A method for continuously preparing 4-chlorobenzenesulfonyl chloride

Abstract

The application discloses a method for continuously preparing 4-chlorobenzenesulfonyl chloride, and the 4-chlorobenzenesulfonyl chloride is prepared through a continuous equipment, and the specific steps are as follows: step one, 4-chlorobenzenesulfonic acid is dissolved in halogenated hydrocarbon to prepare a 4-chlorobenzenesulfonic acid solution for standby; step two, the 4-chlorobenzenesulfonic acid solution and chlorosulfonic acid with a mass concentration of 99% are mixed in a mixing pump; step three, the 4-chlorobenzenesulfonyl chloride is prepared through temperature control and stirring reaction of the mixed solution in an n-stage continuous reaction equipment. The application has the following beneficial effects: through directional selection of halogenated hydrocarbon as chloroform, and through the continuous reaction device, the conversion rate of chlorosulfonic acid in the application reaches more than 92% compared with the selection of other halogenated hydrocarbons, and the molar yield of the 4-chlorobenzenesulfonyl chloride product can reach more than 82%.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of organic synthesis, in particular to a method for continuously preparing 4-chlorobenzenesulfonyl chloride. BACKGROUND

[0002] 4-chlorobenzenesulfonyl chloride is p-chlorobenzenesulfonyl chloride, which is an important organic synthesis intermediate and is widely used in dye, pharmaceutical and other industries. It is also an important raw material for manufacturing engineering plastics such as polysulfone and polyether sulfone. 4-chlorobenzenesulfonic acid is a white prismatic crystal at room temperature, has a pungent odor, is insoluble in water, and soluble in ethanol.

[0003] At present, the industrial production of 4-chlorobenzenesulfonyl chloride is mostly carried out in a batch mode. The production process involves more human participation, and each batch of reaction needs repeated feeding, reaction and discharging, which is prone to errors in operation and cannot be well controlled, resulting in high production cost.

[0004] In summary, the existing batch production method has the following defects:

[0005] 1) The efficiency is low due to manual feeding during production;

[0006] 2) Low yield;

[0007] 3) In addition, the selection of solvents and the setting of process conditions also affect the yield of the final product.

[0008] Therefore, there is an urgent need to provide a method for continuously preparing 4-chlorobenzenesulfonyl chloride to solve the above problems. SUMMARY

[0009] The technical problem to be solved by the present application is:

[0010] A method for continuously preparing 4-chlorobenzenesulfonyl chloride is developed, which has the characteristics of efficiency improvement and high yield.

[0011] The purpose of the present application is to solve the problems existing in the prior art and provide a method for continuously preparing 4-chlorobenzenesulfonic acid.

[0012] In order to achieve the above purpose, the following technical scheme is adopted in the present application:

[0013] A method for continuously preparing 4-chlorobenzenesulfonyl chloride, which comprises the following steps:

[0014] Step one

[0015] Dissolve 4-chlorobenzenesulfonic acid in halogenated hydrocarbon to prepare a 4-chlorobenzenesulfonic acid solution for use;

[0016] Step two

[0017] 4-chlorobenzenesulfonic acid solution and chlorosulfonic acid with mass concentration of 99% are mixed in a mixing pump;

[0018] Step three

[0019] 4-chlorobenzenesulfonoyl chloride is prepared by temperature control and stirring reaction of the mixed solution in an n-stage continuous reaction device.

[0020] As a further improvement of the present solution,

[0021] The continuous reaction device comprises a mixing pump, a circulating pump, a residence kettle and a discharge pump arranged in sequence;

[0022] The chlorosulfonic acid is respectively delivered to the mixing pump and the chlorination residence kettle one through pipelines;

[0023] The 4-chlorobenzenesulfonic acid solution is respectively delivered to the mixing pump and the chlorination residence kettle one through pipelines;

[0024] The mixing pump is provided with a pipeline communicating with the chlorination residence kettle one;

[0025] The circulating pump is provided with a pipeline returning to the mixing pump;

[0026] The bottom of the chlorination residence kettle one is provided with a pipeline returning to the circulating pump;

[0027] The chlorination residence kettle further comprises a plurality of kettle bodies connected in series, and the kettle body at the end communicates with the discharge pump.

[0028] As a further improvement of the present solution,

[0029] The residence kettle further comprises at least a chlorination residence kettle one, a chlorination residence kettle two, a chlorination residence kettle three and a chlorination residence kettle four;

[0030] Further, a stirring paddle is arranged in the sulfonation residence kettle.

[0031] As a further improvement of the present solution, the step 3 further comprises:

[0032] S31 the mixed solution mixed from the mixing pump flows into the chlorination residence kettle one from the top inlet of the chlorination residence kettle one for stirring reaction;

[0033] S32 the reaction liquid in the chlorination residence kettle one is divided into two routes, one of which is returned to the mixing pump through the circulating pump for repeated chlorination reaction, and the other is continuously fed from the second-stage chlorination residence kettle two through the chlorination residence kettle three and the chlorination residence kettle four;

[0034] S33 the reaction liquid in the chlorination residence kettle four is pumped out through the discharge pump, and then recrystallized with an aqueous solvent, centrifuged and dried to prepare 4-chlorobenzenesulfonoyl chloride product.

[0035] The reaction temperature is controlled at 45-50, and the total residence time of the mixed reaction liquid in the mixed pump and the chlorination residence kettle connected in series is 4h.

[0036] As a further improvement of the present solution, the mass ratio of the 4-chlorobenzenesulfonic acid, the halogenated hydrocarbon and the chlorosulfonic acid is 1:0-5:0.7-1.7.

[0037] As a further improvement of the present solution, the mass ratio of the 4-chlorobenzenesulfonic acid, the halogenated hydrocarbon and the chlorosulfonic acid is 1:3:1.5.

[0038] As a further improvement of the present solution, the dissolving agent used in the crystallization is a halogenated hydrocarbon.

[0039] As a further improvement of the present solution, the n is an integer of 2-8.

[0040] As a further improvement of the present solution, the n is an integer of 2-4.

[0041] Compared with the prior art, the present solution has the following beneficial effects:

[0042] 1) The method of the present solution can realize the continuous industrial production of 4-chlorobenzenesulfonic acid, and the 4-chlorobenzenesulfonic acid solution and the chlorosulfonic acid are firstly flowed into the mixed pump for forced mixing reaction, thereby accelerating the reaction speed;

[0043] 2) Furthermore, the reaction liquid flowed out from the mixed pump is again flowed into the n-stage sulfonation residence kettle connected in series for stirring, and the reaction liquid in the first-stage chlorination residence kettle is partially refluxed into the mixed pump for continuous reaction, and this process has the following two advantages, 1, the setting of the n-stage chlorination residence kettle connected in series increases the reaction time, and makes the chlorination reaction more thorough; 2, the generated large amount of heat can be easily removed, thereby avoiding the overheating of the reaction temperature and improving the safety of the reaction;

[0044] 3) In the present solution, more control instruments are introduced and DCS control is adopted, thereby realizing the industrial production of 4-chlorobenzenesulfonyl chloride with industrial automation control, reducing the manual operation, and accurately controlling the raw material input ratio, the raw material input amount and the reaction time, and the industrial production process is safer and more reliable;

[0045] 4) In the present solution, the halogenated hydrocarbon is selected as trichloromethane, and through the continuous reaction device, the conversion rate of the chlorosulfonic acid can reach more than 92%, and the molar yield of the 4-chlorobenzenesulfonyl chloride product can reach more than 82%. BRIEF DESCRIPTION OF DRAWINGS

[0046] Figure 1The structural schematic diagram of the continuous device in the method for continuously preparing 4-chlorobenzenesulfonyl chloride according to the present application. DETAILED DESCRIPTION

[0047] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described below in combination with examples:

[0048] Example 1

[0049] The structural schematic diagram of the reaction device for continuously preparing 4-chlorobenzenesulfonyl chloride in this example 1 is shown in the figure. Figure 1 As can be seen from the figure, Figure 1 the reaction device comprises four-stage chlorination residence tanks 30, a mixing pump 10, a circulating pump 20 and a discharge pump 40 which are connected in series. The outlet of the mixing pump 10 is connected with the top inlet of the first chlorination residence tank 31 by a pipeline, the bottom outlet of the first chlorination residence tank 31 is connected with the inlet of the mixing pump 10 by a pipeline through the circulating pump 20, thereby forming a partial internal circulation of the reaction liquid;

[0050] the middle outlet of the first chlorination residence tank 31 is connected with the top inlet of the second chlorination residence tank 32 by a pipeline, the middle outlet of the second chlorination residence tank 32 is connected with the top inlet of the third chlorination residence tank 33 by a pipeline, and the middle outlet of the third chlorination residence tank 33 is connected with the top inlet of the fourth chlorination residence tank 34 by a pipeline, thereby forming four-stage chlorination residence tanks which are connected in series, and control valves are arranged on the corresponding pipelines;

[0051] 4-chlorobenzenesulfonic acid is dissolved in a halogenated hydrocarbon to prepare a 4-chlorobenzenesulfonic acid solution for standby use;

[0052] The 4-chlorobenzenesulfonic acid solution and chlorosulfonic acid with a mass concentration of 99% are transported into the mixing pump and mixed in the mixing pump, and then the mixed reaction liquid flows into the first chlorination residence tank 1 from the top inlet of the first chlorination residence tank 1 to perform stirring reaction. Meanwhile, the reaction liquid in the first chlorination residence tank 1 is divided into two routes, one of which is returned to the mixing pump through the circulating pump to perform repeated chlorination reaction, and the other of which is transported from the second chlorination residence tank 2 to the fourth chlorination residence tank in a continuous feeding mode. The reaction liquid in the fourth chlorination residence tank is pumped out through the discharge pump, and then subjected to water solvent recrystallization, centrifugation and drying to prepare 4-chlorobenzenesulfonyl chloride product.

[0053] 5- The temperature of the reaction is controlled at about 45-50℃, and the total residence time of the reaction liquid in the mixing pump and the four-stage chlorination residence tanks connected in series is about 4h.

[0054] When the reaction is substantially complete, the molar yield of 4-chlorobenzenesulfonyl chloride product can reach more than 82% by using the above production process. The quality index of the finally prepared 4-chlorobenzenesulfonyl chloride product is as follows: the mass fraction of 4-chlorobenzenesulfonyl chloride is ≥99%.

[0055] Example 2

[0056] The structure of the reaction device for continuous production of 4-chlorobenzenesulfonyl chloride in this example 2 is shown in the figure Figure 1 As can be seen from the figure, the reaction device comprises 4 stages of chlorination residence tanks, a mixing pump, a circulating pump and a discharge pump connected in series. Figure 1 The outlet of the mixing pump is connected to the top inlet of the first stage chlorination residence tank 1 by a pipeline, the bottom outlet of the first stage chlorination residence tank 1 is connected to the inlet of the mixing pump by a pipeline through the circulating pump, forming a partial internal circulation of the reaction liquid. The middle outlet of the first stage chlorination residence tank 1 is connected to the top inlet of the second stage chlorination residence tank 2 by a pipeline, the middle outlet of the second stage chlorination residence tank 2 is connected to the top inlet of the third stage chlorination residence tank 3 by a pipeline, and the middle outlet of the third stage chlorination residence tank 3 is connected to the top inlet of the fourth stage chlorination residence tank 4 by a pipeline, thereby forming 4 stages of chlorination residence tanks connected in series, and control valves are arranged on the corresponding pipelines.

[0057] 4-chlorobenzenesulfonic acid was dissolved in halogenated hydrocarbon to prepare a 4-chlorobenzenesulfonic acid solution for use;

[0058] The 4-chlorobenzenesulfonic acid solution and chlorosulfonic acid with a mass concentration of 99% were transported into the mixing pump and mixed after reaction, and then flowed into the first stage chlorination residence tank 1 from the top inlet of the first stage chlorination residence tank 1 for stirring reaction. At the same time, the reaction liquid in the first stage chlorination residence tank 1 flowed out in two ways, one of which returned to the mixing pump through the circulating pump for repeated chlorination reaction, and the other flowed from the second stage chlorination residence tank 2 to the fourth stage chlorination residence tank in a continuous feeding manner. The reaction liquid in the fourth stage chlorination residence tank was pumped out by the discharge pump and then recrystallized with an aqueous solvent, centrifuged and dried to obtain 4-chlorobenzenesulfonyl chloride product. The reaction temperature was controlled at about 45-50°C, and the total residence time of the reaction liquid in the mixing pump and the 4 stages of chlorination residence tanks connected in series was about 4h.

[0059] Using the above production process, the conversion rate of methylsulfonyl toluene was about 90%, and the molar yield of 4-chlorobenzenesulfonyl chloride product could reach about 82%.

[0060] Comparative Example 1

[0061] The example provides a preparation method of 4-chlorobenzenesulfonyl chloride, which is basically identical with the steps in the example 1, except that: the mixing pump and the circulating pump are not started; the 4-chlorobenzenesulfonic acid solution and the chlorosulfonic acid with a mass concentration of 99% flow into the first-stage chlorination residence kettle 1 from the top inlet of the first-stage chlorination residence kettle 1 for stirring reaction; and the reaction liquid in the first-stage chlorination residence kettle 1 flows to the fourth-stage chlorination residence kettle in a continuous feeding mode, and the reaction liquid in the fourth-stage chlorination residence kettle is pumped out through the discharge pump, and then is recrystallized by using water solvent, centrifuged and dried to obtain the 4-chlorobenzenesulfonic acid product; and the total residence time of the reaction liquid in the chlorination residence kettles connected in sequence is about 10 h.

[0062] By using the above production process, the conversion rate of the 4-chlorobenzenesulfonic acid is about 88%, and the molar yield of the 4-chlorobenzenesulfonyl chloride product can reach about 70%.

[0063] As can be seen from the reaction results of the comparative example 1 and the comparative example 1, the method of the present application can be used for continuous preparation of 4-chlorobenzenesulfonyl chloride, and good reaction effect can be obtained. Moreover, compared with the comparative example 1, the method of the example 1 obtains better reaction effect, and greatly shortens the reaction time, which may be because the mixing pump can effectively strengthen the chlorination reaction process when the reaction device of the example 1 is used for continuous preparation of 4-chlorobenzenesulfonyl chloride, and the residence time of the reaction liquid in the mixing pump is short, the reaction liquid after forced mixing by the mixing pump flows into the chlorination residence kettle, and the large amount of heat generated in the reaction can be easily removed, so that the reaction temperature is prevented from being overheated.

[0064] Comparative example 2:

[0065] The example provides a preparation method of 4-chlorobenzenesulfonyl chloride, which is basically identical with the steps in the example 2, except that: the trichloromethane is replaced by trichloroethane.

[0066] By using the above production process, the conversion rate of the 4-chlorobenzenesulfonic acid is about 88%, and the molar yield of the 4-chlorobenzenesulfonyl chloride product can reach about 70%.

[0067] The above only describes the preferred embodiments of the present application, and does not limit the patent scope of the present application, and any equivalent transformation made by using the present application is within the patent protection scope of the present application.

Claims

1. A process for the continuous production of 4-chlorobenzenesulfonyl chloride, characterized in that, The 4-chlorobenzenesulfonyl chloride is prepared by a continuous device, and the specific steps are as follows: Step one: 4-chlorobenzenesulfonic acid is dissolved in a halogenated hydrocarbon to prepare a 4-chlorobenzenesulfonic acid solution for use; Step two: the 4-chlorobenzenesulfonic acid solution and chlorosulfonic acid with a mass concentration of 99% are mixed in a mixing pump; Step three: the 4-chlorobenzenesulfonyl chloride is prepared by controlling the temperature and stirring the mixed solution in a four-stage continuous reaction device; The step 3 further comprises: S31: the mixed solution mixed in the mixing pump flows into the chlorination residence kettle one (31) from the top inlet of the chlorination residence kettle one (31) for stirring reaction; S32: the reaction solution in the chlorination residence kettle one (31) is divided into two routes, one of which is returned to the mixing pump through a circulating pump for repeated chlorination reaction, and the other is continuously fed into the second-stage chlorination residence kettle two (32) and then flows through the chlorination residence kettle three (33) and the chlorination residence kettle four (34) respectively; S33: the reaction solution in the chlorination residence kettle four (34) is pumped out through a discharge pump and then subjected to solvent recrystallization, centrifugation and drying to prepare the 4-chlorobenzenesulfonyl chloride product; The reaction temperature is controlled at 45-50℃, and the total residence time of the mixed reaction solution in the mixing pump and the four-stage chlorination residence kettles in series is 4h; The mass ratio of the 4-chlorobenzenesulfonic acid, the halogenated hydrocarbon and the chlorosulfonic acid is 1:3:1.5; The halogenated hydrocarbon is chloroform; The continuous reaction device comprises a mixing pump (10), a circulating pump (20), chlorination residence kettles (30) and a discharge pump (40) arranged in series; The chlorosulfonic acid is delivered to the mixing pump (10) and the chlorination residence kettle one (31) through pipelines respectively; The 4-chlorobenzenesulfonic acid solution is delivered to the mixing pump (10) and the chlorination residence kettle one (31) through pipelines respectively; The mixing pump is provided with a pipeline connected to the chlorination residence kettle one (31); The circulating pump (20) is provided with a pipeline returning to the mixing pump; The bottom of the chlorination residence kettle one (31) is provided with a pipeline returning to the circulating pump (20); The chlorination residence kettles (30) further comprise a plurality of kettle bodies connected in series, and the last kettle body is connected to the discharge pump (40); The chlorination residence kettles (30) further comprise the chlorination residence kettle one (31), the chlorination residence kettle two (32), the chlorination residence kettle three (33) and the chlorination residence kettle four (34); The chlorination residence kettles (30) are provided with stirring paddles.

2. The process for the continuous preparation of 4-chlorobenzenesulfonyl chloride according to claim 1, characterized in that, The dissolving agent for crystallization is any one or more of halogenated hydrocarbons and water.

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