An N-butylbenzenesulfonamide, a preparation method and application thereof

Abstract

This invention discloses an N-butylbenzenesulfonamide, its preparation method, and its applications, relating to the field of organic chemical synthesis technology. The preparation method uses benzenesulfonyl chloride and n-butylamine as raw materials, an organic base as catalyst, and a solid alkaline substance as acid-binding agent, reacting in an organic solvent system to obtain N-butylbenzenesulfonamide. The preparation method has the following advantages: low catalyst dosage, significantly reducing costs; high raw material utilization and few side reactions; low acid-binding agent dosage, resulting in less waste salt and wastewater; the reaction is carried out under normal pressure, eliminating the need for high temperature and high pressure conditions; the acid-binding agent and catalyst are readily available chemical raw materials, resulting in low cost and strong feasibility for large-scale production. The obtained N-butylbenzenesulfonamide is widely used in plasticizers, adhesives, printing inks, and surface coatings, showing excellent market prospects.

Description

Technical Field

[0001] This invention relates to the field of organic chemical synthesis technology, and more specifically, to an N-butylbenzenesulfonamide, its preparation method, and its application. Background Technology

[0002] N-Butylbenzenesulfonamide is an important organic intermediate with wide applications. In existing technologies, its synthesis methods mainly include the following routes: using benzenesulfonamide and n-butanol as raw materials, N-butylation is achieved by heating under reflux in the presence of an acid catalyst, followed by extraction and purification to obtain the target product N-butylsulfonamide. However, in this process, n-butanol has low reactivity, and the acid catalysts used are mostly noble metal heteropoly acids, which are expensive. The process route is as follows: .

[0003] N-Butylbenzenesulfonamide is produced using benzenesulfonyl chloride and n-butylamine as raw materials, a silica-alumina composite porous catalyst, a strong base such as sodium hydroxide solution as an acid-binding agent, and ultrasound as an auxiliary means. The process involves direct reaction to achieve N-butylation, followed by extraction and distillation to obtain the target product, N-butylbenzenesulfonamide. However, this process consumes a large amount of n-butylamine, and the high concentration of sodium hydroxide solution leads to excessive alkalinity, causing hydrolysis of benzenesulfonyl chloride and resulting in a low yield. Furthermore, the strong alkalinity of the sodium hydroxide solution inevitably generates the byproduct N-butyldibenzenesulfonylimide, reducing the purity and yield of N-butylbenzenesulfonamide. The process route is as follows: .

[0004] N-Butylsulfonamide is prepared by reaction dehydration using benzenesulfonic acid and n-butylamine as raw materials (refer to technology 3). Benzenesulfonic acid is highly corrosive, requiring high-quality equipment. Furthermore, using benzenesulfonic acid as a raw material necessitates activation of the carboxylic acid groups under strong dehydrating agents (such as ammonium polyphosphate) or high-temperature conditions, which may result in low yields and a significant amount of byproducts. The process route is as follows: .

[0005] The above technologies can all achieve the synthesis of N-butylbenzenesulfonamide, but the following challenges still exist: such as insufficient raw material activity, high catalyst cost, harsh reaction conditions, serious side reactions, or unsatisfactory product purity, which seriously restrict the development and application of efficient, economical, and green synthesis processes for N-butylbenzenesulfonamide.

[0006] In view of this, the present invention is proposed. Summary of the Invention

[0007] The purpose of this invention is to provide an N-butylbenzenesulfonamide, its preparation method, and its application, so as to solve or improve the above-mentioned technical problems.

[0008] This invention is implemented as follows: In a first aspect, the present invention provides a method for preparing N-butylbenzenesulfonamide, using benzenesulfonyl chloride and n-butylamine as raw materials, an organic base as catalyst, and a solid alkaline substance as acid-binding agent, reacting in an organic solvent system to obtain N-butylbenzenesulfonamide.

[0009] In an optional embodiment, the molar ratio of benzenesulfonyl chloride to n-butylamine is 1:(1-3), preferably 1:(1-2), and more preferably 1:(1-1.5).

[0010] In an optional embodiment, the mass of the catalyst is 0%-1% of the mass of benzenesulfonyl chloride, preferably 0.05%-0.5%, more preferably 0.05%-0.25%; And / or, the catalyst is selected from at least one of N,N-dimethylaminopyridine, N-methylimidazolium, bis(2-dimethylaminoethyl) ether and 4-pyrrolylpyridine.

[0011] In an optional embodiment, the mass ratio of the acid-binding agent to the total mass of benzenesulfonyl chloride and n-butylamine is 1:(1-3), preferably 1:(1-2), and more preferably 1:(1-1.5). And / or, the acid-binding agent is selected from at least one of sodium hydroxide, potassium hydroxide, calcium hydroxide, magnesium hydroxide, sodium methoxide, and sodium tert-butyloxide.

[0012] In an optional embodiment, the mass ratio of the organic solvent to the benzenesulfonyl chloride is 1:(1-10), preferably 1:(1-6), and more preferably 1:(1-3). The organic solvent is selected from at least one of toluene, xylene, dichloromethane, chloroform, cyclohexane, n-hexane, ethyl acetate, and butyl acetate.

[0013] In an optional embodiment, the reaction temperature in the organic solvent system is -10°C to 100°C, preferably 0°C to 80°C, and more preferably 10°C to 30°C. And / or, the reaction time is 1h-10h, preferably 1h-8h, more preferably 1h-3h.

[0014] In an optional embodiment, the preparation process of N-butylbenzenesulfonamide is carried out in a protective atmosphere selected from at least one of nitrogen, helium and argon. And / or, after mixing n-butylamine, organic solvent, catalyst and acid-binding agent in proportion, add benzenesulfonyl chloride and control the process within 2 hours; after adding benzenesulfonyl chloride, keep it at a constant temperature for 1-3 hours, and stop the reaction after the benzenesulfonyl chloride reaction is completed.

[0015] In an optional embodiment, the preparation method further includes, after the reaction has stopped: N-Butylbenzenesulfonamide was prepared by collecting the fraction from 180℃ to 190℃ under a pressure of -0.1MPa.

[0016] In a second aspect, the present invention provides an N-butylbenzenesulfonamide, which is prepared by any of the preparation methods described in the foregoing embodiments; The yield of N-butylbenzenesulfonamide is ≥98%, the conversion rate is ≥99%, the selectivity is ≥99%, and the purity is ≥99.5%.

[0017] Thirdly, the present invention provides the use of N-butylbenzenesulfonamide as described in the foregoing embodiments in the preparation of plasticizers, adhesives, printing inks and surface coatings.

[0018] The present invention has the following beneficial effects: The preparation method of N-butylbenzenesulfonamide provided in this invention has the following characteristics: low catalyst dosage, which greatly reduces costs; high raw material utilization and few side reactions; low acid-binding agent dosage, resulting in less waste salt and wastewater; the reaction condition is at atmospheric pressure, without the need for high temperature and high pressure conditions; the acid-binding agent and catalyst are bulk chemical raw materials, which are inexpensive and highly feasible for large-scale production.

[0019] The obtained N-butylbenzene sulfonamide is widely used in plasticizers (such as nylon plastics, polyamide resins, cellulose resins, etc.), adhesives (such as latex adhesives, hot melt adhesives), printing inks and surface coatings, and has a good market prospect. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 The mass spectrum of N-butylbenzenesulfonamide prepared in Example 1 is shown below. Figure 2 The gas phase diagram is shown for N-butylbenzenesulfonamide prepared in Example 1. Figure 3 The infrared spectrum of N-butylbenzenesulfonamide prepared in Example 1 is shown. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0023] In a first aspect, the present invention provides a method for preparing N-butylbenzenesulfonamide, using benzenesulfonyl chloride and n-butylamine as raw materials, an organic base as catalyst, and a solid alkaline substance as acid-binding agent, reacting in an organic solvent system to obtain N-butylbenzenesulfonamide.

[0024] The preparation method provided in this invention uses a low amount of catalyst, which greatly reduces costs; the raw material utilization rate is high and the side reactions are low; the amount of acid-binding agent used is low, resulting in less waste salt and wastewater; the reaction can be carried out under normal pressure, without the need for high temperature and high pressure conditions; the acid-binding agent and catalyst are bulk chemical raw materials, making it highly feasible for large-scale production.

[0025] In an optional embodiment, the molar ratio of benzenesulfonyl chloride to n-butylamine is 1:(1-3), preferably 1:(1-2), and more preferably 1:(1-1.5).

[0026] It should be noted that when multiple raw materials are present in the reaction process, if one of the reactants is used in an appropriate excess, it will help to promote the reaction to move in the forward direction, making the reaction more complete and improving the utilization rate of raw materials.

[0027] In an optional embodiment, the mass of the catalyst is 0%-1% of the mass of benzenesulfonyl chloride, preferably 0.05%-0.5%, and more preferably 0.05%-0.25%.

[0028] Adding a catalyst during the reaction process has the following characteristics: it accelerates the reaction rate, enabling the reaction to meet industrial production requirements under milder conditions (such as lower temperature and pressure); it does not change the equilibrium position of the reaction; and the catalyst itself is not consumed before or after the reaction and can be recycled.

[0029] If the amount of catalyst used is too small and insufficient to provide enough active sites, the reaction rate will be too low or the reaction will be incomplete, and it may also cause an increase in side reactions. If the amount of catalyst used is too large, it will significantly increase the cost of raw materials. Excessive active sites may provide reactant molecules with unintended reaction pathways, leading to over-reaction or secondary reactions. Overly dense active sites may overlap or agglomerate, which will reduce the effective specific surface area and unit activity.

[0030] And / or, the catalyst is selected from at least one of N,N-dimethylaminopyridine, N-methylimidazolium, bis(2-dimethylaminoethyl) ether and 4-pyrrolylpyridine.

[0031] In an optional embodiment, the mass ratio of the acid-binding agent to the total mass of benzenesulfonyl chloride and n-butylamine is 1:(1-3), preferably 1:(1-2), and more preferably 1:(1-1.5). And / or, the acid-binding agent is selected from at least one of sodium hydroxide, potassium hydroxide, calcium hydroxide, magnesium hydroxide, sodium methoxide, and sodium tert-butyloxide.

[0032] It should be noted that the addition of an acid-binding agent can neutralize the acid generated in the reaction, promote the forward shift of the reaction equilibrium, increase the product yield, reduce side reactions, and may also serve as a reaction medium or catalyst support.

[0033] The acid-binding agent used in this invention is solid, and the product generated is a solid salt that is insoluble in organic solvents, which is beneficial for separation. The acid-binding agent consists of bulk chemical raw materials, which are inexpensive and highly feasible for large-scale production. Solid alkalis are generally non-flammable, non-explosive, and have low volatility, making them easy to store and transport, and thus safer. In an optional embodiment, the mass ratio of the organic solvent to the benzenesulfonyl chloride is 1:(1-10), preferably 1:(1-6), and more preferably 1:(1-3). The organic solvent is selected from at least one of toluene, xylene, dichloromethane, chloroform, cyclohexane, n-hexane, ethyl acetate, and butyl acetate.

[0034] Both benzenesulfonyl chloride and n-butylamine in the raw materials are hydrophobic organic compounds with low solubility in pure water. Organic solvents can provide a homogeneous environment for the reaction, allowing the raw materials, acid-binding agents, etc. to fully dissolve and mix. The homogeneous system provided greatly increases the effective collision frequency between molecules, thereby significantly improving the reaction rate and conversion rate. It can also effectively suppress the occurrence of side reactions (such as the hydrolysis reaction of benzenesulfonyl chloride).

[0035] In an optional embodiment, the reaction temperature in the organic solvent system is -10°C to 100°C, preferably 0°C to 80°C, and more preferably 10°C to 30°C. And / or, the reaction time is 1h-10h, preferably 1h-8h, more preferably 1h-3h.

[0036] It should be noted that the reaction can be carried out under normal pressure, without the need for high temperature and high pressure conditions. The temperature can be achieved at 10℃-30℃, and the reaction time is also short. This allows for the efficient synthesis of N-butylbenzenesulfonamide in a short time, which is beneficial for large-scale production.

[0037] In an optional embodiment, the preparation of N-butylbenzenesulfonamide is carried out in a protective atmosphere, which is selected from at least one of nitrogen, helium and argon. Providing a protective atmosphere helps to remove oxygen and moisture from the system, avoids the oxidative degradation of raw materials and the generation of by-products by hydrolysis, ensures the stability of the reaction, improves the product yield and quality, and enhances the safety and reproducibility of the experiment.

[0038] It should be noted that a protective gas should be introduced before adding the raw materials. After the protective gas has been introduced for several minutes to ensure that the air in the reaction apparatus is displaced, the reactants are added and the reaction is carried out. During this process, the protective atmosphere is continuously introduced until the reaction is completed.

[0039] And / or, after mixing n-butylamine, organic solvent, catalyst and acid-binding agent in proportion, add benzenesulfonyl chloride and control the process within 2 hours; after adding benzenesulfonyl chloride, keep it at a constant temperature for 1-3 hours, and stop the reaction after the benzenesulfonyl chloride reaction is completed.

[0040] In an optional embodiment, the preparation method further includes, after the reaction has stopped: N-Butylbenzenesulfonamide was prepared by collecting the fraction from 180℃ to 190℃ under a pressure of -0.1MPa.

[0041] In other embodiments of the present invention, the product can also be collected by extraction. The extractant can be selected reasonably according to actual needs, and the selection criteria for the extractant are as follows: the product does not react with the extractant, the product's solubility in the extractant is greater than that in the organic solvent, and the selected extractant is immiscible and does not react with the organic solvent.

[0042] In summary, the present invention provides a method for preparing N-butylbenzenesulfonamide, which specifically includes the following steps: Under a protective gas atmosphere, n-butylamine, organic solvent, catalyst, and acid-binding agent are added to the reaction vessel in proportion. Benzenesulfonyl chloride is slowly added dropwise to the reaction system using a peristaltic pump at a temperature of 10℃-30℃, controlling the reaction temperature. The addition is completed within 2 hours, followed by heat treatment for 1-3 hours. The reaction is stopped when the benzenesulfonyl chloride content is ≤0.1% as detected by gas phase analysis.

[0043] The organic phase in the system is collected by filtration, and then heated and removed by vacuum distillation to remove the organic solvent and a small amount of water, which is generated by acid-base neutralization during the reaction.

[0044] Then, the product system is heated, and the fraction at 180℃-190℃ is collected under the condition of -0.1MPa, which is the N-butylbenzenesulfonamide product. The collected product is a light yellow oily liquid.

[0045] In a second aspect, the present invention provides an N-butylbenzenesulfonamide, which is prepared by any of the preparation methods described in the foregoing embodiments; The yield of N-butylbenzenesulfonamide is ≥98%, the conversion rate is ≥99%, the selectivity is ≥99%, and the purity is ≥99.5%.

[0046] Thirdly, the present invention provides the use of N-butylbenzenesulfonamide as described in the foregoing embodiments in the preparation of plasticizers, adhesives, printing inks and surface coatings.

[0047] The obtained N-butylbenzene sulfonamide is widely used in plasticizers (such as nylon plastics, polyamide resins, cellulose resins, etc.), adhesives (such as latex adhesives, hot melt adhesives), printing inks and surface coatings, and has a good market prospect.

[0048] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0049] Example 1 This embodiment provides a method for preparing N-butylbenzenesulfonamide, which includes the following steps: Under a nitrogen atmosphere, n-butylamine (73g, 1mol), organic solvent (toluene, 200g), catalyst (4-pyrrolidinylpyridine, 0.5g), and acid-binding agent (solid sodium hydroxide, 40g) were added to the reaction vessel in proportion. At 20°C, benzenesulfonyl chloride (176g) was slowly added dropwise to the reaction system using a peristaltic pump, controlling the reaction temperature at 20°C-25°C. The addition was completed within 2 hours, and the mixture was kept at this temperature for 3 hours after the addition was completed. The reaction was stopped when the benzenesulfonyl chloride content was ≤0.1% as detected by gas phase.

[0050] The organic phase in the system is collected by filtration, and then heated and removed by vacuum distillation to remove the organic phase and a small amount of water.

[0051] Then, the product system was heated, and the fraction at 180℃-190℃ was collected under the condition of -0.1MPa, which was the N-butylbenzenesulfonamide product. 209.8g of light yellow oily liquid product was collected, with a yield of 98.7% and a product purity of 99.7%.

[0052] Example 2 This embodiment provides a method for preparing N-butylbenzenesulfonamide, which includes the following steps: Under a nitrogen atmosphere, n-butylamine (73g, 1mol), organic solvent (toluene, 200g), catalyst (4-pyrrolidinylpyridine, 0.5g), and acid-binding agent (solid sodium hydroxide, 40g) were added to the reaction vessel in proportion. At 20°C, benzenesulfonyl chloride (176g) was slowly added dropwise to the reaction system using a peristaltic pump, controlling the reaction temperature at 20°C-25°C. The addition was completed within 2 hours, and the mixture was kept at this temperature for 3 hours after the addition was completed. The reaction was stopped when the benzenesulfonyl chloride content was ≤0.1% as detected by gas phase.

[0053] The organic phase in the system is collected by filtration, and then heated and removed by vacuum distillation to remove the organic phase and a small amount of water.

[0054] Then, the product system was heated, and the fraction at 150℃-160℃ was collected under the condition of -0.1MPa, which was the N-butylbenzenesulfonamide product. 209.4g of light yellow oily liquid product was collected, with a yield of 98.5% and a product purity of 99.6%.

[0055] Example 3 This embodiment provides a method for preparing N-butylbenzenesulfonamide, which includes the following steps: Under a nitrogen atmosphere, n-butylamine (73g, 1mol), organic solvent (toluene, 200g), catalyst (N-methylimidazole, 0.5g), and acid-binding agent (solid sodium hydroxide, 40g) were added to the reaction vessel in proportion. At 20°C, benzenesulfonyl chloride (176g) was slowly added dropwise to the reaction system using a peristaltic pump, controlling the reaction temperature at 20°C-25°C. The addition was completed within 2 hours, and the mixture was kept at this temperature for 3 hours after the addition was completed. The reaction was stopped when the benzenesulfonyl chloride content was ≤0.1% as detected by gas phase.

[0056] The organic phase in the system is collected by filtration, and then heated and removed by vacuum distillation to remove the organic phase and a small amount of water.

[0057] Then, the product system was heated, and the fraction at 180℃-190℃ was collected under the condition of -0.1MPa, which was the N-butylbenzenesulfonamide product. 209.6g of light yellow oily liquid product was collected, with a yield of 98.4% and a product purity of 99.7%.

[0058] Example 4 This embodiment provides a method for preparing N-butylbenzenesulfonamide, which includes the following steps: Under a nitrogen atmosphere, n-butylamine (73g, 1mol), organic solvent (toluene, 200g), catalyst (N-methylimidazole, 0.5g), and acid-binding agent (solid potassium hydroxide, 59g) were added to the reaction vessel in proportion. At 20°C, benzenesulfonyl chloride (176g) was slowly added dropwise to the reaction system using a peristaltic pump, controlling the reaction temperature at 20°C-25°C. The addition was completed within 2 hours, and the mixture was kept at this temperature for 3 hours after the addition was completed. The reaction was stopped when the benzenesulfonyl chloride content was ≤0.1% as detected by gas phase.

[0059] The organic phase in the system is collected by filtration, and then heated and removed by vacuum distillation to remove the organic phase and a small amount of water.

[0060] Then, the product system was heated, and the fraction at 180℃-190℃ was collected under the condition of -0.1MPa, which was the N-butylbenzenesulfonamide product. 210.1g of light yellow oily liquid product was collected, with a yield of 98.6% and a product purity of 99.7%.

[0061] Example 5 This embodiment provides a method for preparing N-butylbenzenesulfonamide, which includes the following steps: Under a nitrogen atmosphere, n-butylamine (73g, 1mol), organic solvent (toluene, 200g), catalyst (N-methylimidazole, 0.5g), and acid-binding agent (59g solid potassium hydroxide dissolved in 256g water) were added to the reaction vessel in proportion. At 20°C, benzenesulfonyl chloride (176g) was slowly added dropwise to the reaction system using a peristaltic pump, controlling the reaction temperature at 20°C-25°C. The addition was completed within 2 hours, and the mixture was kept at this temperature for 3 hours after the addition was completed. The reaction was stopped when the benzenesulfonyl chloride content was ≤0.1% as detected by gas phase.

[0062] Phase separation: the organic phase is washed once with water, the organic phase in the system is collected, and then the temperature is raised, and the organic phase and a small amount of water in the system are removed by vacuum distillation.

[0063] Then, the product system was heated, and the fraction at 180℃-190℃ was collected under the condition of -0.1MPa, which was the N-butylbenzenesulfonamide product. 209.3g of light yellow oily liquid product was collected, with a yield of 98.3% and a product purity of 99.7%.

[0064] Comparative Example 1 This comparative example provides a method for preparing N-butylbenzenesulfonamide, which involves three parallel experiments and includes the following steps: Parallel Experiment 1: Add 44g of n-butylamine and 100g of toluene to a 500mL reaction flask. Then, add a mixed solution of 100g of benzenesulfonyl chloride and 10g of N,N-dimethylformamide dropwise using a constant pressure dropping funnel. React in a water bath while controlling the temperature of the reaction system to not exceed 50℃. After the addition is complete, stir for 30 minutes and heat to 110℃ for 2 hours. Gas phase detection showed that benzenesulfonyl chloride could not react completely. This was because the hydrogen chloride produced by the reaction of n-butylamine and benzenesulfonyl chloride reacted with n-butylamine to form n-butylamine hydrochloride, resulting in a large amount of benzenesulfonyl chloride remaining. Gas phase detection showed that 43.2% of benzenesulfonyl chloride remained unreacted in the reaction solution and was not further distilled.

[0065] Parallel Experiment 2: Add 44g of n-butylamine and 100g of toluene to a 500mL reaction flask, then add 100g of a mixed solution of benzenesulfonyl chloride and 10g of N,N-dimethylformamide dropwise using a constant pressure dropping funnel. React in a water bath while controlling the temperature of the reaction system in the reactor to not exceed 50℃. After the addition is complete, stir for 30 minutes, then heat to 110℃ and react for 2 hours. Gas phase detection showed that benzenesulfonyl chloride could not react completely. This was because the hydrogen chloride produced by the reaction of n-butylamine and benzenesulfonyl chloride reacted with n-butylamine to form n-butylamine hydrochloride, resulting in a large amount of benzenesulfonyl chloride remaining. Gas phase detection showed that 43.3% of benzenesulfonyl chloride remained unreacted in the reaction solution and was not further distilled.

[0066] Parallel Experiment 3: Add 44g of n-butylamine and 100g of toluene to a 500mL reaction flask, then add 100g of a mixed solution of benzenesulfonyl chloride and 10g of N,N-dimethylformamide dropwise using a constant pressure dropping funnel. React in a water bath while controlling the temperature of the reaction system in the reactor to not exceed 50℃. After the addition is complete, stir for 30 minutes, heat to 110℃ and react for 2 hours. Gas phase detection showed that benzenesulfonyl chloride could not react completely. Due to the hydrogen chloride produced by the reaction of n-butylamine and benzenesulfonyl chloride, which reacts with n-butylamine to form n-butylamine hydrochloride, a large amount of benzenesulfonyl chloride remained. Gas phase detection showed that 43.5% of benzenesulfonyl chloride remained unreacted in the reaction solution and was not further distilled.

[0067] Test Example 1 This test example compares the performance of commercially available N-butylbenzenesulfonamide and the N-butylbenzenesulfonamide prepared in Example 1. The specific test methods refer to the Chinese group standard test method for N-butylbenzenesulfonamide, standard number T / ACCEM202-2024. The relevant results are summarized in Tables 1 and 2, where Table 1 shows the performance data of the commercially available product, and Table 2 shows the performance data of the product prepared in Example 1.

[0068] Table 1 Performance data of products sold in the market

[0069] Note: "-" indicates that there is no corresponding data.

[0070] Table 2 Performance data of the product obtained in Example 1

[0071] Combining the data in Tables 1 and 2, it can be seen that the purity of 99.97% in Table 2 is higher than the 99.8% of the products currently sold on the market in Table 1. The platinum-cobalt color in Table 2 is 15 times lower than that of the products sold on the market in Table 1, and the thermal stability in Table 2 is 2.5 times lower than that of the products sold on the market in Table 1. Therefore, the product obtained in this embodiment of the invention has good stability, can be used under high-temperature conditions, better protects the finished product from displaying a lighter color, and does not suffer from yellowing or other problems.

[0072] Test Example 2 This test example analyzes the mass spectrum and gas phase spectrum of the N-butylbenzenesulfonamide prepared in Example 1. The relevant results are shown in [link to relevant data]. Figures 1-2 ,in, Figure 1 The mass spectrum of N-butylbenzenesulfonamide obtained in Example 1; Figure 2 The image shows the gas phase diagram of N-butylbenzenesulfonamide prepared in Example 1.

[0073] Test Example 3 In this test example, the N-butylbenzenesulfonamide prepared in Example 1 was subjected to infrared spectroscopy. The test results are shown in [Figure 1]. Figure 3 .

[0074] from Figure 3 It can be seen that 3300cm -1 The peak at 1350 cm⁻¹ is the stretching vibration peak of the NH secondary amide group. -1 The asymmetric stretching symmetric peak at 1170 cm⁻¹ and the peak at 1170 cm⁻¹ -1 The symmetrical stretching peaks at 1600 cm⁻¹ correspond to the O=S=O sulfonyl stretching vibration peaks, respectively; -1 and 1500cm -1 These correspond to the vibrational peaks of the benzene ring skeleton; 2960 cm⁻¹ -1 Asymmetric peak and 2870 cm -1 The symmetrical peaks correspond to the butyl stretching vibration peaks, respectively.

[0075] In summary, the preparation method of N-butylbenzenesulfonamide provided in the embodiments of the present invention has the following characteristics: low catalyst dosage, which greatly reduces costs; high raw material utilization and low side reaction rate; low acid-binding agent dosage, resulting in less waste salt and wastewater; the reaction can be carried out under normal pressure, without the need for high temperature and high pressure conditions; the acid-binding agent and catalyst are bulk chemical raw materials, making it highly feasible for large-scale production.

[0076] The obtained N-butylbenzene sulfonamide is widely used in plasticizers (such as nylon plastics, polyamide resins, cellulose resins, etc.), adhesives (such as latex adhesives, hot melt adhesives), printing inks and surface coatings; there are few domestic manufacturers, and the annual demand is increasing by about 7% every year, so the product has a very good market prospect.

[0077] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing N-butylbenzenesulfonamide, characterized in that, N-Butylbenzenesulfonamide was prepared by reacting benzenesulfonyl chloride and n-butylamine in an organic solvent system, using an organic base as the catalyst and a solid alkaline substance as the acid binder.

2. The preparation method according to claim 1, characterized in that, The molar ratio of benzenesulfonyl chloride to n-butylamine is 1:(1-3), preferably 1:(1-2), and more preferably 1:(1-1.5).

3. The preparation method according to claim 1, characterized in that, The catalyst has a mass of 0%-1% of the mass of benzenesulfonyl chloride, preferably 0.05%-0.5%, and more preferably 0.05%-0.25%. The catalyst is selected from at least one of N,N-dimethylaminopyridine, N-methylimidazolium, bis(2-dimethylaminoethyl) ether and 4-pyrrolylpyridine.

4. The preparation method according to claim 1, characterized in that, The mass ratio of the acid-binding agent to the total mass of benzenesulfonyl chloride and n-butylamine is 1:(1-3), preferably 1:(1-2), and more preferably 1:(1-1.5). The acid-binding agent is selected from at least one of sodium hydroxide, potassium hydroxide, calcium hydroxide, magnesium hydroxide, sodium methoxide, and sodium tert-butyloxide.

5. The preparation method according to claim 1, characterized in that, The mass ratio of the organic solvent to the benzenesulfonyl chloride is 1:(1-10), preferably 1:(1-6), and more preferably 1:(1-3). The organic solvent is selected from at least one of toluene, xylene, dichloromethane, chloroform, cyclohexane, n-hexane, ethyl acetate, and butyl acetate.

6. The preparation method according to claim 1, characterized in that, The reaction temperature in the organic solvent system is -10℃ to 100℃, preferably 0℃ to 80℃, and more preferably 10℃ to 30℃; And / or, the reaction time is 1h-10h, preferably 1h-8h, more preferably 1h-3h.

7. The preparation method according to claim 1, characterized in that, The preparation of N-butylbenzenesulfonamide is carried out in a protective atmosphere selected from at least one of nitrogen, helium and argon. And / or, after mixing n-butylamine, organic solvent, catalyst and acid-binding agent in proportion, add benzenesulfonyl chloride and control the process within 2 hours; after adding benzenesulfonyl chloride, keep it at a constant temperature for 1-3 hours, and stop the reaction after the benzenesulfonyl chloride reaction is completed.

8. The preparation method according to claim 7, characterized in that, The preparation method further includes the following after the reaction stops: N-Butylbenzenesulfonamide was prepared by collecting the fraction from 180℃ to 190℃ under a pressure of -0.1MPa.

9. An N-butylbenzenesulfonamide, characterized in that, Prepared by the preparation method according to any one of claims 1-8; The N-butylbenzenesulfonamide has a yield of ≥98%, a conversion rate of ≥99%, a selectivity of ≥99%, and a purity of ≥99.5%.

10. The use of N-butylbenzenesulfonamide as described in claim 9 in the preparation of plasticizers, adhesives, printing inks and surface coatings.

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