阅读说明：本技术 一种1,2,3-三巯基乙基硫代丙烷的制备方法 (Preparation method of 1,2, 3-trithio-ethyl-thiopropane ) 是由 梁万根 张超 周芳晶 崔卫华 孙志利 费潇瑶 许倩倩 于 2019-11-19 设计创作，主要内容包括：本发明公开了一种1,2,3-三巯基乙基硫代丙烷的制备方法,先将三氯丙烷与巯基乙醇进行反应得到中间三醇类化合物,然后三醇类化合物与废气H<Sub>2</Sub>S进行催化反应,最终得到1,2,3-三巯基乙基硫代丙烷。本发明所述制备方法大大提高了合成过程中的原子利用率,属于废气再利用,降低了原料成本,经济环保,特别适合现有环保的大形势。(The invention discloses a preparation method of 1,2, 3-trithio-ethyl-thiopropane, which comprises the steps of firstly reacting trichloropropane with mercaptoethanol to obtain an intermediate triol compound, and then reacting the triol compound with waste gas H 2 And S, carrying out catalytic reaction to finally obtain the 1,2, 3-trithio-ethyl-thiopropane. The preparation method greatly improves the atom utilization rate in the synthesis process, belongs to waste gas recycling, reduces the raw material cost, is economical and environment-friendly, and is particularly suitable for the existing environment-friendly large situation.)

1. A preparation method of 1,2, 3-trithio-ethyl-thiopropane is characterized by comprising the following steps: trichloropropane and mercaptoethane are firstly mixedAlcohol reacts to obtain an intermediate triol compound A, and the intermediate triol compound A and the waste gas H₂And S is reacted to finally obtain the 1,2, 3-trithio-ethyl-thiopropane. The method comprises the following specific steps:

(1) adding trichloropropane and mercaptoethanol into a four-neck flask in sequence, introducing nitrogen to cool, heating in a water bath to 85-90 ℃, slowly dropwise adding 50% KOH solution in percentage by mass, wherein mauve appears in the dropwise adding process, the solution gradually becomes colorless when the KOH is nearly dripped, quickly adding the rest KOH, and then adding concentrated HCl to acidify to neutrality;

(2) sucking and filtering the mixed solution, removing KCl, standing in a separating funnel for layering to obtain an intermediate triol compound A, and distilling at 70 ℃ to remove small molecules;

(3) putting the obtained intermediate triol compound A into a high-pressure reaction kettle, adding a catalyst, and then introducing H₂S, reacting, filtering out the catalyst after the reaction is finished, washing the filtrate with acid, washing the filtrate with ethanol, and removing small molecules to obtain colorless or slightly yellow liquid, namely 1,2, 3-trimercapto ethyl thiopropane;

the catalyst is a molecular sieve catalyst;

the molar ratio of the mercaptoethanol to the trichloropropane in the step (1) is 2.98-3.3, and the molar ratio of the KOH to the trichloropropane is 1.0-1.05.

2. The process for producing 1,2, 3-trimercaptoethylthiopropane according to claim 1, wherein: the catalyst is gamma-Al₂O₃And silica gel.

3. The process for producing 1,2, 3-trimercaptoethylthiopropane according to claim 2, characterized in that: the catalyst is loaded with Ni-Mo, Ni-W, Co-Mn, Co-W, KOH and K₂WO₄、CsWO₄gamma-Al of (2)₂O₃。

4. The process for producing 1,2, 3-trimercaptoethylthiopropane according to claim 2, characterized in that: said catalysisThe agent is loaded with K₂WO₄、CsWO₄gamma-Al of (2)₂O₃。

5. The process for producing 1,2, 3-trimercaptoethylthiopropane according to claim 4, wherein: the gamma-Al₂O₃Upper load K₂WO₄、CsWO₄The loading amount of (A) is 1-12% wt.

6. The process for producing 1,2, 3-trimercaptoethylthiopropane according to claim 4, wherein: the gamma-Al₂O₃Upper load K₂WO₄、CsWO₄The loading of (A) is 2-5% wt.

7. The process for producing 1,2, 3-trimercaptoethylthiopropane according to claim 1, wherein: h in the step (3)₂The addition amount of S is 3-5 times of the molar equivalent of the triol compound A, H₂S is introduced in a gas form, and the flow rate is 0.5L-1.2L/h.

8. The process for producing 1,2, 3-trimercaptoethylthiopropane according to claim 1, wherein: h in the step (3)₂The addition amount of S is 3.2-3.7 times of the molar equivalent of the triol compound A.

9. The process for producing 1,2, 3-trimercaptoethylthiopropane according to claim 1, wherein: the reaction conditions in the step (3): the reaction temperature is 200 ℃ and 500 ℃, the reaction pressure is 0.2-1.5MP, and the reaction time is 4-9 h.

10. The process for producing 1,2, 3-trimercaptoethylthiopropane according to claim 1, wherein: the reaction conditions in the step (3): the reaction temperature is 200 ℃ and 300 ℃, the reaction pressure is 0.5-0.9MPa, and the reaction time is 6-8 h.

Technical Field

The invention belongs to the field of chemical technology, and particularly relates to a preparation method of 1,2, 3-trithioethyl thiopropane.

Background

Sulfur-containing vinyl resins have received much attention because of their relatively high refractive index and low dispersion properties. The resin-polythiourethane formed by polymerizing polythiol and isocyanate has better performance. The existing document molecular design of polymer optical resin and novel optical plastics discloses a method for synthesizing 1,2, 3-trimercapto ethyl thiopropane, which comprises the steps of firstly reacting trichloropropane with mercaptoethanol to obtain an intermediate triol compound, then carrying out sulfhydrylation reaction on the intermediate triol compound, thiourea and hydrochloric acid, adding ammonia water for alkaline hydrolysis after the reaction is finished, adjusting acid, washing with ethanol, and removing small molecules to obtain the 1,2, 3-trimercapto ethyl thiopropane. The method has more process flows, the sulfhydrylation needs to be carried out by thiourea and hydrochloric acid, a large amount of ammonia water needs to be added for alkaline hydrolysis, a large amount of acid needs to be added for neutralization of alkaline hydrolysis waste liquid, the operation is complex, the atom economy is not high, and a large amount of acid waste water is caused because a large amount of inorganic acid and alkali are needed.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a preparation method of 1,2, 3-trithio-ethyl-thiopropane, which comprises the steps of firstly reacting trichloropropane with mercaptoethanol to obtain an intermediate triol compound, and then reacting the intermediate triol compound with waste gas H₂And S is reacted to finally obtain the 1,2, 3-trithio-ethyl-thiopropane. The preparation method greatly improves the atom utilization rate in the synthesis process, belongs to waste gas recycling, reduces the raw material cost, is economical and environment-friendly, and is particularly suitable for the existing environment-friendly large situation.

The technical scheme of the invention is realized as follows:

a process for preparing 1,2, 3-trithio ethyl thiopropane includes reaction of trichloropropane with mercaptoethanol to obtain intermediate triol compound A, and reaction between triol compound A and waste gas H₂And S, carrying out catalytic reaction to finally obtain the 1,2, 3-trithio-ethyl-thiopropane. The reaction equation is as follows:

the method comprises the following specific steps:

(1) adding trichloropropane and mercaptoethanol into a four-neck flask in sequence, introducing nitrogen to cool, heating in a water bath to 85-90 ℃, slowly dropwise adding 50% KOH solution in percentage by mass, wherein mauve appears in the dropwise adding process, the solution gradually becomes colorless when the KOH is nearly dripped, then quickly adding the rest KOH, and then adding concentrated HCl to acidify to neutrality;

(2) sucking and filtering the mixed solution, removing KCl, standing in a separating funnel for layering to obtain an intermediate triol compound A, and distilling at 70 ℃ to remove small molecules;

(3) putting the obtained triol compound A into a high-pressure reaction kettle, adding a catalyst, and then introducing H₂And S, reacting, filtering out the catalyst after the reaction is finished, washing the filtrate with acid, washing the filtrate with ethanol, and removing small molecules to obtain colorless or slightly yellow liquid, namely the 1,2, 3-trithioethyl thiopropane.

The molar ratio of the mercaptoethanol to the trichloropropane in the step (1) is 2.98-3.3, and the molar ratio of the KOH to the trichloropropane is 1.0-1.05.

H in the step (3)₂The amount of S to be added is 3 to 5 times, preferably 3.2 to 3.7 times, the molar equivalent of the triol compound A. Wherein H₂S is introduced in a gas form, and the flow rate is 0.5L-1.2L/h. The reaction conditions in the step (3): the reaction temperature is 200 ℃ and 500 ℃, the reaction pressure is 0.2-1.5MP, and the reaction time is 4-9 h; preferably, the reaction conditions are: the reaction temperature is 200 ℃ and 300 ℃, the reaction pressure is 0.5-0.9MPa, and the reaction time is 6-8 h.

The catalyst is a molecular sieve catalyst, and the catalyst is preferably gamma-Al₂O₃Silica gel; the catalyst is preferably supported Ni-Mo, Ni-W, Co-Mn, Co-W, KOH, K₂WO₄、CsWO₄gamma-Al of (2)₂O₃(ii) a The catalystThe agent is preferably supported K₂WO₄、CsWO₄gamma-Al of (2)₂O₃(ii) a The gamma-Al₂O₃Upper load K₂WO₄、CsWO₄The loading amount of (B) is 1% wt to 12% wt, preferably 2% wt to 5% wt. The load amount here refers to a mass ratio.

The catalyst is a molecular sieve catalyst which is high in selectivity and activity, uniform and regular microporous structures are distributed in the molecular sieve, and molecules of the manholes are limited by different pore sizes, so that the catalyst has high selectivity.

The sulfhydrylation process of the invention is to directly react the intermediate triol compound with the waste gas H₂S reaction, then acid washing and ethanol washing are carried out, and the product 1,2, 3-trithio-ethyl-thiopropane is directly obtained, so that the method is more economical and environment-friendly, namely: by means of exhaust gases H₂S is used as a sulfur source to replace the traditional thiourea and hydrochloric acid scheme, so that the synthesis cost can be effectively reduced, the yield is improved, and the green and environment-friendly concept is met; the synthetic route is simple and feasible, and is suitable for industrial large-scale production.

Example 1

(1) Sequentially adding 0.5mol of trichloropropane and 1.5mol of mercaptoethanol into a four-neck flask, introducing nitrogen to reduce the temperature, heating in a water bath to 85-90 ℃, slowly dropwise adding 0.5mol of KOH solution with the mass fraction of 50%, wherein mauve appears in the dropwise adding process, when the KOH is nearly dripped, the solution gradually becomes colorless, then quickly adding the rest KOH, and then adding concentrated HCl to acidify to neutrality;

(2) sucking and filtering the mixed solution, removing KCl, standing in a separating funnel for layering to obtain an intermediate triol compound A, and distilling at 70 ℃ to remove small molecules;

(3) putting the obtained triol compound A into a high-pressure reaction kettle, and adding 5% wtCsWO₄/γ-Al₂O₃The catalyst is then introduced into the reactor at a flow rate of 1L/H₂S，H₂The adding amount of S is 3.5 times of the molar equivalent of the triol compound, the reaction temperature is controlled to be 250 ℃, and the reaction pressure is 0.9 MPa; the reaction time is 8 h. Filtering out the catalyst after the reaction is finished, pickling the filtrate, washing the filtrate with ethanol, and removing the catalystGetting out small molecules to obtain colorless or slightly yellow liquid, namely the product 1,2, 3-trithiol ethyl thiopropane with the yield of 88 percent and n_d(refractive index) 1.6409.