阅读说明：本技术 二芳基二硫醚的制备方法 (Process for preparing diaryl dithioethers ) 是由 唐杰 曾春玲 李凯 宁状 于 2019-11-26 设计创作，主要内容包括：本发明涉及一种二芳基二硫醚的制备方法,包括如下步骤：将卤代芳香烃与镁粉进行反应以生成格氏试剂,然后加入硫粉,并在酸和氧化剂的作用下反应,得到二芳基二硫醚。该制备方法以廉价易得的卤代芳香烃作为合成原料合成芳香二硫醚,先将其与镁粉进行反应以生成格氏试剂,然后与硫粉在酸和氧化剂的作用下反应,得到二芳基二硫醚。整个方法过程无需重金属催化及复杂的配体,无需中途出料,一锅法直接合成,且绿色环保,转化率高,收率和纯度高,工艺简单操作方便,适合大规模生产。(The invention relates to a preparation method of diaryl disulfide, which comprises the following steps: halogenated aromatic hydrocarbon reacts with magnesium powder to generate a Grignard reagent, then sulfur powder is added, and the reaction is carried out under the action of acid and an oxidant to obtain diaryl disulfide. The preparation method takes cheap and easily-obtained halogenated aromatic hydrocarbon as a synthetic raw material to synthesize the aromatic disulfide, firstly the aromatic disulfide reacts with magnesium powder to generate a Grignard reagent, and then the Grignard reagent reacts with sulfur powder under the action of acid and an oxidant to obtain the diaryl disulfide. The whole method process does not need heavy metal catalysis and complex ligand, does not need discharging midway, is directly synthesized by a one-pot method, is green and environment-friendly, has high conversion rate, high yield and purity, simple process and convenient operation, and is suitable for large-scale production.)

1. A preparation method of diaryl disulfide is characterized by comprising the following steps:

halogenated aromatic hydrocarbon reacts with magnesium powder to generate a Grignard reagent, then sulfur powder is added, and the reaction is carried out under the action of acid and an oxidant to obtain diaryl disulfide.

2. The method of claim 1, wherein the halogenated aromatic hydrocarbon has the formula:

wherein X is selected from Cl, Br or I;

r is selected from C _1-4Alkoxy radical, C _1-6Alkyl, arylalkyl or H.

3. The method of claim 1, wherein the halogenated aromatic hydrocarbon is selected from the group consisting of:

4. the method according to claim 1, wherein the acid is at least one selected from the group consisting of sulfuric acid, hydrochloric acid, glacial acetic acid, p-toluenesulfonic acid, and hydrobromic acid.

5. The method of claim 1, wherein the oxidizing agent is H ₂O ₂。

6. The method according to claim 1, wherein the halogenated aromatic hydrocarbon is reacted with magnesium powder for 6 to 8 hours using a solvent having a boiling point of 10 to 65 ℃.

7. The method according to claim 1, wherein the feeding ratio of the halogenated aromatic hydrocarbon to the magnesium powder to the sulfur powder is 1mol (0.9-1.1) mol (1-1.3) mol.

8. The method according to any one of claims 1 to 7, further comprising, after the halogenated aromatic hydrocarbon is reacted with the magnesium powder and before the addition of the sulfur powder, the steps of: firstly, cooling the reaction system to 5-10 ℃.

9. The preparation method according to any one of claims 1 to 7, wherein the temperature of the system is controlled to be not higher than 20 ℃ in the process of adding the acid and the oxidant, and the reaction time is 1.5h to 2.5 h.

10. The process according to any one of claims 1 to 7, further comprising a step of purifying the diaryl disulfide after the reaction: adding water into the reacted system, mixing, separating, extracting the water layer with petroleum ether to obtain extract, combining organic phases, concentrating, adding ethanol for replacement, and crystallizing.

Technical Field

The invention relates to the technical field of organic synthesis, in particular to a preparation method of diaryl disulfide.

Background

Aryl disulfide is an important organic reagent and a synthetic intermediate, is widely applied to the fields of organic synthesis, high molecules and the like, and can be used as a vulcanizing agent for producing synthetic rubber, natural rubber and other elastomers. Meanwhile, the aryl disulfide is also an important drug synthesis intermediate, and can be applied to synthesis of feed additives, spice essences, pesticides and the like.

The synthesis method of the symmetric aryl disulfide is more reported, and the most common method is to start from thiophenol and obtain the symmetric aryl disulfide by oxidizing hydrogen peroxide under the action of a catalyst, and the method is shown in the following formula. However, the thiophenol used in the method has foul smell and very large pollution to the environment, and cannot be suitable for large-scale production.

The synthesis of aromatic disulfides starting from sulfinates via hydrazine hydrate has also been reported, as shown in the following formula. The hydrazine hydrate used in the method introduces a large amount of ammonia nitrogen wastewater, and meanwhile, the hydrazine hydrate has great potential safety hazard in the use process.

In addition, aryl disulfide is synthesized from aryl boric acid under the action of copper metal catalyst and ligand, as shown in the following formula: the aryl boric acid used as a raw material in the method is generally relatively expensive, so that the cost is too high, the method is not suitable for large-scale synthesis, and the heavy metal exceeds the standard due to the use of copper catalysis and possible residue of ligand.

Synthetic routes using halogenated aromatic hydrocarbons as synthetic starting materials have also been reported, as shown in the following formula: under the action of strong alkali, a heavy metal catalyst catalyzes halogenated aromatic hydrocarbon to react with sulfur to generate disulfide, but the reaction is in a laboratory stage, the catalyst is heavy metals Rh, Pd, Cu, Fe and the like, and meanwhile, a complex ligand needs to be added, and the problems of low yield, more side reactions, higher cost, high pollution and the like exist.

Disclosure of Invention

Therefore, a preparation method of diaryl disulfide which does not need heavy metal catalysis, is green and environment-friendly, is suitable for large-scale production and has high yield and purity is needed to be provided.

A method for preparing diaryl disulfide comprises the following steps:

halogenated aromatic hydrocarbon reacts with magnesium powder to generate a Grignard reagent, then sulfur powder is added, and the reaction is carried out under the action of acid and an oxidant to obtain diaryl disulfide.

The preparation method takes cheap and easily-obtained halogenated aromatic hydrocarbon as a synthetic raw material to synthesize the aromatic disulfide, firstly the aromatic disulfide reacts with magnesium powder to generate a Grignard reagent, and then the Grignard reagent reacts with sulfur powder under the action of acid and an oxidant to obtain the diaryl disulfide. The whole method process does not need heavy metal catalysis and complex ligand, does not need discharging midway, is directly synthesized by a one-pot method, is green and environment-friendly, has high conversion rate, high yield and purity, simple process and convenient operation, and is suitable for large-scale production.

In some of these embodiments, the halogenated aromatic hydrocarbons have the following structural formula:

wherein X is selected from Cl, Br or I;

r is selected from C _1-4Alkoxy radical, C _1-6Alkyl, arylalkyl or H.

In some of these embodiments, the halogenated aromatic hydrocarbon is selected from the group consisting of:

in some of these embodiments, the acid is selected from at least one of sulfuric acid, hydrochloric acid, glacial acetic acid, p-toluenesulfonic acid, and hydrobromic acid.

In some of these embodiments, the oxidizing agent is H ₂O ₂。

In some embodiments, the halogenated aromatic hydrocarbon and the magnesium powder are reacted for 6 to 8 hours, and the boiling point of the solvent is 10 to 65 ℃.

In some embodiments, the feeding ratio of the halogenated aromatic hydrocarbon to the magnesium powder to the sulfur powder is 1mol (0.9-1.1) mol (1-1.3) mol.

In some of these embodiments, after the halogenated aromatic hydrocarbon is reacted with magnesium powder and before the sulfur powder is added, the method further comprises the steps of: firstly, cooling the reaction system to 5-10 ℃.

In some embodiments, the temperature of the system is controlled to be not higher than 20 ℃ in the process of adding the acid and the oxidant, and the reaction time is 1.5-2.5 h.

In some of these embodiments, further comprising a post-reaction purification step of the diaryl disulfide: adding water into the reacted system, mixing, layering, extracting the water layer with petroleum ether to obtain extract, mixing with organic phase, concentrating, adding ethanol for replacement, and crystallizing.

Detailed Description

In order that the invention may be more fully understood, a more particular description of the invention will now be rendered by reference to specific embodiments thereof that are illustrated in the appended drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

One embodiment of the present invention provides a method for preparing diaryl disulfide, comprising the steps of: halogenated aromatic hydrocarbon reacts with magnesium powder to generate a Grignard reagent, then sulfur powder is added, and the reaction is carried out under the action of acid and an oxidant to obtain diaryl disulfide.

The preparation method takes cheap and easily-obtained halogenated aromatic hydrocarbon as a synthetic raw material to synthesize the aromatic disulfide, firstly the aromatic disulfide reacts with magnesium powder to generate a Grignard reagent, and then the Grignard reagent reacts with sulfur powder under the action of acid and an oxidant to obtain the diaryl disulfide. The whole method process does not need heavy metal catalysis and complex ligand, does not need discharging midway, is directly synthesized by a one-pot method, is green and environment-friendly, has high conversion rate, high yield and purity, simple process and convenient operation, and is suitable for large-scale production.

Wherein, the structural formula of the halogenated aromatic hydrocarbon is as follows:

r may be in any substituted position of the phenyl ring other than X, i.e. may be ortho, meta or para to X. R is H or a substituent, and X is halogen.

The reaction process of the above reaction is shown below by a specific example:

wherein, the aromatic hydrocarbon magnesium halide is a Grignard reagent, and the Grignard reagent and sulfur powder further react to generate diaryl disulfide.

In some of these embodiments, the halogenated aromatic hydrocarbons have the following structural formula:

wherein X is selected from Cl, Br or I;

r is selected from C _1-4Alkoxy radical, C _1-6Alkyl, arylalkyl or H.

Further, the halogenated aromatic hydrocarbon is selected from the following compounds:

in some of these embodiments, the acid is selected from at least one of sulfuric acid, hydrochloric acid, glacial acetic acid, p-toluenesulfonic acid, and hydrobromic acid, preferably sulfuric acid.

In some of these embodiments, the oxidizing agent is H ₂O ₂. In a specific example, the oxidant is hydrogen peroxide.

In some of the embodiments, the halogenated aromatic hydrocarbon is reacted with the magnesium powder for 6 to 8 hours, and the boiling point of the solvent is 10 to 65 ℃.

Further, the solvent adopted in the reflux reaction is at least one of tetrahydrofuran, diethyl ether, dioxane and dimethyltetrahydrofuran.

Further, before the reflux reaction, the method also comprises the step of adding iodine elementary substance as an initiator to initiate the reaction of the halogenated aromatic hydrocarbon and the magnesium powder.

In some embodiments, the feeding ratio of the halogenated aromatic hydrocarbon, the magnesium powder and the sulfur powder is 1mol (0.9-1.1) mol (1-2.0) mol. Furthermore, the feeding ratio of the halogenated aromatic hydrocarbon, the magnesium powder and the sulfur powder is 1mol:1mol:1.2 mol.

In some of these embodiments, after the halogenated aromatic hydrocarbon is reacted with magnesium powder and before the sulfur powder is added, the method further comprises the steps of: firstly, cooling the reaction system to 5-10 ℃.

In some embodiments, the temperature of the system is controlled to be not higher than 20 ℃ in the process of adding the acid and the oxidant, and the reaction time is 1.5-2.5 h.

In some of these embodiments, the acid and the oxidizing agent are added as a mixture.

In some of these embodiments, a post-reaction purification step for the diaryl disulfide is also included: adding water into the reacted system, mixing, layering, extracting the water layer with petroleum ether to obtain extract, mixing all organic phases of layering and extraction, concentrating, adding ethanol for replacement, and crystallizing.

The following are specific examples.