental pollution is small, and the green chemical requirements are met.

5. The synthesis method can be used for synthesizing organic intermediates such as olefin, azide, alcohol, ketone, epoxypropane and the like in one step, and greatly shortens the reported synthetic route of the compounds.

Detailed Description