阅读说明：本技术 一种2-硝基-4-甲砜基苯甲酸的制备方法 (Preparation method of 2-nitro-4-methylsulfonylbenzoic acid ) 是由 胡玉林 李精锐 刘湘 李德江 于 2021-09-07 设计创作，主要内容包括：本发明涉及一种2-硝基-4-甲砜基苯甲酸的催化制备新方法,属于精细化工技术领域。以2-硝基-4-甲砜基甲苯为原料,30%双氧水为氧化剂,MOFs为主催化剂,吡啶类离子液体为助催化剂和反应介质,搅拌下进行选择性氧化反应制备2-硝基-4-甲砜基苯甲酸。反应结束后,离子液体/MOFs催化剂相沉于烧瓶底部,通过二氯甲烷萃取分液即可实现催化剂相与产物相的分离,回收溶剂即可得到目标产物,分离出的离子液体/MOFs催化剂相可不经处理即可良好进行循环利用催化氧化反应。该工艺一步制备得到2-硝基-4-甲砜基苯甲酸的方法,工艺过程操作简单、高效、高选择性、绿色环保,是潜在的传统生产工艺替代方法,具有较好的应用前景。(The invention relates to a novel catalytic preparation method of 2-nitro-4-methylsulfonylbenzoic acid, belonging to the technical field of fine chemical engineering. 2-nitro-4-methylsulfonyl toluene is used as a raw material, 30% hydrogen peroxide is used as an oxidant, MOFs is used as a main catalyst, pyridine ionic liquid is used as a cocatalyst and a reaction medium, and the 2-nitro-4-methylsulfonyl benzoic acid is prepared by selective oxidation reaction under stirring. After the reaction is finished, the ionic liquid/MOFs catalyst phase is deposited at the bottom of the flask, the separation of the catalyst phase and the product phase can be realized through dichloromethane extraction liquid separation, the target product can be obtained by recycling the solvent, and the separated ionic liquid/MOFs catalyst phase can be recycled for catalytic oxidation reaction without treatment. The method for preparing the 2-nitro-4-methylsulfonylbenzoic acid by one step has the advantages of simple operation, high efficiency, high selectivity, environmental protection, and is a potential substitute method for the traditional production process, and has good application prospect.)

1. A preparation method of 2-nitro-4-methylsulfonylbenzoic acid is characterized in that 2-nitro-4-methylsulfonyltoluene is used as a raw material, 30% hydrogen peroxide is used as an oxidant, MOFs is used as a main catalyst, pyridine ionic liquid is used as an auxiliary catalyst and a reaction medium, oxidation reaction is carried out under stirring, cooling and standing are carried out after the reaction is finished, the ionic liquid/MOFs catalyst phase is deposited at the bottom of a flask, and an oxidation product phase is extracted by dichloromethane, and a solvent is recovered, so that an oxidation product 2-nitro-4-methylsulfonylbenzoic acid is obtained.

2. The method of producing 2-nitro-4-methylsulfonylbenzoic acid according to claim 1, wherein the MOFs as the procatalyst is one of MOF-5, PCN-222, UiO-66, preferably PCN-222.

3. The method of claim 1, wherein the cocatalyst pyridine ionic liquid is [ BSO ]₃Py]HSO₄、[BSO₃Py]ClO₄、[BSO₃Py]BF₄、[EAPy]MnO₄、[EAPy]PF₆、[EAPy]HSeO₄Is preferably [ BSO ]₃Py]ClO₄Or [ EAPy]HSeO₄。

4. The method according to claim 1, wherein the molar ratio of the materials used is 2-nitro-4-methylsulfonyltoluene: the 30% hydrogen peroxide is = 1: 1-6, and more preferably 1: 2-4.

5. The method according to claim 1, wherein the amount of the MOFs catalyst is 1-30% by mass of the 2-nitro-4-methylsulfonyltoluene, and more preferably 5-20% by mass of the 2-nitro-4-methylsulfonyltoluene.

6. The method according to claim 1, wherein the amount of the ionic liquid is 20 to 200% by mass, and more preferably 50 to 150% by mass, of the 2-nitro-4-methylsulfonyltoluene.

7. The process of claim 1, wherein the reaction temperature is 20 ℃^oC~60^oC, more preferably 25^oC~50^oC。

8. The process according to claim 1, wherein the reaction time is 0.5 to 5 hours, preferably 0.5 to 3 hours.

9. The process of claim 1, wherein the recovered ionic liquid/MOFs catalyst phase is recycled without treatment for further catalytic oxidation.

Technical Field

The invention belongs to the technical field of fine chemical engineering. Relates to an intermediate, in particular to a catalytic preparation method of 2-nitro-4-methylsulfonylbenzoic acid.

Technical Field

2-nitro-4-methylsulfonylbenzoic acid is an important organic synthesis intermediate, is widely applied to the fields of dyes, medicines, pesticides and the like, and is a key intermediate for synthesizing the herbicide mesotrione particularly in the field of pesticides. The mesotrione has the characteristics of wide weed control spectrum, high activity, strong mixability, flexible use, safety to succeeding crops and the like, is environment-friendly, and has excellent market prospect in China. At present, the domestic process for producing the 2-nitro-4-methylsulfonylbenzoic acid is incomplete, and the domestic popularization and use of the mesotrione are greatly limited, so that the development of a new synthesis process of the 2-nitro-4-methylsulfonylbenzoic acid is very important (CN 107056662A; CN 111254456A; CN 106432006A; pesticide, 2013,52(3): 174-. The production process of 2-nitro-4-methylsulfonylbenzoic acid is oxidation process, which is one oxidation process of oxidizing methyl in benzene ring with 2-nitro-4-methylsulfonyl toluene as material to prepare corresponding acid. The preparation method is simple and easy to operate, but because the benzene ring of the 2-nitro-4-methylsulfonyl toluene is connected with two electron-withdrawing groups, the oxidation difficulty is higher, and the oxidation degree is difficult to control, a strong oxidant such as a potassium permanganate oxidation method, a dichromate oxidation method, a nitric acid oxidation method, a ferrate oxidation method and the like (CN 101921215; US5424481, WO9427959, CN108715581A and CN108752247A) is usually needed in the oxidation process, and although the oxidation methods have mild reaction conditions, simple and convenient operation and low equipment requirements, the oxidation methods have different problems of high production cost, high corrosion on equipment, low product yield, environmental pollution, large three-waste treatment capacity and the like. The molecular oxygen or hydrogen peroxide is used as an oxidant, has small harm to the environment and has the characteristic of being clean and environment-friendly, so the method is always considered as a clean production way for preparing the 2-nitro-4-methylsulfonylbenzoic acid and is also always the key point of research in various countries. The air (oxygen) liquid phase oxidation method (CN102329256A, CN103787934B) uses a lower fatty acid as a solvent and a transition metal compound as a catalyst, and oxidizes a methyl group on a benzene ring with air or oxygen to prepare a carboxylic acid. Its advantages are high reaction selectivity, no generation of waste gas and waste liquid, high requirement to reactor, limited oxidizing power, low conversion rate, high cost of catalyst, complex post-treatment and low productivity. The oxydol oxidation is higher than molecular oxygen, the only by-product in the reaction process is water, and the oxydol oxidation catalyst has the advantages of higher selectivity and conversion rate, simple operation, high atom economy and the like, and is widely applied to green oxidation reaction. The existing oxidation preparation method of 2-nitro-4-methylsulfonylbenzoic acid (CN 104262215A; CN 102584650A; CN101503383A) still has the problems of low reaction selectivity and product yield, large consumption of hydrogen peroxide, three-waste treatment and the like. Therefore, how to design a novel catalyst with high conversion rate and high selectivity to promote the high-selectivity oxidation reaction of 2-nitro-4-methylsulfonyltoluene to prepare the 2-nitro-4-methylsulfonylbenzoic acid is a challenging research topic.

Disclosure of Invention

The invention aims to develop an environment-friendly method for preparing 2-nitro-4-methylsulfonylbenzoic acid by one-step oxidation of 2-nitro-4-methylsulfonyltoluene with high conversion rate and high selectivity.

The technical solution for realizing the purpose of the invention is as follows: the novel method for preparing the 2-nitro-4-methylsulfonylbenzoic acid by catalyzing the selective oxidation of 2-nitro-4-methylsulfonyltoluene hydrogen peroxide by using pyridine ionic liquid/metal-organic framework Materials (MOFs), namely, the method takes the 2-nitro-4-methylsulfonyltoluene as a raw material, 30% hydrogen peroxide as an oxidant, the MOFs as a main catalyst, the pyridine ionic liquid as an auxiliary catalyst and a reaction medium, and realizes the selective control synthesis reaction of the 2-nitro-4-methylsulfonylbenzoic acid under mild conditions without adding other organic solvents.

The commercial pyridine ionic liquid reaction medium used by the invention is from Shanghai magnesium strontium barium industry Co., Ltd and Shanghai Chengjie chemical Co., Ltd, and has the following structure:

the main catalysts used in the invention are commercial metal-organic framework materials MOF-5, PCN-222 and UiO-66, and are from Siam Qieyue biotechnology limited and Siam Rexi biotechnology limited.

The invention is characterized in that 2-nitro-4-methylsulfonyl toluene is used as a raw material, 30% hydrogen peroxide is used as an oxidant, MOFs is used as a main catalyst, pyridine ionic liquid is used as an auxiliary catalyst and a reaction medium, and the materials, the MOFs and the pyridine ionic liquid are fed in proportion, mixed and stirred for reaction.

The molar ratio of the materials used in the invention is 2-nitro-4-methylsulfonyl toluene: the 30% hydrogen peroxide is 1:1 to 6, and more preferably 1:2 to 4.

The dosage of the MOFs main catalyst used in the invention is 1-30% of the mass of the 2-nitro-4-methylsulfonyl toluene, and the preferred dosage is 5-20%.

The dosage of the ionic liquid used in the invention is 20-200% of the mass of the 2-nitro-4-methylsulfonyl toluene, and the preferred dosage is 50-150%.

The reaction temperature is 20-60 ℃, and more preferably 25-50 ℃.

The reaction time is 0.5 to 5 hours, and more preferably 0.5 to 3 hours.

The catalyst is one of MOF-5, PCN-222 and UiO-66, preferably PCN-222.

The pyridine ionic liquid is [ BSO ]₃Py]HSO₄、[BSO₃Py]ClO₄、[BSO₃Py]BF₄、[EAPy]MnO₄、[EAPy]PF₆、[EAPy]HSeO₄Is preferably [ BSO ]₃Py]ClO₄Or [ EAPy]HSeO₄。

The invention relates to a method for preparing 2-nitro-4-methylsulfonylbenzoic acid by selective oxidation of 2-nitro-4-methylsulfonyltoluene hydrogen peroxide based on pyridine ionic liquid/MOFs catalysis. After the reaction is finished, cooling and standing are carried out, an ionic liquid/catalyst phase is deposited at the bottom of the flask, and an oxidation product phase is extracted by dichloromethane, and a solvent is recovered, so that an oxidation product 2-nitro-4-methylsulfonylbenzoic acid can be obtained. The ionic liquid/MOFs catalyst phase can be recycled without treatment for the next batch of catalytic oxidation reactions.

The key technology of the method for preparing 2-nitro-4-methylsulfonylbenzoic acid provided by the invention is to adopt pyridine ionic liquid/MOFs to catalyze 2-nitro-4-methylsulfonyltoluene hydrogen peroxide for selective oxidation reaction to prepare the 2-nitro-4-methylsulfonylbenzoic acid.

Compared with the prior art, the invention has the advantages that: (1) a novel catalytic oxidation reaction system of the pyridine ionic liquid cocatalyst/MOFs main catalyst is constructed, and the catalytic system is good in stability and can be well recycled. (2) The catalytic reaction system has high catalytic activity, high reaction selectivity, good product quality and high yield. (3) The traditional reaction process has the environmental problems of three-waste treatment and the like, the catalytic reaction system is simple to operate, only products and water are generated in the reaction process, and the system is environment-friendly.

Drawings

FIG. 1 is a HPLC chart of example 7.

Detailed Description

The following embodiments are merely descriptions of the best mode of the present invention and do not limit the scope of the present invention in any way, and the spirit of the present invention is further explained by the following examples.

Example 1

In a reaction flask, 2-nitro-4-methylsulfonylbenzoic acid (0.1mol), [ BSO ] was added₃Py]HSO₄(30g) MOF-5(3g), slowly adding 30% hydrogen peroxide (0.4mol) under stirring, and then continuing to stir at 45 ℃ for reaction for 3 hours. And (3) cooling and standing, extracting the oxidation product phase by dichloromethane (30mL), and separating to recover the ionic liquid/MOFs catalyst phase. The dichloromethane product was phase distilled to recover the solvent and dried to obtain the oxidation product 2-nitro-4-methylsulfonylbenzoic acid in 69% yield and 93.5% purity by HPLC analysis as in example 7.

Example 2

In a reaction flask, 2-nitro-4-methylsulfonylbenzoic acid (0.1mol), [ BSO ] was added₃Py]HSO₄(25g) PCN-222(2.5g), slowly adding 30% hydrogen peroxide (0.3mol) under stirring, and then continuing to stir at 40 ℃ for reaction for 2 hours. Cooling and standing, and oxidizingThe product phase was extracted with dichloromethane (30mL) and the ionic liquid/MOFs catalyst phase was recovered by separation. The dichloromethane product was subjected to phase distillation to recover the solvent and dried to obtain 2-nitro-4-methylsulfonylbenzoic acid in 83% yield and 94.6% purity by HPLC analysis as in example 7.

Example 3

In a reaction flask, 2-nitro-4-methylsulfonylbenzoic acid (0.1mol), [ BSO ] was added₃Py]HSO₄(30g) UiO-66(4g), 30% hydrogen peroxide (0.4mol) was slowly added with stirring, and then the reaction was continued at 50 ℃ with stirring for 3 hours. And (3) cooling and standing, extracting the oxidation product phase by dichloromethane (30mL), and separating to recover the ionic liquid/MOFs catalyst phase. The dichloromethane product was subjected to phase distillation to recover the solvent and dried to obtain 2-nitro-4-methylsulfonylbenzoic acid in 57% yield and 92.3% purity by HPLC analysis as in example 7.

Example 4

In a reaction flask, 2-nitro-4-methylsulfonylbenzoic acid (0.1mol), [ BSO ] was added₃Py]ClO₄(25g) PCN-222(3g), slowly adding 30% hydrogen peroxide (0.3mol) under stirring, and then continuing to stir at 40 ℃ for reaction for 2 hours. And (3) cooling and standing, extracting the oxidation product phase by dichloromethane (30mL), and separating to recover the ionic liquid/MOFs catalyst phase. The dichloromethane product is subjected to phase distillation to recover the solvent and is dried to obtain the 2-nitro-4-methylsulfonylbenzoic acid with the yield of 92 percent and the purity of 96.8 percent by HPLC analysis in the same way as in example 7.

Example 5

In a reaction flask, 2-nitro-4-methylsulfonylbenzoic acid (0.1mol), [ BSO ] was added₃Py]BF₄(30g) PCN-222(4g), slowly adding 30% hydrogen peroxide (0.4mol) under stirring, and then continuing to stir at 45 ℃ for reaction for 2.5 hours. And (3) cooling and standing, extracting the oxidation product phase by dichloromethane (30mL), and separating to recover the ionic liquid/MOFs catalyst phase. The dichloromethane product is subjected to phase distillation to recover the solvent and is dried to obtain the 2-nitro-4-methylsulfonylbenzoic acid with yield of 78 percent and purity of 95.2 percent by HPLC analysis in the same manner as in example 7.

Example 6

In a reaction flask, 2-nitro-4-methylsulfonylbenzoic acid (0.1mol), [ EAPy ] was added]MnO₄(30g)，PCN-222(3g)，Slowly adding 30% hydrogen peroxide (0.3mol) while stirring, and then continuously stirring and reacting for 3 hours at 45 ℃. And (3) cooling and standing, extracting the oxidation product phase by dichloromethane (30mL), and separating to recover the ionic liquid/MOFs catalyst phase. The dichloromethane product was subjected to phase distillation to recover the solvent and dried to obtain 2-nitro-4-methylsulfonylbenzoic acid in 81% yield and 94.5% purity by HPLC analysis as in example 7.

Example 7

In a reaction flask, 2-nitro-4-methylsulfonylbenzoic acid (0.1mol), [ EAPy ] was added]HSeO₄(25g) PCN-222(2.5g), slowly adding 30% hydrogen peroxide (0.3mol) under stirring, and then continuing to stir at 40 ℃ for reaction for 2 hours. And (3) cooling and standing, extracting the oxidation product phase by dichloromethane (30mL), and separating to recover the ionic liquid/MOFs catalyst phase. The dichloromethane product is subjected to phase distillation to recover the solvent and is dried to obtain the 2-nitro-4-methylsulfonylbenzoic acid with the yield of 96 percent and the purity of 97.5 percent (shown in figure 1 by HPLC).

Example 8

In a reaction flask, 2-nitro-4-methylsulfonylbenzoic acid (0.1mol), [ EAPy ] was added]PF₆(30g) PCN-222(3.5g), slowly adding 30% hydrogen peroxide (0.4mol) under stirring, and then continuing to stir at 50 ℃ for reaction for 2.5 hours. And (3) cooling and standing, extracting the oxidation product phase by dichloromethane (30mL), and separating to recover the ionic liquid/MOFs catalyst phase. The dichloromethane product is subjected to phase distillation to recover the solvent and is dried to obtain the 2-nitro-4-methylsulfonylbenzoic acid with the yield of 62 percent and the purity of 92.8 percent by HPLC analysis in the same way as in example 7.

Example 9

The catalyst in the example 7 is recovered, the catalytic reaction is carried out according to the conditions in the example 7, the recovered catalyst is repeatedly used for 4 times, and the experimental result shows that the activity of the catalyst is not reduced, the product yield is 92-95%, and the content is more than 96%.