WO2008017197A1

WO2008017197A1 - A method for preparing p-bromofluorobenzene

Info

Publication number: WO2008017197A1
Application number: PCT/CN2006/001858
Authority: WO
Inventors: Keng Zong
Original assignee: Keng Zong
Priority date: 2006-07-26
Filing date: 2006-07-26
Publication date: 2008-02-14

Abstract

Disclosed is a method for preparing p-bromofluorobenzene, wherein bromination is carried out between liquid fluorobenzene and bromine in the presence of catalyst to produce p-bromofluorobenzene and hydrogen bromide. The method is characterised by introducing chlorine gas into the reaction system for oxidation reaction with hydrogen bromide to produce hydrogen chloride and oxide of hydrogen bromide, and then reacting the oxide of hydrogen bromide with fluorobenzene to produce p-bromofluorobenzene. After the bromination, the product is used as final product or post-treated to eliminate at least one of hydrogen chloride, p-chlorofluorobenzene and m-bromofluorobenzene in the product for higher purity of p-bromofluorobenzene.

Description

Method for preparing p-bromofluorobenzene

This invention relates to a process for the preparation of a dibasic halogenated aromatic hydrocarbon in an organic compound. Background technique

Parabromofluorobenzene is an important intermediate for the synthesis of fine chemicals such as pharmaceuticals, pesticides and dyes, and is widely used in industrial production. There are two main methods for preparing p-bromofluorobenzene. One method is to make fluorobenzene into p-nitrofluorobenzene after nitration reaction, and then to reduce p-nitrofluorobenzene to obtain p-fluoroaniline, p-fluoroaniline and sodium nitrite, and dilute sulfuric acid to obtain diazonium salt by low temperature, diazo The salt is then reacted with cuprous bromide to produce p-bromofluorobenzene. This method has a long technical route, high energy consumption, large equipment, high cost, low product conversion rate and serious pollution. Another method is direct bromination of fluorobenzene, which uses liquid bromine to react directly with fluorobenzene to form p-bromofluorobenzene; since liquid bromine reacts with fluorobenzene, the reaction temperature is controlled from 30 Ό to 40 ° C, while fluorobenzene The boiling point is 84. 73 ° C, and the volatile, and because the reaction produces a large amount of hydrogen bromide, liquid bromine and fluorobenzene with the hydrogen bromide escape is very serious, not easy to recycle; at the same time generate 2% to 3% of bromine Fluorobenzene; o-bromofluorobenzene has a boiling point of 156 Ό and p-bromofluorobenzene has a boiling point of 150 ° C. The boiling point of the bromofluorobenzene is very close and it is not easy to separate by distillation. Usually, bromine is added to the material to change the o-bromofluorobenzene. Dibromofluorobenzene, because its boiling point differs greatly from the boiling point of p-bromofluorobenzene, it can be removed by distillation, but because of the addition of bromine to the material, some of the bromofluorobenzene reacts with bromine to form dibromofluoro Benzene, therefore, the yield of the method is only 75% to 80%, and the bromine consumption is large, and the production of 1 ton of p-bromofluorobenzene requires 1.2 to 1.4 tons of bromine, which is costly.

It is disclosed in JP 62 221 640 and JP 62 93224 that a mixture of fluorobenzene, hydrogen bromide, oxygen and nitrogen is heated to a temperature of from 190 ° C to 200 ° C in the presence of a Cu-Y type zeolite, and the reaction is continued for 2 hours to 3 hours. A method for producing p-bromofluorobenzene yielded p-bromofluorobenzene having a conversion ratio of 50% and a purity of 93 to 98%.

JP 63 14,742 discloses a process for producing p-bromofluorobenzene by reacting fluorobenzene with liquid bromine (molar ratio of about 1: 1.27) using iron powder as a catalyst at 5 ° C to 4 CTC. When this method is used to produce p-bromofluorobenzene, the product is a mixture of 1% o-bromofluorobenzene, 0.5% m-bromofluorobenzene and 98.5% p-bromofluorobenzene, and then the isomer is separated by crystallization to obtain a purity of 99.8% of p-bromofluorobenzene; this method of making p-bromofluorobenzene has the disadvantage of being cumbersome and energy intensive.

No. 5,874,241 discloses a process for preparing high purity and high yield of p-bromofluorobenzene by reacting liquid bromine with fluorobenzene at minus 3 CTC to 0 °C. The patented method uses a low temperature reaction method to inhibit the production of o-bromofluorobenzene, and then uses an excessive bromination method to convert o-bromofluorobenzene into a dibromide, thereby achieving the purpose of separating o-bromofluorobenzene. This kind The shortcoming of the method is to maintain a very low temperature, low temperature cryogenic equipment, and high energy consumption. Moreover, in this method, when the brominated bromobenzene is converted to the dibromide by excessive bromination, a part of the p-bromofluorobenzene is also converted into a dibromide, especially when the content of o-bromofluorobenzene reaches At about 1%, the conversion of o-bromofluorobenzene to dibromide and the simultaneous conversion of p-bromofluorobenzene to dibromide, while the o-bromofluorobenzene is difficult to fall to within 0.1%. Summary of the invention

It is an object of the present invention to provide a process for the preparation of p-bromofluorobenzene which has low liquid bromine consumption and low cost.

The technical scheme for achieving the object of the present invention is: generating bromine fluorobenzene and hydrogen bromide by the bromination reaction of liquid fluorobenzene and elemental bromine as a reactant under the action of a catalyst; wherein: chlorine gas is introduced into the reaction system, The chlorine gas reacts with hydrogen bromide to form an oxidation product of hydrogen chloride and hydrogen bromide. The oxidation product of hydrogen bromide continues to bromine the fluorobenzene to form p-bromofluorobenzene, so that the bromination reaction is carried out. Chlorine gas participates in the bromination reaction; after the bromination reaction is completed, the obtained material is directly used as a finished product or the obtained material is post-treated to obtain a finished product.

The oxidation products formed by the oxidation reaction of chlorine gas with hydrogen bromide are elemental bromine and bromine bromide, while both elemental bromine and bromine bromide are used as brominating agents to react with fluorobenzene to form p-bromofluorobenzene.

The catalyst for the bromination reaction is a powdery inorganic catalyst containing iron. The mass ratio of fluorobenzene to the catalyst is 500: 0.5 to 3; the reaction temperature of the bromination reaction is O'C to 40 Torr, and the bromination reaction The system is open to the atmosphere.

When the catalyst is selected as powdered iron tribromide or powdered ferric chloride, in the bromination reaction, the liquid fluorobenzene and the catalyst are added to the reactor connected to the atmosphere, and the reactor is connected to the atmosphere under stirring. Liquid bromine is added thereto, and chlorine gas is introduced into the liquid surface of the material until the bromination reaction is complete; the main products of the reaction are p-bromofluorobenzene and hydrogen chloride, and the by-products are o-bromofluorobenzene and p-chlorofluorobenzene. In the bromination reaction, the amount of chlorine in the bromination reaction is theoretically increased by adjusting the liquid bromine and chlorine gas in a molar ratio of 1. 03~1. 06:1; .

The theoretical ratio of the above chlorine gas, the theoretical amount of liquid bromine to the amount of fluorobenzene added is 1: 1:2. When the catalyst is selected as iron powder or powdered iron tribromide or powdered ferric chloride, in the bromination reaction, the liquid fluorobenzene and the catalyst are added to the reactor connected to the atmosphere, and stirred into the reactor. Add liquid bromine, after the bromination reaction is initiated, then pass chlorine gas under the liquid level of the material until the bromination reaction is complete; the main products of the reaction are p-fluorene benzene and hydrogen chloride, and the by-product is o-bromofluorobenzene and Chlorofluorobenzene. The initiation time of the bromination reaction is 5 to 15 minutes, and the amount of liquid bromine added is 3% to 6% of the theoretical amount, so that the liquid bromine is excessive in the entire bromination reaction; In the stage of introducing chlorine gas, the liquid bromine and chlorine gas are added to the material in a molar ratio of 1:1 by adjusting the rate of addition of liquid bromine and chlorine gas, and the amount of chlorine added is the theoretical amount, and the amount of liquid bromine added is also Theoretical dosage. The reactor for the bromination reaction is a reactor equipped with a stirrer, a thermometer, a bromine tube, a vent tube and a reflux condenser, and the reactor is passed through a reflux condenser to the atmosphere; the reactant liquid bromine is reacted through the bromine tube. Included in the material, and the outlet of the bromine tube is located below the liquid level of the material or on the inner wall of the reactor above the liquid level of the material; chlorine gas is added to the reactor material through the vent tube, and the vent tube is The outlet is located below the level of the material.

The first post-treatment of the material after the bromination reaction is to wash the material with water, alkali, or alkali washing, and then the hydrogen chloride is removed by: firstly, the material after the bromination reaction is carried out. After washing with water, the organic phase obtained by liquid separation or liquid separation is the finished product, or the organic phase obtained by adding the aqueous solution of the inorganic alkali to the material after the bromination reaction for neutralization reaction, and then liquid separation and liquid separation is the finished product. Or the aqueous solution of the inorganic base is added to the material after the bromination reaction to carry out the neutralization reaction, and then the liquid phase is separated, and the organic phase obtained by the liquid separation is washed with water, and then the liquid phase is separated again, and the organic phase obtained by the liquid separation again is For the finished product.

The second post-treatment of the brominated material is the sequential removal of hydrogen chloride and p-chlorofluorobenzene in the material, wherein the removal of hydrogen chloride in the material is by washing with water, causing alkali washing or washing with alkali. Realizing, the removal of p-chlorofluorobenzene in the material is achieved by rectification; the method comprises the following steps: firstly, the material after the bromide reaction is washed with water, then separated, and then the organic phase obtained by liquid separation is rectified, After the distillation, the finished product can be obtained, or the aqueous solution of the inorganic alkali is first added to the material after the bromination reaction to carry out the neutralization reaction, and then the liquid phase is separated, and then the organic phase obtained by the liquid separation is subjected to rectification and rectification. The finished product can be obtained, or the aqueous solution of the inorganic base is added to the material after the bromination reaction to carry out the neutralization reaction, and then the liquid phase is separated, and the organic phase obtained by the liquid separation is washed with water, and then liquid separation is performed again, and the liquid separation is performed again. The obtained organic phase is subjected to rectification and rectification to obtain a finished product. The third post-treatment of the brominated material is to remove the o-bromofluorobenzene in the material by a sulfonation reaction by: controlling the temperature of the brominated material to 20 Ό to 100 Ό. Within the range, the sulfonating agent is added to the material under stirring, and stirring is continued for 2 to 5 hours to complete the sulfonation reaction, and the material obtained after the reaction is the finished product.

In the third post-treatment of the material after the bromination reaction, the sulfonation reaction in the present invention can effectively remove the o-bromofluorobenzene in the material after the bromination reaction, which is also an innovation of the present invention, although In the material after the sulfonation reaction, in addition to p-bromofluorobenzene, p-chlorofluorobenzene, hydrogen chloride, a new impurity, 3-bromo-4-fluorobenzenesulfonic acid, was introduced, but the relative bromide was removed from p-bromofluorobenzene. In the case of fluorocarbon, 3-bromo-4_fluorobenzenesulfonic acid can be removed by alkali washing or water washing or alkali washing and water washing, and the operation process is simple, and the customer can purchase the material after the third post-treatment. Use it according to your own requirements or remove the relevant impurities before use.

The fourth post-treatment of the brominated material is the sequential removal of o-bromofluorobenzene and hydrogen chloride in the material, wherein the removal of o-bromofluorobenzene in the material is achieved by sulfonation reaction. The removal of hydrogen chloride is achieved by washing with water, caustic washing, or washing with alkali and then washing with water. The removal of p-chlorofluorobenzene in the material is passed through fine Distillation is achieved; the method is: firstly, the temperature of the material after the bromination reaction is controlled within a range of 2 CTC to 10 (TC), and a sulfonating agent is added to the material under stirring, and stirring is continued for 2 to 5 hours to effect a sulfonation reaction. The organic phase obtained by completely and re-washing the material and then liquid separation and liquid separation is the finished product, or the temperature of the material after the bromination reaction is first controlled within a range of 20 ° (to 100 ° 0) under stirring. Adding a sulfonating agent, stirring for 2 to 5 hours to complete the sulfonation reaction, adding an aqueous solution of the inorganic base to the material for neutralization reaction, and then separating and separating the organic phase to obtain a finished product, or first The temperature of the material after the bromination reaction is controlled at 2 (TC to 10 (the range of TC, adding sulfonating agent to the material under stirring, stirring for 2 to 5 hours to complete the sulfonation reaction, and then the inorganic base) The aqueous solution is added to the material to carry out the neutralization reaction, and then the liquid phase is separated, and the organic phase obtained by the liquid separation is washed with water and then separated again, and the organic phase obtained by the liquid separation is the finished product.

The fifth post-treatment of the brominated material is the sequential removal of o-bromofluorobenzene, hydrogen chloride and p-chlorofluorobenzene in the material, wherein the removal of o-bromofluorobenzene in the material is by sulfonation reaction. To achieve, the removal of hydrogen chloride in the material is achieved by washing with water, caustic washing, or washing with alkali and water, by: first controlling the temperature of the material after the bromination reaction within the range of 2 CTC to 100 Torr, The sulfonating agent is added to the material under stirring, stirring is continued, and the sulfonation reaction is completed for 2 to 5 hours, and then the material is washed with water, and then separated, and the organic phase obtained by liquid separation is subjected to rectification and rectification. The finished product can be obtained, or the temperature of the brominated material can be controlled within 2 (TC to 100 ° C), the sulfonating agent is added to the material under stirring, and the sulfonation reaction is continued for 2 to 5 hours. Completely, the aqueous solution of the inorganic base is added to the material for neutralization reaction, and then the liquid phase is separated, and the organic phase obtained by liquid separation is refined and rectified to obtain the finished product, or the bromination reaction is first carried out. Material temperature In the range of 2o °c to locrc, the sulfonating agent is added to the material under stirring, stirring is continued for 2 to 5 hours to complete the sulfonation reaction, and an aqueous solution of the inorganic alkali is added to the material for neutralization reaction. After the liquid separation, the organic phase obtained by liquid separation is washed with water, and the liquid phase is separated again, and the organic phase obtained by liquid separation is refined and rectified to obtain a finished product. In the above post treatment, a separate alkali is used. Washing and washing can theoretically remove the hydrogen chloride contained in the brominated material, but in industrial large production, the organic phase obtained after washing will have very little chlorinated gas dissolved, while hydrogen chloride is in rectification. It will corrode fine equipment; it will neutralize hydrogen chloride by adding alkali solution during alkali washing, but in industrial large production, precise adjustment and control of pH is often difficult to achieve, resulting in very little organic phase in alkali washing. Chlorination gas or alkali, in the subsequent rectification operation, will also corrode the rectification equipment and use the first alkali washing and water washing method to effectively remove the hydrogen chloride.

The above alkaline washing is directed to the aqueous solution of the alkali added to the bromination reaction, neutralizing the hydrogen chloride in the material, and separating the material after the neutralization reaction into the organic phase layer solution and the aqueous phase layer solution by standing. a method of obtaining an organic phase layer solution by liquid separation; or an aqueous solution of a base added to the material after the sulfonation reaction, and the material The hydrogen chloride and 3-bromo-4-fluorobenzenesulfonic acid are neutralized, and the material after the neutralization reaction is separated into an organic phase layer solution and an aqueous phase layer solution by standing, and then the organic phase layer solution is obtained by liquid separation. method.

The above washing is directed to the material after the bromination reaction or the addition of water to the material after the sulfonation reaction, and the solubility of the inorganic substance such as hydrogen chloride in water is large, and the solubility of organic substances such as bromofluorobenzene in water is small, and The method of separating the mixture after the addition of water into an organic phase layer solution and an aqueous phase layer solution, and then obtaining a solution of the organic phase layer by liquid separation.

The neutralization solution used in the neutralization reaction carried out in the above-mentioned post-treatment is a 3% to 5% aqueous sodium carbonate solution or a 10% to 30% aqueous sodium hydroxide solution, and the neutralization reaction is carried out until the pH of the material in the reactor It is from 6 to 7.

The rectification carried out in the above post-treatment is atmospheric distillation or depressurization, and the number of theoretical plates is 10 to 30; when atmospheric distillation is used, the evaporator temperature is 160 Ό to 180 Ό, and the temperature at the top of the column is 13CTC to 156 ° C, the reflux ratio is (1-20): 1.

The sulfonating agent to be carried out in the above post-treatment is sulfur trioxide, chlorosulfonic acid or fuming sulfuric acid, and the temperature during the sulfonation reaction is controlled at 40 to 90 °C.

The reaction of liquid bromine with fluorobenzene is an organic reaction. As the main reaction of p-bromofluorobenzene is carried out, more side reactions occur, so in the actual reaction, not only p-bromofluorobenzene, o-bromofluorobenzene, but also chlorine are formed. Products such as fluorobenzene and hydrogen chloride, and substances such as dibromofluorobenzene and o-chlorofluorobenzene which are extremely low in content; in the fine bismuth, dibromofluorobenzene can be removed from p-bromofluorobenzene together with p-chlorofluorobenzene. In the sulfonation treatment, o-chlorofluorobenzene can be removed together with o-bromofluorobenzene; however, the formation and removal of such low-content dibromofluorobenzene, o-chlorofluorobenzene and the like do not affect the method and purpose of the present invention, so It will not be described in detail in this manual.

In the post-treatment process of the above-mentioned preparation method of p-bromofluorobenzene, the sulfonation reaction is used to remove the o-bromofluorobenzene, and the specific method is sulfur trioxide, chlorosulfonic acid or fuming sulfuric acid as a sulfonating agent. In the temperature range of 20 Torr to 100 Torr, 3-bromo-4-fluorobenzenesulfonic acid which is easily reacted with a base with o-bromofluorobenzene can be separated by neutralization and liquid separation. In the temperature range selected in the present technical solution, the sulfonating agent hardly reacts with p-bromofluorobenzene, but only with o-bromofluorobenzene, and the resulting 3-bromo-4-fluorobenzenesulfonic acid is easily Washed with an alkali solution; thereby reducing the content of o-bromofluorobenzene to below 0.02%, so that a relatively high purity p-bromofluorobenzene can be prepared by a simplified method. Taking chlorosulfonic acid as an example, the anti-banking is as follows (the equation is not balanced):

HBr + ci ₂ Br ₂ + HCI

In the above reaction process, there is also a certain amount of the following reaction:

HBr + CL > BrCI + HCI

F

Br

In the post-treatment process in the preparation method of the above-mentioned p-bromofluorobenzene, before the sulfonation reaction, in order to save the amount of the sulfonating agent, the weight content of o-bromofluorobenzene in the material to be sulfonated may be measured first. The method of testing can be performed by gas chromatography, and then the theoretical amount of sulfonating agent is calculated. The calculation method is as follows: 1 When chlorosulfonic acid or sulfur trioxide is selected as the sulfonating agent, the weight of the sulfonating agent added == the total weight of the material X The weight content of the o-bromofluorobenzene X The molar mass of the sulfonating agent used The molar mass of bromofluorobenzene; specifically, when chlorosulfonic acid is selected, the weight of chlorosulfonic acid added = The total weight of the material X The weight content of o-bromofluorobenzene The molar mass of X chlorosulfonic acid The molar mass of o-bromofluorobenzene; When sulfur trioxide is used, the weight of sulfur trioxide added = the total weight of the material X o-bromofluoro The weight content of benzene X The molar mass of sulfur trioxide is the molar mass of o-bromofluorobenzene; 2 When the 3⁄4β acid is used as the sulfonating agent, the concentration is 20% to 40% of fuming sulfuric acid, and the fuming sulfuric acid The amount of addition is calculated by the amount of free sulfur trioxide contained therein, that is, the amount of fuming sulfuric acid added in the concentration of _Χ = the total amount of the material X the content of o-bromofluorobenzene X the molar mass of sulfur trioxide ÷χ% ÷ The molar mass of o-bromofluorobenzene, where x% is the mass percentage of sulfur trioxide in fuming sulfuric acid; for example, when 20% fuming sulfuric acid is used, x% = 20%, so 20% of the fumes The amount of sulfuric acid added to the total weight of the material X the weight content of o-bromofluorobenzene X molar mass of sulfur trioxide ÷ 20% molar mass of o-bromofluorobenzene; 30% of fuming sulfuric acid, 30% of fuming The amount of sulfuric acid added = the total weight of the material X The weight content of o-bromofluorobenzene X The molar mass of sulfur trioxide ÷ 30 % ÷ bromofluorobenzene Molar mass. Other sulfonating agents may be calculated based on the amount of free sulfur trioxide contained therein as compared to the above formula.

The amount calculated by the above formula is the theoretical amount of the sulfonating agent. Since the sulfonating agent is easily hydrolyzed, in the actual production, the prepared bromide fluorobenzene containing o-bromofluorobenzene and p-chlorofluorobenzene always contains some water. The actual amount of the sulfonating agent to be added is in excess of the theoretical amount, so the actual amount is from 1 to 4 times the theoretical amount, preferably 1.3 times the chamber.

The present invention has positive effects: (1) In the prior art, hydrogen bromide formed by the reaction of fluorobenzene with bromine cannot continue to participate in the reaction, and is volatile, thereby causing a large loss of bromine; and the method of the present invention is Chlorine gas is added, and the resulting bromide is oxidized to elemental bromine and bromine bromide. ₂ Elemental bromine and chlorobromide can continue to react with fluorobenzene to form p-bromofluorobenzene. By adding chlorine gas, the consumption of liquid bromine is greatly reduced, so that the amount of liquid bromine used is only about 55% in the prior art; although the reaction consumes more chlorine than the known technology, chlorine as an industrial raw material The price is much lower than the price of liquid bromine, so it effectively reduces the production cost and has significant economic benefits in industrial production. (2) Since the newly generated elemental bromine and chlorobromide have high reactivity, the reaction temperature is lowered, thereby reducing the escape of fluorobenzene and increasing the conversion rate of fluorobenzene. It was found by gas chromatography analysis that the conversion of fluorobenzene in the process of the present invention can reach 100%. (3) The present invention can effectively inhibit the formation of by-product p-chlorofluorobenzene by slightly increasing the liquid bromine ratio in the reactor material by a theoretical excess of 1% to 6%, preferably 3% to 5%. The content of p-chlorofluorobenzene is less than 1%. (4) The boiling point of o-bromofluorobenzene is 156 ° C, the boiling point of p-bromofluorobenzene is 15 CTC, the boiling point of the two is very close, to separate the rectification column which requires a very high theoretical plate, and generate a large amount of post-fraction, It is uneconomical, and in the process of the present invention, o-bromofluorobenzene is removed from the crude bromofluorobenzene containing o-bromofluorobenzene by a sulfonation method. In a specific temperature range, the sulfonating agent hardly reacts with p-bromofluorobenzene, and 3-bromo-4-fluorobenzenesulfonic acid can be separated from the o-bromofluorobenzene to form an easy-to-base reaction, thereby achieving purification. Purpose; this can make the content of o-bromofluorobenzene from 2% to 3% It is reduced to 0.02% or less, and the method of preparing high-purity p-bromofluorobenzene can be simplified. (5) The boiling point of p-chlorofluorobenzene is 129. C, p-bromofluorobenzene has a boiling point of 150 ° C, and the boiling points of the two are quite different, and can be separated by a rectification column having 10 to 30 theoretical plates; using the method of the invention and selecting appropriate post-treatment In the process, p-bromofluorobenzene having a purity of up to 99.9% or more can be obtained. BRIEF abstract

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a gas chromatogram of the finished product of p-bromofluorobenzene prepared in Example 9.

Figure 2 is a gas chromatogram of the finished product of p-bromofluorobenzene prepared in Example 21.

Figure 3 is a schematic view showing the structure of a batch distillation column.

Figure 4 is a gas chromatogram of the finished product of p-bromofluorobenzene prepared in Example 36. Implementation

(Example 1) In a 1000 ml five-neck glass reaction flask with an electric stirrer, a thermometer, a balance funnel, a vent tube, and a reflux condenser, 500 g of liquid fluorobenzene was first added, and the balance funnel was The outlet of the vent pipe is located under the surface of the fluorobenzene; the reaction temperature is controlled by a cold water bath of 2 ± 2 ° C; while stirring, 2 g of iron powder as a catalyst is added to the reaction flask, and the mixture is passed through a balance funnel to the reaction flask. Add 23 g of liquid bromine to start the reaction of the bromination reaction in the reaction flask. The liquid bromine reacts with fluorobenzene to form hydrogen bromide and p-bromofluorobenzene. The by-product is o-bromofluorobenzene. The reaction is initiated for 15 minutes. After that, the bromination reaction in the reaction flask is started by introducing chlorine gas into the reaction system in the reaction flask through a vent pipe to become a bromination reaction in which the generated hydrogen bromide is oxidized by chlorine gas into a brominating agent (even if bromination reaction) To be a bromination reaction with chlorine gas, the same as below, add 417 g of liquid bromine to the reaction flask at a molar ratio of 1:1 for the next 8 hours, and pass 185 g of chlorine gas. Over Stirring was continued throughout the process, and when liquid bromine and chlorine were all added, the reaction was terminated. The mixture obtained after the reaction was 875 g of a finished product, and the yield of fluorobenzene was 94.5%. The content of the relevant ingredients in the finished product is shown in Table 1. Since the reactor is open to the atmosphere and the reaction time is long, almost all of the hydrogen chloride generated by the reaction is volatilized during the whole reaction, and the fluorobenzene and liquid bromine are also partially volatilized, so that the bromofluorobenzene can be obtained in this embodiment. A higher content of the finished product. The material volatilized in this embodiment can be passed into water for absorption and the like to prevent environmental pollution. The same phenomena and effects were also observed in the preparation of p-bromofluorobenzene in the following Examples 2 to 8.

(Embodiment 2)

The rest was the same as in Example 1, except that the iron powder as a catalyst added in the bromination reaction was 1 g, and the temperature of the bromination reaction was controlled at 15 ± 2 °C. After the reaction, 868 g of a finished product was obtained, and the yield of fluorobenzene was 93%. The contents of the relevant ingredients are shown in Table 1.

(Embodiment 3)

The rest is the same as in Example 1, except that the iron powder as a catalyst added in the bromination reaction is 0.5 g, and the reaction temperature of the bromination reaction is controlled at 25 ± 2 858 after the reaction, 858 g of the finished product, The yield of fluorobenzene was 91.5%, and the contents of the relevant components are shown in Table 1.

(Embodiment 4)

The rest was the same as in Example 1, except that the iron powder as a catalyst added in the bromination reaction was 2.5 g, and the reaction temperature of the bromination reaction was controlled at 38 ± 2 °C. After the reaction, 840 g of a finished product was obtained, and the yield of fluorobenzene was 89%, and the contents of the relevant components are shown in Table 1.

Table 1

In the methods of Examples 1 to 4, the bromination reaction is a bromination reaction having a reaction initiation stage, and after the user purchases the finished products obtained in Examples 1 to 4, they can be directly used according to different use requirements or The impurities are removed before use.

(Embodiment 5)

In a 1000 ml five-glass reaction vial with an electric stirrer, thermometer, balance funnel, vent tube and reflux condenser, add 500 grams of liquid fluorobenzene and place the balance funnel and vent outlet The surface temperature of fluorobenzene was controlled by using a cold water bath to control the reaction temperature to 2 ± 2 ° C; while stirring, 2 g of ferric chloride powder as a catalyst was added to the reaction flask, and a solution was added to the reaction flask through a balance funnel. The bromine reaction was carried out in the reaction flask, and the bromination reaction in the reaction flask was carried out in a molar ratio of 1.06:1. Adding ratio, adding 440 g of liquid bromine to the reaction flask, introducing 18 ⁵ g of chlorine gas, reacting to form hydrogen chloride and p-bromofluorobenzene, the by-products are o-bromofluorobenzene and chlorofluorobenzene; when liquid bromine and chlorine are all added, End the reaction. The mixture obtained after the reaction is a finished product. The finished product is 868 grams, of which the weight percentage of the relevant ingredients 4%。 Containing p-bromofluorobenzene 1. 1%, containing p-chlorofluorobenzene 0. 4%.

(Example 6)

The rest was the same as in Example '5 except that the iron trichloride powder as a catalyst added in the bromination reaction was 1 g, and the temperature of the bromination reaction was controlled to 15 ± 2 Torr. After the reaction, 858 g of the finished product was obtained, wherein the content by weight of the component was: 95. 0% of p-bromofluorobenzene, 2. 2% of o-bromofluorobenzene, and 0.8% of p-chlorofluorobenzene.

(Example 7)

The rest was the same as in Example 5, except that the ferric chloride powder as a catalyst was added in the bromination reaction to 0.5 g, and the temperature of the bromination reaction was controlled at 25 ± 2 °C. After the reaction, 850 g of the finished product was obtained, wherein the content of the relevant components was: 96.80 % of p-bromofluorobenzene, 1.9% of o-bromofluorobenzene, and chlorofluorobenzene.

(Embodiment 8)

The rest was the same as in Example 5 except that the ferric chloride powder as a catalyst added in the bromination reaction was 2.5 g, and the temperature of the bromination reaction was controlled at 38 ± 2 °C. After the reaction, 848 g of the finished product was obtained, wherein the content of the relevant components was: 95.80 % of p-bromofluorobenzene, 2. 2% of o-bromofluorobenzene, and 0.9% of p-chlorofluorobenzene. In the methods of Examples 5 to 8, the bromination reaction is a bromination reaction without initiating a reaction stage, and after the user purchases the finished products obtained in Examples 5 to 8, it can be directly used or used according to different use requirements. The impurities are removed and used.

(Embodiment 9)

The process of the bromination reaction of this example is the same as that of Example 1. After repeating the bromination reaction of Example 1 two to three times, 1000 g of the obtained material is taken out, and the alkali treatment is followed by washing with water and then post-treatment with water washing. wherein the hydrogen chloride is removed, the material is particularly _s is transferred to a separatory funnel, first subjected to caustic, i.e., a suitable amount of addition of 5% aqueous sodium carbonate solution after shaking in a separatory funnel, so that the bromination reaction The latter material is neutralized to a pH of 7 by an aqueous solution of sodium carbonate, and then allowed to stand for stratification, followed by liquid separation, and the organic phase of the lower layer is transferred to another separatory funnel; then the organic phase solution is washed with water. more thoroughly remove the hydrogen chloride which, ie the organic phase was added 200 g of distilled water was allowed to stand until their stratification after ₅ shaken, the organic phase obtained after the liquid separation is, after removal of the hydrogen chloride-containing chlorofluorocarbons benzene, o-bromo-fluorobenzene Finished product of bromofluorobenzene.

The gas chromatogram shown in Fig. 1 was obtained by sampling and analyzing the finished product of p-bromofluorobenzene obtained in the present example, and the image data thereof is shown in Table 2. The substance corresponding to each peak name in Table 2 can be obtained by infrared spectrum identification. In the section of the retention time of 3 to 4 minutes in Fig. 1, there are three characteristic peaks, and the values of the three characteristic peaks are relatively close, so the gas chromatograph overlaps the data of the three characteristic peaks when printing the map. Together, the specific values of these three data are given in the table column with the peak numbers 4, 5 and 6 in Table 2, and their retention times are 3. 568, 3. 622 and 3. 672 minutes. The instrumentation and analysis conditions used are as follows:

The instrument model is: GC9790 gas chromatograph manufactured by Zhejiang Wenling Fuli Analytical Instrument Co., Ltd.; the column type is SE54, diameter is 0.35 mm, length is 30 m. Chromatographic conditions: column temperature 130 ° C, vaporization chamber 250 Ό, detector 250 ° C. The detector model is a hydrogen flame ionization detector FID; the injector is split; the column front pressure: 0. IMPa; injection volume: 0.2 microliter.

Table 2

(Embodiment 10)

The procedure of the bromination reaction of this example was the same as in Example 2, and after repeating the bromination reaction of Example 2 two to three times, 1000 g of the obtained material was taken out, X!l" which was carried out in the same manner as in Example 9. The post-treatment step is to remove the hydrogen chloride to obtain a purified product of p-bromofluorobenzene having a purity of 97.2%.

(Example 11)

The procedure of the bromination reaction of this example was the same as that of Example 3. After repeating the bromination reaction of Example 3 two to three times, 1000 g of the obtained material was taken out, and the same procedure as in Example 9 was carried out. The chlorofluorobenzene having a purity of 97.8% is obtained by a step of removing the hydrogen chloride.

(Embodiment 12)

The procedure of the bromination reaction of this example was the same as that of Example 4. After repeating the bromination reaction of Example 4 two to three times, 1000 g of the obtained material was taken out, and the same post treatment as in Example 9 was carried out. The step of removing the hydrogen chloride to obtain p-bromofluorobenzene having a purity of 97.5%. .

(Embodiment 13)

The procedure of the bromination reaction in this example was the same as in Example 1. After repeating the bromination reaction of Example 1 two to three times, 1000 g of the obtained material was taken out, and subjected to alkali washing for post-treatment to remove the bromination reaction. Hydrogen chloride, the specific method is: Move the material to the separatory funnel, add an appropriate amount of 5% aqueous sodium carbonate solution, and then oscillate to make bromine The material after the reaction is neutralized to a pH of 7 by an aqueous solution of sodium carbonate, and then left to stand for stratification, and the organic phase obtained after liquid separation is a pair containing p-chlorofluorobenzene and o-bromofluorobenzene. Finished product of bromofluorobenzene.

(Example U)

The process of the bromination reaction of this example is the same as that of Example 1. After repeating the bromination reaction of Example 1 two to three times, 1000 g of the obtained material is taken out, and subjected to post-treatment with water washing to remove the bromination reaction. Hydrogen chloride, the specific method is: the material is moved to the separatory funnel, 300 grams of water is added to the material, and then shaken, and then left to stand for stratification, liquid separation, the organic phase obtained after liquid separation is containing chlorofluoro Finished product of p-bromofluorobenzene of benzene and o-bromofluorobenzene.

In the methods of Examples 9 to 14, the bromination reaction is a bromination reaction in the initiation reaction stage, and the bromination reaction is carried out after the removal of hydrogen chloride; the user purchases Examples 9 to 14. After the finished product is obtained, it can be used directly according to different use requirements or the relevant impurities can be removed before use.

(Embodiment 15)

The process for preparing p-bromofluorobenzene in this embodiment is a manufacturing process in industrial large-scale production, including a bromination reaction process and a first alkaline washing of the material after the bromination reaction, followed by water washing to remove hydrogen chloride and rectification to remove p-chlorofluorocarbon. The post-treatment process of benzene; the specific implementation process is as follows: In 2Q00 liter reactor with electric stirrer, thermometer, bromine high level tank, chlorine tube, exhaust gas absorption tower, put 1500 kg of fluorobenzene, add 10 kg of trichloro Iron, 40 kg of bromine (ie, industrial liquid bromine, which contains 99.8% liquid bromine), and the reaction in the reactor begins the bromination reaction, control the reaction temperature is 10 Ό to 20 ° C, stirring 15 minutes; then, within 30 hours, according to the molar ratio of bromine: chlorine gas of 1:1, adding 1255 kg of bromine by adding bromine high-level tank, and introducing 555 kg of chlorine gas, so that the bromination reaction becomes Chlorine gas participates in the bromination reaction; after the chlorine gas and liquid bromine are completely added and the reaction is terminated, the material after the bromination reaction is obtained, and the reaction is kept stirring. The material after the bromination reaction is then subjected to an alkali washing treatment, that is, the material after the bromination reaction is neutralized with a 5% aqueous sodium carbonate solution under stirring until the pH is 7. The material is sent to the liquid-phase two-phase separation device, and after standing and layering, the organic phase solution is separated and sent to another liquid-phase two-phase separation device; then the separated organic phase solution is washed with water, that is, the separated organic The phase solution was stirred with ice, and the organic phase solution was separated after standing to separate the layer, thereby obtaining the crude p-bromofluorobenzene, the weight of which was 2700 kg; at this time, the sample was subjected to gas chromatography analysis, and the content of p-bromofluorobenzene was measured. It is 97.5 %. Then, according to the following steps, the obtained crude p-bromofluorobenzene is subjected to rectification treatment: 1 The structure of the batch rectification column is shown in Fig. 3, and 2700 kg of crude product is added to the evaporator (also called reboiler) in the rectification column. p-Bromofluorobenzene; 2 control evaporator temperature 160 Ό to 180 Ό, _: top temperature 13CTC to 156 ° C; 3 refining process by controlling the reflux ratio and collecting the corresponding weight of the fraction to carry out the purification of p-bromofluorobenzene. At the beginning of the period, the reflux ratio was controlled to be 20:1, and the 100 kg fraction distilled was collected in a 1 # receiver, which was called No. 1 split; then the reflux ratio was controlled to 15: 1, and the distilled fraction was 160. Kilogram fraction collection In the 2# receiver, it is called the No. 2 fraction; finally, the reflux ratio is controlled to 1:10, and the remaining fractions from the rectification are collected in the 3# receiver, which is called the No. 3 fraction. The No. 1 fraction, the No. 2 fraction and the No. 3 fraction were sampled and analyzed by gas chromatography, and the content of p-chlorofluorobenzene in the fraction No. 1 was about 10%, and the content of p-chlorofluorobenzene in the fraction No. 2 was about 3. % 。 The content of p-chlorofluorobenzene in fraction No. 3 is reduced to 0.03%, and the content of p-bromofluorobenzene therein is about 98. 5%; The finished product of fluorobenzene is p-bromofluorobenzene.

(Embodiment 16)

The rest is the same as in the first embodiment except that: after the alkali-washing treatment of the material after the bromination reaction, the organic phase obtained after the alkali washing is not washed with water, and the organic obtained directly after the alkali washing is used. After the rectification and rectification, the finished p-bromofluorobenzene containing o-bromofluorobenzene can be obtained.

(Embodiment 17)

The rest is the same as in the first embodiment except that the material after the bromination reaction is not subjected to the alkali washing treatment, and the material is directly washed with water and the organic phase obtained after the water washing is directly subjected to rectification, and after the distillation, The finished p-bromofluorobenzene containing o-bromofluorobenzene is available.

In the methods of Examples 15 to 17, the bromination reaction is a bromination reaction in which a reaction phase is initiated, and the material after the bromination reaction is subjected to a post-treatment of sequentially removing hydrogen chloride and p-chlorofluorobenzene; After the finished products obtained in Examples 15 to 17 can be directly used according to different use requirements or the related impurities are removed and used.

(Embodiment 18)

The procedure of the bromination reaction of this example was the same as that of Example 2. After repeating the bromination reaction of Example 2 two to three times, 1000 g of the obtained material was taken out, and the post-treatment of the sulfonation reaction was removed. The corresponding method is: sampling for gas chromatography analysis, the content of o-bromofluorobenzene in the material is 2.2%; then the material is transferred to a three-necked flask equipped with a stirrer, a thermometer and a reflux condenser. The temperature of the material in the reactor was controlled by a cold water bath to be 22±2° C. While stirring, 35 g of chlorosulfonic acid as a sulfonating agent was added to the reaction flask, and the sulfonation reaction was completed after 5 hours, and the entire sulfonation reaction was completed. Stirring is maintained throughout the process. The mixture obtained after the sulfonation reaction is a finished p-bromofluorobenzene containing 3-bromo-4-fluorobenzenesulfonic acid, hydrogen chloride, p-chlorofluorobenzene, and chlorosulfonic acid.

(Embodiment 19)

The rest was the same as in Example 18 except that the sulfonating agent used in the post-bromination reaction was 200 g of 20% fuming sulfuric acid. The mixture obtained after the sulfonation reaction is a finished p-bromofluorobenzene containing 3-bromo-4-fluorobenzenesulfonic acid, hydrogen chloride, p-chlorofluorobenzene, sulfuric acid.

(Embodiment 20) The rest was the same as in Example 18 except that the sulfonating agent used in the post-treatment of the bromination reaction was 20 g of sulfur trioxide. The mixture obtained after the sulfonation reaction is a finished p-bromofluorobenzene containing 3-bromo-4-fluorobenzenesulfonic acid, hydrogen chloride, p-chlorofluorobenzene, and sulfur trioxide.

In the methods of Examples 18 to 20, the bromination reaction is a bromination reaction in the initiation reaction stage, and the bromination reaction is carried out after the removal of o-bromofluorobenzene; the user purchases Example 18 to After the finished product obtained in Example 20 can be directly used according to different use requirements or the related impurities are removed and used.

(Example 21)

The procedure of the bromination reaction of this example was the same as that of Example 2. After repeating the bromination reaction of Example 2 two to three times, 1000 g of the obtained material was taken out, and the post-treatment of the sulfonation reaction was removed. The o-bromofluorobenzene, the specific method is: sampling for gas chromatography analysis, the content of ortho-bromofluorobenzene in the material is 2. 2%; then the material is transferred to a three-necked flask with a stirrer, thermometer and reflux condenser In the cold water bath, the temperature of the material in the reactor was controlled to be 22±2° C. While stirring, 35 g of chlorosulfonic acid as a sulfonating agent was added to the reaction flask, and the sulfonation reaction was completed after 5 hours, and the entire sulfonation was completed. Stirring is maintained during the reaction; the material after the sulfonation reaction is transferred to a separatory funnel, which is firstly washed with alkali, that is, an appropriate amount of a 5% aqueous solution of sodium carbonate is added to the separatory funnel, and then shaken to thereby sulphur The material after the reaction is neutralized to a pH of 7 by an aqueous solution of sodium carbonate, and then left to stand for stratification, and the organic phase of the lower layer is transferred to another separatory funnel; Washed, That is, 300 g of water was added to the organic phase, and after shaking, it was allowed to stand for stratification, and the organic phase obtained after liquid separation was the finished product of p-chlorofluorobenzene containing p-chlorofluorobenzene after removal of o-bromofluorobenzene.

The gas chromatogram shown in Fig. 2 was obtained by sampling and analyzing the finished product of p-bromofluorobenzene obtained in this example, and the image data thereof is shown in Table 4. The substances corresponding to the respective peak names in Table 4 were identified by infrared spectroscopy. In the section of the retention time of 4 to 5 minutes in Fig. 2, there are two characteristic peaks, and the values of the characteristic peaks are relatively close, so the gas chromatograph superimposes the data of the two characteristic 'peaks when printing the map. 。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。。 The characteristic peak of o-bromofluorobenzene in Figure 2 is because the content of o-bromofluorobenzene in the sample is extremely low, so that the gas chromatograph can not detect its existence. It can be seen that the bromination reaction can effectively remove the bromine in the present invention. O-bromofluorobenzene contained in fluorobenzene. The instrumentation and analysis conditions used are as follows:

The instrument model is: GC9790 gas chromatograph manufactured by Zhejiang Wenling Fuli Analytical Instrument Co., Ltd.; the column type is SE54, diameter is 0.35 mm, length is 30 m. Chromatographic conditions: column temperature 130 Ό, vaporization chamber 250 Ό, detector 250 Ό. Detector model: Hydrogen flame ionization detector FID; Injector is split; Precolumn pressure: .0. IMPa; Injection volume: 0.2 μl. (Example 22)

The rest was the same as in Example 21 except that the temperature of the sulfonation reaction was controlled at 35 ± 2 ° C and the reaction time was 4.5 hours. The content of the relevant components in the finished product obtained after the reaction is shown in Table 3.

(Embodiment 23)

The rest is the same as in Example 21, except that: The sample after bromination is sampled by gas chromatography to determine that the content of o-bromofluorobenzene in the material is 2.3%, and the temperature of the sulfonation reaction is controlled at 55 ± 2 °C. The reaction time is 4 hours. The content of the relevant components in the finished product obtained after the reaction is shown in Table 3.

(Embodiment 24)

The rest is the same as in Example 21, except that: The sample after bromination is sampled by gas chromatography to determine that the content of o-bromofluorobenzene in the material is 2.3%, and the temperature of the sulfonation reaction is controlled at 65±2 °C. , the reaction time is 3.5 hours. The content of the relevant components in the finished product obtained after the reaction is shown in Table 3.

(Embodiment 25)

The rest is the same as in Example 21, except that: The sample after bromination is sampled by gas chromatography to determine that the content of o-bromofluorobenzene in the material is 2.3%, and the temperature of the sulfonation reaction is controlled at 75 ± 2 °C. , the reaction time is 2.5 hours. The content of the relevant components in the finished product obtained after the reaction is shown in Table 3.

(Embodiment 26)

The rest is the same as in Example 21, except that: The sample after bromination is sampled by gas chromatography to determine that the content of o-bromofluorobenzene in the material is 2.2%, and the temperature of the sulfonation reaction is controlled at 98 ± 2 °C. The reaction time is 2 hours. The content of the relevant components in the finished product obtained after the reaction is shown in Table 3.

table 3

Table 4 Peak number retention time (minutes) peak peak area mass content peak name

1 1. 690 3360. 083 5996. 400 0. 9171 % p-chlorofluorobenzene

2 2. 440 168690. 969 637417. 313 97. 4831 % p-bromofluorobenzene

3 3. 723 181. 545 498. 800 0. 0763% Impurity

4 4. 165 1026. 138 1705. 660 0. 2609% dibromofluorobenzene

5 4. 223 2544. 276 3943. 590 0. 6031%

6 5. 215 365. 458 0. 1173% impurities

7 5. 865 1527. 000 3546. 200 0. 5423%

(Embodiment 27)

The rest is the same as that of the embodiment 21, except that: after the alkali-washing treatment of the material after the sulfonation reaction, the organic phase obtained after the alkali washing is no longer washed with water, and DC and O are directly washed with the alkali. The obtained organic phase is subjected to rectification, and after rectification, the finished p-bromofluorobenzene containing p-chlorofluorobenzene can be obtained.

(Embodiment 28)

The rest was the same as in Example 21 except that the material after the sulfonation reaction was no longer subjected to an alkali washing treatment, but directly washed with water, and the organic phase obtained after washing with water was used as a finished p-bromofluorobenzene.

(Example 29)

The rest was the same as in Example 21 except that: as a sulfonating agent, 200 g of 20% fuming sulfuric acid was added in the sulfonation reaction, and the sulfonation reaction time was 3 hours. The content of the relevant components in the finished product obtained after the reaction is shown in Table 5.

(Embodiment 30)

The remainder is the same as in Example 21, except that: the difference is that the content of the material after the bromination reaction is analyzed by gas chromatography to determine the content of the o-bromofluorobenzene is 2.4%, and the sulfonation reaction is added as a sulfonating agent. The 20% fuming sulfuric acid 3⁄4 180 g, the sulfonation reaction temperature was controlled to 55 ± 2 Ό, and the sulfonation reaction time was 2 hours. The content of the relevant components in the finished product obtained after the reaction is shown in Table 5.

(Example 31)

The rest is the same as in Example 21, except that: the difference is that the content of the material after the bromination reaction is analyzed by gas chromatography, and the content of the o-bromofluorobenzene is 2.3%, and the sulfonation reaction is added as a sulfonating agent. The 20% fuming sulfuric acid was 190 g, the sulfonation reaction temperature was controlled to 98 ± 2 ° C, and the sulfonation reaction time was 2 hours. The content of the relevant components in the finished product obtained after the reaction is shown in Table 5.

table 5 Implementation of oxybromofluorenyl acetophenone (mass ratio)

Example No. Quality Before sulfonation After sulfonation (mass ratio)

29 22±2°C 200g 3 hours 2.2% 0.18% 98.5%

30 55±2°C 180g 2 hours 2.4% 0.03% 98.6%

31 98±2°C 190g 2 hours 2.3% 0.04% 98.8%

(Embodiment 32)

The rest was the same as in Example 21 except that 30 g of sulfur trioxide was added as a sulfonating agent in the sulfonation reaction, and the sulfonation reaction time was 5 hours. The content of the relevant components in the finished product obtained after the reaction is shown in Table 6.

(Example 33)

The rest is the same as in Example 32, except that: The sample after the bromination reaction is subjected to gas chromatography to determine that the content of o-bromofluorobenzene is 2.1%, and the sulfonation reaction temperature is controlled to 55 ± 2 ° C, sulfonation. The reaction time was 4 hours. The content of the relevant components in the finished product obtained after the reaction is shown in Table 6.

(Embodiment 34)

The rest is the same as in Example 32, except that: the sample after the bromination reaction is sampled by gas chromatography, and the content of the o-bromofluorobenzene is 2.0%, and the sulfonation reaction temperature is controlled to 80±2'C. The reaction time was 3.5 hours. The content of the relevant components in the finished product obtained after the reaction is shown in Table 6.

, (Embodiment 35)

The rest was the same as in Example 32 except that the sulfonation reaction temperature was controlled to 98 ± 2 ° C and the reaction time was 2 hours. The content of the relevant components in the finished product obtained after the reaction is shown in Table 6.

Table 6

In the methods of Examples 21 to 35, the bromination reaction is a bromination reaction in which a reaction phase is initiated, and the material after the bromination reaction is subjected to a post-treatment of sequentially removing o-bromofluorobenzene and hydrogen chloride; After the finished products obtained in Examples 2i to 35 can be directly used according to different use requirements or the related impurities are removed and used. (Example 36)

The process for preparing p-bromofluorobenzene in this embodiment is a manufacturing process in industrial large-scale production, including a bromination reaction process and a sulfonation reaction of a material after bromination to remove o-bromofluorobenzene, followed by washing with a base and then washing with water. The post-treatment process for removing hydrogen chloride and finally using rectification to remove p-chlorofluorobenzene is as follows: In a 2000 liter reactor equipped with a electric stirrer, a thermometer, a bromine high-position tank, a chlorine tube, and a tail gas absorption tower. , put 1500 kg of fluorobenzene, add 10 kg of ferric chloride, 40 kg of bromine (ie, industrial liquid bromine, containing 99.8 % liquid bromine), and start the reaction of the bromination reaction in the reactor , control the reaction temperature is 10 ° C to 20 ° C, stirring for 15 minutes; then in a ratio of bromine: chlorine molar ratio of 1:1 in 30 hours, adding 2255 kg of bromine through the addition of bromine high tank, while 555 kg of chlorine gas is introduced, and the bromination reaction becomes a bromination reaction under the participation of chlorine gas; after the chlorine gas and liquid bromine are completely added, the reaction is terminated, and the material after the bromination reaction is obtained, and the reaction is maintained. Mix. Then, the brominated material is first subjected to sulfonation treatment, that is, 90 kg of chlorosulfonic acid is added to the mixture obtained by the reaction under stirring, and the sulfonation reaction temperature is controlled to 2 (TC, and the reaction is terminated after 4 hours; The material after the sulfonation reaction is subjected to an alkali washing treatment, that is, the material after the sulfonation reaction is neutralized with a 5% sodium carbonate aqueous solution under stirring until the pH value is 7. The material is sent to the liquid night two phases. Separating device, after standing layering, separating the organic phase solution and transferring to another liquid-phase two-phase separation device; and then separating the separated organic phase by water washing, that is, adding the water to the separated organic phase solution, stirring After the layer, the organic phase solution was separated, and the crude p-fluorobromobenzene was obtained, and the weight was 2,650 kg. Then, the content of p-bromofluorobenzene was 98.5 %. The crude bromofluorobenzene obtained by the following steps is rectified: 1 The structure of the batch rectification column is shown in Figure 3. 2650 kg of crude p-bromofluorobenzene is added to the evaporator in the rectification column; The temperature of the generator is 160 Ό to 180 Ό, and the temperature at the top of the column is 130 Ό to 156 Ό. 3 During the rectification process, the rectification of p-bromofluorobenzene is carried out by controlling the reflux ratio and collecting the corresponding weight fraction. The initial reflux ratio is 20:1. At this point, the sputum is collected in the 1 # receiver, which is called the No. 1 fraction. After collecting 100 kg, the sample is analyzed by gas chromatography to obtain a p-chlorofluorobenzene content of about 10%. Then, the reflux ratio is controlled to 15:1. The fraction was collected in a 2# receiver, which was called No. 2, and after collecting 160 kg, the sample was analyzed by gas chromatography to obtain a p-chlorofluorobenzene content of about 3%. Finally, the reflux ratio was controlled to 1: 10, and the fraction was collected. 3%的提取分中。 The 3# receiver, referred to as the No. 3 fraction, the sample was analyzed by gas chromatography to obtain a content of p-bromofluorobenzene of about 99.9%, the content of p-chlorofluorobenzene was reduced to 0.03%; The finished product of p-bromofluorobenzene has a mass of 2253 kg; 4 the bottom substrate retained in the evaporator is p-bromofluorobenzene enriched with high-boiling impurities, and the mass is 106 kg.

In addition, the fractions retained in the evaporator, that is, the bottoms, the No. 1 fraction, and the No. 2 fraction are collected, and when they are accumulated to a certain amount, they are separately subjected to rectification, and high-purity p-bromofluorobenzene can also be obtained. .

3⁄4 sampling and analysis of the finished product of bromide fluorobenzene obtained in the present example, the gas chromatogram shown in FIG. 4 is obtained, The image data are shown in Table 7, and the substances corresponding to the respective peak names in Table 7 were identified by infrared spectroscopy. The instrument and analysis conditions used are as follows - the instrument model is: GC9790 gas chromatograph manufactured by Zhejiang Wenling Fuli Analytical Instrument Co., Ltd.; the column type is 0V 1701, diameter is 0.35 mm, length is 30 m. Chromatographic conditions were column temperature 130 ° C, vaporization chamber 25 (TC, detector 250 ° C. The detector model was hydrogen flame ionization detector FID; the injector was split; column pressure: 0. IMPa; Sample size: 0. 2 microliters.

Table 7

(Example 37)

The rest is the same as that of the embodiment 36, except that: after the alkali-washing treatment of the material after the sulfonation reaction, the water-washing treatment is not carried out, and the organic phase solution obtained after the alkali washing is directly subjected to rectification, after the distillation. 02%。 The content of p-bromofluorobenzene is 99.9%, the content of p-chlorofluorobenzene is 0.02%.

(Example 38)

The rest is the same as that of the embodiment 36, except that the material after the sulfonation reaction is no longer subjected to alkali washing, but the material after the sulfonation reaction is directly washed with water, and the organic phase obtained after washing is directly carried out. After the rectification, the content of p-bromofluorobenzene is obtained, wherein the content of p-bromofluorobenzene is 99.9%, and the content of p-chlorofluorobenzene is 0.015%.

In the methods of Examples 36 to 38, the bromination reaction is a bromination reaction in the initiation reaction stage, and the bromination reaction is carried out by sequentially removing o-bromofluorobenzene, hydrogen chloride and p-chlorofluorobenzene. Post-processing; After purchasing the finished products obtained in Examples 36 to 38, the user can directly use them according to the use requirements. The above examples can prove that the method of the present invention is practical and has excellent effects; at the same time, it can be understood that since the control conditions are different in the actual reaction, the products obtained by the reaction and some of the entire manufacturing process are some Variations in the details of the process steps are possible without departing from the scope and spirit of the invention. Further, the data on the percentage of the relevant components in the materials mentioned in the section of the embodiment of the present invention, if no specific measurement method is mentioned, are analyzed by gas chromatography. Industrial applicability

The invention can be used in large-scale industrial production, and the finished product can be used to prepare a finished p-bromofluorobenzene product having a weight percentage of p-bromofluorobenzene of more than 99.9%.

Claims

Rights request

1. A method for preparing p-bromofluorobenzene, wherein bromination reaction is carried out by using a liquid fluorobenzene and elemental bromine as a reactant under the action of a catalyst to form p-bromofluorobenzene and hydrogen bromide; wherein: Chlorine gas is introduced, chlorine gas reacts with hydrogen bromide to form an oxidation product of hydrogen chloride and hydrogen bromide, and the oxidation product of hydrogen bromide continues to bromine the fluorobenzene to form p-bromofluorobenzene, thereby causing the bromine to be carried out. The bromination reaction is carried out under the participation of chlorine gas; after the bromination reaction is completed, the obtained material is directly used as a finished product or the obtained material is post-treated to obtain a finished product.

The mass ratio of the fluorobenzene to the catalyst is 500: 0.5. The mass ratio of the fluorobenzene to the catalyst is 500: 0.5. ~3; The reaction temperature of the bromination reaction is from 0 Ό to 40 Ό, and the system of the bromination reaction is open to the atmosphere.

The method for preparing p-bromofluorobenzene according to claim 2, wherein the catalyst is powdered iron tribromide or powdered ferric chloride, and the liquid fluorobenzene and the catalyst are used in the bromination reaction. Adding to the reactor connected to the atmosphere, adding liquid bromine to the reactor under stirring, while introducing chlorine gas under the liquid level of the material until the bromination reaction is complete; the main products of the reaction are p-bromofluorobenzene and hydrogen chloride, The products are o-bromofluorobenzene and p-chlorofluorobenzene.

The method for preparing p-bromofluorobenzene according to claim 3, wherein the reactor for bromination is a reactor equipped with a stirrer, a thermometer, a bromine tube, a vent tube and a reflux condenser, and the reaction The liquid is passed through the reflux condenser to the atmosphere; the liquid bromine is added to the reactor material through the bromine tube, and the outlet of the bromine tube is located below the liquid level of the material or on the inner wall of the reactor above the liquid level of the material. Chlorine gas is added to the reactor material through a vent pipe, and the outlet of the vent pipe is located below the liquid level of the material; in the bromination reaction, the liquid bromine and chlorine gas are added in a molar ratio of 1 by adjusting the rate of addition of liquid bromine and chlorine gas. 03~1. The amount of 06:1 is added to the material; the amount of chlorine added in the bromination reaction is the theoretical amount.

The method for preparing p-bromofluorobenzene according to claim 2, wherein the catalyst is iron powder or powdered iron tribromide or powdered ferric chloride, and the liquid fluorine is used in the bromination reaction. The benzene and the catalyst are added to the reactor connected to the atmosphere, and liquid bromine is added to the reactor under stirring. After the bromination reaction is initiated, chlorine gas is introduced under the liquid surface of the material until the bromination reaction is complete; The product is p-bromofluorobenzene and hydrogen chloride, and the by-products are o-bromofluorobenzene and p-chlorofluorobenzene.

6. The method for preparing p-bromofluorobenzene according to claim 5, wherein: the reactor for bromination is a reactor equipped with a stirrer, a thermometer, a bromine tube, a vent tube and a reflux condenser, the reactor Passing through the reflux condenser and the atmosphere; the reactant liquid bromine is added to the reactor material through the bromine tube, and the outlet of the bromine tube is located below the liquid level of the material or at the inner wall of the reactor above the liquid level of the material The chlorine gas is added to the reactor material through a vent pipe, and the outlet of the vent pipe is located below the liquid level of the material; For a period of 5 to 15 minutes, the amount of liquid bromine added is 3% to 6 ° of the theoretical amount, so that the liquid bromine is excessive in the entire bromination reaction; in the stage of introducing chlorine into the bromination reaction, The addition rate of liquid bromine and chlorine gas was adjusted so that liquid bromine and chlorine gas were added to the material in a molar ratio of 1:1, and the chlorine gas was added in a theoretical amount.

7. The method for preparing p-bromofluorobenzene according to claim 1, wherein: the post-treatment of the material after the bromination reaction is performed by washing the substrate with water, causing alkali washing, or washing with alkali and then washing the water. The hydrogen chloride is removed by first washing the material after the bromination reaction, then separating and separating the organic phase to obtain a finished product, or first adding an aqueous solution of the inorganic alkali to the material after the bromination reaction. And the organic phase obtained by liquid separation and liquid separation after the reaction is the finished product, or the aqueous solution of the inorganic alkali is first added to the material after the bromination reaction to carry out the neutralization reaction, and then the liquid is obtained by liquid separation and liquid separation. After the phase is washed with water, the liquid phase is again separated, and the organic phase obtained by the liquid separation is the finished product.

8. The method for preparing p-bromofluorobenzene according to claim 1, wherein: the post-treatment of the material after the bromination reaction is carried out by sequentially removing hydrogen chloride and p-chlorofluorobenzene in the material, wherein The removal of hydrogen chloride is achieved by washing with water, caustic washing, or washing with alkali and then washing with water. The removal of p-chlorofluorobenzene in the material is achieved by rectification; the method is: first washing the material after bromination After liquid separation, the organic phase obtained by liquid separation is rectified and refined to obtain a finished product, or an aqueous solution of an inorganic alkali is first added to the material after the bromination reaction for neutralization reaction, and then liquid separation is carried out. Then, the organic phase obtained by liquid separation is subjected to rectification and rectification to obtain a finished product, or an aqueous solution of an inorganic alkali is first added to the material after the bromination reaction for neutralization reaction, and then liquid separation and re-division The organic phase obtained by the liquid is washed with water, and then liquid-separated, and the organic phase obtained by re-separation is subjected to rectification and purification to obtain a finished product.

9. The method for preparing p-bromofluorobenzene according to claim 1, wherein: the post-treatment of the material after the bromination reaction is performed by sulfonating the o-bromofluorobenzene in the material, and the method is removed. Yes: The temperature of the material after the bromination reaction is controlled within the range of 2CTC to 10CTC. The sulfonating agent is added to the material under stirring, and stirring is continued for 2 to 5 hours to complete the sulfonation reaction. The material obtained after the reaction is Finished product.

10. The method for preparing p-bromofluorobenzene according to claim 1, wherein: the post-treatment of the material after the bromination reaction is carried out by sequentially removing o-bromofluorobenzene and hydrogen chloride in the material; The removal of o-bromofluorobenzene in the middle is achieved by a sulfonation reaction, and the removal of hydrogen chloride in the material is achieved by washing with water, causing alkali washing, or washing with alkali washing, and removing the chlorofluorobenzene in the material. Rectification is carried out; the method is: firstly, the temperature of the material after the bromination reaction is controlled within a range of 20 ° C to 100 ° C, and a sulfonating agent is added to the material under stirring, and stirring is continued for 2 to 5 hours. The organic phase obtained by sulfonation reaction is complete, and then the material is hydrolyzed and then separated and separated, or the organic phase obtained by liquid separation is the finished product, or the temperature of the material after the bromination reaction is controlled within the range of 20 ° C to 100 Torr under stirring. Adding a sulfonating agent to the material, stirring for 2 to 5 hours to complete the sulfonation reaction, and adding an aqueous solution of the inorganic base to the material. After the neutralization reaction in the feed, the organic phase obtained by liquid separation and liquid separation is the finished product, or the temperature of the material after the bromination is controlled within the range of 20 ° C to 100 ° C, and the material is stirred under the condition. The sulfonating agent is added, stirring is continued for 2 to 5 hours to complete the sulfonation reaction, and an aqueous solution of the inorganic base is added to the material to carry out the neutralization reaction, and then the liquid phase is separated, and the organic phase obtained by the liquid separation is washed again. The organic phase obtained by liquid separation and the liquid separation is completed.

Ά

11. The method for preparing p-bromofluorobenzene according to claim 1, wherein: the post-treatment of the material after the bromination reaction is carried out by sequentially removing o-bromofluorobenzene, hydrogen chloride and p-chlorofluorobenzene from the material. , wherein the removal of o-bromofluorobenzene in the material is achieved by a sulfonation reaction, and the removal of hydrogen chloride in the material is achieved by washing with water, causing alkali washing, or washing with alkali washing, by: first bromine The temperature of the material after the reaction is controlled in the range of 2 CTC to 100 ° C, the sulfonating agent is added to the material under stirring, stirring is continued for 2 to 5 hours to complete the sulfonation reaction, and then the material is washed with water and then separated. Then, the organic phase obtained by liquid separation is refined and refined to obtain the finished product, or the temperature of the material after the bromination reaction is controlled within the range of 20 ° C to 10 CTC, and the material is added under stirring. The sulfonating agent is stirred for 2 to 5 hours to complete the sulfonation reaction, and the aqueous solution of the inorganic base is added to the material for neutralization reaction, and then the liquid phase is separated, and the organic phase obtained by the liquid separation is refined and refined. After that, the finished product can be obtained, or the temperature of the brominated reaction material is controlled within the range of 20 Torr to 1 CXTC, and the sulfonating agent is added to the material under stirring, and stirring is continued for 2 to 5 hours to complete the sulfonation reaction. The aqueous solution of the inorganic base is added to the material to carry out the neutralization reaction, and then the liquid phase is separated, and the organic phase obtained by the liquid separation is washed with water, and then the liquid phase is separated again, and the organic phase obtained by the liquid separation is rectified and refined. You can get the finished product.

The method for producing p-bromofluorobenzene according to claim 7, 8, 10 or 11, characterized in that: the aqueous solution of the base used for the neutralization reaction is 3% to 5% aqueous sodium carbonate solution, or 10% to 30% The aqueous sodium hydroxide solution is subjected to a neutralization reaction until the pH of the material in the reactor is 6 to 7.

The method for preparing p-bromofluorobenzene according to claim 8 or 11, characterized in that the rectification is atmospheric distillation or vacuum distillation, and the number of theoretical plates is 10 to 30; when atmospheric distillation is employed The evaporator temperature is 160 ° C to 180 ° C, the temperature at the top of the column is 130 Ό to 156 ° C, and the reflux ratio is 1 to 20:1.

The method for preparing p-bromofluorobenzene according to any one of claims 9 to 11, wherein the sulfonating agent is sulfur trioxide, chlorosulfonic acid or fuming sulfuric acid, and the temperature during the sulfonation reaction is controlled at 4 CTC to 90Ό.