A polyethylenepolyamine-based ammonium salt ionic liquid, its preparation method and application

Abstract

The present invention discloses a polyethylenepolyamine-based ammonium salt ionic liquid and its preparation method and application. The polyethylenepolyamine-based ammonium salt ionic liquid is prepared from polyethylenepolyamine and a corresponding protonic acid. The anion in the ammonium salt is derived from the protonic acid and is selected from one or more anions of HSO4 ‑ , HSO4(H2SO4) ‑ , HSO4(H2SO4)2 ‑ , CF3SO3 ‑ , CH3SO3 ‑ and R'-C6H4SO3 ‑ , wherein R' is H or an alkyl group; the cation in the ammonium salt ionic liquid is an ammonium cation formed from polyethylenepolyamine. In the ammonium salt ionic liquid, the molar ratio of nitrogen atoms to the protonic acid is 1:(1 to 3); the polyethylenepolyamine includes two or more polyethyleneimine oligomers, and the amine value or nitrogen content % of the polyethylenepolyamine is 10-50 wt%. The substrate conversion rate of the ionic liquid synthesized by the present invention can reach more than 90%.

Description

Technical Field

[0001] The present invention relates to the fields of organic chemical synthesis technology and green catalysis, and particularly to a multi-ethylene polyamine type ammonium salt ionic liquid, a preparation method thereof and an application thereof. Background Art

[0002] Acid catalysts are indispensable in the modern chemical industry and are widely used in representative synthetic routes such as nitration reactions, esterification reactions, alkylation, etc. At present, in industrial acid catalysis methods, especially in esterification and aromatic nitration, inorganic acid catalysts such as hydrochloric acid, sulfuric acid, and phosphoric acid are more commonly used to improve the reaction activity. However, this causes equipment corrosion, high separation, recovery and regeneration costs, and it is difficult to reuse. Therefore, a large amount of alkali is required to neutralize the waste acid generated, and the additional processes of alkali neutralization and removal of inorganic salts bring additional raw material and energy consumption.

[0003] In order to address the deficiencies of traditional inorganic acid catalysts, the development of green and efficient new catalysts has become a trend. In recent years, acidic ionic liquid catalysts have been introduced and developed, which have the characteristics of low vapor pressure and non-volatility, relatively simple synthesis process, and can be regenerated and reused after separation, recovery and water removal.

[0004] Imidazole-based ionic liquids are the most common and earliest commercialized acidic ionic liquids. D. Gong et al. successfully synthesized the room temperature ionic liquid [Hmim]HSO4 using methylimidazole and sulfuric acid as raw materials (Asian Journal of Chemistry, Vol. 22, No. 8, 6413 - 6416). In US20040024266A1, 10 [C

[0005] 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, due to the high price and certain toxicity of imidazole precursors, there is currently no large-scale industrial production, resulting in a small market supply.

[0006] CN105732439A, CN101648894A, and CN101348487A first perform the sulfonation functionalization reaction of polyamine, and then add a stoichiometric equivalent of acid for protonation to obtain an ionic liquid with a high acid value. The sulfonium quaternary ammonium salt acidic ionic liquid reflects the strong designability of ionic liquids. However, the disadvantage of this method is that the functionalization step of polyamine requires adding multiple times the equivalent of inner salt compared to the amine, increasing the raw material consumption, prolonging the synthesis process, and easily introducing impurities, weakening the process advantage of easy synthesis of ionic liquids.

[0007] Therefore, it is very necessary to find ionic liquids with low cost and high efficiency. Summary of the Invention

[0008] In view of the problems existing in the prior art, the present invention provides a polyethylenepolyamine-based ammonium salt ionic liquid, its preparation method, and application.

[0009] To achieve the above object, the present invention adopts the following technical solutions:

[0010] A polyethylenepolyamine-based ammonium salt ionic liquid, characterized in that

[0011] the ammonium salt ionic liquid is prepared from polyethylenepolyamine and a corresponding protonic acid (HA), and the anion (A) in the ammonium salt comes from the protonic acid, selected from one of the anions of HSO4 - 、HSO4(H2SO4) - 、HSO4(H2SO4)2 - 、CF3SO3 - 、CH3SO3 - and R'-C6H4SO3 - wherein R' is an alkyl group, preferably H, CH3 or C 12 H 25 ; the cation in the ammonium salt ionic liquid comes from the ammonium cation formed by polyethylenepolyamine, and in the ammonium salt ionic liquid, the molar ratio of nitrogen atom to protonic acid is 1:(1 - 3);

[0012] the polyethylenepolyamine includes two or more polyethyleneimine oligomers, and the amine value or nitrogen content % of the polyethylenepolyamine is 10 - 50 wt%;

[0013] The polyethyleneimine oligomer has the following general formula: wherein, n = 1 - 6.

[0014] For the above ionic liquid, as a preferred embodiment, the polyethylenepolyamine further includes at least one of polyethyleneimine polymer and tertiary amine;

[0015] The structural formula of the polyethyleneimine polymer is as follows:

[0016]

[0017] Among them, x = 0 to 100, y = 0 to 100, and x + y ≥ 7, R is selected from H, C1-C12 alkyl, and z = 2 to 15, and one of the following;

[0018] 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''-pentamethyldiethylenetriamine, N,N,N′,N′-tetramethylmethylenediamine, N,N,N′,N′-tetramethyl-1,3-propanediamine, tris[2-(dimethylamino)ethyl]amine, and cetyl dimethyl tertiary amine.

[0019] The CAS numbers of various tertiary amines are as follows:

[0020] 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”-Pentamethyldiethylenetriamine 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 Cetyl dimethyl tertiary amine 112-69-6

[0021] The ammonium salt ionic liquid of the present invention is labeled as [polyethylenepolyamine][HA] x' , where x' is the molar ratio of the proton acid to the nitrogen atom in the polyethylenepolyamine, x' = 1 to 3, and HA is the proton acid.

[0022] For the above ionic liquid, as a preferred embodiment, 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.

[0023] For the above ionic liquid, as a preferred embodiment, the CAS number of the polyethyleneimine polymer is selected from one of 9002-98-6, 25987-06-8, 106899094-9, and 68130-97-2.

[0024] For the above ionic liquid, as a preferred embodiment, the polyethylenepolyamine is selected from at least one of the following commercial products or similar commercial products:

[0025] 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 polyethylenepolyamine is one of 68131-73-7, 37231-61-2, and 68551-30-4.

[0026] The polyethylene polyamines of the present invention are a mixture. In a specific embodiment, the polyethylene polyamines (abbreviated as PEPA) include, but are not limited to, a mixture containing ethylenediamine, diethylenetriamine, triethylenetetramine, and tetraethylenepentamine, and may also include pentaethylenehexamine, hexaethyleneheptamine, and / or higher molecular weight polyethyleneimine polymers. The mixture of polyethylene polyamines 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 10-50 wt%.

[0027] In the present invention, the anion of the ionic liquid is HSO4(H2SO4) - or HSO4(H2SO4)2 - When it is, compared with the traditional hydrogen sulfate (HSO4 - ) anion, HSO4(H2SO4) - or HSO4(H2SO4)2 - has stronger acidity, higher activity and stability, and shows more uniqueness when combined with quaternary ammonium salt cations.

[0028] The polyethylene polyamine-based ammonium salt ionic liquid of the present invention is liquid at room temperature. On the one hand, it has the characteristics of low viscosity and strong fluidity; on the other hand, since it belongs to protonated ionic liquid and has a high acid value, it can protonate the acceptor more completely and shows stronger catalytic activity in acid-catalyzed reactions.

[0029] The present invention also provides a preparation method of the above-mentioned polyethylene polyamine-based ammonium salt ionic liquid, adopting the following technical scheme:

[0030] A polyethylene polyamine-based ammonium salt ionic liquid and its preparation method as described above. Starting from polyethylene polyamines, by adding an appropriate amount of protonic acid under specific experimental conditions, a polyethylene polyamine-based ammonium salt ionic liquid is constructed with the ammonium salt of polyethylene polyamines as the cation and the anion from the protonic acid (HA).

[0031] In the above preparation method, as a preferred embodiment, the preparation method includes the following steps:

[0032] Step 1: In a reactor equipped with a stirring device and a condensation reflux device, add the above-mentioned polyethylene polyamines, start stirring, and set the rotation speed to 100-1000 revolutions per minute, preferably 400-800 revolutions per minute;

[0033] Step 2: Add the above protonic acid to the reactor in Step 1 in batches within 30 - 60 minutes, and control the temperature inside the reactor to be between 0 - 30°C; after the feeding is completed, stir for 2 - 3 hours at a temperature between 0 - 30°C to obtain a viscous ionic liquid; the molar ratio of the nitrogen atom in polyethylenepolyamine to the protonic acid is 1:(1 - 3).

[0034] In the above preparation method, as a preferred embodiment, when the anion of the ammonium salt ionic liquid is HSO4 - or hydrogen sulfate hydrogen-bonded sulfuric acid, i.e., HSO4 - 、HSO4(H2SO4) - or HSO4(H2SO4)2 - , the preparation method includes:

[0035] Step 1: In a container equipped with a stirring device and a condensation reflux device, add polyethylenepolyamine, start stirring, and set the rotation speed to 400 - 800 revolutions per minute;

[0036] Step 2: Place the container in Step 1 in an ice-water bath, and dropwise add 93 - 98% sulfuric acid within 30 - 60 minutes. During the process, control the temperature inside the container to be less than 30°C. After the addition is completed, continue to stir at room temperature for 2 - 3 hours, stop stirring, and obtain an ionic liquid with a brownish-black viscous appearance. The molar ratio of the nitrogen atom in polyethylenepolyamine to sulfuric acid is 1:(1 - 3), and the room temperature is 20 - 30°C.

[0037] The present invention also provides an application of the above polyethylenepolyamine-based ammonium salt ionic liquid as a catalyst in the field of industrial acid-catalyzed reactions, and the industrial acid-catalyzed reaction is a nitration reaction; preferably, the nitration reaction is an aromatic nitration reaction.

[0038] In the above application, as a preferred embodiment, the polyethylenepolyamine-based ammonium salt ionic liquid is used to catalyze the nitration reaction of aromatics. The aromatics include benzene and substituted benzene, and the substituted benzene is selected from one of monosubstituted, disubstituted, and polysubstituted. Preferably, the structure of the substituted benzene is selected from one of the following structures:

[0039]

[0040] When the substituted benzene is monosubstituted, X is selected from one of halogen, alkyl, halogen-substituted alkyl, alkoxy, and amide group. Preferably, X is selected from one of F, Cl, Br, I, CF3, CH3, OCH3, C2H5, C4H9, C 10 H 21 、C 12 H 25 、C 18 H 37 and NHCOCH3;

[0041] 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, CH3, and OCH2CH2O.

[0042] The polyethylenepolyamine-based ammonium salt ionic liquid is used in the catalytic nitration reaction of aromatic hydrocarbons, and the structure of the aromatic hydrocarbons can also be selected from one of the following:

[0043] wherein A is O, CH2, or S.

[0044] Furthermore, the mass ratio of the substrate to the ionic liquid is 1:1 to 3;

[0045] Furthermore, the temperature of the nitration reaction is 50 to 80 °C;

[0046] Furthermore, the time of the nitration reaction is 1 to 20 h;

[0047] Furthermore, the molar ratio of nitric acid to the substrate is 1 to 2:1; furthermore, the aqueous ionic liquid layer can be reused after evaporation to remove water;

[0048] Furthermore, the concentration of the nitric acid is above 65%;

[0049] Furthermore, after the reaction is completed, it is cooled to 40 - 50 °C;

[0050] Furthermore, the nitration product is mainly a mononitro product.

[0051] Compared with the prior art, the technical solution adopted by the present invention has the following beneficial technical effects:

[0052] (1) The ionic liquid obtained by adopting the technical solution of the present invention has the characteristics of low melting point, low viscosity, and strong fluidity. Due to the characteristic of low melting point, this type of ionic liquid is in a liquid state at room temperature, which means that it can also be used as a catalyst to be fully mixed with the reactants under non-heating conditions. In addition, due to its high fluidity, the mixing degree between the reactants and the ionic liquid is greatly improved, which is beneficial to improving the conversion rate of the main reaction;

[0053] (2) This type of ionic liquid can be applied to nitration reactions, esterification reactions, alkylation reactions, condensation reactions, oxidation reactions, and so on;

[0054] (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 produced 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.

[0055] (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.

[0056] (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

[0057] 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.

[0058] 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, can be 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.

[0059] Example 1

[0060] Weigh 8.58 g of E-100 polyethylenepolyamine (CAS: 68131-73-7, nitrogen content 32.65%) into a 100 mL four-necked flask. Under ice bath stirring, slowly add 20.03 g of 98% sulfuric acid (0.2 mol, equimolar to the nitrogen in polyethylenepolyamine, i.e., the molar ratio of N to sulfuric acid is 1:1) dropwise within 40 min. After dropping, continue stirring and reacting at room temperature for 2 h to obtain a brown viscous ionic liquid with the composition [polyethylenepolyamine][H2SO4], numbered A1, and the yield is 99.9%.

[0061] Change the sulfuric acid equivalent to prepare ionic liquids:

[0062] Weigh 8.58 g of E-100 polyethylenepolyamine (CAS: 68131-73-7, nitrogen content 32.65%) into a 100 mL four-necked flask. Under ice bath stirring, slowly add 30.47 g of 98% sulfuric acid (0.4 mol) dropwise within 40 min. After dropping, continue stirring and reacting at room temperature for 2 h to obtain a brown viscous ionic liquid with the composition [polyethylenepolyamine][H2SO4]2, numbered A2, and the yield is 99.9%.

[0063] Weigh 8.58 g of E-100 polyethylenepolyamine (CAS: 68131-73-7, nitrogen content 32.65%) into a 100 mL four-necked flask. Under ice bath stirring, slowly add 60.03 g of 98% sulfuric acid (0.6 mol) dropwise within 40 min. After dropping, continue stirring and reacting at room temperature for 2 h to obtain a brown viscous ionic liquid with the composition [polyethylenepolyamine][H2SO4]3, numbered A3, and the yield is 99.9%.

[0064] Table 1 Viscosity of ionic liquid A3 prepared in Example 1 at different temperatures

[0065]

[0066] Example 2

[0067] Weigh 8.58 g of polyethylenepolyamine (CAS: 68131-73-7, nitrogen content 32.65%) into a 100 mL four-necked flask. Under ice bath stirring, slowly add 21.09 g of 93% sulfuric acid (0.2 mol) dropwise within 30 min. After dropping, continue stirring and reacting at room temperature for 1.5 h to obtain a brown viscous ionic liquid with the composition [polyethylenepolyamine][H2SO4], and the yield is 99.8%.

[0068] Change the sulfuric acid equivalent to prepare ionic liquids:

[0069] Weigh 8.58 g of polyethylenepolyamine (CAS: 68131-73-7, nitrogen content 32.65%) into a 100 mL four-necked flask. Under ice bath stirring, slowly add 42.17 g (0.4 mol) of 93% sulfuric acid dropwise within 30 min. After dropping, continue stirring and reacting at room temperature for 1.5 h to obtain a brownish viscous ionic liquid with the composition [polyethylenepolyamine][H2SO4]2, and the yield is 99.8%.

[0070] Weigh 8.58 g of polyethylenepolyamine (CAS: 68131-73-7, nitrogen content 32.65%) into a 100 mL four-necked flask. Under ice bath stirring, slowly add 63.26 g (0.6 mol) of 93% sulfuric acid dropwise within 30 min. After dropping, continue stirring and reacting at room temperature for 1.5 h to obtain a brownish viscous ionic liquid with the composition [polyethylenepolyamine][H2SO4]3, and the yield is 99.8%.

[0071] Example 3

[0072] Weigh 8.58 g of polyethylenepolyamine (CAS: 68131-73-7, nitrogen content 32.65%) into a 100 mL four-necked flask. Under ice bath stirring, slowly add 20.43 g (0.2 mol) of 96% sulfuric acid dropwise within 40 min. After dropping, continue stirring and reacting at room temperature for 2 h to obtain a brownish viscous ionic liquid with the composition [polyethylenepolyamine][H2SO4], and the yield is 99.5%.

[0073] Change the sulfuric acid equivalent to prepare ionic liquids:

[0074] Weigh 8.58 g of polyethylenepolyamine (CAS: 68131-73-7, nitrogen content 32.65%) into a 100 mL four-necked flask. Under ice bath stirring, slowly add 40.85 g (0.4 mol) of 96% sulfuric acid dropwise within 40 min. After dropping, continue stirring and reacting at room temperature for 2 h to obtain a brownish viscous ionic liquid with the composition [polyethylenepolyamine][H2SO4]2, and the yield is 99.5%.

[0075] Weigh 8.58 g of polyethylenepolyamine (CAS: 68131-73-7, nitrogen content 32.65%) into a 100 mL four-necked flask. Under ice bath stirring, slowly add 61.28 g (0.6 mol) of 96% sulfuric acid dropwise within 40 min. After dropping, continue stirring and reacting at room temperature for 2 h to obtain a brownish viscous ionic liquid with the composition [polyethylenepolyamine][H2SO4]3, and the yield is 99.5%.

[0076] Example 4:

[0077] Weigh a quantitative amount of polyethylenepolyamine (CAS: 68131-73-7) (nitrogen content is 32.65%) into a 100 mL four-necked flask. Under ice bath stirring, slowly add a quantitative amount of 99% trifluoromethanesulfonic acid dropwise within 40 min. After dropping, continue stirring and reacting at room temperature for 1.5 h to obtain a brown viscous ionic liquid, and its composition is [polyethylenepolyamine][CF3SO3H] x' , and the dosages and yields of the corresponding raw materials used for different products are shown in Table 2 below.

[0078] Table 2 Experimental conditions and yields for the preparation of [polyethylenepolyamine][CF3SO3H] in Example 4 x'

[0079] Example Polyethylenepolyamine (g) Trifluoromethanesulfonic acid (g) <![CDATA[[Polyethylenepolyamine][CF3SO3H] 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

[0080] Among them, when x' = 1, the anion of the ionic liquid is CF3SO3 - ; when x' = 2, the anion of the ionic liquid is CF3SO3(CF3SO3H) - ; when x' = 3, the anion of the ionic liquid is CF3SO3(CF3SO3H)2 - .

[0081] Example 5

[0082] Weigh a quantitative amount of polyethylenepolyamine (CAS: 68131-73-7) (nitrogen content is 32.65%) into a 100 mL four-necked flask. Under ice bath stirring, slowly add a quantitative amount of 99% methanesulfonic acid dropwise within 40 min. After dropping, continue stirring and reacting at room temperature for 1.5 h to obtain a brown viscous ionic liquid, and its composition is [polyethylenepolyamine][CH3SO3H] x' , and the dosages and yields of the corresponding raw materials used for different products are shown in Table 3 below.

[0083] Table 3 Experimental conditions and yields for the preparation of [polyethylenepolyamine][CH3SO3H] in Example 5 x'

[0084]

[0085]

[0086] Among them, when x' = 1, the anion of the ionic liquid is CH3SO3 - ; when x' = 2, the anion of the ionic liquid is CH3SO3(CH3SO3H) - ; when x' = 3, the anion of the ionic liquid is CH3SO3(CH3SO3H)2 - .

[0087] Example 6

[0088] Weigh a quantitative amount of polyethylenepolyamine (CAS: 68131-73-7) (nitrogen content is 32.65%) into a 100 mL four-necked flask. Under ice bath stirring, slowly add a quantitative amount of 99% benzenesulfonic acid dropwise within 40 min. After dropping, continue stirring and reacting at room temperature for 1.5 h to obtain a brownish viscous ionic liquid, whose composition is [polyethylenepolyamine][C6H5SO3H] x' The usage amounts and yields of the corresponding raw materials for different products are shown in Table 4 below.

[0089] Table 4 Experimental conditions and yields for the preparation of [polyethylenepolyamine][C6H5SO3H] in Example 5 x' and its yield

[0090] Example Polyethylenepolyamine (g) Benzenesulfonic acid (g) <![CDATA[[Polyethylene polyamine][C6H5SO3H] 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

[0091] Among them, when x' = 1, the anion of the ionic liquid is C6H5SO3 - ; when x' = 2, the anion of the ionic liquid is C6H5SO3(C6H5SO3H) - ; when x' = 3, the anion of the ionic liquid is C6H5SO3(C6H5SO3H)2 - .

[0092] Example 7

[0093] Similarly, more preparation examples of ionic liquids 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, select one or more tertiary amines, mix them in a specific molar ratio or mix them with E-100 to form a polyethylenepolyamine mixture. The mixing ratio is shown in Table 5. Then, add protonic acid for reaction according to the molar ratio of the amine group to the protonic acid of 1:1, 1:2, and 1:3 in sequence to prepare the corresponding ionic liquids. Based on the ionic liquid product numbers (A1, A2, and A3) in Example 1, Table 5 below gives other ionic liquid products [polyethylenepolyamine][HA] x' and the corresponding numbers, where the numbers 1, 2, and 3 represent the molar ratio of the protonic acid to the N atom in the ionic liquid respectively.

[0094] Table 5 Composition and numbers for the preparation of [polyethylenepolyamine][HA] in Example 7 x' and its number

[0095]

[0096] The following is a better illustration of the value of the novel ionic liquid in the present invention in the nitration reaction of aromatic hydrocarbons in combination with the specific embodiments. It should be understood that the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. The feeding method of the nitration reaction in the embodiments is uniformly described as follows: Add the ionic liquid and nitric acid, heat up to 70 - 80 °C, add the substrate, and carry out the nitration reaction. In each of the embodiments and comparative examples, when adjusting the concentration of nitric acid for the experiment, the actual amount of nitric acid should be adjusted according to the molar ratio of the substrate to pure nitric acid of 1:1. In the present invention, the ortho - ratio is the molar ratio of the ortho - product to the para - product, the conversion rate is the molar percentage of the substrate converted to the product in the nitration reaction, and the yield is the percentage of the actual molar amount of the mononitration product to the theoretical molar amount. The technical solution of the present invention has a high yield of mononitration products, and there are very few by - products other than the mononitration products, or even undetectable. Therefore, the conversion rate and the yield are basically the same, and the difference between the two is less than 1%.

[0097] Example 8

[0098] In a four - necked flask equipped with a reflux condenser, 28.0 g of ionic liquid A3 prepared in Example 1, 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 the nitration reaction of chlorobenzene. After the reaction ended in 12 h, it was cooled to 40 - 50 °C, allowed to stand and separate layers. The lower layer of the water - containing ionic liquid layer was separated, and the upper layer was light - yellow solid mononitrochlorobenzene. The conversion rate of chlorobenzene exceeded 95%. The ortho - ratio of the product analyzed by liquid chromatography was 2.1. The water - containing ionic liquid layer can be reused after evaporation of water. The upper organic phase was analyzed by gas chromatography, and there was no dinitrochlorobenzene except for mononitrochlorobenzene products and unreacted chlorobenzene.

[0099] According to the above nitration method, nitration of chlorobenzene was carried out using nitric acid of other concentrations or appropriately adjusting the amount of ionic liquid used. The specific reaction conditions and results are listed in Table 6.

[0100] Table 6 Nitration reaction of chlorobenzene catalyzed by [polyethylene polyamine][H2SO4]3 ionic liquid A3

[0101]

[0102] Example 9

[0103] In a four - necked flask equipped with a reflux condenser, 42.0 g of ionic liquid A3 prepared in Example 1, 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 the nitration reaction of toluene. After the reaction ended in 9 h, it was cooled to 40 - 50 °C, allowed to stand and separate layers. The lower layer of the water - containing ionic liquid layer was separated, and the upper layer was mononitrotoluene. The conversion rate of toluene exceeded 94%. The ortho - ratio of the product analyzed by liquid chromatography was 2.1. The water - containing ionic liquid layer can be reused after evaporation of water.

[0104] According to the above nitration method, toluene was nitrated using nitric acid of other concentrations. The specific reaction conditions and results are listed in Table 7.

[0105] Table 7 Nitration reaction of toluene catalyzed by [polyethylene polyamine][H2SO4]3 ionic liquid A3

[0106] Example Toluene / ionic liquid weight ratio Nitric acid % Temperature °C Reaction time Conversion rate % Adjacent 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

[0107] Example 10

[0108] In a four-necked flask equipped with a reflux condenser, 48.0 g of ionic liquid A3 prepared in Example 1, 26.2 g of 68% nitric acid were successively added, heated to 70 - 80 °C, and 30.0 g of o-xylene was added for nitration reaction. After the reaction ended in 8 h, it was cooled to 40 - 50 °C, allowed to stand for layering, and the lower layer of water-containing ionic liquid layer was separated. The upper layer was mononitro-o-xylene, and the conversion rate exceeded 94%. The water-containing ionic liquid layer could be reused after evaporation to remove water.

[0109] According to the above nitration method, o-xylene was nitrated using nitric acid of other concentrations. The specific reaction conditions and results are listed in Table 8.

[0110] Table 8 Nitration reaction of o-xylene catalyzed by [polyethylene polyamine][H2SO4]3 ionic liquid A3

[0111] Example O-Xylene / ionic liquid weight ratio Nitric acid % Temperature °C 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

[0112] Example 11

[0113] 80 g of 1,2-dichloroethane and 20 g of naphthalene were added to a four-necked flask equipped with a reflux condenser, and 20.0 g of [polyethylene polyamine][H2SO4]3 ionic liquid A3 prepared in Example 1 was added. 10.5 g of 95% nitric acid was added dropwise at room temperature, and the dropping temperature was controlled not to exceed 30 °C. After dropping, it was heated to 65 - 70 °C for reaction. After the reaction ended in 5 h, it was allowed to stand for layering, and the lower layer of water-containing ionic liquid layer was separated. The upper layer of organic layer containing mononitro-naphthalene was detected by GC. The molar ratio of 1-nitronaphthalene to 2-nitronaphthalene was about 30:1, and the conversion rate exceeded 92%. The water-containing ionic liquid layer could be reused after evaporation to remove water.

[0114] According to the above nitration method, mononitration of naphthalene was carried out using nitric acid of other concentrations. The specific reaction conditions and results are listed in Table 9.

[0115] Table 9 Mononitration reaction of naphthalene catalyzed by [polyethylene polyamine][H2SO4]3 ionic liquid A3

[0116] Example Naphthalene / ionic liquid weight ratio Nitric acid % Temperature °C 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

[0117] Take the 1,2-dichloroethane organic layer prepared in Example 11 (calculated based on the actual content of 20 g of mononitronaphthalene), add it to a four-necked flask equipped with a reflux condenser, and sequentially add 20.0 g of the [polyethylene polyamine][H2SO4]3 ionic liquid A3 prepared in Example 1. At room temperature, slowly add 7.8 g of 95% nitric acid dropwise, controlling the dropping temperature not to exceed 30 °C. After dropping, heat to 65 - 70 °C and carry out the second nitration reaction of nitronaphthalene for 12 h. After the reaction is completed, cool to room temperature. A large amount of yellow solid product precipitates. Add 80 g of water to the reaction system, stir evenly, filter to obtain a yellow solid, and wash the upper solid with 30 g of methanol to obtain light yellow solid dinitronaphthalene. The molar ratio of 1,5-dinitronaphthalene to 1,8-dinitronaphthalene analyzed by liquid phase is about 0.5:1, and the conversion rate exceeds 89%. The ionic liquid layer containing water can be reused after evaporation to remove water.

[0118] According to the above second nitration method, use nitric acid with other concentrations for the second nitration of nitronaphthalene. The specific reaction conditions and results are listed in Table 10.

[0119] Table 10 Nitration reaction of mononitronaphthalene catalyzed by [polyethylene polyamine][H2SO4]3 ionic liquid A3

[0120] Example Substrate Substrate / ionic liquid weight ratio Nitric acid % Temperature °C Reaction time Conversion rate % 11-1 1-Nitronaphthalene 1:1 65 65-70 12h 89.2 11-2 1-Nitronaphthalene 1:1 68 65-70 12h 90.1 11-3 1-Nitronaphthalene 1:1 95 65-70 12h 92.5 11-4 1-Nitronaphthalene 1:1 98 65-70 12h 93.0

[0121] Example 12

[0122] According to the nitration method in Example 8, using the ionic liquid A3 described in Example 1 as a catalyst, carry out the nitration reaction on other aromatic hydrocarbons and substituted aromatic hydrocarbons. The specific reaction conditions and results are listed in Table 11.

[0123] Table 11 Nitration reaction of aromatic hydrocarbons catalyzed by [polyethylene polyamine][H2SO4]3 ionic liquid A3

[0124]

[0125]

[0126] Note: " / " in Table 11 represents "or".

[0127] Example 13

[0128] In a four-necked flask equipped with a reflux condenser, 28.0 g of the [polyethylene polyamine][CF3SO3H]3 ionic liquid 4-1 prepared in Example 4, 16.5 g of 68% nitric acid were successively added, heated to 70-80 °C, 20.0 g of chlorobenzene was added, and the nitration reaction of chlorobenzene was carried out. After the reaction ended in 12 h, it was cooled to 40-50 °C, allowed to stand and separate layers. The lower layer of ionic liquid layer containing water was separated, and the upper layer was mononitrochlorobenzene with a conversion rate of 94.3%. The ortho-para ratio of the product analyzed by liquid chromatography was 2.2. The ionic liquid layer containing water could be reused after evaporation to remove water.

[0129] According to the above nitration method, nitration of chlorobenzene was carried out using nitric acid of other concentrations, and the specific reaction conditions and results are listed in Table 12.

[0130] Table 12 Nitration reaction of chlorobenzene catalyzed by [polyethylene polyamine][CF3SO3H]3 ionic liquid 4-1

[0131]

[0132] Example 14

[0133] In a four-necked flask equipped with a reflux condenser, 42.0 g of the [polyethylene polyamine][CF3SO3H]3 ionic liquid 4-1 prepared in Example 4, 30.5 g of 68% nitric acid were successively added, heated to 70-80 °C, 30.0 g of toluene was added, and the nitration reaction of toluene was carried out. After the reaction ended in 11 h, it was cooled to 40-50 °C, allowed to stand and separate layers. The lower layer of ionic liquid layer containing water was separated, and the upper layer was mononitrotoluene with a conversion rate exceeding 95%. The ortho-para ratio of the product analyzed by liquid chromatography was 2.3. The ionic liquid layer containing water could be reused after evaporation to remove water.

[0134] According to the above nitration method, nitration of toluene was carried out using nitric acid of other concentrations, and the results are listed in Table 13.

[0135] Table 13 Nitration reaction of toluene catalyzed by [polyethylene polyamine][CF3SO3H]3 ionic liquid 4-1

[0136] Example Toluene / ionic liquid weight ratio Nitric acid % Temperature °C Reaction time Conversion rate % Adjacent 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

[0137] Example 15

[0138] According to the nitration method in Example 13, using the ionic liquid 4-1 described in Example 4 as a catalyst, nitration reactions of other aromatic hydrocarbons and substituted aromatic hydrocarbons were carried out, and the specific reaction conditions and results are listed in Table 14.

[0139] Table 14 Nitration reaction of aromatic hydrocarbons catalyzed by [polyethylene polyamine][CF3SO3H]3 ionic liquid 4-1

[0140]

[0141]

[0142] Note: " / " in Table 14 represents "or".

[0143] Example 16

[0144] In a four-necked flask equipped with a reflux condenser, 42.0 g of the [polyethylene polyamine][CH3SO3H]3 ionic liquid 5-1 prepared in Example 5, 24.8 g of 68% nitric acid were successively added, heated to 70 - 80 °C, and 30.0 g of chlorobenzene was added to carry out the nitration reaction of chlorobenzene. After the reaction ended in 12 h, it was cooled to 40 - 50 °C, allowed to stand for layering, the lower layer of the ionic liquid layer containing water was separated, and the upper layer was mononitrochlorobenzene with a conversion rate of 92.1%. The ortho-para ratio of the product analyzed by liquid chromatography was 2.2. The ionic liquid layer containing water could be reused after evaporation to remove water.

[0145] According to the above nitration method, nitration of chlorobenzene was carried out using nitric acid of other concentrations, and the specific reaction conditions and results are listed in Table 15.

[0146] Table 15 Nitration reaction of chlorobenzene catalyzed by [polyethylene polyamine][CH3SO3H]3 ionic liquid 5-1

[0147] Example Chlorobenzene / ionic liquid weight ratio Nitric acid Temperature °C Reaction time Conversion rate % Adjacent 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

[0148] Example 17

[0149] In a four-necked flask equipped with a reflux condenser, 42.0 g of the [polyethylene polyamine][CH3SO3H]3 ionic liquid 5-1 prepared in Example 5, 30.5 g of 68% nitric acid were successively added, heated to 70 - 80 °C, and 30.0 g of toluene was added to carry out the nitration reaction of toluene. After the reaction ended in 11 h, it was cooled to 40 - 50 °C, allowed to stand for layering, the lower layer of the ionic liquid layer containing water was separated, and the upper layer was basically mononitrotoluene with a toluene conversion rate exceeding 94%. The ortho-para ratio of the product analyzed by liquid chromatography was 2.3. The ionic liquid layer containing water could be reused after evaporation to remove water.

[0150] According to the above nitration method, nitration of toluene was carried out using nitric acid of other concentrations, and the specific reaction conditions and results are listed in Table 16.

[0151] Table 16 Nitration reaction of toluene catalyzed by [polyethylene polyamine][CH3SO3H]3 ionic liquid 5-1

[0152] Example Toluene / ionic liquid weight ratio Nitric acid % Temperature °C Reaction time Conversion rate % Adjacent 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

[0153] Example 18

[0154] According to the nitration method in Example 17, using the [polyethylene polyamine][CH3SO3H]3 ionic liquid 5-1 described in Example 5 as a catalyst, nitration reactions were carried out on other aromatic hydrocarbons and substituted aromatic hydrocarbons. The specific reaction conditions and results are listed in Table 17.

[0155] Table 17 Nitration reaction of aromatic hydrocarbons catalyzed by [polyethylene polyamine][CH3SO3H]3 ionic liquid 5-1

[0156]

[0157]

[0158]

[0159] Note: " / " in Table 17 represents "or".

[0160] Example 19

[0161] In a four-necked flask equipped with a reflux condenser, 42.0 g of the [polyethylene polyamine][C6H5SO3H]3 ionic liquid 6-1 prepared in Example 6, 24.8 g of 68% nitric acid were successively added, heated to 70 - 80 °C, and 30.0 g of chlorobenzene was added to carry out the nitration reaction of chlorobenzene. After the reaction ended in 12 h, it was cooled to 40 - 50 °C, allowed to stand and separate layers. The lower layer of the ionic liquid layer containing water was separated, and the upper layer was mononitrochlorobenzene with a conversion rate of 92.1%. The ortho-para ratio of the product analyzed by liquid chromatography was 2.2. The ionic liquid layer containing water can be reused after evaporation to remove water.

[0162] According to the above nitration method, nitration of chlorobenzene was carried out using nitric acid of other concentrations. The specific reaction conditions and results are listed in Table 18.

[0163] Table 18 Nitration reaction of chlorobenzene catalyzed by [polyethylene polyamine][C6H5SO3H]3 ionic liquid 6-1

[0164] Example Chlorobenzene / ionic liquid weight ratio Nitric acid Temperature °C Reaction time Conversion rate % Adjacent 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

[0165] Example 20

[0166] In a four-necked flask equipped with a reflux condenser, 42.0 g of the [polyethylene polyamine][C6H5SO3H]3 ionic liquid 6-1 prepared in Example 6, 30.5 g of 68% nitric acid were successively added, heated to 70 - 80 °C, and 30.0 g of toluene was added to carry out the nitration reaction of toluene. After the reaction ended in 9 h, it was cooled to 40 - 50 °C, allowed to stand and separate layers. The lower layer of the ionic liquid layer containing water was separated, and the upper layer was mononitrotoluene with a conversion rate exceeding 92%. The ortho-para ratio of the product analyzed by liquid chromatography was 2.2. The ionic liquid layer containing water can be reused after evaporation to remove water.

[0167] According to the above nitration method, toluene nitration was carried out using nitric acid with other concentrations, and the specific reaction conditions and results are listed in Table 19.

[0168] Table 19 Nitration reaction of toluene catalyzed by [polyethylene polyamine][C6H5SO3H]3 ionic liquid 6-1

[0169] Example Toluene / ionic liquid weight ratio Nitric acid % Temperature °C Reaction time Conversion rate % Adjacent 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

[0170] Example 21

[0171] According to the nitration method in Example 20, using the [polyethylene polyamine][C6H5SO3H]3 ionic liquid 6-1 described in Example 6 as a catalyst, nitration reactions were carried out on other aromatic hydrocarbons and substituted aromatic hydrocarbons, and the specific reaction conditions and results are listed in Table 20.

[0172] Table 20 Nitration reaction of aromatic hydrocarbons catalyzed by [polyethylene polyamine][C6H5SO3H]3 ionic liquid 6-1

[0173]

[0174]

[0175] Note: " / " in Table 20 represents "or".

[0176] Example 22

[0177] 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. After heating to 70-80 °C, 30.0 g of chlorobenzene was added to carry out the nitration reaction of chlorobenzene. After the reaction ended in 11 h, it was cooled to 40-50 °C, allowed to stand and layer. The lower layer of the ionic liquid layer containing water was separated, and the upper layer was basically mononitrochlorobenzene with a conversion rate of more than 96%. The ortho ratio of the product analyzed by liquid chromatography was 2.2. The upper organic phase was analyzed by gas chromatography, and the product was only mononitrochlorobenzene and unreacted chlorobenzene.

[0178] The ionic liquid layer containing water was evaporated to remove water (70 °C under vacuum) and could be reused.

[0179] According to the above nitration method, nitration of chlorobenzene was carried out using nitric acid with other concentrations, and the specific reaction conditions and results are listed in Table 21.

[0180] Table 21 Nitration reaction of chlorobenzene catalyzed by ionic liquid B3

[0181]

[0182] Example 23

[0183] 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 successively added. The mixture was heated to 70 - 80 °C, 30.0 g of toluene was added, and the toluene nitration reaction was carried out. After 9 h of reaction, it was cooled to 40 - 50 °C, allowed to stand and separate into layers. The lower layer of ionic liquid layer containing water was separated, and the upper layer was mononitrotoluene with a conversion rate exceeding 95%. The ortho-para ratio of the product analyzed by liquid chromatography was 2.2. The ionic liquid layer containing water could be reused after evaporation to remove water.

[0184] According to the above nitration method, toluene nitration was carried out using nitric acid of other concentrations. The specific reaction conditions and results are listed in Table 22.

[0185] Table 22 Nitration reaction of toluene catalyzed by ionic liquid B3

[0186] Example Toluene / ionic liquid weight ratio Nitric acid % Temperature °C Reaction time Conversion rate % Adjacent 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

[0187] Example 24

[0188] According to the nitration method in Example 23, using the ionic liquid B3 described in Example 7 as a catalyst, nitration reactions were carried out on other aromatic hydrocarbons and substituted aromatic hydrocarbons. The specific reaction conditions and results are listed in Table 23.

[0189] Table 23 Nitration reaction of aromatic hydrocarbons catalyzed by ionic liquid B3

[0190]

[0191]

[0192] Note: " / " in Table 23 represents "or".

[0193] Example 25

[0194] In a four-necked flask equipped with a reflux condenser, 28.0 g of the ionic liquid H3 prepared in Example 7 and 16.5 g of 68% nitric acid were successively added. The mixture was heated to 70 - 80 °C, 20.0 g of chlorobenzene was added, and the chlorobenzene nitration reaction was carried out under this temperature condition. After 12 h of reaction, it was cooled to 40 - 50 °C, allowed to stand and separate into layers. The lower layer of ionic liquid layer containing water was separated, and the upper layer was mononitrochlorobenzene with a conversion rate exceeding 96%. The upper organic phase was taken for gas chromatography analysis of the chlorobenzene conversion rate and composition, which was only mononitrochlorobenzene and unreacted chlorobenzene. The ortho-para ratio of the product analyzed by liquid chromatography was 2.3. The ionic liquid layer containing water could be reused after evaporation to remove water.

[0195] According to the above nitration method, chlorobenzene nitration was carried out using nitric acid of other concentrations. The specific reaction conditions and results are listed in Table 24.

[0196] Table 24 Nitration reaction of chlorobenzene catalyzed by ionic liquid H3

[0197]

[0198] Example 26

[0199] In a four-necked flask equipped with a reflux condenser, 42.0 g of the ionic liquid H3 prepared in Example 7, 30.5 g of 68% nitric acid were successively added, heated to 70-80 °C, 30.0 g of toluene was added, and the toluene nitration reaction was carried out. After the reaction was completed in 11 h, it was cooled to 40-50 °C, allowed to stand for liquid separation, the lower layer of ionic liquid layer containing water was separated, and the upper layer was mononitrotoluene, and the conversion rate exceeded 96%. The o / p ratio of the product analyzed by liquid chromatography was 2.3. The ionic liquid layer containing water can be reused after evaporation to remove water.

[0200] According to the above nitration method, toluene nitration was carried out using nitric acid of other concentrations, and the specific reaction conditions and results are listed in Table 25.

[0201] Table 25 Nitration reaction of toluene catalyzed by ionic liquid H3

[0202] Example Toluene / ionic liquid weight ratio Nitric acid % Temperature °C Reaction time Conversion rate % Adjacent 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

[0203] Example 27

[0204] In a four-necked flask equipped with a reflux condenser, 48.0 g of the ionic liquid H3 prepared in Example 7, 18.9 g of 68% nitric acid were successively added, heated to 70-80 °C, 30.0 g of o-dichlorobenzene was added, and the nitration reaction was carried out. After the reaction was completed in 8 h, it was cooled to 40-50 °C, allowed to stand for liquid separation, the lower layer of ionic liquid layer containing water was separated, and the upper layer was mononitro-o-dichlorobenzene, and the conversion rate exceeded 94%. The ionic liquid layer containing water can be reused after evaporation to remove water.

[0205] According to the above nitration method, o-dichlorobenzene nitration was carried out using nitric acid of other concentrations, and the specific reaction conditions and results are listed in Table 25.

[0206] Table 26 Nitration reaction of o-dichlorobenzene catalyzed by ionic liquid H3

[0207] Example O-Dichlorobenzene / ionic liquid weight ratio Nitric acid % Temperature °C 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

[0208] Example 28

[0209] In a four-necked flask equipped with a reflux condenser, 48.0 g of the ionic liquid H3 prepared as described in Example 7, 26.2 g of 68% nitric acid were successively added, heated to 70-80 °C and 30.0 g of o-xylene was added, and the nitration reaction was carried out. After the reaction was completed in 11 h, it was cooled to 40-50 °C, allowed to stand for liquid separation, the lower layer of ionic liquid layer containing water was separated, and the upper layer was mononitro-o-xylene, and the conversion rate exceeded 94%. The ionic liquid layer containing water can be reused after evaporation to remove water.

[0210] According to the above nitration method, o-xylene was nitrated using nitric acid with other concentrations. The specific reaction conditions and results are listed in Table 27.

[0211] Table 27 Nitration reaction of o-xylene catalyzed by ionic liquid H3

[0212] Example O-Xylene / ionic liquid weight ratio Nitric acid % Temperature °C 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

[0213] Example 29

[0214] 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.

[0215] Table 28 Nitration reaction of aromatic hydrocarbons catalyzed by ionic liquid H3

[0216]

[0217]

[0218] Note: " / " in Table 28 represents "or".

[0219] Example 30

[0220] In a four-necked flask equipped with a reflux condenser, 28.0 g of ionic liquid J3 prepared in Example 7 and 16.5 g of 68% nitric acid were successively added. The mixture was heated to 70 - 80 °C, and 20.0 g of chlorobenzene was added. The nitration reaction of chlorobenzene was carried out under this temperature condition. After the reaction ended in 12 h, it was cooled to 40 - 50 °C, allowed to stand for stratification, and the lower layer of ionic liquid layer containing water was separated. The upper layer was mononitrochlorobenzene, and the conversion rate was above 97%. The upper organic phase was taken for gas chromatography analysis of the chlorobenzene conversion rate and composition, which were only mononitrochlorobenzene and unreacted chlorobenzene. The ortho-ratio of the product analyzed by liquid chromatography was 2.2. The ionic liquid layer containing water could be reused after evaporation to remove water.

[0221] According to the above nitration method, chlorobenzene was nitrated using nitric acid with other concentrations. The specific reaction conditions and results are listed in Table 29.

[0222] Table 29 Nitration reaction of chlorobenzene catalyzed by ionic liquid J3

[0223] Example Chlorobenzene / ionic liquid weight ratio Nitric acid Temperature °C Reaction time Conversion rate % Adjacent 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

[0224] Example 31

[0225] In a four-necked flask equipped with a reflux condenser, 42.0 g of the ionic liquid J3 prepared in Example 7, 30.5 g of 68% nitric acid were successively added, heated to 70 - 80 °C, 30.0 g of toluene was added, and the toluene nitration reaction was carried out. After 11 h of the reaction, it was cooled to 40 - 50 °C, allowed to stand for liquid separation, the lower layer of the ionic liquid layer containing water was separated out, and the upper layer was basically mononitrotoluene with a conversion rate of over 96%. The ortho-ratio of the product analyzed by liquid chromatography was 2.3. The ionic liquid layer containing water can be reused after evaporation to remove water.

[0226] According to the above nitration method, toluene nitration was carried out using nitric acid of other concentrations, and the specific reaction conditions and results are listed in Table 30.

[0227] Table 30 Nitration reaction of toluene catalyzed by ionic liquid J3

[0228] Example Toluene / ionic liquid weight ratio Nitric acid % Temperature °C Reaction time Conversion rate % Adjacent 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

[0229] Example 32

[0230] According to the nitration method described in Example 31, using the ionic liquid J3 described in Example 7 as a catalyst, nitration reactions were carried out on other aromatic hydrocarbons and substituted aromatic hydrocarbons, and the specific reaction conditions and results are listed in Table 31.

[0231] Table 31 Nitration reaction of aromatic hydrocarbons catalyzed by ionic liquid J3

[0232]

[0233]

[0234] Note: " / " in Table 31 represents "or".

[0235] Example 33

[0236] According to the nitration method described in Example 30, using other ionic liquids described in Example 7 as catalysts, the nitration reaction of chlorobenzene was carried out, and the product was mononitrochlorobenzene. The specific reaction conditions and results are listed in Table 32.

[0237] Table 32 Nitration reaction of chlorobenzene catalyzed by other ionic liquids in Example 7

[0238]

[0239]

[0240] Example 34

[0241] According to the nitration method described in Example 31, using other ionic liquids described in Example 7 as catalysts, the nitration reaction of toluene was carried out, and the product was mononitrotoluene. The specific reaction conditions and results are listed in Table 33.

[0242] Table 33 Nitration reaction of toluene catalyzed by other ionic liquids in Example 7

[0243]

[0244]

[0245] The ionic liquid used in the following comparative examples is N,N-tetramethylethylenediamine sulfate, i.e., [N,N-tetramethylethylenediamine][H2SO4]3. The specific preparation method is as described in Example 1, that is, replacing the polyethylenepolyamine in Example 1 with N,N-tetramethylethylenediamine, and the molar ratio of N to sulfuric acid is 1:1.

[0246] Comparative Example 1

[0247] Add 28.0 g of ionic liquid (N,N-tetramethylethylenediamine sulfate, molar ratio of cationic nitrogen element to sulfuric acid = 1:3), 16.5 g of 68% nitric acid into a four-necked flask equipped with a reflux condenser, heat to 70 - 80 °C, add 20 g of chlorobenzene, and carry out the nitration reaction of chlorobenzene. After the reaction ends in 12 h, cool to 40 - 50 °C, let it stand for layering, separate out the lower ionic liquid layer containing water, and the upper organic phase is nitrochlorobenzene. Take the upper organic phase for gas phase analysis, and the content of mononitrochlorobenzene in the product is 88.3%, and the content of dinitrochlorobenzene is 3.8%.

[0248] Examples of the nitration of chlorobenzene catalyzed by [N,N-tetramethylethylenediamine][H2SO4]3 ionic liquid with other concentrations of nitric acid can be carried out in a similar manner by the general method mentioned in Comparative Example 1. The specific conditions are shown in Table 34:

[0249] Table 34 Nitration reaction of chlorobenzene catalyzed by N,N-tetramethylethylenediamine sulfate ionic liquid

[0250]

[0251] Note: The contents in Table 34 are the contents of the corresponding substances in the upper organic phase.

[0252] From the results of Examples 8, 22, 25, 30 and Comparative Example 1 respectively, it can be seen that when using sulfate ionic liquids formed by different ammonium ions to catalyze the nitration reaction of chlorobenzene, there are essential differences in the nitration products. Among the nitrochlorobenzene products obtained by using the ionic liquids A3, B3, H3 and J3 of the present invention as catalysts, the content of mononitrochlorobenzene is higher, above 95%, and dinitrochlorobenzene cannot be detected in the products. While when using N,N-tetramethylethylenediamine sulfate ionic liquid as the catalyst, the content of mononitrochlorobenzene in the nitrochlorobenzene product is only about 89%, and the amount of doped dinitrochlorobenzene reaches 3.8%. The ionic liquids of the present invention have higher selectivity for the mononitration reaction.

Claims

1. Application of a polyethylenepolyamine-based ammonium salt ionic liquid as a catalyst in the field of industrial acid-catalyzed reactions, characterized in that The ammonium salt ionic liquid is prepared from polyethylenepolyamine and the corresponding protonic acid. The anion in the ammonium salt comes from the protonic acid and is selected from one or more of HSO4 - , HSO4(H2SO4) - , HSO4(H2SO4)2 - , CF3SO3 - , CH3SO3 - and R'-C6H4SO3 - . One or more of these anions are present, where R' is H or an alkyl group. The cation in the ammonium salt ionic liquid comes from the ammonium cation formed by polyethylenepolyamine. In the ammonium salt ionic liquid, the molar ratio of nitrogen atoms to the protonic acid is 1:(1 - 3); the polyethylenepolyamine is Ethyleneamine E-100; the industrial acid-catalyzed reaction is an aromatic nitration reaction.

2. The application of the polyethylenepolyamine-based ammonium salt ionic liquid as a catalyst in the field of industrial acid-catalyzed reactions according to claim 1, characterized in that, The polyethylenepolyamine further includes a tertiary amine; 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''-pentamethyldiethylenetriamine, N,N,N′,N′-tetramethylmethylenediamine, N,N,N′,N′-tetramethyl-1,3-propanediamine, tris[2-(dimethylamino)ethyl]amine, and cetyl dimethyl tertiary amine.

3. Application of the polyethylenepolyamine-based ammonium salt ionic liquid as a catalyst in the field of industrial acid-catalyzed reactions according to claim 1 or 2, characterized in that the polyethylenepolyamine-based ammonium salt ionic liquid is used to catalyze the nitration reaction of an aromatic hydrocarbon, the aromatic hydrocarbon is selected from benzene and substituted benzene, and 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 group; when the substituted benzene is disubstituted or polysubstituted, X is selected from one of halogen, alkyl, and alkoxy.

4. Application of the polyethylenepolyamine-based ammonium salt ionic liquid as a catalyst in the field of industrial acid-catalyzed reactions according to claim 3, characterized in that When the substituted benzene is monosubstituted, X is selected from one of F, Cl, Br, I, CF3, CH3, OCH3, C2H5, C4H9, C 10 H 21 、C 12 H 25 、C 18 H 37 and NHCOCH3; when the substituted benzene is disubstituted or polysubstituted, X is selected from at least one of F, Cl, and CH3.

5. Application of the polyethylenepolyamine-based ammonium salt ionic liquid as a catalyst in the field of industrial acid-catalyzed reactions according to claim 1 or 2, characterized in that the polyethylenepolyamine-based ammonium salt ionic liquid is used to catalyze the nitration reaction of an aromatic hydrocarbon, and the structure of the aromatic hydrocarbon is selected from one of the following structures: , , , where A is O, CH2 or S.

Images