Preparation method of thiodimercaptan

Abstract

The invention discloses a preparation process of thiodimercaptan, which comprises the following steps: introducing thiodiglycol and hydrogen sulfide into a mixer, then feeding into a reactor filled with a catalyst, separating the product and unreacted hydrogen sulfide after the reaction is finished, and preparing thiodimercaptan by replacing more components in the current reaction process with hydrogen sulfide, so that the process line is simple, the operation is simple, and the production cost is low. The invention further discloses a catalyst, in the preparation process of the catalyst, F127 serves as a template agent, citric acid serves as a complexing agent, hydrochloric acid serves as a catalyst, aluminum isopropoxide serves as an aluminum source, and the porous aluminum oxide loaded cobalt catalyst is prepared in an in-situ generation mode. The porous structure of the carrier can increase the contact area and further catalyze and improve the reaction rate.

Description

Technical Field

[0001] This invention relates to the field of thiol compound synthesis technology, specifically to a method for preparing thiodiglycol. Background Technology

[0002] Thiodiethylene glycol is a dithiol organic compound with two thiol groups at its end. It is mainly used in dye cosolvents, optical resin materials, pesticides, textile finishing, and pharmaceutical intermediates. The preparation method typically involves reacting thiodiethylene glycol with thiourea and hydrochloric acid to generate isothiourea salt of thiodiethylene glycol, followed by alkaline hydrolysis. However, the addition of hydrochloric acid easily produces highly toxic mustard gas.

[0003] Invention patent CN110655481 provides a method for preparing thiodiethylene mercaptan. Specifically, the method involves thoroughly mixing thiodiethylene mercaptan and hydrogen sulfide in a mixer, and then passing the uniformly mixed raw materials through a fixed-bed reactor containing a catalyst. The thiodiethylene mercaptan reacts with hydrogen sulfide to produce thiodiethylene mercaptan. This invention uses hydrogen sulfide to replace chemicals such as thiourea, hydrochloric acid, and alkali in the original process, but it has relatively high requirements for equipment. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a method for preparing thiodiglycol.

[0005] The objective of this invention can be achieved through the following technical solutions: A method for preparing thiodiglycol includes the following steps: Thiodiethylene glycol and hydrogen sulfide are fed into a mixer and then into a reactor containing a catalyst. After the reaction is completed, the product and unreacted hydrogen sulfide are separated to obtain thiodiethylene mercaptan. The catalyst is a porous alumina-supported cobalt catalyst.

[0006] Furthermore, the molar ratio of thiodiethylene glycol to hydrogen sulfide is 1:3-5.

[0007] Furthermore, the reaction temperature was 130℃ and the reaction time was 42-45 min.

[0008] Furthermore, the reaction pressure is 1 MPa.

[0009] Furthermore, the porous alumina-supported cobalt catalyst is prepared by the following steps: The soft template agent was added to anhydrous ethanol and stirred at a constant speed for 15-30 min. Citric acid and hydrochloric acid were then added and stirred for 4 h. Aluminum isopropoxide and cobalt nitrate hexahydrate were added in sequence and stirred for 20-24 h. After stirring, the mixture was dried under vacuum at 55-65℃ and then calcined at 500-550℃ for 4-8 h to obtain a porous alumina-supported cobalt catalyst.

[0010] Furthermore, the soft template agent is a triblock amphiphilic copolymer (F127).

[0011] Furthermore, the ratio of citric acid, hydrochloric acid, aluminum isopropoxide, cobalt nitrate hexahydrate, and anhydrous ethanol is 10-15g:10-15mL:30-35g:3.5-3.8g:150-200mL, and the amount of soft template agent is 15-20% of the weight of anhydrous ethanol.

[0012] The beneficial effects of this invention are as follows: This invention discloses a preparation process for thiodiglycol, which relates to the manufacturing technology of chemical pharmaceutical raw materials. It uses hydrogen sulfide to replace more components in the current reaction process, simplifying the process route. Furthermore, this application also discloses a catalyst. In the preparation process, F127 is used as a template agent, citric acid as a complexing agent, hydrochloric acid as a catalyst, and aluminum isopropoxide as an aluminum source to prepare a porous alumina-supported cobalt catalyst through in-situ generation. Compared with traditional catalysts, this catalyst can increase the contact area through the porous structure of the support, further catalyzing and improving the reaction rate. Detailed Implementation

[0013] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0014] Example 1, a method for preparing thiodiglycol, comprising the following steps: Thiodiethylene glycol and hydrogen sulfide were passed into a mixer and then into a reactor containing a catalyst. After the reaction was completed, the product and unreacted hydrogen sulfide were separated to obtain thiodiethylene mercaptan with a yield of 98.7%. The catalyst is a porous alumina-supported cobalt catalyst.

[0015] The molar ratio of thiodiethylene glycol to hydrogen sulfide is 1:3.

[0016] The reaction temperature was 130℃ and the reaction time was 43 min.

[0017] The reaction pressure is 1 MPa.

[0018] The porous alumina-supported cobalt catalyst is prepared by the following steps: The soft template agent was added to anhydrous ethanol and stirred at a constant speed for 15 min. Citric acid and hydrochloric acid were then added and stirred for another 4 h. Aluminum isopropoxide and cobalt nitrate hexahydrate were added sequentially and stirred for another 20 h. After stirring, the mixture was dried under vacuum at 55 °C and then calcined at 500 °C for 4 h to obtain a porous alumina-supported cobalt catalyst.

[0019] The soft template agent is a triblock amphiphilic copolymer F127.

[0020] The ratio of citric acid, hydrochloric acid, aluminum isopropoxide, cobalt nitrate hexahydrate, and anhydrous ethanol is 10g:10mL:30g:3.5g:150mL, and the amount of soft template agent is 15% of the weight of anhydrous ethanol.

[0021] Example 2, a method for preparing thiodiglycol, comprising the following steps: Thiodiethylene glycol and hydrogen sulfide were passed into a mixer and then into a reactor containing a catalyst. After the reaction was completed, the product and unreacted hydrogen sulfide were separated to obtain thiodiethylene mercaptan with a yield of 98.8%. The catalyst is a porous alumina-supported cobalt catalyst.

[0022] The molar ratio of thiodiethylene glycol to hydrogen sulfide is 1:4.

[0023] The reaction temperature was 130℃ and the reaction time was 45 min.

[0024] The reaction pressure is 1 MPa.

[0025] The porous alumina-supported cobalt catalyst is prepared by the following steps: The soft template agent was added to anhydrous ethanol and stirred at a constant speed for 20 min. Citric acid and hydrochloric acid were then added and stirred for another 4 h. Aluminum isopropoxide and cobalt nitrate hexahydrate were added sequentially and stirred for another 22 h. After stirring, the mixture was dried under vacuum at 60 °C and then calcined at 520 °C for 6 h to obtain a porous alumina-supported cobalt catalyst.

[0026] The soft template agent is a triblock amphiphilic copolymer F127.

[0027] The ratio of citric acid, hydrochloric acid, aluminum isopropoxide, cobalt nitrate hexahydrate, and anhydrous ethanol is 12g:12mL:32g:3.6g:180mL, and the amount of soft template agent is 18% of the weight of anhydrous ethanol.

[0028] Example 3, a method for preparing thiodiglycol, comprising the following steps: Thiodiethylene glycol and hydrogen sulfide were passed into a mixer and then into a reactor containing a catalyst. After the reaction was completed, the product and unreacted hydrogen sulfide were separated to obtain thiodiethylene mercaptan with a yield of 98.8%. The catalyst is a porous alumina-supported cobalt catalyst.

[0029] The molar ratio of thiodiethylene glycol to hydrogen sulfide is 1:4.

[0030] The reaction temperature was 130℃ and the reaction time was 45 min.

[0031] The reaction pressure is 1 MPa.

[0032] The porous alumina-supported cobalt catalyst is prepared by the following steps: The soft template agent was added to anhydrous ethanol and stirred at a constant speed for 30 min. Citric acid and hydrochloric acid were then added and stirred for another 4 h. Aluminum isopropoxide and cobalt nitrate hexahydrate were added sequentially and stirred for another 24 h. After stirring, the mixture was dried under vacuum at 65 °C and then calcined at 550 °C for 8 h to obtain a porous alumina-supported cobalt catalyst.

[0033] The soft template agent is a triblock amphiphilic copolymer F127.

[0034] The ratio of citric acid, hydrochloric acid, aluminum isopropoxide, cobalt nitrate hexahydrate, and anhydrous ethanol is 15g:15mL:35g:3.8g:200mL, and the amount of soft template agent is 20% of the weight of anhydrous ethanol.

[0035] Comparative Example 1: Compared with Example 1, this comparative example uses a commercially available alumina-supported cobalt catalyst, and the rest is the same as the example. The preparation method is as follows: Thiodiethylene glycol and hydrogen sulfide were passed into a mixer and then into a reactor containing a catalyst. After the reaction was completed, the product and unreacted hydrogen sulfide were separated to obtain thiodiethylene mercaptan with a yield of 96.8%. The catalyst is a porous alumina-supported cobalt catalyst.

[0036] The molar ratio of thiodiethylene glycol to hydrogen sulfide is 1:3.

[0037] The reaction temperature was 130℃ and the reaction time was 43 min.

[0038] The reaction pressure is 1 MPa.

[0039] The above description is merely an example and illustration of the concept of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the concept of the invention or exceed the scope defined in the claims, they should all fall within the protection scope of the present invention.

Claims

1. A method for preparing thiodiglycol, characterized in that, Includes the following steps: Thiodiethylene glycol and hydrogen sulfide are fed into a mixer and then into a reactor containing a catalyst. After the reaction is completed, the product and unreacted hydrogen sulfide are separated to obtain thiodiethylene mercaptan. The catalyst is a porous alumina-supported cobalt catalyst.

2. The method for preparing thiodiglycol according to claim 1, characterized in that, The molar ratio of thiodiethylene glycol to hydrogen sulfide is 1:3-5.

3. The method for preparing thiodiglycol according to claim 1, characterized in that, The reaction temperature is 130℃ and the reaction time is 42-45 min.

4. The method for preparing thiodiglycol according to claim 1, characterized in that, The reaction pressure is 1 MPa.

5. The method for preparing thiodiglycol according to claim 1, characterized in that, The porous alumina-supported cobalt catalyst is prepared by the following steps: The soft template agent was added to anhydrous ethanol and stirred at a constant speed for 15-30 min. Citric acid and hydrochloric acid were then added and stirred for 4 h. Aluminum isopropoxide and cobalt nitrate hexahydrate were added in sequence and stirred for 20-24 h. After stirring, the mixture was dried under vacuum at 55-65℃ and then calcined at 500-550℃ for 4-8 h to obtain a porous alumina-supported cobalt catalyst.

6. The method for preparing thiodiglycol according to claim 5, characterized in that, The soft template agent is a triblock amphiphilic copolymer.

7. The method for preparing thiodiglycol according to claim 5, characterized in that, The ratio of citric acid, hydrochloric acid, aluminum isopropoxide, cobalt nitrate hexahydrate, and anhydrous ethanol is 10-15g:10-15mL:30-35g:3.5-3.8g:150-200mL, and the amount of soft template agent is 15-20% of the weight of anhydrous ethanol.