CN116041190A - Polyethylene polyamine type ammonium salt ionic liquid and preparation method and application thereof - Google Patents

Abstract

The invention discloses a polyethylene polyamine type ammonium salt ionic liquid, a preparation method and application thereof. The polyethylene polyamine type ammonium salt ionic liquid is prepared from polyethylene polyamine and corresponding protonic acid, the anion in the ammonium salt comes from the protonic acid, and is selected from HSO ₄ ^‑ , HSO ₄ (H ₂ SO ₄ ) ^‑ , HSO One or more anions of ₄ (H ₂ SO ₄ ) ₂ ^‑ , CF ₃ SO ₃ ^‑ , CH ₃ SO ₃ ^‑ and R'‑C ₆ H ₄ SO ₃ ^‑ , wherein R' is H or alkane base; the cation in the ammonium salt ionic liquid is from the ammonium root cation formed by polyethylene polyamine, and in the ammonium salt ionic liquid, the molar ratio of nitrogen atom to protonic acid is 1:(1～3); the described The polyethylene polyamine includes two or more polyethyleneimine oligomers, and the amine value or nitrogen content of the polyethylene polyamine is 10-50wt%. The substrate conversion rate of the ionic liquid synthesized by the invention can reach more than 90%.

Description

A kind of polyethylene polyamine type ammonium salt ionic liquid and its preparation method and application

Technical Field

The invention relates to the field of organic chemical synthesis technology and green catalysis, in particular to a polyethylene polyamine type ammonium salt ionic liquid and a preparation method and application thereof.

Background Art

Acid catalysts are indispensable in the modern chemical industry and are widely used in representative synthetic routes such as nitration, esterification, and alkylation. At present, industrial acid catalysis, especially esterification and aromatic nitration, uses more inorganic acid catalysts such as hydrochloric acid, sulfuric acid, and phosphoric acid to improve the reaction activity, but at the same time causes equipment corrosion, high separation and recovery costs, and difficult to reuse. Therefore, the waste acid generated requires a large amount of alkali neutralization, and the additional alkali neutralization and inorganic salt removal steps bring additional raw materials and energy consumption.

酸性离子液体催化剂，其具有蒸汽压低不易挥发、合成工艺相对简易和分离回收除水后即可再生利用的特点。In order to cope with the shortcomings of traditional inorganic acid catalysts, the development of green and efficient new catalysts has become a trend.

Acidic ionic liquid catalysts have the characteristics of low vapor pressure and low volatility, relatively simple synthesis process, and can be recycled after separation and recovery and water removal.

酸性离子液体之一。D.Gong等以甲基咪唑和硫酸为原料成功合成室温离子液体[Hmim]HSO₄(Asian Journal ofChemistry,Vol.22,No.8,6413-6416)，US20040024266A1中以[C₁₀min](OTf)为催化剂硝化底物苯，得到了接近理论产率的硝基苯，但该方法存在部分催化剂自身被硝化的局限。此外，由于咪唑类前体价格昂贵、有一定的毒性，目前尚无大规模工业生产，导致市场供应量小。Imidazolium ionic liquids are the most common and earliest commercialized

One of the acidic ionic liquids. D. Gong et al. successfully synthesized room temperature ionic liquid [Hmim]HSO ₄ using methylimidazole and sulfuric acid as raw materials (Asian Journal of Chemistry, Vol. 22, No. 8, 6413-6416). In US20040024266A1, [C ₁₀ min] (OTf) was used as a catalyst to nitrate the substrate benzene, and nitrobenzene with a yield close to the theoretical yield was obtained. However, this method has the limitation that part of the catalyst itself is nitrated. In addition, since imidazole precursors are expensive and have certain toxicity, there is currently no large-scale industrial production, resulting in a small market supply.

CN1772739A discloses a method for synthesizing ionic liquids in one step by using lactam instead of imidazole, which is simple in reaction and reduces the cost of raw materials. The Hammett acid strength H ₀ of the ionic liquid synthesized by this method is relatively small (using methyl yellow as an indicator) and the catalytic activity is relatively low.

CN105732439A, CN101648894A, and CN101348487A first perform sulfonic functionalization reaction of polyamines, and then add stoichiometric equivalents of acid for protonation to obtain high acid value ionic liquids. Sulfonic acid onium quaternary ammonium salt acidic ionic liquids embody the powerful designability of ionic liquids, but the disadvantage of this method is that the functionalization step of polyamines requires the addition of ylide salts that are multiple times the amine equivalent, which increases raw material consumption, prolongs the synthesis process, and easily introduces impurities, weakening the process advantage of ionic liquids that are easy to synthesize.

Therefore, it is very necessary to find low-cost and high-efficiency ionic liquids.

Summary of the invention

In view of the problems existing in the prior art, the present invention provides a polyethylene polyamine type ammonium salt ionic liquid and a preparation method and application thereof.

In order to achieve the above object, the present invention adopts the following technical solution:

A polyethylene polyamine type ammonium salt ionic liquid, characterized in that:

The ammonium salt ionic liquid is prepared from polyethylene polyamine and corresponding protonic acid (HA), the anion (A) in the ammonium salt comes from the protonic acid, and is selected from one of HSO ₄ ^- , HSO ₄ (H ₂ SO ₄ ) ^- , HSO ₄ (H ₂ SO ₄ ) ₂ ^- , CF ₃ SO ₃ ^- , CH ₃ SO ₃ ^- and R'-C ₆ H ₄ SO ₃ ^- , wherein R' is an alkyl group, preferably H, CH ₃ or C ₁₂ H ₂₅ ; the cation in the ammonium salt ionic liquid comes from the ammonium cation formed by polyethylene polyamine, and in the ammonium salt ionic liquid, the molar ratio of nitrogen atom to protonic acid is 1:(1-3);

The polyethylene polyamine comprises two or more polyethylene imine oligomers, and the amine value or nitrogen content of the polyethylene polyamine is 10-50wt%;

其中，n＝1～6。The polyethyleneimine oligomer has the following general formula:

Among them, n=1~6.

As a preferred embodiment of the above ionic liquid, the polyethylene polyamine further comprises at least one of polyethyleneimine polymer and tertiary amine;

The structural formula of the polyethyleneimine polymer is as follows:

且z＝2～15、和

中的一种；Wherein, x=0-100, y=0-100, and x+y≥7, R is selected from H, C1-C12 alkyl,

and z = 2 to 15, and

One of the following;

The tertiary amine is selected from at least one of triethylamine, tripropylamine, tributylamine, N,N-diisopropylethylamine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N",N"-pentamethyldivinyltriamine, N,N,N',N'-tetramethylmethanediamine, N,N,N',N'-tetramethyl-1,3-propylenediamine, tri[2-(dimethylamino)ethyl]amine and hexadecyldimethyl tertiary amine.

The CAS numbers of various tertiary amines are as follows:

Tertiary amine CAS Triethylamine 121-44-8 Tripropylamine 102-69-2 Tributylamine 102-82-9 N,N-Diisopropylethylamine 7087-68-5 N,N,N',N'-Tetramethylethylenediamine 110-18-9 N,N,N',N",N"-pentamethyldivinyltriamine 3030-47-5 N,N,N′,N′-Tetramethylmethanediamine 51-80-9 N,N,N′,N′-Tetramethyl-1,3-propanediamine 110-95-2 Tris[2-(dimethylamino)ethyl]amine 33527-91-2 Hexadecyl dimethyl tertiary amine 112-69-6

The ammonium salt ionic liquid of the present invention is marked as [polyethylene polyamine][HA] _x' , where x' is the molar ratio of protonic acid to nitrogen atoms in polyethylene polyamine, x'=1-3, and HA is protonic acid.

As a preferred embodiment of the above-mentioned ionic liquid, the two or more polyethyleneimine oligomers are a mixture of ethylenediamine, diethylenetriamine, triethylenetetramine and tetraethylenepentamine; preferably, the two or more polyethyleneimine oligomers also include at least one of pentaethylenehexamine and hexaethyleneheptamine.

As a preferred embodiment of the above ionic liquid, the CAS number of the polyethyleneimine polymer is selected from one of 9002-98-6, 25987-06-8, 106899094-9 and 68130-97-2.

As a preferred embodiment, the above-mentioned ionic liquid is selected from at least one of the following commercial products or similar commercial products:

Heavy Polyamine XE (Dow), Ethyleneamine E-100 (Huntsman), Polyethylenepolyamine (Cameo Chemicals), PEPA (Silkor), ethyleneamine mixture Poly-7 (Tosoh Corporation); preferably, the CAS registration number of the polyethylene polyamine is one of 68131-73-7, 37231-61-2 and 68551-30-4.

The polyethylene polyamines of the present invention are a mixture. In a specific embodiment, the polyethylene polyamines (PEPA) include but are not limited to a mixture containing ethylenediamine, diethylenetriamine, triethylenetetramine, and tetraethylenepentamine, and may also include pentaethylenehexamine, hexaethyleneheptamine, and/or a polyethyleneimine polymer with a higher molecular weight. The polyethylene polyamine mixture includes but is not limited to a mixture containing polyethyleneimine oligomers and/or polymers and one or more tertiary amines; the amine value of the mixture is 10-50wt%.

In the present invention, when the anion of the ionic liquid is HSO ₄ (H ₂ SO ₄ ) ^- or HSO ₄ (H ₂ SO ₄ ) ₂ ^- , compared with the traditional hydrogen sulfate (HSO ₄ ^- ) anion, HSO ₄ (H ₂ SO ₄ ) ^- or HSO ₄ (H ₂ SO ₄ ) ₂ ^- has stronger acidity, higher activity and stability, and is more unique when combined with quaternary ammonium salt cations.

The polyethylene polyamine type ammonium salt ionic liquid of the present invention is in liquid state at room temperature. On the one hand, the polyethylene polyamine type ammonium salt ionic liquid has the characteristics of low viscosity and strong fluidity; on the other hand, since it is a protonated ionic liquid, it has a high acid value, can make the receptor protonated more completely, and exhibits stronger catalytic activity in acid-catalyzed reactions.

The present invention also provides a method for preparing the above-mentioned polyethylene polyamine type ammonium salt ionic liquid, which adopts the following technical scheme:

The above-mentioned polyethylene polyamine type ammonium salt ionic liquid and its preparation method start from polyethylene polyamine, by adding an appropriate amount of protonic acid, under specific experimental conditions, to construct a polyethylene polyamine type ammonium salt ionic liquid with the ammonium salt of polyethylene polyamine as the cation and the anion from the protonic acid (HA).

In the above preparation method, as a preferred embodiment, the preparation method comprises the following steps:

Step 1: Add the above-mentioned polyethylene polyamine into a reactor equipped with a stirring device and a condensing reflux device, start stirring, and set the speed to 100-1000 rpm, preferably 400-800 rpm;

Step 2: Add the above-mentioned protonic acid to the reactor of step 1 in batches within 30-60 minutes, and control the temperature in the reactor to be between 0-30°C; after the addition is completed, stir at 0-30°C for 2-3 hours to obtain a viscous ionic liquid; wherein the molar ratio of nitrogen atoms in polyethylene polyamine to protonic acid is 1:(1-3).

In the above preparation method, as a preferred embodiment, when the anion of the ammonium salt ionic liquid is HSO ₄ ^- or hydrogen sulfate hydrogen-bonded sulfuric acid, that is, HSO ₄ ^- , HSO ₄ (H ₂ SO ₄ ) ^- or HSO ₄ (H ₂ SO ₄ ) ₂ ^- , the preparation method comprises:

Step 1: Add polyethylene polyamine into a container equipped with a stirring device and a condensing reflux device, start stirring, and set the speed to 400-800 rpm;

Step 2: Place the container in the above step 1 in an ice water bath, and dropwise add 93-98% sulfuric acid within 30-60 minutes, during which the temperature in the container is controlled to be less than 30° C. After the addition, continue stirring at room temperature for 2-3 hours, stop stirring, and obtain a brown viscous ionic liquid, wherein the molar ratio of nitrogen atoms in polyethylene polyamine to sulfuric acid is 1:(1-3), and the room temperature is 20-30° C.

The present invention also provides an application of the above-mentioned polyethylene polyamine type ammonium salt ionic liquid as a catalyst in the field of industrial acid catalysis reaction, wherein the industrial acid catalysis reaction is a nitration reaction; preferably, the nitration reaction is an aromatic hydrocarbon nitration reaction.

In the above application, as a preferred embodiment, the polyethylene polyamine type ammonium salt ionic liquid is used to catalyze the nitration reaction of aromatic hydrocarbons, wherein the aromatic hydrocarbons include benzene and substituted benzenes, wherein the substituted benzenes are selected from one of monosubstituted, disubstituted and polysubstituted, and preferably, the structure of the substituted benzene is selected from one of the following structures:

When the substituted benzene is monosubstituted, X is selected from one of halogen, alkyl, halogen-substituted alkyl, alkoxy, and amide. Preferably, X is selected from one of F, Cl, Br, I, CF ₃ , CH ₃ , OCH ₃ , C ₂ H ₅ , C ₄ H ₉ , C ₁₀ H ₂₁ , C ₁₂ H ₂₅ , C ₁₈ H ₃₇ , and NHCOCH ₃ ;

When the substituted benzene is disubstituted or polysubstituted, X is selected from one of halogen, alkyl, and alkoxy. Preferably, X is selected from one of F, Cl, CH ₃ , and OCH ₂ CH ₂ O.

The polyethylene polyamine type ammonium salt ionic liquid is used for the catalytic nitration reaction of aromatic hydrocarbons, and the structure of the aromatic hydrocarbons can also be selected from one of the following:

其中A为O、CH₂或S。

Where A is O, _CH2 or S.

Further, the mass ratio of substrate to ionic liquid is 1:1 to 3;

Further, the temperature of the nitration reaction is 50 to 80°C;

Furthermore, the nitration reaction time is 1 to 20 hours;

Further, the molar ratio of nitric acid to substrate is 1 to 2:1; further, the aqueous ionic liquid layer can be reused after evaporation to remove water;

Further, the nitric acid concentration is above 65%;

Further, after the reaction is completed, the temperature is cooled to 40-50°C;

Furthermore, the nitration product is mainly a mononitro product.

Compared with the prior art, the technical solution adopted by the present invention has the following beneficial technical effects:

(1) The ionic liquid obtained by the technical solution of the present invention has the characteristics of low melting point, low viscosity and strong fluidity. Due to the low melting point, this type of ionic liquid is liquid at room temperature, which means that it can be fully mixed with the reactants as a catalyst under non-heating conditions. In addition, due to its high fluidity, the degree of mixing between the reactants and the ionic liquid is greatly improved, which is conducive to improving the conversion rate of the main reaction;

(2) This type of ionic liquid can be used in nitration reactions, esterification reactions, alkylation reactions, condensation reactions, oxidation reactions, etc.

酸性室温离子液体属于绿色的新型催化剂，具有蒸汽压低不易挥发，合成工艺相对简易，分离回收除水后即可再生利用的特点；(3) Industrial acid catalysis, especially for the nitration of aromatic hydrocarbons, uses more inorganic acid catalysts such as hydrochloric acid, sulfuric acid, and phosphoric acid to improve the reaction activity, but at the same time causes equipment corrosion, high regeneration costs after separation and recovery, and low reuse rate. Therefore, the waste acid generated requires a large amount of alkali neutralization. The additional alkali neutralization and inorganic salt removal steps bring additional raw materials and energy consumption.

Acidic room temperature ionic liquids are a new type of green catalyst with low vapor pressure, low volatility, relatively simple synthesis process, and can be recycled after separation and dehydration.

(4) The ionic liquid prepared by the method of the present invention is a protonated ionic liquid. As a catalyst, it has a higher acid value, can make the acceptor protonated more completely, and exhibits stronger catalytic activity in acid-catalyzed reactions.

(5) The ionic liquid synthesized in the present invention has a high yield of mononitro products when catalyzing the nitration reaction of aromatic hydrocarbons. In addition to the mononitro products, other by-products in the product are very rare or even undetectable, and the substrate conversion rate can reach more than 90%.

DETAILED DESCRIPTION

The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the specific implementation of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other implementations obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

Among the polyethylene polyamines used in the following examples, the product with the trade name Ethyleneamine E-100 (Huntsman) (CAS: 68131-73-7) is a co-product of ethylenediamine, diethylenetriamine, triethylenetetramine and tetraethylenepentamine. It has an ammonia smell, easily absorbs moisture and carbon dioxide in the air, and forms corresponding salts with acids. It solidifies at low temperatures, is strongly alkaline, is miscible with water, alcohol and ether, and is corrosive. Boiling point: 250°C, density: 1.070kg/L, refractive index: n20/D: 1.5120, flash point: 110°C.

Example 1

Weigh 8.58 g of E-100 polyethylene polyamine (CAS: 68131-73-7) (nitrogen content of 32.65%) into a 100 mL four-necked flask, and slowly drop 20.03 g of 98% sulfuric acid (0.2 mol, equimolar to the nitrogen in the polyethylene polyamine, i.e., the molar ratio of N to sulfuric acid is 1:1) over 40 min under ice bath stirring. After the dropwise addition, continue stirring and reacting at room temperature for 2 h to obtain a brown viscous ionic liquid with a composition of [polyethylene polyamine][H ₂ SO ₄ ], numbered A1, and a yield of 99.9%.

Preparation of ionic liquid by changing sulfuric acid equivalent:

Weigh 8.58 g of E-100 polyethylene polyamine (CAS: 68131-73-7, nitrogen content 32.65%) into a 100 mL four-necked flask, slowly drop 30.47 g (0.4 mol) of 98% sulfuric acid over 40 min under ice bath stirring, continue stirring and react at room temperature for 2 h to obtain a brown viscous ionic liquid with a composition of [polyethylene polyamine][H ₂ SO ₄ ] ₂ , numbered A2, and a yield of 99.9%.

8.58 g of E-100 polyethylene polyamine (CAS: 68131-73-7, nitrogen content 32.65%) was weighed into a 100 mL four-necked flask, and 60.03 g (0.6 mol) of 98% sulfuric acid was slowly added dropwise within 40 min under ice bath stirring. After the addition was completed, the mixture was stirred and reacted at room temperature for 2 h to obtain a brown viscous ionic liquid with a composition of [polyethylene polyamine][H ₂ SO ₄ ] ₃ , numbered A3, and a yield of 99.9%.

Table 1 Viscosity of ionic liquid A3 prepared in Example 1 at different temperatures

Example 2

Weigh 8.58 g of polyethylene polyamine (CAS: 68131-73-7) (nitrogen content: 32.65%) into a 100 mL four-necked flask, slowly drop 21.09 g (0.2 mol) of 93% sulfuric acid within 30 min under ice bath stirring, continue stirring and react at room temperature for 1.5 h to obtain a brown viscous ionic liquid with a composition of [polyethylene polyamine][H ₂ SO ₄ ] and a yield of 99.8%.

Preparation of ionic liquid by changing sulfuric acid equivalent:

Weigh 8.58 g of polyethylene polyamine (CAS: 68131-73-7) (nitrogen content: 32.65%) into a 100 mL four-necked flask, slowly drop 42.17 g (0.4 mol) of 93% sulfuric acid within 30 min under ice bath stirring, continue stirring and react at room temperature for 1.5 h after the dropwise addition, and obtain a brown viscous ionic liquid with a composition of [polyethylene polyamine][H ₂ SO ₄ ] ₂ and a yield of 99.8%.

Weigh 8.58 g of polyethylene polyamine (CAS: 68131-73-7) (nitrogen content: 32.65%) into a 100 mL four-necked flask, slowly drop 63.26 g (0.6 mol) of 93% sulfuric acid within 30 min under ice bath stirring, continue stirring and react at room temperature for 1.5 h after the dropwise addition, and obtain a brown viscous ionic liquid with a composition of [polyethylene polyamine][H ₂ SO ₄ ] ₃ and a yield of 99.8%.

Example 3

Weigh 8.58 g of polyethylene polyamine (CAS: 68131-73-7) (nitrogen content: 32.65%) into a 100 mL four-necked flask, slowly drop 20.43 g (0.2 mol) of 96% sulfuric acid over 40 min under ice bath stirring, continue stirring and react at room temperature for 2 h after the dropwise addition, and obtain a brown viscous ionic liquid with a composition of [polyethylene polyamine][H ₂ SO ₄ ] and a yield of 99.5%.

Preparation of ionic liquid by changing sulfuric acid equivalent:

Weigh 8.58 g of polyethylene polyamine (CAS: 68131-73-7) (nitrogen content: 32.65%) into a 100 mL four-necked flask, slowly drop 40.85 g (0.4 mol) of 96% sulfuric acid within 40 min under ice bath stirring, continue stirring and react at room temperature for 2 h after the dropwise addition, and obtain a brown viscous ionic liquid with a composition of [polyethylene polyamine][H ₂ SO ₄ ] ₂ and a yield of 99.5%.

Weigh 8.58 g of polyethylene polyamine (CAS: 68131-73-7) (nitrogen content: 32.65%) into a 100 mL four-necked flask, slowly drop 61.28 g (0.6 mol) of 96% sulfuric acid over 40 min under ice bath stirring, continue stirring and react at room temperature for 2 h after the dropwise addition, and obtain a brown viscous ionic liquid with a composition of [polyethylene polyamine][H ₂ SO ₄ ] ₃ and a yield of 99.5%.

Embodiment 4:

A certain amount of polyethylene polyamine (CAS: 68131-73-7) (nitrogen content: 32.65%) was weighed into a 100 mL four-necked flask, and a certain amount of 99% trifluoromethanesulfonic acid was slowly added dropwise within 40 min under ice bath stirring. After the addition was completed, the reaction was continued under stirring at room temperature for 1.5 h to obtain a brown viscous ionic liquid with a composition of [polyethylene polyamine][CF ₃ SO ₃ H] _x' . The amounts and yields of the corresponding raw materials used for different products are shown in Table 2 below.

Table 2 Experimental conditions and yields of preparing [polyethylene polyamine][CF ₃ SO ₃ H] _x' in Example 4

Example Polyethylene polyamine (g) Trifluoromethanesulfonic acid(g) [Polyethylene polyamine][CF ₃ SO ₃ H] _x' Yield (%) 4-1 8.58 90.0 x'＝3 99.5 4-2 8.58 60.0 x'＝2 99.6 4-3 8.58 30.0 x'＝1 99.2

When x'=1, the anion of the ionic liquid is CF ₃ SO ₃ ^- ; when x'=2, the anion of the ionic liquid is CF ₃ SO ₃ (CF ₃ SO ₃ H) ^- ; when x'=3, the anion of the ionic liquid is CF ₃ SO ₃ (CF ₃ SO ₃ H) ₂ ^- .

Example 5

A certain amount of polyethylene polyamine (CAS: 68131-73-7) (nitrogen content: 32.65%) was weighed into a 100 mL four-necked flask, and a certain amount of 99% methanesulfonic acid was slowly added dropwise within 40 min under ice bath stirring. After the addition was completed, the reaction was continued under stirring at room temperature for 1.5 h to obtain a brown viscous ionic liquid with a composition of [polyethylene polyamine][CH ₃ SO ₃ H] _x' . The amounts and yields of the corresponding raw materials used for different products are shown in Table 3 below.

Table 3 Experimental conditions and yields of preparing [polyethylene polyamine][CH ₃ SO ₃ H] _x' in Example 5

When x'=1, the anion of the ionic liquid is CH ₃ SO ₃ ^- ; when x'=2, the anion of the ionic liquid is CH ₃ SO ₃ (CH ₃ SO ₃ H) ^- ; when x'=3, the anion of the ionic liquid is CH ₃ SO ₃ (CH ₃ SO ₃ H) ₂ ^- .

Example 6

A certain amount of polyethylene polyamine (CAS: 68131-73-7) (nitrogen content: 32.65%) was weighed into a 100 mL four-necked flask, and a certain amount of 99% benzenesulfonic acid was slowly added dropwise within 40 min under ice bath stirring. After the addition was completed, the reaction was continued under stirring at room temperature for 1.5 h to obtain a brown viscous ionic liquid with a composition of [polyethylene polyamine][C ₆ H ₅ SO ₃ H] _x' . The amounts and yields of the corresponding raw materials used for different products are shown in Table 4 below.

Table 4 Experimental conditions and yields of preparing [polyethylene polyamine][C ₆ H ₅ SO ₃ H] _x' in Example 5

Example Polyethylene polyamine (g) Benzenesulfonic acid(g) [Polyethylenepolyamine][C ₆ H ₅ SO ₃ H] _x' Yield (%) 6-1 8.58 94.9 x'＝3 99.5 6-2 8.58 63.3 x'＝2 99.4 6-3 8.58 31.6 x'＝1 99.3

When x'=1, the anion of the ionic liquid is C ₆ H ₅ SO ₃ ^- ; when x'=2, the anion of the ionic liquid is C ₆ H ₅ SO ₃ (C ₆ H ₅ SO ₃ H) ^- ; when x'=3, the anion of the ionic liquid is C ₆ H ₅ SO ₃ (C ₆ H ₅ SO ₃ H) ₂ ^- .

Example 7

Similarly, more ionic liquid preparation examples can be prepared by the general method mentioned in A1-A3 in Example 1. Here, taking the tertiary amines in Table 5 as an example, one or more tertiary amines are selected, mixed in a specific molar ratio or mixed with E-100 to form a polyethylene polyamine mixture, the mixing ratio is shown in Table 5, and then the proton acid is added to react according to the molar ratio of the amine group to the proton acid of 1:1, 1:2 and 1:3 to prepare the corresponding ionic liquid. Based on the ionic liquid product numbers (A1, A2 and A3) of Example 1, the following Table 5 gives other ionic liquid products [polyethylene polyamine] [HA] _x' and the corresponding numbers, and the numbers 1, 2 and 3 represent the molar ratio of the proton acid to the N atom in the ionic liquid.

Table 5 Composition and numbering of [polyethylene polyamine] [HA] _x' prepared in Example 7

The following is a combination of the specific implementation methods of the ionic liquid of the present invention in the nitration reaction of aromatic hydrocarbons to better illustrate the value of the new ionic liquid in the present invention. It should be understood that the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The feeding method of the nitration reaction in the embodiment is uniformly described as: adding ionic liquid and nitric acid, heating to 70-80°C, adding substrate, and conducting nitration reaction. In each embodiment and comparative example, when adjusting the concentration of nitric acid for testing, the actual amount of the corresponding nitric acid should be adjusted according to the molar ratio of substrate to pure nitric acid of 1:1. The ortho-to-para ratio described in the present invention refers to the molar ratio of ortho-product to para-product, the conversion rate is the molar percentage of substrate converted to product in the nitration reaction, and the yield is the percentage of the actual molar amount of mononitration product to the theoretical molar amount. The technical solution of the present invention has a high yield of mononitration product, and by-products other than mononitration product are rarely or even undetectable. Therefore, the conversion rate is basically the same as the yield, and the difference between the two is less than 1%.

Example 8

In a four-necked flask equipped with a reflux condenser, 28.0g of the ionic liquid A3 prepared in Example 1 and 16.5g of 68% nitric acid were added in sequence, heated to 70-80°C, and 20.0g of chlorobenzene was added to carry out nitration of chlorobenzene. After the reaction was completed for 12 hours, it was cooled to 40-50°C, allowed to stand for stratification, and the lower layer of water-containing ionic liquid layer was separated. The upper layer was light yellow solid mononitrochlorobenzene, and the chlorobenzene conversion rate exceeded 95%. The ortho-to-difference ratio of the liquid chromatography analysis product was 2.1. The water-containing ionic liquid layer can be reused after evaporation and dehydration. The upper organic phase was taken for gas phase analysis of the product. Except for the mononitrochlorobenzene product and unconverted chlorobenzene, there was no dinitrochlorobenzene.

According to the above nitration method, chlorobenzene nitration was carried out using nitric acid of other concentrations or by appropriately adjusting the amount of ionic liquid. The specific reaction conditions and results are listed in Table 6.

Table 6 Nitration of chlorobenzene catalyzed by [polyethylene polyamine][H ₂ SO ₄ ] ₃ ionic liquid A3

Example 9

In a four-necked flask equipped with a reflux condenser, 42.0 g of the ionic liquid A3 prepared in Example 1 and 30.5 g of 68% nitric acid were added in sequence, heated to 70-80°C, and 30.0 g of toluene was added to carry out toluene nitration reaction. After the reaction was completed for 9 hours, it was cooled to 40-50°C, allowed to stand for stratification, and the lower layer of water-containing ionic liquid was separated, and the upper layer was mononitrotoluene, and the toluene conversion rate exceeded 94%. The ortho-toluene ratio of the product by liquid chromatography analysis was 2.1. The water-containing ionic liquid layer can be reused after evaporation and dehydration.

According to the above nitration method, other concentrations of nitric acid were used to nitrate toluene. The specific reaction conditions and results are listed in Table 7.

Table 7 Nitration of toluene catalyzed by [polyethylene polyamine][H ₂ SO ₄ ] ₃ ionic liquid A3

Example Toluene/ionic liquid weight ratio Nitric acid% Temperature ℃ Reaction time Conversion Rate % Neighbor Comparison 9-1 1:1.4 65 70-80 9h 96.3 2.1 9-2 1:1.4 68 70-80 9h 95.2 2.1 9-3 1:1.4 95 70-80 8h 97.1 2.3 9-4 1:1.4 98 70-80 8h 96.0 2.2

Example 10

In a four-necked flask equipped with a reflux condenser, 48.0 g of the ionic liquid A3 prepared in Example 1 and 26.2 g of 68% nitric acid were added in sequence, heated to 70-80°C, and 30.0 g of o-xylene was added for nitration reaction. After the reaction was completed for 8 hours, it was cooled to 40-50°C, allowed to stand for stratification, and the lower layer of the ionic liquid containing water was separated, and the upper layer was mononitro o-xylene, with a conversion rate of more than 94%. The ionic liquid layer containing water can be reused after evaporation to remove water.

According to the above nitration method, other concentrations of nitric acid were used to nitrate o-xylene. The specific reaction conditions and results are listed in Table 8.

Table 8 Nitration of o-xylene catalyzed by [polyethylene polyamine][H ₂ SO ₄ ] ₃ ionic liquid A3

Example o-Xylene/ionic liquid weight ratio Nitric acid% Temperature ℃ Reaction time Conversion Rate % 10-1 1:1.6 65 70-80 8h 95.2 10-2 1:1.6 68 70-80 8h 95.0 10-3 1:1.6 95 70-80 7h 96.2 10-4 1:1.6 98 70-80 7h 96.3

Embodiment 11

In a four-necked flask equipped with a reflux condenser, 80 g of 1,2-dichloroethane, 20 g of naphthalene, and 20.0 g of the [polyethylene polyamine][H ₂ SO ₄ ] ₃ ionic liquid A3 prepared in Example 1 were added, and 10.5 g of 95% nitric acid was added dropwise at room temperature, and the temperature of the addition was controlled not to be higher than 30°C. After the addition was completed, the mixture was heated to 65-70°C for reaction. After the reaction was completed for 5 hours, the mixture was allowed to stand for stratification, and the lower layer of the ionic liquid containing water was separated. The upper organic layer containing nitronaphthalene was taken for GC detection. The molar ratio of 1-nitronaphthalene to 2-nitronaphthalene was about 30:1, and the conversion rate exceeded 92%. The ionic liquid layer containing water can be reused after evaporation to remove water.

According to the above nitration method, naphthalene was nitrated using nitric acid of other concentrations. The specific reaction conditions and results are listed in Table 9.

Table 9 Mononitration of naphthalene catalyzed by [polyethylene polyamine][H ₂ SO ₄ ] ₃ ionic liquid A3

Example Naphthalene/ionic liquid weight ratio Nitric acid% Temperature ℃ Reaction time Conversion Rate % 11-1 1:1 65 65-70 5h 92.5 11-2 1:1 68 65-70 5h 93.1 11-3 1:1 95 65-70 5h 94.5 11-4 1:1 98 65-70 5h 94.2

Take the 1,2-dichloroethane organic layer prepared by Example 11 (calculated based on the actual content of 20g of nitronaphthalene), add it to a four-necked flask equipped with a reflux condenser, and add 20.0g of [polyethylene polyamine][H ₂ SO ₄ ] ₃ ionic liquid A3 prepared by Example 1 in sequence, add 7.8g of 95% nitric acid dropwise at room temperature, control the dropping temperature not higher than 30°C, and after the dropping is completed, heat to 65-70°C for the second nitration reaction of nitronaphthalene for 12h. After the reaction is completed, cool to room temperature, and a large amount of yellow solid product precipitates. Add 80g of water to the reaction system, stir evenly, filter to obtain a yellow solid, and wash the upper solid with 30g of methanol to obtain a light yellow solid dinitronaphthalene. Liquid phase analysis shows that the molar ratio of 1,5-dinitronaphthalene to 1,8-dinitronaphthalene is about 0.5:1, and the conversion rate exceeds 89%. The water-containing ionic liquid layer can be reused after evaporation and dehydration.

According to the above secondary nitration method, other concentrations of nitric acid were used to carry out the secondary nitration of nitronaphthalene. The specific reaction conditions and results are listed in Table 10.

Table 10 Nitration of nitronaphthalene catalyzed by [polyethylene polyamine][H ₂ SO ₄ ] ₃ ionic liquid A3

Example Substrate Substrate/ionic liquid weight ratio Nitric acid% Temperature ℃ Reaction time Conversion Rate % 11-1 Nitronaphthalene 1:1 65 65-70 12h 89.2 11-2 Nitronaphthalene 1:1 68 65-70 12h 90.1 11-3 Nitronaphthalene 1:1 95 65-70 12h 92.5 11-4 Nitronaphthalene 1:1 98 65-70 12h 93.0

Example 12

According to the nitration method in Example 8, other aromatic hydrocarbons and substituted aromatic hydrocarbons were subjected to nitration reaction using the ionic liquid A3 described in Example 1 as a catalyst. The specific reaction conditions and results are listed in Table 11.

Table 11 Nitration of aromatic hydrocarbons catalyzed by [polyethylene polyamine][H ₂ SO ₄ ] ₃ ionic liquid A3

Note: “/” in Table 11 means “or”.

Example 13

In a four-necked flask equipped with a reflux condenser, 28.0 g of [polyethylene polyamine][CF ₃ SO ₃ H] ₃ ionic liquid 4-1 prepared in Example 4 and 16.5 g of 68% nitric acid were added in sequence, heated to 70-80°C, and 20.0 g of chlorobenzene was added to carry out chlorobenzene nitration reaction. After the reaction was completed for 12 hours, it was cooled to 40-50°C, allowed to stand for stratification, and the lower layer of water-containing ionic liquid was separated, and the upper layer was mononitrochlorobenzene, with a conversion rate of 94.3%. The ortho-to-difference ratio of the product by liquid chromatography analysis was 2.2. The water-containing ionic liquid layer can be reused after evaporation to remove water.

According to the above nitration method, chlorobenzene was nitrated using nitric acid of other concentrations. The specific reaction conditions and results are listed in Table 12.

Table 12 Nitration of chlorobenzene catalyzed by [polyethylene polyamine][CF ₃ SO ₃ H] ₃ ionic liquid 4-1

Embodiment 14

In a four-necked flask equipped with a reflux condenser, 42.0 g of [polyethylene polyamine][CF ₃ SO ₃ H] ₃ ionic liquid 4-1 prepared in Example 4 and 30.5 g of 68% nitric acid were added in sequence, heated to 70-80°C, and 30.0 g of toluene was added to carry out toluene nitration reaction. After the reaction was completed for 11 hours, it was cooled to 40-50°C, allowed to stand for stratification, and the lower layer containing water of the ionic liquid was separated, and the upper layer was mononitrotoluene, with a conversion rate of more than 95%. The ortho-toluene ratio of the product by liquid chromatography analysis was 2.3. The water-containing ionic liquid layer can be reused after evaporation to remove water.

According to the above nitration method, other concentrations of nitric acid were used to nitrate toluene, and the results are listed in Table 13.

Table 13 Nitration of toluene catalyzed by [polyethylene polyamine][CF ₃ SO ₃ H] ₃ ionic liquid 4-1

Example Toluene/ionic liquid weight ratio Nitric acid% Temperature ℃ Reaction time Conversion Rate % Neighbor Comparison 14-1 1:1.4 65 70-80 11h 95.8 2.3 14-2 1:1.4 68 70-80 11h 96 2.3 14-3 1:1.4 95 70-80 10h 96.2 2.3 14-4 1:1.4 98 70-80 10h 96 2.3

Embodiment 15

According to the nitration method in Example 13, other aromatic hydrocarbons and substituted aromatic hydrocarbons were subjected to nitration reaction using the ionic liquid 4-1 described in Example 4 as a catalyst. The specific reaction conditions and results are listed in Table 14.

Table 14 Nitration of aromatic hydrocarbons catalyzed by [polyethylene polyamine][CF ₃ SO ₃ H] ₃ ionic liquid 4-1

Note: “/” in Table 14 represents “or”.

Example 16

In a four-necked flask equipped with a reflux condenser, 42.0 g of [polyethylene polyamine][CH ₃ SO ₃ H] ₃ ionic liquid 5-1 prepared in Example 5 and 24.8 g of 68% nitric acid were added in sequence, heated to 70-80°C, and 30.0 g of chlorobenzene was added to carry out chlorobenzene nitration reaction. After the reaction was completed for 12 hours, it was cooled to 40-50°C, allowed to stand for stratification, and the lower layer of water-containing ionic liquid was separated, and the upper layer was mononitrochlorobenzene, with a conversion rate of 92.1%. The ortho-to-difference ratio of the product by liquid chromatography analysis was 2.2. The water-containing ionic liquid layer can be reused after evaporation to remove water.

According to the above nitration method, chlorobenzene was nitrated using nitric acid of other concentrations. The specific reaction conditions and results are listed in Table 15.

Table 15 Nitration of chlorobenzene catalyzed by [polyethylene polyamine][CH ₃ SO ₃ H] ₃ ionic liquid 5-1

Example Chlorobenzene/ionic liquid weight ratio Nitric Acid Temperature ℃ Reaction time Conversion Rate % Neighbor Comparison 16-1 1:1.4 65% 70-80 12h 92 2.2 16-2 1:1.4 68% 70-80 12h 92.1 2.2 16-3 1:1.4 95% 70-80 11h 93 2.2 16-4 1:1.4 98% 70-80 11h 93.4 2.2

Embodiment 17

In a four-necked flask equipped with a reflux condenser, 42.0 g of [polyethylene polyamine][CH ₃ SO ₃ H] ₃ ionic liquid 5-1 prepared in Example 5 and 30.5 g of 68% nitric acid were added in sequence, heated to 70-80°C, and 30.0 g of toluene was added to carry out toluene nitration reaction. After the reaction was completed for 11 hours, it was cooled to 40-50°C, allowed to stand for stratification, and the lower layer of water-containing ionic liquid was separated, and the upper layer was basically mononitrotoluene, and the toluene conversion rate exceeded 94%. The ortho-toluene ratio of the product by liquid chromatography analysis was 2.3. The water-containing ionic liquid layer can be reused after evaporation to remove water.

According to the above nitration method, other concentrations of nitric acid were used to nitrate toluene. The specific reaction conditions and results are listed in Table 16.

Table 16 Nitration of toluene catalyzed by [polyethylene polyamine][CH ₃ SO ₃ H] ₃ ionic liquid 5-1

Example Toluene/ionic liquid weight ratio Nitric acid% Temperature ℃ Reaction time Conversion Rate % Neighbor Comparison 17-1 1:1.4 65 70-80 11h 95 2.3 17-2 1:1.4 68 70-80 11h 95.2 2.3 17-3 1:1.4 95 70-80 10h 96 2.3 17-4 1:1.4 98 70-80 10h 96.4 2.3

Embodiment 18

According to the nitration method in Example 17, other aromatic hydrocarbons and substituted aromatic hydrocarbons were nitrated using the [polyethylene polyamine][CH ₃ SO ₃ H] ₃ ionic liquid 5-1 described in Example 5 as a catalyst. The specific reaction conditions and results are listed in Table 17.

Table 17 Nitration of aromatic hydrocarbons catalyzed by [polyethylene polyamine][CH ₃ SO ₃ H] ₃ ionic liquid 5-1

Note: “/” in Table 17 means “or”.

Embodiment 19

In a four-necked flask equipped with a reflux condenser, 42.0 g of [polyethylene polyamine][C ₆ H ₅ SO ₃ H] ₃ ionic liquid 6-1 prepared in Example 6 and 24.8 g of 68% nitric acid were added in sequence, heated to 70-80°C, and 30.0 g of chlorobenzene was added to carry out chlorobenzene nitration reaction. After the reaction was completed for 12 hours, it was cooled to 40-50°C, allowed to stand for stratification, and the lower layer of water-containing ionic liquid was separated, and the upper layer was mononitrochlorobenzene, with a conversion rate of 92.1%. The ortho-to-difference ratio of the product by liquid chromatography analysis was 2.2. The water-containing ionic liquid layer can be reused after evaporation to remove water.

According to the above nitration method, chlorobenzene was nitrated using nitric acid of other concentrations. The specific reaction conditions and results are listed in Table 18.

Table 18 Nitration of chlorobenzene catalyzed by [polyethylene polyamine][C ₆ H ₅ SO ₃ H] ₃ ionic liquid 6-1

Example Chlorobenzene/ionic liquid weight ratio Nitric Acid Temperature ℃ Reaction time Conversion Rate % Neighbor Comparison 19-1 1:1.4 65% 70-80 12h 91.2 2.1 19-2 1:1.4 68% 70-80 12h 92.1 2.1 19-3 1:1.4 95% 70-80 11h 93 2.2 19-4 1:1.4 98% 70-80 11h 93.1 2.2

Embodiment 20

In a four-necked flask equipped with a reflux condenser, 42.0 g of [polyethylene polyamine][C ₆ H ₅ SO ₃ H] ₃ ionic liquid 6-1 prepared in Example 6 and 30.5 g of 68% nitric acid were added in sequence, heated to 70-80°C, and 30.0 g of toluene was added to carry out toluene nitration reaction. After the reaction was completed for 9 hours, it was cooled to 40-50°C, allowed to stand for stratification, and the lower layer of water-containing ionic liquid was separated, and the upper layer was mononitrotoluene, with a conversion rate of more than 92%. The ortho-toluene ratio of the product by liquid chromatography analysis was 2.2. The water-containing ionic liquid layer can be reused after evaporation to remove water.

According to the above nitration method, other concentrations of nitric acid were used for toluene nitration. The specific reaction conditions and results are listed in Table 19.

Table 19 Nitration of toluene catalyzed by [polyethylene polyamine][C ₆ H ₅ SO ₃ H] ₃ ionic liquid 6-1

Example Toluene/ionic liquid weight ratio Nitric acid% Temperature ℃ Reaction time Conversion Rate % Neighbor Comparison 20-1 1:1.4 65 70-80 9h 93 2.1 20-2 1:1.4 68 70-80 9h 93.2 2.2 20-3 1:1.4 95 70-80 8h 94 2.3 20-4 1:1.4 98 70-80 8h 94.2 2.3

Embodiment 21

According to the nitration method in Example 20, other aromatic hydrocarbons and substituted aromatic hydrocarbons were subjected to nitration reaction using the [polyethylene polyamine][C ₆ H ₅ SO ₃ H] ₃ ionic liquid 6-1 described in Example 6 as a catalyst. The specific reaction conditions and results are listed in Table 20.

Table 20 Nitration of aromatic hydrocarbons catalyzed by [polyethylene polyamine][C ₆ H ₅ SO ₃ H] ₃ ionic liquid 6-1

Note: “/” in Table 20 means “or”.

Example 22

In a four-necked flask equipped with a reflux condenser, 42.0 g of the ionic liquid product B3 in Example 7 and 17.7 g of 95% nitric acid (1.0 eq.) were added in sequence, heated to 70-80°C, and 30.0 g of chlorobenzene was added to carry out the nitration reaction of chlorobenzene. After the reaction was completed for 11 hours, it was cooled to 40-50°C, allowed to stand for stratification, and the lower layer of water-containing ionic liquid layer was separated. The upper layer was basically mononitrochlorobenzene, and the conversion rate was more than 96%. The ortho-to-difference ratio of the product in liquid chromatography analysis was 2.2. The upper organic phase was taken for gas phase analysis, and the product was only mononitrochlorobenzene and unconverted chlorobenzene.

The aqueous ionic liquid layer can be reused after evaporation (70°C under vacuum).

According to the above nitration method, chlorobenzene was nitrated using nitric acid of other concentrations. The specific reaction conditions and results are listed in Table 21.

Table 21 Nitration of chlorobenzene catalyzed by ionic liquid B3

Embodiment 23

In a four-necked flask equipped with a reflux condenser, 42.0 g of the ionic liquid product B3 in Example 7 and 30.5 g of 68% nitric acid were added in sequence, heated to 70-80°C, and 30.0 g of toluene was added to carry out toluene nitration reaction. After the reaction was completed for 9 hours, it was cooled to 40-50°C, allowed to stand for stratification, and the lower layer of water-containing ionic liquid was separated, and the upper layer was mononitrotoluene, with a conversion rate of more than 95%. The ortho-toluene ratio of the product by liquid chromatography analysis was 2.2. The water-containing ionic liquid layer can be reused after evaporation to remove water.

According to the above nitration method, other concentrations of nitric acid were used for toluene nitration. The specific reaction conditions and results are listed in Table 22.

Table 22 Nitration of toluene catalyzed by ionic liquid B3

Example Toluene/ionic liquid weight ratio Nitric acid% Temperature ℃ Reaction time Conversion Rate % Neighbor Comparison 23-1 1:1.4 65 70-80 9h 95.1 2.2 23-2 1:1.4 68 70-80 9h 95.5 2.2 23-3 1:1.4 95 70-80 8h 96.2 2.3 23-4 1:1.4 98 70-80 8h 96 2.3

Embodiment 24

According to the nitration method in Example 23, other aromatic hydrocarbons and substituted aromatic hydrocarbons were subjected to nitration reaction using the ionic liquid B3 described in Example 7 as a catalyst. The specific reaction conditions and results are listed in Table 23.

Table 23 Nitration of aromatic hydrocarbons catalyzed by ionic liquid B3

Note: “/” in Table 23 means “or”.

Embodiment 25

In a four-necked flask equipped with a reflux condenser, 28.0g of the ionic liquid H3 prepared in Example 7 and 16.5g of 68% nitric acid were added in sequence, heated to 70-80°C, and 20.0g of chlorobenzene was added to carry out chlorobenzene nitration reaction under temperature conditions. After the reaction was completed for 12h, it was cooled to 40-50°C, allowed to stand for stratification, and the lower layer of water-containing ionic liquid layer was separated. The upper layer was mononitrochlorobenzene, and the conversion rate exceeded 96%. The upper organic phase was taken for gas chromatography analysis of the chlorobenzene conversion rate and composition, which was only mononitrochlorobenzene and unconverted chlorobenzene. The ortho-to-negative ratio of the product by liquid chromatography analysis was 2.3. The water-containing ionic liquid layer can be reused after evaporation and dehydration.

According to the above nitration method, chlorobenzene was nitrated using nitric acid of other concentrations. The specific reaction conditions and results are listed in Table 24.

Table 24 Nitration of chlorobenzene catalyzed by ionic liquid H3

Embodiment 26

In a four-necked flask equipped with a reflux condenser, 42.0 g of the ionic liquid H3 prepared in Example 7 and 30.5 g of 68% nitric acid were added in sequence, heated to 70-80°C, and 30.0 g of toluene was added to carry out toluene nitration reaction. After the reaction was completed for 11 hours, it was cooled to 40-50°C, allowed to stand for stratification, and the lower layer of water-containing ionic liquid was separated, and the upper layer was mononitrotoluene, with a conversion rate of more than 96%. The ortho-toluene ratio of the product by liquid chromatography analysis was 2.3. The water-containing ionic liquid layer can be reused after evaporation and dehydration.

According to the above nitration method, other concentrations of nitric acid were used for toluene nitration. The specific reaction conditions and results are listed in Table 25.

Table 25 Nitration of toluene catalyzed by ionic liquid H3

Example Toluene/ionic liquid weight ratio Nitric acid% Temperature ℃ Reaction time Conversion Rate % Neighbor Comparison 26-1 1:1.4 65 70-80 11h 96.5 2.2 26-2 1:1.4 68 70-80 11h 96.8 2.3 26-3 1:1.4 95 70-80 10h 97.4 2.3 26-4 1:1.4 98 70-80 10h 98.2 2.3

Embodiment 27

In a four-necked flask equipped with a reflux condenser, 48.0 g of the ionic liquid H3 prepared in Example 7 and 18.9 g of 68% nitric acid were added in sequence, heated to 70-80°C, and 30.0 g of o-dichlorobenzene was added to carry out nitration reaction. After the reaction was completed for 8 hours, it was cooled to 40-50°C, allowed to stand for stratification, and the lower layer of the ionic liquid containing water was separated, and the upper layer was mononitro o-dichlorobenzene, with a conversion rate of more than 94%. The ionic liquid layer containing water can be reused after evaporation to remove water.

According to the above nitration method, other concentrations of nitric acid were used for nitration of o-dichlorobenzene. The specific reaction conditions and results are listed in Table 25.

Table 26 Nitration reaction of o-dichlorobenzene catalyzed by ionic liquid H3

Example o-Dichlorobenzene/ionic liquid weight ratio Nitric acid% Temperature ℃ Reaction time Conversion rate (%) 27-1 1:1.6 65 70-80 8h 96.2 27-2 1:1.6 68 70-80 8h 96.3 27-3 1:1.6 95 70-80 7h 96.4 27-4 1:1.6 98 70-80 7h 96.8

Embodiment 28

In a four-necked flask equipped with a reflux condenser, 48.0 g of the ionic liquid H3 prepared as described in Example 7 and 26.2 g of 68% nitric acid were added in sequence, heated to 70-80°C, and 30.0 g of o-xylene was added to carry out nitration reaction. After the reaction was completed for 11 hours, it was cooled to 40-50°C, allowed to stand for stratification, and the lower layer of water-containing ionic liquid was separated, and the upper layer was mononitro o-xylene, with a conversion rate of more than 94%. The water-containing ionic liquid layer can be reused after evaporation to remove water.

According to the above nitration method, other concentrations of nitric acid were used for nitration of o-xylene. The specific reaction conditions and results are listed in Table 27.

Table 27 Nitration reaction of o-xylene catalyzed by ionic liquid H3

Example o-Xylene/ionic liquid weight ratio Nitric acid% Temperature ℃ Reaction time Conversion Rate % 28-1 1:1.6 65 70-80 11h 94.3 28-2 1:1.6 68 70-80 11h 94.2 28-3 1:1.6 95 70-80 10h 95.2 28-4 1:1.6 98 70-80 10h 95.6

Embodiment 29

According to the nitration method described in Example 28, other aromatic hydrocarbons and substituted aromatic hydrocarbons were nitrated using ionic liquid H3 as a catalyst. The specific reaction conditions and results are listed in Table 28.

Table 28 Nitration of aromatic hydrocarbons catalyzed by ionic liquid H3

Note: “/” in Table 28 means “or”.

Embodiment 30

In a four-necked flask equipped with a reflux condenser, 28.0g of the ionic liquid J3 prepared in Example 7 and 16.5g of 68% nitric acid were added in sequence, heated to 70-80°C, and 20.0g of chlorobenzene was added. The nitration reaction of chlorobenzene was carried out under the temperature conditions. After the reaction was completed for 12h, it was cooled to 40-50°C, and the layers were allowed to stand for stratification. The lower layer of the ionic liquid layer containing water was separated, and the upper layer was mononitrochlorobenzene with a conversion rate of more than 97%. The upper organic phase was taken for gas chromatography analysis of the chlorobenzene conversion rate and composition, which was only mononitrochlorobenzene and unconverted chlorobenzene. The ortho-to-pair ratio of the liquid chromatography analysis product was 2.2. The aqueous ionic liquid layer can be reused after evaporation and dehydration.

According to the above nitration method, chlorobenzene was nitrated using nitric acid of other concentrations. The specific reaction conditions and results are listed in Table 29.

Table 29 Nitration of chlorobenzene catalyzed by ionic liquid J3

Example Chlorobenzene/ionic liquid weight ratio Nitric Acid Temperature ℃ Reaction time Conversion Rate % Neighbor Comparison 30-1 1:1.4 65% 70-80 12h 97.5 2.2 30-2 1:1.4 68% 70-80 12h 97.6 2.2 30-3 1:1.4 95% 70-80 11h 98.2 2.2 30-4 1:1.4 98% 70-80 11h 98.3 2.2

Embodiment 31

In a four-necked flask equipped with a reflux condenser, 42.0g of the ionic liquid J3 prepared in Example 7 and 30.5g of 68% nitric acid were added in sequence, heated to 70-80°C, and 30.0g of toluene was added to carry out toluene nitration reaction. After 11 hours of reaction, the mixture was cooled to 40-50°C, allowed to stand for stratification, and the lower layer of the ionic liquid containing water was separated. The upper layer was basically mononitrotoluene, and the conversion rate was above 96%. The ortho-toluene ratio of the product was 2.3 by liquid chromatography analysis. The ionic liquid layer containing water can be reused after evaporation to remove water.

According to the above nitration method, other concentrations of nitric acid were used for toluene nitration. The specific reaction conditions and results are listed in Table 30.

Table 30 Nitration of toluene catalyzed by ionic liquid J3

Example Toluene/ionic liquid weight ratio Nitric acid% Temperature ℃ Reaction time Conversion Rate % Neighbor Comparison 31-1 1:1.4 65 70-80 11h 96.1 2.2 31-2 1:1.4 68 70-80 11h 96.5 2.3 31-3 1:1.4 95 70-80 10h 97.1 2.3 31-4 1:1.4 98 70-80 10h 97.3 2.3

Embodiment 32

According to the nitration method described in Example 31, other aromatic hydrocarbons and substituted aromatic hydrocarbons were subjected to nitration reaction using the ionic liquid J3 described in Example 7 as a catalyst. The specific reaction conditions and results are listed in Table 31.

Table 31 Nitration of aromatic hydrocarbons catalyzed by ionic liquid J3

Note: “/” in Table 31 means “or”.

Embodiment 33

According to the nitration method described in Example 30, chlorobenzene was nitrated using the other ionic liquids described in Example 7 as catalysts, and the product was mononitrochlorobenzene. The specific reaction conditions and results are listed in Table 32.

Table 32 Nitration of chlorobenzene catalyzed by other ionic liquids in Example 7

Embodiment 34

According to the nitration method described in Example 31, toluene was nitrated using the other ionic liquids described in Example 7 as catalysts, and the product was mononitrotoluene. The specific reaction conditions and results are listed in Table 33.

Table 33 Nitration of toluene catalyzed by other ionic liquids in Example 7

The ionic liquid used in the following comparative examples is N,N-tetramethylethylenediamine sulfate, ie, [N,N-tetramethylethylenediamine][H ₂ SO ₄ ] ₃ . The specific preparation method is as in Example 1, that is, the raw material polyethylene polyamine in Example 1 is replaced by N,N-tetramethylethylenediamine, and the molar ratio of N to sulfuric acid is 1:1.

Comparative Example 1

In a four-necked flask equipped with a reflux condenser, add 28.0g of ionic liquid (N,N-tetramethylethylenediamine sulfate, molar ratio of cationic nitrogen element: sulfuric acid = 1:3), 16.5g of 68% nitric acid, heat to 70-80°C, add 20g of chlorobenzene, and carry out nitration of chlorobenzene. After the reaction is completed for 12h, cool to 40-50°C, stand and separate, separate the lower layer of water-containing ionic liquid layer, and the upper organic phase is nitrochlorobenzene. Take the upper organic phase gas phase analysis product mononitrochlorobenzene content is 88.3%, dinitrochlorobenzene content is 3.8%.

The examples of nitration of chlorobenzene catalyzed by [N,N-tetramethylethylenediamine][H ₂ SO ₄ ] ₃ ionic liquid and nitric acid at other concentrations can be similarly implemented by the general method mentioned in Comparative Example 1. The specific conditions are shown in Table 34:

Table 34 Nitration of chlorobenzene catalyzed by N,N-tetramethylethylenediamine sulfate ionic liquid

Note: The contents in Table 34 are the contents of the corresponding substances in the upper organic phase.

The results of Examples 8, 22, 25, and 30 and Comparative Example 1 show that when sulfate ionic liquids formed by different ammonium ions are used to catalyze the nitration reaction of chlorobenzene, the nitration products are essentially different. The nitrochlorobenzene products obtained when the ionic liquids A3, B3, H3, and J3 of the present invention are used as catalysts have a higher content of mononitrochlorobenzene, which is above 95%, and dinitrochlorobenzene cannot be detected in the product. When the nitrochlorobenzene product obtained when N, N-tetramethylethylenediamine sulfate ionic liquid is used as a catalyst, the content of mononitrochlorobenzene is only about 89%, and the amount of doped dinitrochlorobenzene reaches 3.8%. The ionic liquid of the present invention has a higher selectivity for the mononitration reaction.

Claims (10)

1. A polyethylene polyamine type ammonium salt ionic liquid, characterized in that: The ammonium salt ionic liquid is prepared from polyethylene polyamine and corresponding protonic acid. The anions in the ammonium salt come from the protonic acid, and are selected from one or more anions of HSO ₄ ^- , HSO ₄ (H ₂ SO ₄ ) ^- , HSO ₄ (H ₂ SO ₄ ) ₂ ^- , CF ₃ SO ₃ ^- , CH ₃ SO ₃ ^- and R'-C ₆ H ₄ SO ₃ ^- , wherein R' is H or alkyl. The cations in the ammonium salt ionic liquid come from ammonium cations formed by polyethylene polyamine. In the ammonium salt ionic liquid, the molar ratio of nitrogen atoms to protonic acid is 1:(1-3). The polyethylene polyamine comprises two or more polyethylene imine oligomers, and the amine value or nitrogen content of the polyethylene polyamine is 10-50wt%; The polyethyleneimine oligomer has the following general formula:

Among them, n=1~6. 2. The polyethylene polyamine type ammonium salt ionic liquid according to claim 1, characterized in that the polyethylene polyamine further comprises at least one of polyethyleneimine polymer and tertiary amine; The structural formula of the polyethyleneimine polymer is as follows:

Wherein, x=0-100, y=0-100, and x+y≥7, R is selected from H, C1-C12 alkyl,

and z = 2 to 15, and

One of the following; The tertiary amine is selected from at least one of triethylamine, tripropylamine, tributylamine, N,N-diisopropylethylamine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N",N"-pentamethyldivinyltriamine, N,N,N',N'-tetramethylmethanediamine, N,N,N',N'-tetramethyl-1,3-propylenediamine, tri[2-(dimethylamino)ethyl]amine and hexadecyldimethyl tertiary amine. 3. The polyethylene polyamine type ammonium salt ionic liquid according to claim 3, characterized in that: The two or more polyethyleneimine oligomers are a mixture of ethylenediamine, diethylenetriamine, triethylenetetramine and tetraethylenepentamine; preferably, the two or more polyethyleneimine oligomers further include at least one of pentaethylenehexamine and hexaethyleneheptamine. 4. The polyethylene polyamine type ammonium salt ionic liquid according to claim 1, characterized in that The CAS number of the polyethyleneimine polymer is selected from one of 9002-98-6, 25987-06-8, 106899094-9 and 68130-97-2. 5. The polyethylene polyamine type ammonium salt ionic liquid according to claim 1, characterized in that: The polyethylene polyamine is selected from at least one of the following commercial products: Heavy Polyamine XE (Dow), Ethyleneamine E-100 (Huntsman), Polyethylenepolyamine (Cameo Chemicals), PEPA (Silkor), Ethyleneamine mixture Poly-7 (Tosoh Corporation); Preferably, the CAS registration number of the polyethylene polyamine is at least one of 68131-73-7, 37231-61-2 and 68551-30-4. 6. The method for preparing the polyethylene polyamine type ammonium salt ionic liquid according to any one of claims 1 to 5, characterized in that the method comprises the following steps: Step 1: Add the polyethylene polyamine according to any one of claims 1 to 5 into a reactor equipped with a stirring device and a condensing reflux device, start stirring, and set the speed to 100-1000 rpm, preferably 400-800 rpm; Step 2: Add the protonic acid to the reactor of step 1 in batches within 30-60 minutes, and control the temperature in the reactor to be between 0-30°C; after the addition is completed, stir at 0-30°C for 2-3 hours to obtain a viscous ionic liquid; wherein: the molar ratio of nitrogen atoms in polyethylene polyamine to protonic acid is 1:(1-3). 7. Use of the polyethylene polyamine type ammonium salt ionic liquid as claimed in any one of claims 1 to 5 as a catalyst in the field of industrial acid catalytic reaction, characterized in that: The industrial acid catalyzed reaction is an aromatic hydrocarbon nitration reaction. 8. The use of the polyethylene polyamine type ammonium salt ionic liquid according to claim 7 as a catalyst in the field of industrial acid catalysis reaction, characterized in that: The polyethylene polyamine type ammonium salt ionic liquid is used to catalyze the nitration reaction of aromatic hydrocarbons, wherein the aromatic hydrocarbons include benzene and substituted benzenes, wherein the substituted benzenes are selected from one of monosubstituted, disubstituted and polysubstituted benzenes, and preferably, the structure of the substituted benzenes is selected from one of the following structures:

When the substituent benzene is monosubstituted, X is selected from one of halogen, alkyl, halogen-substituted alkyl, alkoxy, and amide. When the substituted benzene is disubstituted or polysubstituted, X is selected from one of halogen, alkyl and alkoxy. 9. The use of the quaternary ammonium salt ionic liquid according to claim 8 as a catalyst in the field of industrial acid catalysis reactions, characterized in that: When the substituent benzene is monosubstituted, X is selected from one of F, Cl, Br, I, CF ₃ , CH ₃ , OCH ₃ , C ₂ H ₅ , C ₄ H ₉ , C ₁₀ H ₂₁ , C ₁₂ H ₂₅ , C ₁₈ H ₃₇ and NHCOCH ₃ ; When the substituted benzene is disubstituted or polysubstituted, X is selected from at least one of F, Cl, CH ₃ and OCH ₂ CH ₂ O. 10. The use of the quaternary ammonium salt ionic liquid according to claim 8 as a catalyst in the field of industrial acid catalysis reaction, characterized in that: The polyethylene polyamine type ammonium salt ionic liquid is used to catalyze the nitration reaction of aromatic hydrocarbons, and the structure of the aromatic hydrocarbons is also selected from one of the following structures:

Where A is O, _CH2 or S.