阅读说明：本技术 一种采用微流场反应技术制备邻氨基苯甲醚的方法 (Method for preparing o-aminoanisole by adopting micro-flow field reaction technology ) 是由 郭凯 毛益阳 段金电 黄达 李玉光 于 2019-11-21 设计创作，主要内容包括：本发明提供了一种采用微流场反应技术制备邻氨基苯甲醚的方法,在相转移催化剂或碱性催化剂作用下,以邻氨基苯酚与无毒无污染的碳酸二甲酯(DMC)为原料,采用微通道模块反应装置进行反应,该装置构思新颖,制备简单,且制备方法具有绿色环保、安全高效、原料易得且价格低廉、无剧毒反应物残留、反应速度快等优点。(The invention provides a method for preparing o-aminoanisole by adopting a micro-flow field reaction technology, which takes o-aminophenol and nontoxic and pollution-free dimethyl carbonate (DMC) as raw materials under the action of a phase transfer catalyst or an alkaline catalyst, and adopts a micro-channel module reaction device for reaction.)

1. A method for preparing o-aminoanisole by adopting a micro-flow field reaction technology is characterized by comprising the following steps: the method comprises the following steps:

(1) mixing o-aminophenol with dimethyl carbonate or dimethyl sulfoxide to obtain a mixed system for later use;

(2) preparing a mixed solution of a catalyst and a solvent according to a certain proportion for later use;

(3) carrying out reaction on the prepared two mixed solutions at a certain temperature for a certain time by a micro-channel modular reaction device;

(4) and filtering and distilling the product obtained after the reaction, collecting the product, and analyzing the product.

2. The process for producing anthranilic ether according to claim 1, characterized in that: in the step (1), the solvent is dimethyl carbonate or dimethyl sulfoxide.

3. The process for producing anthranilic ether according to claim 1, characterized in that: in the step (2), the catalyst comprises a first catalyst phase transfer catalyst and a second catalyst which is a basic catalyst or a metal catalyst, wherein the phase transfer catalyst is tetramethylammonium chloride, tetramethylammonium bromide or tetrabutylammonium bromide, the second catalyst is sodium carbonate, potassium hydroxide, sodium hydroxide, cesium carbonate, organic amine, strongly basic anion exchange resin, cuprous iodide, copper oxide, copper chloride, copper bromide, iron acetate, silver nitrate or palladium acetate, and the first catalyst and/or the second catalyst is/are selected during the reaction.

4. The process for producing anthranilic ether according to claim 1, characterized in that: when the solvent is dimethyl carbonate, the reaction is carried out by using o-aminophenol: dimethyl carbonate: the molar ratio of the catalyst is 1: 10-25: 0.05 to 0.3.

5. The process for producing anthranilic ether according to claim 1, characterized in that: the microchannel modular reaction device comprises a raw material storage tank, a micromixer, a microstructure reactor and a product collector which are sequentially connected through pipelines, wherein the raw material storage tank is provided with a plurality of groups; the reaction temperature is set to be 105-145 ℃, the reaction residence time is 12-25min, the flow rate of the mixed solution obtained after mixing by the micro mixer is 0.5-1.2mL/min, and the volume of the micro-structure reactor is 8-20 mL.

6. The method as claimed in claim 1, wherein the distillation comprises distilling the solvent and the dimethyl carbonate under normal pressure, and distilling under reduced pressure, and collecting the fraction at 580-610Pa and 130-140 ℃.

Technical Field

The invention belongs to the field of chemical synthesis, and particularly relates to a method for preparing o-aminoanisole by adopting a micro-flow field reaction technology.

Background

Anthranilic ether, also known as o-anisidine. It is not only an important fine chemical product, but also an important intermediate for synthesizing fine chemical products such as medicine, pesticide, perfume, etc., and can be used for inhibiting polymerization and ultraviolet ray of ethylene high polymer monomer and synthesizing food antioxidant, and its application is very extensive. At present, two main traditional methods for synthesizing the o-aminoanisole exist. 1. Dimethyl sulfate method: dimethyl sulfate is taken as a methylating agent and reacts with o-aminophenol under alkaline condition to prepare the compound; 2. the methanol method comprises the following steps: under the action of catalyst, o-aminophenol reacts with methanol to obtain the product. The synthesis methods have the defects that the dimethyl sulfate belongs to high-risk highly toxic and highly corrosive medicines, a large amount of alkali is needed to neutralize the by-product acid in the organic synthesis, and the yield is low and generally does not exceed 50%. The methanol method has the defects that the mixture of the mono-methyl ether and the dimethyl ether is not easy to separate, the product quality is poor, and the problems restrict the production of the o-aminoanisole.

Disclosure of Invention

In order to synthesize the o-aminoanisole efficiently and greenly, the invention takes o-aminophenol and nontoxic and pollution-free dimethyl carbonate (DMC) as raw materials, and adopts a micro flow field reaction technology to synthesize the o-aminoanisole rapidly and efficiently under the action of a catalyst, in particular to a method for preparing the o-aminoanisole by adopting the micro flow field reaction technology, which comprises the following steps:

(1) mixing o-aminophenol with dimethyl carbonate or dimethyl sulfoxide to obtain a mixed system for later use;

(2) preparing a mixed solution of a catalyst and a solvent according to a certain proportion for later use;

(3) carrying out reaction on the prepared two mixed solutions at a certain temperature for a certain time by a micro-channel modular reaction device;

(4) and filtering and distilling the product obtained after the reaction, collecting the product, and analyzing the product.

As an improvement, in the step (1), the solvent is dimethyl carbonate or dimethyl sulfoxide.

In the step (2), the catalyst comprises a first catalyst phase transfer catalyst and a second catalyst which is a basic catalyst or a metal catalyst, wherein the phase transfer catalyst is tetramethylammonium chloride, tetramethylammonium bromide or tetrabutylammonium bromide, and the second catalyst is sodium carbonate, potassium hydroxide, sodium hydroxide, cesium carbonate, organic amine, strongly basic anion exchange resin, cuprous iodide, cupric oxide, cupric chloride, cupric bromide, ferric acetate, silver nitrate or palladium acetate.

As an improvement, when the solvent is dimethyl carbonate, the reaction is carried out by reacting ortho-aminophenol: dimethyl carbonate: the molar ratio of the catalyst is 1: 10-25: 0.05 to 0.3.

As an improvement, the microchannel modular reaction device comprises a raw material storage tank, a micromixer, a microstructure reactor and a product collector which are sequentially connected through pipelines, wherein the raw material storage tank is provided with a plurality of groups; the reaction temperature is set to be 105-145 ℃, the reaction residence time is 12-25min, the flow rate of the mixed solution obtained after mixing by the micro mixer is 0.5-1.2mL/min, and the volume of the micro-structure reactor is 8-20 mL.

As an improvement, the distillation is to distill the solvent and the dimethyl carbonate at normal pressure, and then to distill at reduced pressure, and collect the fraction with the conditions of 580-610Pa and 130-140 ℃.

Has the advantages that: the method for preparing the o-aminoanisole by adopting the micro-flow field reaction technology provided by the invention takes o-aminophenol and nontoxic and pollution-free dimethyl carbonate (DMC) as raw materials under the action of a phase transfer catalyst or an alkaline catalyst, and adopts a micro-channel module reaction device for reaction.

Drawings

FIG. 1 is a schematic structural view of a microchannel module reactor apparatus according to the present invention.

Detailed Description

The present invention is further illustrated below with reference to examples.

The synthetic route of the anthranilic ether in the technical scheme of the invention is as follows:

a microchannel module reaction device is adopted, and a raw material storage tank is arranged into a first raw material storage tank and a second raw material storage tank.

Mixing o-aminophenol and dimethyl carbonate or dimethyl sulfoxide to obtain a mixed system for later use, and placing the mixed system in a first raw material storage tank; and preparing a mixed solution of the catalyst and the solvent according to a certain proportion, placing the mixed solution in a second raw material storage tank, and sequentially passing the two groups of raw material storage tanks through a micro mixer, a micro-structure reactor and a product collector to obtain the product. The solvent is dimethyl carbonate or dimethyl sulfoxide.

The method has the characteristics of high catalytic efficiency, mild reaction conditions, high yield of the target compound, convenience in operation and the like, and has the characteristics of high catalytic efficiency, mild reaction conditions, high yield of the target compound, convenience in operation and the like.

The catalyst comprises a first catalyst phase transfer catalyst and the second catalyst is a basic catalyst or a metal catalyst. The first catalyst employs a phase transfer catalyst. The phase transfer catalyst is used for catalyzing two-phase reaction, and the reaction process mainly comprises the transfer of reactants from one phase to another phase and the chemical reaction of a transferred substance and a substance to be transferred. The phase transfer catalyst of the present invention comprises: tetramethylammonium chloride, tetramethylammonium bromide, or tetrabutylammonium bromide.

Preferably, in the method for producing anthranilic ether according to the present invention, the phase transfer catalyst is tetrabutylammonium bromide. When tetrabutylammonium bromide is used as a phase transfer catalyst, very good results can be obtained both in terms of reaction yield and product purity.

In addition to the phase transfer catalyst, the catalyst in the synthesis method according to the embodiment of the present invention further includes a second catalyst. The second catalyst is primarily used to provide a specific environment. In some experimental measures of the present invention, the inventors also investigated the influence of the kind and amount of the second catalyst on the reaction yield. The results show that when the second catalyst is selected from cesium carbonate, potassium hydroxide, very good results are obtained both in terms of reaction yield and product purity. The catalyst may be either the first catalyst or the second catalyst, or both of them may be selected.

Setting the reaction temperature to be 105-145 ℃, setting the reaction retention time to be 12-25min, and setting the flow rate of the mixed solution obtained after mixing by the micro mixer to be 0.5-1.2mL/min, wherein the volume of the micro-structure reactor is 8-20 mL. Preferably, the temperature of the methylation reaction in the present invention is 130 ℃ and the reaction time is 15 min.

And after the reaction is finished, filtering, distilling and collecting a product to obtain the o-aminoanisole. The filtration is performed to recover insoluble substances such as a catalyst, and may be performed by a filtration method and a filtration apparatus which are conventional in the art. And (4) carrying out reduced pressure distillation on the product obtained after the reaction, collecting the product, and analyzing the product.

The distillation can also be rotary distillation, namely distilling the solvent and the dimethyl carbonate at normal pressure, then distilling at reduced pressure, and collecting the fraction with the conditions of 580-610Pa and 130-140 ℃, preferably 600Pa and 130-140 ℃. The process can be carried out using methods and apparatus conventional in the art, such as a rotary evaporator or the like. The reactant dimethyl carbonate of the present invention may be used as a solvent, or dimethyl sulfoxide may be used as a solvent.