CN114133345A - Preparation method of 2-chlorosulfonyl-4-methanesulfonamide methyl benzoate - Google Patents
Preparation method of 2-chlorosulfonyl-4-methanesulfonamide methyl benzoate Download PDFInfo
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- CN114133345A CN114133345A CN202011522365.2A CN202011522365A CN114133345A CN 114133345 A CN114133345 A CN 114133345A CN 202011522365 A CN202011522365 A CN 202011522365A CN 114133345 A CN114133345 A CN 114133345A
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C303/00—Preparation of esters or amides of sulfuric acids; Preparation of sulfonic acids or of their esters, halides, anhydrides or amides
- C07C303/36—Preparation of esters or amides of sulfuric acids; Preparation of sulfonic acids or of their esters, halides, anhydrides or amides of amides of sulfonic acids
- C07C303/40—Preparation of esters or amides of sulfuric acids; Preparation of sulfonic acids or of their esters, halides, anhydrides or amides of amides of sulfonic acids by reactions not involving the formation of sulfonamide groups
Abstract
The invention relates to a preparation method of 2-chlorosulfonyl-4-methanesulfonamide methyl benzoate, which comprises the steps of diazotization reaction and sulfonylation reaction. The method selects the cupric chloride as the catalyst, and has the advantages of simple operation, environmental protection, less material feeding amount and high catalytic efficiency compared with cuprous chloride. The invention adopts sodium hypochlorite as a chlorine oxidant, can promote the forward reaction, accelerate the generation of sulfonyl chloride, quickly convert a sulfonic acid intermediate into sulfonyl chloride, and greatly shorten the reaction time, thereby improving the reaction yield and purity. The preparation method provided by the application has the advantages that the final yield can be improved by more than 20%, the purity of the crude product can reach more than 96%, a complex post-treatment process is not needed, the cost and equipment investment are saved, the three-waste discharge amount is reduced, and the preparation method is suitable for industrial production.
Description
Technical Field
The invention relates to the field of organic synthesis, in particular to a preparation method of 2-chlorosulfonyl-4-methanesulfonamide methyl benzoate.
Technical Field
2-chlorosulfonyl-4-methanesulfonamide methyl benzoate, molecular formula: c10H12ClNO6S2。
The 2-chlorosulfonyl-4-methanesulfonamide methyl benzoate is a key intermediate for preparing the herbicide mesosulfuron, and the following synthetic methods are mainly adopted at present:
sodium methanethiol method (patent CN 109879817 a): 2-nitro-4-cyano methyl benzoate reacts with sodium methyl mercaptide to produce methide, cyano is reduced to methylene amino, and then the methylene amino reacts with methanesulfonyl chloride, and finally chlorine is oxidized to produce the product 2-chlorosulfonyl-4-methanesulfonamide methyl benzoate. In addition, the reaction yield is not high, and chlorine gas is used in the final step of oxychlorination, belongs to dangerous chemicals for national heavy supervision and is not suitable for industrial production.
Cuprous chloride catalytic process (patent CN 1443159 a): 2-amino-4-methanesulfonamide methyl benzoate is used as an initial raw material and subjected to diazotization and sulfonylation to obtain 2-chlorosulfonyl-4-methanesulfonamide methyl benzoate, but the literature reports that the sulfonylation reaction is performed on CuCl and SO2Carried out in the presence of simultaneous chlorosulfonylation with 63% yield. The method is still obviously insufficient, partial products obtained by the process are remained in an organic phase, a large amount of products are separated out from a solvent toluene, and the products are decomposed with water to generate a large amount of impurities; the reaction rate of the process is slow, the reaction is not thorough, and partial unreacted intermediates exist, so that the overall yield is not high; the products exist in both aqueous phase and organic phase, and a large amount of impurities are generated in the reaction process, so that the post-treatment is complex, and more three wastes are caused.
Disclosure of Invention
The invention aims to solve the problems of more impurities and low yield in the process, and provides a preparation method of 2-chlorosulfonyl-4-methanesulfonamide methyl benzoate with high yield and high purity.
In order to achieve the purpose, the technical scheme provided by the application is as follows:
a preparation method of 2-chlorosulfonyl-4-methanesulfonamide methyl benzoate comprises the following steps:
(1) diazotization reaction: stirring and heating the aqueous solution of 2-amino-4-methanesulfonamide methyl benzoate to 35-42 ℃, dropwise adding a hydrochloric acid solution, then keeping the temperature for 0.5h, cooling to 0-5 ℃, and slowly dropwise adding a sodium nitrite aqueous solution until the reaction is finished to prepare a diazonium salt solution;
(2) sulfonylation reaction: mixing methyl isobutyl ketone and a phase transfer catalyst to obtain a mixture 1; dissolving sulfur dioxide in the mixture 1 to obtain a mixture 2; adding 0.05-0.15 molar equivalent of copper chloride relative to 2-amino-4-methanesulfonamide methyl benzoate into the mixture 2, and carrying out heat preservation reaction to obtain a mixture 3; slowly dropwise adding the diazonium salt reaction solution prepared in the step (1) into the mixture 3 to obtain a mixture 4; slowly dropwise adding a sodium hypochlorite aqueous solution into the mixture 4; after dripping, stirring uniformly, standing, removing a water layer, evaporating to remove methyl isobutyl ketone in an organic layer, adding dimethylbenzene, crystallizing, centrifuging and drying to obtain a product;
in the reaction, the molar ratio of the 2-amino-4-methanesulfonamide methyl benzoate to the sodium hypochlorite is 1: 1.5-3.
The phase transfer catalyst is selected from trioctylmethylammonium chloride, benzyltriethylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium hydrogen sulfate, benzalkonium chloride, dodecyltrimethylammonium chloride and tetradecyltrimethylammonium chloride; more preferably, trioctylmethylammonium chloride, benzalkonium chloride or a mixture of the two is used.
The molar ratio of methyl isobutyl ketone to phase transfer catalyst in the reaction was 1: 0.03.
In the invention, a phase transfer catalyst is added in the reaction, the reaction is carried out in the same phase, reactants are fully contacted, and the reaction is thorough. The invention adopts methyl isobutyl ketone as a reaction solvent, and overcomes the problem that toluene is separated out as a solvent product and is decomposed when meeting water. The solubility of the product in toluene is low, the product is continuously separated out to a water phase in the reaction process, part of the product is decomposed in water, a large amount of impurities are generated, and the product yield is reduced. In the invention, the product has higher solubility in the methyl isobutyl ketone, and the reaction and contact are sufficient in the presence of the phase transfer catalyst, the product is completely dissolved in the methyl isobutyl ketone in the reaction process, and the product finally exists only in an organic phase, so that the problem of water decomposition is avoided. Compared with the traditional process, the process reduces the post-treatment processes of extraction of water phase, product purification and the like, the crude product can meet the requirement of industrial production without purification, the solvent methyl isobutyl ketone is easy to recycle, the recovery rate can reach more than 85 percent, and the three wastes, equipment investment and raw material cost are greatly reduced.
The method selects the cupric chloride as the catalyst, and has the advantages of simple operation, environmental protection, less material feeding amount and high catalytic efficiency compared with cuprous chloride. Because the cuprous chloride is solid and is insoluble in water, the cuprous chloride is dissolved in the concentrated hydrochloric acid, the dosage of the acid is increased, and the discharge of three wastes is increased. The molar ratio of methyl 2-amino-4-methanesulfonamide methylbenzoate to copper chloride in the present invention is 1:0.05-0.15, which is significantly lower than the conventional amount of copper catalyst used in such reactions, and the molar ratio of reactants to cuprous chloride in patent CN1195732C is about 1: 0.3.
The sulfonylation reaction is a reversible reaction, a reactant firstly generates a sulfonic acid intermediate in the sulfonylation reaction process, and then the sulfonic acid intermediate is slowly converted into sulfonyl chloride in a hydrochloric acid system, the reaction rate of the traditional process is slow, the reaction is not thorough, the unreacted sulfonic acid intermediate still exists in the reaction system, and the yield of the product sulfonyl chloride is low and the impurities are more.
The invention adopts sodium hypochlorite as a chlorine oxidant, can promote the forward reaction, accelerate the generation of sulfonyl chloride, quickly convert a sulfonic acid intermediate into sulfonyl chloride, and greatly shorten the reaction time, thereby improving the reaction yield and purity. Compare chlorine, the security is high, green, and it is more simple and convenient to operate, changes control reaction rate in reaction process, controls the emergence of side reaction effectively, avoids producing unnecessary impurity.
Through the route of the invention, the final yield can be improved by more than 20%, the purity of the crude product can reach more than 96%, a complex post-treatment process is not needed, the cost and the equipment investment are saved, the discharge amount of three wastes is reduced, and the method is suitable for industrial production.
Detailed Description
Example 1
(1) Diazotization reaction: 41.27g (34.75eq) of water and 17.00g (1.00eq) of 2-amino-4-methanesulfonamide methyl benzoate are put into a round-bottom flask, the temperature is raised to 35-42 ℃, 29.20g (3.64eq) of 30% hydrochloric acid is dropwise added with stirring, after the dropwise addition, the stirring is continued for 0.5h, and the temperature is reduced to 0-5 ℃. And slowly dropwise adding 12.59g (1.10eq) of 40% sodium nitrite solution, preserving the temperature for 0.5h after finishing dripping, detecting by using KI/starch test paper, if the test paper is positive, continuously reacting for 0.5h, then adding 1.07g (0.05eq) of 30% sulfamic acid aqueous solution until the test paper is negative, and after the reaction is finished, storing the diazonium salt reaction solution at 0-5 ℃.
(2) Sulfonylation reaction: a round-bottomed flask was charged with 53.08g (8.00eq) of methyl isobutyl ketone and 1.42g (0.03eq) of benzalkonium chloride. 8.97g (2.10eq) of sulfur dioxide gas was slowly passed through. 3.17g (0.11eq) of 31% copper chloride solution was added, stirred for 15 minutes and then warmed to 35 ℃. Slowly dripping the diazonium salt reaction solution in the previous step into a round-bottom flask, controlling the temperature to be 35-40 ℃ after dripping, and stirring for 0.5 h. Slowly adding 9.68g (2.00eq) of 30% sodium hypochlorite aqueous solution dropwise, standing for layering, and taking an upper organic layer for detection. And (3) after the detection result reaches the standard, dividing the organic layer into a round-bottom flask, distilling under reduced pressure to remove the solvent, stopping distillation when 46.80g of methyl isobutyl ketone liquid is distilled out, adding 18.05g of dimethylbenzene, slowly stirring, cooling, crystallizing the feed liquid at the temperature of-5-0 ℃ for 2 hours, filtering, drying and cooling to obtain the product.
Yield (calculated as aniline): 88.10%, purity: 96.56 percent
Example 2
Example 1 was repeated, except that the amount of the catalyst was changed to 4.29g (0.15 eq).
Product yield 87.24% and purity 95.81%
Example 3
Example 1 was repeated, except that the amount of the catalyst was changed to 1.43g (0.05 eq).
The product yield is 86.83 percent, and the purity is 95.78 percent
Example 4
Example 1 was repeated, except that the amount of the chlorine oxidizing agent was changed to 7.37g (1.5 eq).
The product yield is 87.62 percent, and the purity is 95.24 percent
Example 5
Example 1 was repeated, except that the amount of the chlorine oxidizing agent was changed to 14.74g (3.0 eq).
The product yield is 85.10 percent, and the purity is 95.06 percent
Example 6
Example 1 was followed except that 1.40g of 50% benzalkonium chloride was replaced with 0.80g of trioctylmethylammonium chloride.
Product yield 87.21% and purity 96.10%
Example 7
Example 1 was followed except that 1.40g of 50% benzalkonium chloride was replaced with 0.40g of trioctylmethylammonium chloride and 0.71g of 50% benzalkonium chloride.
The product yield is 85.97 percent, and the purity is 95.94 percent
Comparative example 1
Example 1 was repeated except that the chlorine oxidizing agent was replaced with 9.22g (2.0eq) of chlorine.
The product yield is 71.18 percent, and the purity is 84.10 percent
Comparative example 2
The procedure is as in example 1 except that no oxychlorinating agent is added.
The product yield is 67.40 percent, and the purity is 83.67 percent
Comparative example 3
Example 1 was followed except that the catalyst was replaced with 0.72g (0.11eq) of cuprous chloride.
The product yield is 80.85 percent, and the purity is 92.20 percent
Comparative example 4
Example 1 was followed except that the solvent was replaced with 48.83g (8.00eq) of toluene.
The product yield is 70.41 percent, and the purity is 78.64 percent
Comparative example 5
Example 1 was repeated, except that the amount of the chlorine oxidizing agent was changed to 6.40g (1.30 eq).
The product yield is 77.61 percent, and the purity is 91.80 percent
Comparative example 6
Example 1 was repeated, except that the amount of chlorine oxidant was changed to 15.63g (3.20 eq).
The product yield is 75.70 percent, and the purity is 90.49 percent
Comparative example 7
Example 1 was repeated, except that the amount of the catalyst was changed to 1.14g (0.04 eq).
Product yield 78.45% and purity 89.84%
Comparative example 8
The same procedure as in example 1 was repeated, except that no phase transfer catalyst was added.
Product yield 69.73% and purity 85.56%
Comparative example 9
Referring to patent CN1195732C, toluene is used as solvent, cuprous chloride is used as catalyst, and the molar ratio of methyl 2-amino-4-methanesulfonamide benzoate to cuprous chloride is 1: 0.3.
The product yield is 58.76 percent, and the purity is 63.80 percent
Comparative example 10
The procedure is as in comparative example 9 except that 1.71g (2.0eq) of sodium hypochlorite is added.
Product yield 62.62% and purity 68.34%
Comparative example 11
The same procedure as in comparative example 9 was repeated, except that the catalyst was replaced with 1.51g (0.3eq) of a 31% copper chloride solution and 1.71g (2.0eq) of sodium hypochlorite was added.
The product yield is 64.15%, and the purity is 72.11%
As can be seen from examples 1-7 and comparative examples 1-11, the product yield and purity of the process are closely related to the chloroxidizing agent, catalyst, solvent and phase transfer catalyst.
In the comparative example 1, only chlorine is replaced by the chlorine oxychloride agent sodium hypochlorite, so that the product yield is reduced, the purity is reduced, the impurities are obviously increased, and the solvent recovery rate is reduced; in comparative example 2, sodium hypochlorite was not added, and the reaction yield was significantly reduced; in comparative examples 5 and 6, when the amount of the chloroxidizer is too low or too high, the reaction yield is lowered, and when the amount of the chloroxidizer is too high, impurities are increased.
Cuprous chloride was used as a reaction catalyst (comparative example 3) and the reaction yield was slightly lower than in example 1. When the amount of the catalyst used was too low (comparative example 7), the reaction rate was slow and the yield was lowered; the use amount of the catalyst is too high, so that three wastes are increased, and the production cost is increased.
The kind of solvent also affects the yield of the product, and in comparative example 4, toluene is used as the reaction solvent, the yield and purity are decreased, and the amount of impurities is increased.
Whether the addition of the phase transfer catalyst also has obvious influence on the product yield or not is judged, and compared with the comparative example 8, the addition of the phase transfer catalyst in the reaction system improves the product yield by 15-18 percentage points and obviously improves the purity.
Comparative example 9 reaction with toluene as solvent and cuprous chloride as catalyst, low purity and yield less than 60%. The yield of examples 1 to 5 was improved by 20% or more as compared with that of comparative example 9.
The results of the comparisons of examples 1-7 and comparative examples 1-11 are summarized in Table 1.
TABLE 1 EXAMPLES 1-7 AND COMPARATIVE EXAMPLES 1-11
The preparation method of methyl 2-chlorosulfonyl-4-methanesulfonamide methylbenzoate according to the present invention has been described by way of specific examples, and those skilled in the art can use the contents of the present invention to appropriately modify the raw materials, process conditions and the like to achieve the corresponding other objects without departing from the contents of the present invention, and all such similar substitutes and modifications will be obvious to those skilled in the art and are deemed to be included in the scope of the present invention.
Claims (5)
1. A preparation method of 2-chlorosulfonyl-4-methanesulfonamide methyl benzoate is characterized by comprising the following steps of:
(1) diazotization reaction: stirring an aqueous solution of 2-amino-4-methanesulfonamide methyl benzoate, heating to 35-42 ℃, dropwise adding a hydrochloric acid solution, keeping the temperature for 0.5h, cooling to 0-5 ℃, and slowly dropwise adding a sodium nitrite aqueous solution until the reaction is finished to obtain a diazonium salt solution;
(2) sulfonylation reaction: mixing methyl isobutyl ketone and a phase transfer catalyst to obtain a mixture 1; dissolving sulfur dioxide in the mixture 1 to obtain a mixture 2; adding 0.05-0.15 molar equivalent of copper chloride relative to 2-amino-4-methanesulfonamide methyl benzoate into the mixture 2, and carrying out heat preservation reaction to obtain a mixture 3; slowly dropwise adding the diazonium salt reaction solution prepared in the step (1) into the mixture 3 to obtain a mixture 4; slowly dropwise adding a sodium hypochlorite aqueous solution into the mixture 4; after dripping, stirring uniformly, standing, removing a water layer, evaporating to remove methyl isobutyl ketone in an organic layer, adding dimethylbenzene, crystallizing, centrifuging and drying to obtain a product;
in the reaction, the molar ratio of the 2-amino-4-methanesulfonamide methyl benzoate to the sodium hypochlorite is 1: 1.5-3.
2. The method of claim 1, wherein the phase transfer catalyst is selected from the group consisting of trioctylmethylammonium chloride, benzyltriethylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium hydrogen sulfate, benzalkonium chloride, dodecyltrimethylammonium chloride, and tetradecyltrimethylammonium chloride.
3. The method of claim 2, wherein the phase transfer catalyst is trioctylmethylammonium chloride or benzalkonium chloride or a mixture thereof.
4. The method of claim 3, wherein the molar ratio of the phase transfer catalyst trioctylmethylammonium chloride to benzalkonium chloride is 1: 0.2-5.
5. The method of claim 1, wherein the molar ratio of methyl isobutyl ketone to phase transfer catalyst in the reaction is 1: 0.03.
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