Preparation method of peptizer DBD

Abstract

The invention provides a preparation method of a peptizer DBD, and belongs to the technical field of synthesis. The preparation method of the peptizer provided by the invention comprises the following steps: mixing benzothiazole with alkali liquor, and then carrying out ring-opening reaction in a micro-flow field reactor to obtain a solution containing o-amino thiophenol salt; mixing the solution containing o-amino thiophenol salt, a solvent and an oxidizing agent, and then carrying out oxidation reaction in a micro-flow field reactor to obtain a solution containing 2, 2 '-diphenylamine disulfide; and mixing the solution containing 2, 2 '-diphenylamine disulfide with benzoyl chloride, and then carrying out acylation reaction in a micro-flow field reactor to obtain the peptizer DBD. By means of the confinement reaction characteristics of the micro-flow field reactor and the micro-reaction environment with efficient mass transfer and efficient heat transfer, the uniform temperature and material concentration environment can be guaranteed, the reaction is more complete, the reaction time is shortened, and the quality stability of the peptizer DBD is guaranteed.

Description

Technical Field

[0001] The invention belongs to the field of synthesis technology, and particularly relates to a method for preparing a peptizer DBD. Background Art

[0002] 2,2'-Dibenzamidodiphenyl disulfide, also known as peptizer DBD, is an important chemical substance widely used as a peptizer in the rubber industry.

[0003] At present, 2,2'-dibenzamido diphenyl disulfide is mainly prepared by batch reaction, that is, using benzothiazole as raw material in a reactor, and undergoing ring-opening reaction, oxidation reaction and acylation reaction to prepare it. However, the batch reaction is time-consuming, and the entire reaction process takes more than ten hours, and the product quality is unstable. Therefore, how to improve the preparation method so as to prepare 2,2'-dibenzamido diphenyl disulfide in a short time has become a technical problem that needs to be solved in this field. Summary of the invention

[0004] The purpose of the present invention is to provide a preparation method of a peptizer DBD. The preparation method provided by the present invention can significantly shorten the reaction time.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The present invention provides a method for preparing a peptizer DBD, comprising the following steps:

[0007] (1) mixing benzothiazole with an alkali solution, and then performing a ring-opening reaction in a microfluidic field reactor to obtain a solution containing o-aminobenzenethiophenol salt;

[0008] (2) mixing the solution containing o-aminobenzenethiophenol salt obtained in step (1), a solvent and an oxidant, and then performing an oxidation reaction in a microfluidic reactor to obtain a solution containing 2,2'-diphenylamine disulfide;

[0009] (3) The solution containing 2,2'-diphenylamine disulfide obtained in step (2) is mixed with benzoyl chloride, and then an acylation reaction is carried out in a microfluidic field reactor to obtain a peptizer DBD.

[0010] Preferably, in step (1), the molar ratio of benzothiazole to the alkali in the alkali solution is 1:(2-5).

[0011] Preferably, the feeding rate of the solution obtained by mixing benzothiazole and alkali solution in the microfluidic field reactor in step (1) is 1 to 200 mL / min.

[0012] Preferably, the temperature of the ring-opening reaction in step (1) is 100 to 180° C., and the time of the ring-opening reaction is 15 to 20 minutes.

[0013] Preferably, the mixture of the solution containing o-aminothiophenol salt, the solvent and the oxidant in step (2) is:

[0014] mixing a solution containing o-aminobenzenethiophenol salt and a solvent to obtain a mixed phase;

[0015] The mixed phase and an oxidizing agent are mixed.

[0016] Preferably, the feed rates of the mixed phase and the oxidant are independently 1 to 200 mL / min.

[0017] Preferably, the temperature of the oxidation reaction in step (2) is 30 to 50° C., and the time of the oxidation reaction is 1 to 5 minutes.

[0018] Preferably, the feeding rate of the solution containing 2,2'-diphenylamine disulfide in step (3) is 1 to 200 mL / min.

[0019] Preferably, the feeding rate of benzoyl chloride in step (3) is 1 to 200 mL / min.

[0020] Preferably, the temperature of the acylation reaction in step (3) is 20 to 80° C., and the time of the acylation reaction is 1 to 10 min.

[0021] The present invention provides a preparation method of a peptizer DBD, comprising the following steps: mixing benzothiazole with an alkali solution, and then performing a ring-opening reaction in a microfluidic reactor to obtain a solution containing o-aminobenzenethiophenol salt; mixing the solution containing o-aminobenzenethiophenol salt, a solvent and an oxidant, and then performing an oxidation reaction in a microfluidic reactor to obtain a solution containing 2,2'-diphenylamine disulfide; mixing the solution containing 2,2'-diphenylamine disulfide with benzoyl chloride, and then performing an acylation reaction in a microfluidic reactor to obtain a peptizer DBD. The present invention, by means of the confined reaction characteristics of the microfluidic reactor, its micro-reaction environment with efficient mass transfer and efficient heat transfer, helps to ensure a uniform temperature and material concentration environment, so that the ring-opening reaction, oxidation reaction and acylation reaction can react quickly and react more completely, thereby shortening the reaction time, and at the same time ensuring the quality stability of the peptizer DBD. Experimental results show that the total reaction time of the preparation method provided by the present invention is 30min. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of the ring-opening reaction in the microfluidic field reactor in Example 1;

[0023] Figure 2The HPLC spectrum of the solution containing 2,2'-diphenylamine disulfide prepared by the oxidation reaction in Example 1;

[0024] Figure 3 Schematic diagram of the oxidation reaction in the microfluidic reactor in Example 1;

[0025] Figure 4 Schematic diagram of the acylation reaction in the microfluidic reactor in Example 1;

[0026] Figure 5 This is the mass spectrum of the peptizer DBD prepared in Example 1. DETAILED DESCRIPTION

[0027] The present invention provides a method for preparing a peptizer DBD, comprising the following steps:

[0028] (1) mixing benzothiazole with an alkali solution, and then performing a ring-opening reaction in a microfluidic field reactor to obtain a solution containing o-aminobenzenethiophenol salt;

[0029] (2) mixing the solution containing o-aminobenzenethiophenol salt obtained in step (1), a solvent and an oxidant, and then performing an oxidation reaction in a microfluidic reactor to obtain a solution containing 2,2'-diphenylamine disulfide;

[0030] (3) The solution containing 2,2'-diphenylamine disulfide obtained in step (2) is mixed with benzoyl chloride, and then an acylation reaction is carried out in a microfluidic field reactor to obtain a peptizer DBD.

[0031] The present invention has no particular limitation on the sources of the raw materials, and commercially available products known to those skilled in the art may be used.

[0032] The invention mixes benzothiazole with alkali solution, and then performs a ring-opening reaction in a microfluidic field reactor to obtain a solution containing o-aminobenzenethiophenol salt.

[0033] In the present invention, the alkali solution is preferably a solution containing a strong base; the strong base is preferably sodium hydroxide and / or potassium hydroxide; the mass concentration of the alkali solution is preferably 30-50%.

[0034] As an embodiment, the mass concentration of the alkali solution may be 35%, 40% or 45%.

[0035] In the present invention, the molar ratio of the benzothiazole to the alkali in the alkali solution is preferably 1:(2-5). As an embodiment, the molar ratio of the benzothiazole to the alkali in the alkali solution may be 1:(3-4). The present invention limits the molar ratio of the benzothiazole to the alkali in the alkali solution to the above range to increase the degree of the ring-opening reaction, thereby increasing the yield.

[0036] The present invention has no special limitation on the operation of mixing the benzothiazole and the alkali solution, and the technical scheme for preparing the mixed material well known to those skilled in the art can be adopted.

[0037] The present invention has no particular limitation on the model of the microfluidic field reactor, and any instrument or equipment familiar to those skilled in the art may be used.

[0038] In the present invention, the feeding rate of the solution obtained by mixing benzothiazole and alkali solution in the microfluidic field reactor is preferably 1 to 200 mL / min. As an embodiment, the feeding rate of the solution obtained by mixing benzothiazole and alkali solution can be 50 mL / min, 60 mL / min, 65 mL / min, 70 mL / min, 72 mL / min, 75 mL / min, 80 mL / min, 90 mL / min, 100 mL / min, 120 mL / min, 150 mL / min, 160 mL / min, 180 mL / min or 190 mL / min.

[0039] In the present invention, the temperature of the ring-opening reaction is preferably 100 to 180°C; the time of the ring-opening reaction is preferably 15 to 20 minutes. As an embodiment, the temperature of the ring-opening reaction can be 120°C, 130°C, 140°C, 150°C, 160°C or 170°C; the time of the ring-opening reaction can be 16 minutes, 17 minutes, 18 minutes or 19 minutes. The present invention can further improve the degree of the ring-opening reaction by limiting the temperature and time of the ring-opening reaction within the above range, thereby improving the yield.

[0040] In the present invention, when the alkali solution is an aqueous solution of sodium hydroxide, the equation of the ring-opening reaction is as shown in Formula I:

[0041]

[0042] After obtaining the solution containing o-aminothiophenol salt, the present invention mixes the solution containing o-aminothiophenol salt, a solvent and an oxidant, and then performs an oxidation reaction in a microfluidic field reactor to obtain a solution containing 2,2'-diphenylamine disulfide.

[0043] In the present invention, the solvent is preferably an organic solvent, more preferably chloroform. The added solvent in the present invention can dissolve the solids obtained in the subsequent reaction, and avoid the solids precipitated in the subsequent oxidation reaction and acylation reaction from clogging the pipeline.

[0044] In the present invention, the mass ratio of the solvent to benzothiazole is preferably (3-10): 1. As an embodiment, the mass ratio of the solvent to benzothiazole may be 4:1, 5:1, 6:1, 7:1, 8:1 or 9:1.

[0045] In the present invention, the mass ratio of the o-aminothiophenol salt to the solvent is preferably 290:(300-500). As an embodiment, the mass ratio of the o-aminothiophenol salt to the solvent may be 290:(350-450), or 290:400.

[0046] In the present invention, the oxidant is preferably a mixed solution of sulfuric acid solution and hydrogen peroxide. In the present invention, hydrogen peroxide provides an oxidizing environment; sulfuric acid provides an acidic environment, which is conducive to the oxidation reaction of hydrogen peroxide.

[0047] In the present invention, the mass concentration of sulfuric acid in the oxidant is preferably 22 to 25%, more preferably 23.2 to 23.5%.

[0048] In the present invention, the mass concentration of hydrogen peroxide in the oxidant is preferably 8-10%, more preferably 8.15-8.3%.

[0049] In the present invention, the mixture of the solution containing o-aminothiophenol salt, the solvent and the oxidant is preferably:

[0050] mixing a solution containing o-aminobenzenethiophenol salt and a solvent to obtain a mixed phase;

[0051] The mixed phase and an oxidizing agent are mixed.

[0052] In the present invention, it is preferred to mix a solution containing o-aminobenzenethiophenol salt and a solvent to obtain a mixed phase.

[0053] The present invention has no special limitation on the operation of mixing the solution containing o-aminobenzenethiophenol salt and the solvent, and the technical scheme for preparing the mixed material well known to those skilled in the art can be adopted.

[0054] In the present invention, the feed rate of the mixed phase is preferably 1 to 200 mL / min. As an embodiment, the feed rate of the mixed phase can be 10 mL / min, 11.4 mL / min, 15 mL / min, 19 mL / min, 20 mL / min, 30 mL / min, 40 mL / min, 50 mL / min, 58.6 mL / min, 60 mL / min, 70 mL / min, 80 mL / min, 90 mL / min, 100 mL / min, 110 mL / min, 120 mL / min, 130 mL / min, 140 mL / min, 150 mL / min, 160 mL / min, 170 mL / min, 180 mL / min or 190 mL / min.

[0055] After obtaining the mixed phase, the present invention preferably mixes the mixed phase with an oxidant.

[0056] In the present invention, the feeding rate of the oxidant is preferably 1 to 200 mL / min. As an embodiment, the feeding rate of the oxidant can be 1 mL / min, 2.6 mL / min, 4.5 mL / min, 5 mL / min, 10 mL / min, 12.9 mL / min, 13.4 mL / min, 15 mL / min, 20 mL / min, 30 mL / min, 40 mL / min, 50 mL / min, 58.6 mL / min, 60 mL / min, 70 mL / min, 80 mL / min, 90 mL / min, 100 mL / min, 110 mL / min, 120 mL / min, 130 mL / min, 140 mL / min, 150 mL / min, 160 mL / min, 170 mL / min, 180 mL / min or 190 mL / min.

[0057] The present invention has no special limitation on the operation of mixing the mixed phase with the oxidant, and the technical scheme for preparing the mixed material well known to those skilled in the art can be adopted.

[0058] In the present invention, the microfluidic reactor is preferably a screw reactor. In the present invention, solid (product) will be generated when o-aminothiophenol salt and oxidant undergo oxidation reaction. Although the solid will slowly dissolve in the solvent, there is still a certain risk of clogging. By using a screw reactor, the stirring device thereof can avoid the risk of clogging.

[0059] The present invention has no particular limitation on the model of the screw reactor, and any equipment well known to those skilled in the art may be used.

[0060] In the present invention, the temperature of the oxidation reaction is preferably 30-50°C; the time of the oxidation reaction is preferably 1-5 minutes. As an embodiment, the temperature of the oxidation reaction can be 40-50°C; the time of the oxidation reaction can be 3-5 minutes. The present invention limits the temperature and time of the oxidation reaction within the above ranges to further improve the degree of the oxidation reaction, thereby improving the yield.

[0061] In the present invention, when the solvent is chloroform and the oxidant is a mixed solution of sulfuric acid solution and hydrogen peroxide, the oxidation reaction equation is as shown in Formula II:

[0062]

[0063] After obtaining the solution containing 2,2'-diphenylamine disulfide, the present invention mixes the solution containing 2,2'-diphenylamine disulfide with benzoyl chloride, and then performs an acylation reaction in a microfluidic field reactor to obtain a peptizer DBD.

[0064] In the present invention, the feeding rate of the solution containing 2,2'-diphenylamine disulfide is preferably 1 to 200 mL / min. As an embodiment, the feeding rate of the solution containing 2,2'-diphenylamine disulfide can be 10 mL / min, 11.4 mL / min, 15 mL / min, 20 mL / min, 30 mL / min, 40 mL / min, 50 mL / min, 60 mL / min, 70 mL / min, 80 mL / min, 90 mL / min, 100 mL / min, 110 mL / min, 120 mL / min, 130 mL / min, 140 mL / min, 150 mL / min, 160 mL / min, 170 mL / min, 180 mL / min or 190 mL / min.

[0065] In the present invention, the feeding rate of the benzoyl chloride is preferably 1 to 200 mL / min. As an embodiment, the feeding rate of the benzoyl chloride can be 2 mL / min, 2.6 mL / min, 5 mL / min, 10 mL / min, 20 mL / min, 30 mL / min, 40 mL / min, 50 mL / min, 60 mL / min, 70 mL / min, 80 mL / min, 90 mL / min, 100 mL / min, 110 mL / min, 120 mL / min, 130 mL / min, 140 mL / min, 150 mL / min, 160 mL / min, 170 mL / min, 180 mL / min or 190 mL / min.

[0066] The present invention has no special limitation on the operation of mixing the solution containing 2,2'-diphenylamine disulfide with benzoyl chloride, and the technical scheme for preparing the mixed material well known to those skilled in the art can be adopted.

[0067] In the present invention, the microfluidic field reactor is preferably a screw reactor. In the present invention, solid (product) will be generated during the acylation reaction. Although the solid will slowly dissolve, there is still a certain risk of clogging. The use of a screw reactor can avoid the risk of clogging with its stirring device.

[0068] The present invention has no particular limitation on the model of the screw reactor, and any equipment well known to those skilled in the art may be used.

[0069] In the present invention, the temperature of the acylation reaction is preferably 20 to 80°C; the time of the acylation reaction is preferably 1 to 10 minutes. As an embodiment, the temperature of the acylation reaction can be 30°C, 40°C, 50°C, 60°C or 70°C; the time of the acylation reaction can be 2 minutes, 3 minutes, 4 minutes, 5 minutes, 6 minutes, 7 minutes, 8 minutes or 9 minutes. In the present invention, limiting the temperature and time of the acylation reaction within the above range can improve the degree of the acylation reaction, thereby improving the yield.

[0070] After the acylation reaction is completed, the present invention preferably performs post-treatment on the product obtained by the acylation reaction to obtain a peptizer DBD.

[0071] In the present invention, the post-treatment preferably includes heating to remove the solvent, centrifugation, washing and drying in sequence.

[0072] The present invention has no particular limitation on the operations of heating to remove the solvent, centrifuging, washing and drying, and operations well known to those skilled in the art may be used.

[0073] In the present invention, the equation of the acylation reaction is shown in Formula III:

[0074]

[0075] The present invention utilizes the confined reaction characteristics of the microfluidic field reactor and its micro-reaction environment with efficient mass transfer and efficient heat transfer to help ensure a uniform temperature and material concentration environment, so that the ring-opening reaction, oxidation reaction and acylation reaction can react quickly and more completely, thereby shortening the reaction time, ensuring the quality stability of the peptizer DBD, and obtaining a peptizer DBD with high purity and high yield.

[0076] The existing intermittent reaction is time-consuming, and the entire reaction process requires more than ten hours. The preparation method provided by the present invention only takes about 30 minutes, saving time cost, energy consumption, and stable product quality.

[0077] The ring-opening reaction of the invention can completely react into a uniform phase, and the liquid phase normalization area is 92-99.5%; the oxidation reaction is fast and the temperature is low, and the reaction can be completely reacted at 30-50°C for 1-5 minutes, and the liquid phase normalization area is 94-99.8%; in the acylation reaction, solids are generated by mixing two phases, and the reaction with water can basically solve the problem of solid precipitation, and the reaction at 20-80°C for 1-10 minutes, the raw materials react completely, and the liquid phase normalization area reaches 96%.

[0078] The technical solutions in the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0079] Example 1

[0080] The preparation method of the peptizer DBD comprises the following steps:

[0081] (1) benzothiazole is mixed with an alkali solution, and then a ring-opening reaction is carried out in a microfluidic field reactor for 20 minutes to obtain a solution containing sodium o-aminobenzenethiophenol; wherein the alkali solution is a sodium hydroxide aqueous solution with a mass concentration of 32%; the molar ratio of benzothiazole to sodium hydroxide is 1:2; the feeding rate of the solution obtained by mixing benzothiazole and the alkali solution in the microfluidic field reactor is 72 mL / min; and the temperature of the ring-opening reaction is 160° C.;

[0082] (2) mechanically stirring the solution containing sodium o-aminothiophenol obtained in step (1) and chloroform to obtain a mixed phase, mixing it with an oxidant, and then performing an oxidation reaction in a microfluidic reactor for 5 minutes to obtain a solution containing 2,2'-diphenylamine disulfide; wherein the mass ratio of chloroform to benzothiazole is 5:1 ， The mass ratio of sodium o-aminobenzenethiophenol to chloroform is 290:300; the oxidant is a mixed solution of sulfuric acid solution and hydrogen peroxide; the mass concentration of sulfuric acid in the oxidant is 23.5%, and the mass concentration of hydrogen peroxide is 8.3%; the feed rate of the mixed phase is 11.4 mL / min; the feed rate of the oxidant is 2.6 mL / min; the microfluidic field reactor is a screw reactor; the temperature of the oxidation reaction is 50°C;

[0083] (3) The solution containing 2,2'-diphenylamine disulfide obtained in step (2) is mixed with benzoyl chloride, and then an acylation reaction is carried out in a microfluidic reactor for 5 minutes, and then the material is transported to an autoclave container, heated to 80° C. for desolventizing, and the chloroform solvent is recovered, and then centrifuged, washed and dried in sequence to obtain a peptizer DBD; wherein the feed rate of the solution containing 2,2'-diphenylamine disulfide is 11.4 mL / min; the feed rate of benzoyl chloride is 2.6 mL / min; the microfluidic reactor is a screw reactor; and the temperature of the acylation reaction is 60° C.

[0084] The yield of the peptizer DBD in Example 1 is 95.2%, and the detected melting point is 138.5°C.

[0085] The schematic diagram of the ring-opening reaction in the microfluidic reactor in Example 1 is as follows Figure 1 shown.

[0086] from Figure 1 It can be seen that benzothiazole undergoes a ring-opening reaction in the microfluidic reactor after being mixed with alkali solution.

[0087] The HPLC spectrum of the solution containing 2,2'-diphenylamine disulfide prepared by the oxidation reaction in Example 1 is as follows: Figure 2 shown.

[0088] from Figure 2 At the same time, combined with the signal data, it can be seen that the peak position of 2,2'-diphenylamine disulfide is 10.952 min, and the liquid phase normalized yield is 99.23%.

[0089] The schematic diagram of the oxidation reaction in the microfluidic reactor in Example 1 is as follows Figure 3 shown.

[0090] from Figure 3 It can be seen that the mixed phase obtained by the solution containing sodium o-aminobenzenethiol and chloroform is mixed with the oxidant, and then an oxidation reaction is carried out in the microflow field reactor.

[0091] The schematic diagram of the acylation reaction in the microfluidic reactor in Example 1 is as follows Figure 4 shown.

[0092] from Figure 4 It can be seen that the solution containing 2,2'-diphenylamine disulfide is mixed with benzoyl chloride and then undergoes acylation reaction in the microfluidic reactor.

[0093] The mass spectrum of the peptizer DBD prepared in Example 1 is as follows: Figure 5 shown.

[0094] from Figure 5 It can be seen that the present invention prepares the peptizer DBD.

[0095] Comparative Example 1

[0096] The preparation method of the solution containing sodium o-aminothiophenol is:

[0097] Based on Example 1, steps (2) and (3) were omitted, and the time of the ring-opening reaction was changed to 10 min, while other conditions remained unchanged.

[0098] By comparing Example 1 with Comparative Example 1, it can be seen that benzothiazole can be detected when the reaction time is shortened to 10 min, indicating that the ring-opening reaction is incomplete.

[0099] Example 2

[0100] Step (2) was changed based on Example 1, while other conditions remained unchanged;

[0101] Step (2): mechanically stirring the solution containing sodium o-aminothiophenol obtained in step (1) and chloroform to obtain a mixed phase, mixing it with an oxidant, and then performing an oxidation reaction in a microfluidic reactor for 5 minutes to obtain a solution containing 2,2'-diphenylamine disulfide; wherein the mass ratio of chloroform to benzothiazole is 5:1 ， The mass ratio of sodium o-aminothiophenol to chloroform is 290:300; the oxidant is a mixed solution of sulfuric acid solution and hydrogen peroxide; the mass concentration of sulfuric acid in the oxidant is 23.2%, and the mass concentration of hydrogen peroxide is 8.15%; the feed rate of the mixed phase is 19 mL / min; the feed rate of the oxidant is 4.5 mL / min; the microflow field reactor is a screw reactor; and the temperature of the oxidation reaction is 40°C.

[0102] The yield of the peptizer DBD in Example 2 is 94.1%, and the detected melting point is 137.9°C.

[0103] Comparative Example 2 Batch Reaction

[0104] The preparation method of the peptizer comprises the following steps:

[0105] (1) 1 mol of benzothiazole and 2 mol of sodium hydroxide aqueous solution (mass concentration of 32%) were added to a container at the same time, stirring was started, the temperature was raised to 120° C., and the reaction was carried out for 2 hours to obtain a bright yellow solution containing sodium o-aminothiophenol;

[0106] (2) cooling the solution containing sodium o-aminothiophenol obtained in step (1) to 30° C., adding an appropriate amount of chloroform, and then dropping a mixed liquid of sulfuric acid and hydrogen peroxide to carry out oxidation at 30° C. (the mass concentration of sulfuric acid is 23.5%, and the mass concentration of hydrogen peroxide is 8.3%), until the oxidation end point is when there is no material in the upper liquid, thereby obtaining a solution containing 2,2'-diphenylamine disulfide;

[0107] (3) Add 1.1 mol of benzoyl chloride dropwise to the solution containing 2,2'-diphenylamine disulfide obtained in step (2), carry out acylation reaction at 30°C for 4 hours, heat to 80°C to remove chloroform, centrifuge, wash, dry and grind to obtain the peptizer DBD.

[0108] The yield of the peptizer DBD in Comparative Example 2 was 92%, and the detected melting point was 137.8°C.

[0109] It can be seen from the above examples and comparative examples that the preparation method provided by the present invention takes a short time, and the prepared 2,2'-dibenzamidodiphenyl disulfide has stable quality, high purity and high yield.

[0110] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a peptizer DBD, comprising the following steps: (1) mixing benzothiazole with an alkali solution, and then performing a ring-opening reaction in a microfluidic field reactor to obtain a solution containing o-aminobenzenethiophenol salt; (2) mixing the solution containing o-aminobenzenethiophenol salt obtained in step (1), a solvent and an oxidant, and then performing an oxidation reaction in a microfluidic reactor to obtain a solution containing 2,2'-diphenylamine disulfide; (3) The solution containing 2,2'-diphenylamine disulfide obtained in step (2) is mixed with benzoyl chloride, and then an acylation reaction is carried out in a microfluidic field reactor to obtain a peptizer DBD.

2. The preparation method according to claim 1, characterized in that: In the step (1), the molar ratio of benzothiazole to the alkali in the alkali solution is 1:(2-5).

3. The preparation method according to claim 1, characterized in that: In the step (1), the feeding rate of the solution obtained by mixing benzothiazole and alkali solution in the microfluidic field reactor is 1 to 200 mL / min.

4. The preparation method according to claim 1, characterized in that: The temperature of the ring-opening reaction in step (1) is 100 to 180° C., and the time of the ring-opening reaction is 15 to 20 minutes.

5. The preparation method according to claim 1, characterized in that: The solution containing o-aminothiophenol salt, the solvent and the oxidant in step (2) are mixed as follows: mixing a solution containing o-aminobenzenethiophenol salt and a solvent to obtain a mixed phase; The mixed phase and an oxidizing agent are mixed.

6. The preparation method according to claim 5, characterized in that: The feed rates of the mixed phase and the oxidant are independently 1 to 200 mL / min.

7. The preparation method according to claim 1, characterized in that: The temperature of the oxidation reaction in step (2) is 30 to 50° C., and the time of the oxidation reaction is 1 to 5 minutes.

8. The preparation method according to claim 1, characterized in that: The feeding rate of the solution containing 2,2'-diphenylamine disulfide in step (3) is 1 to 200 mL / min.

9. The preparation method according to claim 1, characterized in that: The feeding rate of benzoyl chloride in the step (3) is 1 to 200 mL / min.

10. The preparation method according to claim 1, characterized in that: The temperature of the acylation reaction in step (3) is 20 to 80° C., and the time of the acylation reaction is 1 to 10 minutes.

Images