Method for preparing nitroso aromatic hydrocarbon, N-hydroxy arylamine and arylamine from nitroaromatic hydrocarbon

Abstract

The invention relates to the field of catalytic hydrogenation of nitro-aromatic hydrocarbon, and discloses a method for preparing nitroso-aromatic hydrocarbon, N-hydroxy arylamine and arylamine from nitro-aromatic hydrocarbon, which comprises the following steps: by taking metal nanoparticles loaded by a reducible carrier as a catalyst, hydrogen as a hydrogen source and bidentate amine as an auxiliary agent, keeping the hydrogen pressure at 0.1-0.6 MPa, and reacting at the temperature of 30-60 DEG C; the nitroso aromatic hydrocarbon, the N-hydroxy arylamine and the arylamine are prepared from the nitroaromatic hydrocarbon by controlling different temperatures. The catalytic hydrogenation of the nitroaromatic hydrocarbon can be realized with high selectivity and high conversion rate.

Description

Technical Field

[0001] The present invention relates to the field of catalytic hydrogenation of nitroaromatics, in particular to a method for preparing nitrosoaromatics, N-hydroxyaromaticamines and aromaticamines from nitroaromatics. Background Art

[0002] Catalysis is a key discipline for sustainable development. It allows chemical transformations to be carried out at lower temperatures while reducing or even avoiding the formation of by-products. Therefore, it is very important to prepare more active and especially more selective catalysts. Selectivity is crucial for chemical transformations, especially when a chemical reaction involves multiple reactive groups and only a specific group needs to be converted while avoiding other conversions. A typical example is the selective catalytic hydrogenation of nitroaromatics to the corresponding nitrosoaromatics, N-hydroxyaromatic amines and aromatic amines. The reaction includes direct, condensation and disproportionation pathways, and many pathways contain many products. In addition, there are one or more substituents on the aromatic ring, such as C=C, C≡C, C=O, C=N, C≡N and CX (halogen), etc. It is very challenging to "recognize" and convert the nitro group with high selectivity to obtain functionalized nitroso, hydroxylamine and amine compounds. At the same time, the design and synthesis of new catalysts with high catalytic selectivity also contains great application value.

[0003] Nitrosaromatics, N-hydroxyaromatic amines and aromatic amines are important intermediates necessary for the production of many fine and bulk chemicals, such as dyes, pharmaceuticals and agricultural chemicals. According to literature reports (ChemCatChem, 2009, 1, 210-221; Chem.Rev., 2019, 119, 2611-2680), although the current catalysts can well achieve the deep hydrogenation of nitroaromatics to produce the corresponding amines, the highly selective production of hydroxylamine or nitroso compounds is still a scientific and technological problem that has plagued the scientific community for many years. The difficulty in achieving highly selective hydrogenation to produce hydroxylamine is that hydroxylamine is an intermediate product that is extremely unstable in thermodynamics and is more easily deeply hydrogenated to amines. Only the Zheng research group recently reported for the first time a breakthrough in the use of organic modification to induce the interfacial electronic effect of Pt-based nanocatalysts to achieve catalytic hydrogenation of nitrobenzene to produce hydroxyaniline (Nat.Mater., 2016, 15, 564-569). In fact, there are no successful cases reported on the catalytic hydrogenation of nitroaromatics to produce nitrosoaromatics. In summary, it is very meaningful and challenging to achieve the selective catalytic hydrogenation of nitroaromatics to obtain nitrosoaromatics, N-hydroxyaromatic amines and aromatic amines in the same catalytic system.

[0004] As is well known, heterogeneous noble metal catalysts can continuously activate H2 at low temperature and realize rapid hydrogenation of unsaturated groups, usually showing high activity. However, this type of catalyst has no recognition of the target group, resulting in very low selectivity. On the other hand, stoichiometric reducing agents, such as Na2S2O4, Fe, Sn or Zn, etc., although they can selectively hydrogenate many unsaturated compounds, are low-cost and easy to operate, their fatal flaw is that a large amount of solid waste will be formed during the reaction, which is unfriendly to the environment and difficult to sustain (Science, 2006, 313, 332-334). If their shortcomings can be avoided and their advantages can be integrated, it is undoubtedly the best choice. Summary of the invention

[0005] Therefore, it is necessary to provide a method for preparing nitrosoaromatics, N-hydroxyaromatic amines and aromatic amines from nitroaromatics to solve the problem that the existing catalytic hydrogenation of nitroaromatics cannot be selectively catalyzed.

[0006] To achieve the above-mentioned purpose, the present invention provides a method for preparing nitroso aromatics from nitro aromatics, using metal nanoparticles supported by a reducible carrier as a catalyst, hydrogen as a hydrogen source, and a bidentate amine as an auxiliary agent to prepare nitroso aromatics from nitro aromatics. During the reaction, the hydrogen pressure is maintained at 0.1-0.6MPa and the reaction temperature is 20-70°C.

[0007] Another aspect of the present invention provides a method for preparing N-hydroxy aromatic amine from nitro aromatic hydrocarbons, using metal nanoparticles supported by a reducible carrier as a catalyst, hydrogen as a hydrogen source, and a bidentate amine as an auxiliary agent, wherein the bidentate amine accounts for 40%-100% of the total volume of the reaction solvent, and the N-hydroxy aromatic amine is prepared from the nitro aromatic hydrocarbons. During the reaction, the hydrogen pressure is 0.1-0.6 MPa and the reaction temperature is -10-19°C.

[0008] Another aspect of the present invention provides a method for preparing aromatic amines from nitroaromatic hydrocarbons, using metal nanoparticles supported by a reducible carrier as a catalyst, hydrogen as a hydrogen source, bidentate amines and vanadium-containing compounds as auxiliary agents, and maintaining the hydrogen pressure at 0.1-0.6 MPa and the reaction temperature at -10-70°C during the reaction.

[0009] The above technical solution has the following beneficial effects:

[0010] In the present invention, metal nanoparticles supported on a reducible carrier are used as a catalyst, and bidentate amines are introduced as an auxiliary agent. By controlling the reaction temperature, nitrosoaromatics and N-hydroxyaromatic amines can be selectively hydrogenated to prepare aromatic amines. By adding a vanadium-containing compound as an auxiliary agent in the reaction system, nitroaromatics can be selectively catalyzed to hydrogenate to prepare aromatic amines. The three preparation methods of the present invention have mild reaction conditions, high nitroaromatic conversion rates and target product selectivity, and good cycle stability.

[0011] Terminology

[0012] In the present invention, "room temperature" or "normal temperature" refers to the ambient temperature, which is from about 10°C to about 40°C. In some embodiments, "room temperature" or "normal temperature" refers to a temperature from about 20°C to about 30°C; in other embodiments, "room temperature" or "normal temperature" refers to a temperature from about 25°C to about 30°C; in still other embodiments, "room temperature" or "normal temperature" refers to 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, 40°C, etc.

[0013] The term "nitroaromatic hydrocarbon" in the present invention refers to nitrobenzene or nitrobenzene having a substituent on the benzene ring.

[0014] The term "nitrosoaromatic hydrocarbon" in the present invention refers to nitrosobenzene or nitrosobenzene containing substituents on the benzene ring.

[0015] The term "aromatic amine" in the present invention refers to aniline or aniline having a substituent on the benzene ring.

[0016] The term "anaerobic" in the present invention 1 H-NMR technology refers to the process of hydrogenation of nitroaromatics by sampling, preparing and conducting 1 H-NMR test.

[0017] The term "bidentate amine" in the present invention refers to one of ethylenediamine, propylenediamine, butylenediamine, pentylenediamine and hexylenediamine.

[0018] The term "chelation" in the present invention refers to the coordination effect between a bidentate ligand or a polydentate ligand and a coordination center atom.

[0019] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a transmission electron microscope photograph of the Pt NPs / SnO2 catalyst with a metal loading of 1 wt% prepared in Example 1;

[0021] Figure 2 is a powder X-ray diffraction spectrum of the Pt NPs / SnO2 catalyst with a metal loading of 1 wt% prepared in Example 1;

[0022] Figure 3 is a scanning transmission electron micrograph of the Pt NPs / SnO2 catalyst with a metal loading of 1 wt% prepared in Example 1;

[0023] Figure 4 It is the energy dispersive spectroscopy characterization of the Pt NPs / SnO2 catalyst with a metal loading of 1 wt% prepared in Example 1;

[0024] Figure 5 is a high-resolution transmission electron microscopy photograph of a Pt NPs / SnO2 catalyst with a metal loading of 1 wt% prepared in Example 1 and a corresponding fast Fourier transform analysis photograph;

[0025] Figure 6 The results of preparing nitrosobenzene in Example 1 under anaerobic conditions are as follows: 1 H-NMR spectrum;

[0026] Figure 7 The reactant conversion curve (Conv.) and each product selectivity curve (Sel.) of preparing nitrosobenzene in Example 1 are shown in FIG. 1 , wherein the abscissa is the reaction time and the ordinate is the conversion / selectivity;

[0027] Figure 8 This is the HPLC characterization spectrum of nitrosobenzene prepared in Example 1, wherein the abscissa is the reaction time and the ordinate is the signal intensity of each detected object;

[0028] Fig. 9 The results of the comparative example 4 in which nitrosobenzene was prepared under oxygen-free conditions are shown in Table 1. 1 H-NMR spectrum;

[0029] Fig.10 1 is a reactant conversion curve (Conv.) and each product selectivity curve (Sel.) for preparing nitrosobenzene in Comparative Example 4, wherein the abscissa is the reaction time and the ordinate is the conversion rate / selectivity;

[0030] Fig.11 The results of Example 73 in the preparation of N-hydroxyaniline under anaerobic conditions are as follows: 1 H-NMR spectrum;

[0031] Fig.12 The reactant conversion curve (Conv.) and each product selectivity curve (Sel.) for preparing N-hydroxyaniline in Example 73, wherein the abscissa is the reaction time and the ordinate is the conversion / selectivity;

[0032] Fig.13 This is the HPLC characterization spectrum of the preparation of N-hydroxyaniline in Example 73, wherein the abscissa is the reaction time and the ordinate is the signal intensity of each detected object;

[0033] Fig.14 The reactant conversion curve (Conv.) and each product selectivity curve (Sel.) of the preparation of N-hydroxyaniline in Comparative Example 11 are shown in FIG. 11, wherein the abscissa represents the reaction time and the ordinate represents the conversion rate / selectivity;

[0034] Fig.15 It is the reactant conversion rate curve (Conv.) and each product selectivity curve (Sel.) for preparing aniline in Example 137, wherein the horizontal axis is the reaction time and the vertical axis is the conversion rate / selectivity.

[0035] Fig.16 It is the high performance liquid chromatography characterization spectrum of nitrosobenzene prepared in Example 2-3 and Comparative Example 1-3, wherein the abscissa is the reaction time and the ordinate is the signal intensity of each detected object;

[0036] Fig.17 The results of preparing nitrosobenzene in Examples 2-3 and Comparative Examples 1-3 under anaerobic conditions are as follows: 1 H-NMR spectrum.

[0037] Fig.18 The reactant conversion curve (Conv.) and each product selectivity curve (Sel.) for preparing N-hydroxyarylamine in Comparative Examples 12-16, wherein the abscissa is the reaction time and the ordinate is the conversion / selectivity;

[0038] Fig.19 The reactant conversion rate curve (Conv.) and the selectivity curve (Sel.) of the product nitrosobenzene prepared in Examples 62-72 are shown in FIG. 1 , wherein the line graph is the reactant conversion rate curve (Conv.), corresponding to the left ordinate (the left ordinate is the conversion rate), and the bar graph is the selectivity curve (Sel.) of the product nitrosobenzene, corresponding to the right ordinate (the right ordinate is the selectivity);

[0039] Fig. 20 The reactant conversion curve (Conv.) and the selectivity curve (Sel.) of the product N-hydroxyaniline prepared in Examples 126-136 are shown, wherein the line graph is the reactant conversion curve (Conv.), corresponding to the left ordinate (the left ordinate is the conversion), and the bar graph is the selectivity curve (Sel.) of the product N-hydroxyaniline, corresponding to the right ordinate (the right ordinate is the selectivity);

[0040] Fig.21The reactant conversion rate curve (Conv.) and the selectivity curve (Sel.) of the product aniline prepared in Examples 195-205 are shown in FIG. 195, wherein the line graph is the reactant conversion rate curve (Conv.), corresponding to the left ordinate (the left ordinate is the conversion rate), and the bar graph is the selectivity curve (Sel.) of the product aniline, corresponding to the right ordinate (the right ordinate is the selectivity). DETAILED DESCRIPTION

[0041] The invention discloses a method for preparing nitroso aromatics from nitro aromatics. The method comprises taking metal nanoparticles supported by a reducible carrier as a catalyst, taking hydrogen as a hydrogen source and taking bidentate amine as an auxiliary agent to prepare nitroso aromatics from nitro aromatics. During the reaction, the hydrogen pressure is maintained at 0.1-0.6 MPa and the reaction temperature is 20-70°C.

[0042] In some embodiments, the metal includes one or more of Pt, Pd, Ni, Ir, Ru, and Rh.

[0043] In some embodiments, the metal nanoparticles have a particle size less than 5 nm.

[0044] In some embodiments, based on the total mass of the catalyst, the content of the metal nanoparticles in the catalyst is 0.5-10 wt %, and the content of the reducing carrier loading is 90-99.5 wt %.

[0045] In some embodiments, the reducible carrier includes one or more of SnO2, Fe2O3, Fe3O4, FeO, Co3O4, TiO2, MnO2, CuO, ZnO, Ga2O3, In2O3 and GeO2.

[0046] In some embodiments, the bidentate amine adjuvant includes one or more of ethylenediamine, propylenediamine, butylenediamine, pentylenediamine, and hexylenediamine.

[0047] In some embodiments, the bidentate amine accounts for 10%-100% of the total volume of the reaction solvent, and preferably the bidentate amine accounts for 40%-100% of the total volume of the reaction solvent.

[0048] In some embodiments, the reaction solvent is one or more of water, methanol, ethanol, acetonitrile, toluene, n-hexane and cyclohexane.

[0049] In some embodiments, the reducible carrier is preferably SnO2, the metal is preferably Pt, the bidentate amine auxiliary is preferably ethylenediamine, the metal content in the catalyst is preferably 1 wt %, and the reaction solvent is preferably ethanol.

[0050] The invention discloses a method for preparing N-hydroxy aromatic amine from nitro aromatic hydrocarbons. The method comprises taking metal nanoparticles supported by a reducible carrier as a catalyst, taking hydrogen as a hydrogen source and taking bidentate amine as an auxiliary agent to prepare N-hydroxy aromatic amine from nitro aromatic hydrocarbons. During the reaction, the hydrogen pressure is 0.1-0.6 MPa and the reaction temperature is -10-19°C.

[0051] In some embodiments, the metal includes one or more of Pt, Pd, Ni, Ir, Ru, and Rh.

[0052] In some embodiments, the metal nanoparticles have a particle size less than 5 nm.

[0053] In some embodiments, based on the total mass of the catalyst, the content of the metal nanoparticles in the catalyst is 0.5-10 wt %, and the content of the reducing carrier loading is 90-99.5 wt %.

[0054] In some embodiments, the reducible carrier includes one or more of SnO2, Fe2O3, Fe3O4, FeO, Co3O4, TiO2, MnO2, CuO, ZnO, Ga2O3, In2O3 and GeO2.

[0055] In some embodiments, the bidentate amine adjuvant includes one or more of ethylenediamine, propylenediamine, butylenediamine, pentylenediamine, and hexylenediamine.

[0056] In some embodiments, the bidentate amine accounts for 0.01%-10% of the total volume of the reaction solvent.

[0057] In some embodiments, the reaction solvent is one or more of water, methanol, ethanol, acetonitrile, toluene, n-hexane and cyclohexane.

[0058] In some embodiments, the reducible carrier is preferably SnO2, the metal is preferably Pt, the bidentate amine auxiliary is preferably ethylenediamine, the metal content in the catalyst is preferably 1wt%, and the solvent is preferably ethanol, wherein the proportion of the bidentate amine to the total volume of the solvent is 0.1%-10%, preferably 0.2%.

[0059] The invention discloses a method for preparing aromatic amine from nitroaromatic hydrocarbons. The method comprises taking metal nanoparticles supported by a reducible carrier as a catalyst, taking hydrogen as a hydrogen source, taking bidentate amine and a vanadium-containing compound as auxiliary agents, preparing aromatic amine from nitroaromatic hydrocarbons, and maintaining the hydrogen pressure at 0.1-0.6 MPa and the reaction temperature at -10-70°C during the reaction.

[0060] In some embodiments, the metal includes one or more of Pt, Pd, Ni, Ir, Ru, and Rh.

[0061] In some embodiments, the metal nanoparticles have a particle size less than 5 nm.

[0062] In some embodiments, based on the total mass of the catalyst, the content of the metal nanoparticles in the catalyst is 0.5-10 wt %, and the content of the reducing carrier loading is 90-99.5 wt %.

[0063] In some embodiments, the reducible carrier includes one or more of SnO2, Fe2O3, Fe3O4, FeO, Co3O4, TiO2, MnO2, CuO, ZnO, Ga2O3, In2O3 and GeO2.

[0064] In some embodiments, the vanadium-containing compound comprises one of NaVO3, NH4VO3, VOSO4, V2O5, VO2, V2O3, VO(acac)2, V(acac)3, VCl4 and VCl3. VO(acac)2 is preferred.

[0065] In some embodiments, the molar ratio of the nitroaromatic hydrocarbon to the vanadium-containing compound additive is 1:(1-10000), preferably 1:1000.

[0066] In some embodiments, the bidentate amine adjuvant includes one or more of ethylenediamine, propylenediamine, butylenediamine, pentylenediamine, and hexylenediamine.

[0067] In some embodiments, the bidentate amine accounts for 0.01%-10% of the total volume of the reaction solvent.

[0068] In some embodiments, the reaction solvent is one or more of water, methanol, ethanol, acetonitrile, toluene, n-hexane and cyclohexane.

[0069] In some embodiments, the reducible carrier is preferably SnO2, the metal is preferably Pt, the bidentate amine auxiliary is preferably ethylenediamine, the metal content in the catalyst is preferably 1wt%, and the solvent is preferably ethanol. The ratio of the bidentate amine to the total volume of the solvent is preferably 0.2%.

[0070] In the catalysts described above, there is a metal-support interface between the metal particles and the reducible support, which includes a strong metal-support interaction and a metal-oxygen-support metal chemical bond. There is an organic ligand-metal interface between the bidentate amine additive and the metal nanoparticles, which has a chelating effect of the bidentate amine and contains a metal-nitrogen coordination bond.

[0071] In order to explain the technical content, structural features, achieved objectives and effects of the technical solution in detail, the following is a detailed description in conjunction with specific embodiments.

[0072] Catalytic hydrogenation of nitroaromatics to prepare nitrosoaromatics

[0073] Example 1

[0074] Weigh 1 g of SnO2 carrier and place it in a 250 mL round-bottom flask, add 150 mL of ultrapure water, ultrasonically disperse for 1 min, stir thoroughly with a stirrer for 2 h, slowly add 5 mL of potassium chloroplatinate (K2PtCl4) aqueous solution (5 mg / mL), slowly add 4 mL of sodium borohydride (NaBH4) aqueous solution (1 mg / mL), continue stirring for 2 h, collect the solid by centrifugation or filtration, wash three times with ultrapure water, and dry at 60 ° C in a forced air drying oven for 24 h to obtain a Pt NPs / SnO2 catalyst with a Pt loading of 1 wt%.

[0075] The 1wt% Pt NPs / SnO2 catalyst was characterized. Figure 1 This is a transmission electron microscopy photograph of the catalyst. The results show that only small-sized Pt NPs are dispersed on the surface of the SnO2 carrier, and there are no large-sized particles. The particle size is less than 5nm.

[0076] Figure 2 The figure is the powder X-ray diffraction spectrum of the catalyst, where Pt NPs / SnO2 is the X-ray diffraction spectrum of the catalyst and SnO2 is the X-ray diffraction spectrum of the standard product, respectively analyzed against PDF#41-1445SnO2 and PDF#07-0802Pt X-ray diffraction crystal phase data cards. Figure 2 Only the diffraction peak of SnO2 can be seen. SnO2 has a rutile structure, belongs to the tetragonal system, and has a space group of P42 / mnm. There is no diffraction peak corresponding to the face-centered cubic Pt NPs, which further proves that the nanoparticles are all small in size and there are no large particles.

[0077] Figure 3 This is a scanning transmission electron micrograph of the catalyst. The results also show that there are only small-sized Pt NPs on the surface of the SnO2 carrier, no large-sized particles, and the particle size is less than 5nm.

[0078] Figure 4 The energy dispersive spectroscopy characterization of the catalysts showed that small-sized Pt NPs were uniformly loaded on the surface of the SnO2 support.

[0079] Figure 5 The high-resolution transmission electron micrograph of the catalyst and the corresponding fast Fourier transform (FFT) analysis show that the (111) interplanar spacing of Pt NPs is It is a face-centered cubic lattice structure with a space group of Fm-3m. In summary, the structure of the Pt NPs / SnO2 catalyst is that the ultra-small Pt NPs of uniform size are uniformly loaded on the surface of the SnO2 carrier.

[0080] Preparation of nitrosobenzene (NSB): 19.5 mg of Pt NPs / SnO2 catalyst with a metal loading of 1 wt% was uniformly dispersed in 5 mL of ethylenediamine, added to a 48 mL thick-walled glass pressure bottle, heated the reaction bottle and maintained at 60°C, added 102 μL of nitrobenzene (NB), introduced 0.1 MPa of hydrogen, purged for 1 min, removed the air in the bottle, sealed the pressure bottle, retained 0.1 MPa of hydrogen, and reacted under sufficient stirring. Under anaerobic conditions, 1 H NMR was used to detect the conversion and selectivity of the reaction.

[0081] like Figure 6-7 As shown in the figure, nitrobenzene was completely converted within 12 minutes, and the product was nitrosobenzene. Even if the reaction time was extended to 15 minutes, no deep hydrogenation product N-hydroxyaniline (PHA) was generated, and only a trace amount of aniline (AN) was produced. High performance liquid chromatography also confirmed 1 H NMR results ( Figure 8 ). The retention times of nitrobenzene, nitrosobenzene and aniline are 3.10, 3.44 and 2.21 min, respectively. In addition, nitrosobenzene is extremely unstable in the air and mainly generates azoxy (10.84 min, Ph-NO=N-Ph). Therefore, in order to accurately detect the process of hydrogenating nitroaromatics to prepare nitrosobenzene, detection technology under anaerobic conditions is necessary.

[0082] Embodiment 2-4

[0083] Keeping other conditions in Example 1 unchanged and keeping the total volume of the solvent at 5 mL, only replacing ethylenediamine with a mixture of ethanol and ethylenediamine, and changing the ratio of ethanol to ethylenediamine to 4 mL ethylenediamine and 1 mL ethanol, 3 mL ethylenediamine and 2 mL ethanol, and 2 mL ethylenediamine and 3 mL ethanol, nitrobenzene was completely converted within 15 min, and the selectivity of nitrosobenzene was greater than 99.9%, 98% and 97%, respectively.

[0084] Comparative Examples 1-3

[0085] Keeping other conditions in Example 1 unchanged and keeping the total volume of the solvent at 5 mL, only changing the ratio of ethanol to ethylenediamine to 1 mL ethylenediamine and 4 mL ethanol, 0.5 mL ethylenediamine and 4.5 mL ethanol, and 0.25 mL ethylenediamine and 4.75 mL ethanol, nitrobenzene was completely converted within 15 min, and the selectivity of nitrosobenzene was less than 80%.

[0086] The liquid phase and NMR spectra of Examples 2-3 and Comparative Examples 1-3 are as follows: Figure 16-17 .

[0087] Comparative Example 4

[0088] 19.5 mg of Pt NPs / SnO2 catalyst with a metal loading of 1 wt% was evenly dispersed in 5 mL of ethanol and added to a 48 mL thick-walled glass pressure bottle. The reaction bottle was heated and maintained at 60°C. 102 μL of nitrobenzene was added, and 0.1 MPa of hydrogen was introduced. The air in the bottle was purged for 1 min, and the air in the bottle was removed. The pressure bottle was sealed, and 0.1 MPa of hydrogen was retained. The reaction was carried out under sufficient stirring. Nitrobenzene was completely converted within 30 min, and the selectivity of nitrosobenzene was basically 0%. Only the intermediate product N-hydroxyaniline and the final product aniline were observed to be generated ( Figure 9-10 ).

[0089] Comparative Examples 5-10

[0090] While keeping other reaction conditions in Comparative Example 4 unchanged, a single variable was controlled, the ethanol solvent was changed to one of water, methanol, acetonitrile, toluene, n-hexane and cyclohexane, and the reaction was carried out under sufficient stirring. Nitrobenzene was completely converted within 30 minutes, and the selectivity of nitrosobenzene was substantially 0%.

[0091] Embodiment 5-10

[0092] While keeping other reaction conditions in Example 1 unchanged, a single variable was controlled, the ethanol solvent was changed to one of water, methanol, acetonitrile, toluene, n-hexane and cyclohexane, and the reaction was carried out under sufficient stirring. Nitrobenzene was completely converted within 40 minutes, and the selectivity of nitrosobenzene was greater than 99.9%.

[0093] Examples 11-17

[0094] While keeping other reaction conditions in Example 1 unchanged, a single variable was controlled, and the reaction temperature was changed to 70° C., 50° C., 40° C., 30° C., 20° C., 10° C. or 0° C. Nitrobenzene was completely converted within 100 min, and the selectivity of nitrosobenzene was greater than 99.9%.

[0095] Examples 18-25

[0096] While keeping other reaction conditions in Example 1 unchanged, a single variable was controlled, and ethylenediamine was changed to 1,2-propylenediamine, 1,3-propylenediamine, 1,2-butylenediamine, 1,3-butylenediamine, 1,4-butylenediamine, 2,3-butylenediamine, 1,5-pentanediamine and 1,6-hexanediamine. Nitrobenzene was completely converted within 60 minutes, and the selectivity of nitrosobenzene was greater than 99%.

[0097] Examples 26-31

[0098] While keeping other reaction conditions in Example 1 unchanged, a single variable was controlled to change the metal loading to 0.5wt%, 2wt%, 4wt%, 6wt%, 8wt% and 10wt%. Nitrobenzene was completely converted within 60 minutes, and the selectivity of nitrosobenzene was greater than 99.9%.

[0099] Embodiment 32-61

[0100] While keeping other reaction conditions in Example 1 unchanged, a single variable was controlled to change the type of substrate. Examples 32-61 use p-methylnitrobenzene, m-methylnitrobenzene, o-methylnitrobenzene, p-chloronitrobenzene, m-chloronitrobenzene, o-chloronitrobenzene, p-fluoronitrobenzene, m-fluoronitrobenzene, o-fluoronitrobenzene, p-bromonitrobenzene, p-iodonitrobenzene, p-ethylnitrobenzene, p-propylnitrobenzene, p-tert-butylnitrobenzene, p-nitrobenzaldehyde, p-nitroacetophenone, p-nitrobenzenenitrile, p-nitrostyrene, p-nitrophenylacetylene, p-nitrobenzamide, p-nitrobenzoyl chloride, p-nitroaniline, p-nitrophenol, 2,3-dichloronitrobenzene, 2,4-dichloronitrobenzene, 2,5-dichloronitrobenzene, 2,6-dichloronitrobenzene, 2,3,4-trichloronitrobenzene, 2,4,6-trichloronitrobenzene and 3,4,5-trichloronitrobenzene as substrates, respectively. The nitro group can be completely converted within 60 minutes, the selectivity of the nitroso group is greater than 99.9%, and other substituents can be retained.

[0101] Examples 62-72

[0102] Keeping the other conditions in Example 1 unchanged, only changing the carrier to one of Fe2O3, Fe3O4, FeO, Co3O4, TiO2, MnO2, CuO, ZnO, Ga2O3, In2O3 and GeO2, the obtained Pt / Fe2O3, Pt / Fe3O4, Pt / FeO, Pt / Co3O4, Pt / TiO2, Pt / MnO2, Pt / CuO, Pt / ZnO, Pt / Ga2O3, Pt / In2O3 and Pt / GeO2 can complete the conversion of nitrobenzene within 15 min, and the selectivity of nitrosobenzene is about 100%. The conversion rate and selectivity are shown in FIG. Fig.19 .

[0103] Catalytic hydrogenation of nitroaromatics to prepare N-hydroxyaromatic amines

[0104] Embodiment 73

[0105] The catalyst was the catalyst used in Example 1.

[0106] Preparation of N-hydroxyaniline: 19.5 mg of Pt NPs / SnO2 catalyst with a metal loading of 1 wt% was uniformly dispersed in 4.9 mL of ethanol containing 0.1 mL of ethylenediamine, and added to a 48 mL thick-walled glass pressure bottle. The reaction bottle was cooled and maintained at 0°C, 102 μL of nitrobenzene was added, and 0.1 MPa of hydrogen was introduced. The air in the bottle was purged for 1 min, and the air in the bottle was removed. The pressure bottle was sealed, and 0.1 MPa of hydrogen was retained. The reaction was carried out under sufficient stirring. Under anaerobic conditions, 1 H NMR was used to detect the conversion and selectivity of the reaction.

[0107] like Figure 11-12 As shown in the figure, nitrobenzene was completely converted within 75 minutes, and the product was N-hydroxyaniline. Even if the reaction time was extended to 150 minutes, the selectivity could be well maintained. High performance liquid chromatography also confirmed 1 H NMR results ( Fig.13 ). The retention times of nitrobenzene, N-hydroxyaniline and aniline are 3.10, 2.02 and 2.21 min, respectively. In addition, N-hydroxyaniline is extremely unstable in the air and mainly produces nitrosobenzene. Therefore, in order to accurately detect the process of hydrogenating nitroaromatics to prepare N-hydroxyaniline, detection technology under anaerobic conditions is necessary.

[0108] Comparative Example 11

[0109] 19.5 mg of Pt NPs / SnO2 catalyst with a metal loading of 1 wt% was evenly dispersed in 5 mL of ethanol and added to a 48 mL thick-walled glass pressure bottle. The reaction bottle was cooled and maintained at 0°C, 102 μL of nitrobenzene was added, 0.1 MPa of hydrogen was introduced, and the air in the bottle was purged for 1 min. The air in the bottle was removed, the pressure bottle was sealed, 0.1 MPa of hydrogen was retained, and the reaction was carried out under sufficient stirring. Nitrobenzene was completely converted within 50 min, and the selectivity of N-hydroxyaniline was basically 0%. Only the formation of the final product aniline was observed ( Fig.14 ).

[0110] Examples 74-79

[0111] While keeping other reaction conditions in Example 73 unchanged, a single variable was controlled, the ethanol solvent was changed to one of water, methanol, acetonitrile, toluene, n-hexane and cyclohexane, and the reaction was carried out under sufficient stirring. Nitrobenzene was completely converted within 80 minutes, and the product was N-hydroxyaniline with a selectivity of more than 98%.

[0112] Embodiment 80-81

[0113] While keeping other reaction conditions in Example 73 unchanged, a single variable was controlled, and the reaction temperature was changed to 10° C. and −10° C. Nitrobenzene was completely converted within 100 min, and the selectivity of N-hydroxyaniline was greater than 97%.

[0114] Examples 82-89

[0115] While keeping other reaction conditions in Example 73 unchanged, a single variable was controlled to change ethylenediamine to 1,2-propylenediamine, 1,3-propylenediamine, 1,2-butylenediamine, 1,3-butylenediamine, 1,4-butylenediamine, 2,3-butylenediamine, 1,5-pentanediamine and 1,6-hexanediamine. Nitrobenzene was completely converted within 80 minutes, and the selectivity of N-hydroxyaniline was greater than 98%.

[0116] Examples 90-95

[0117] While keeping other reaction conditions in Example 73 unchanged, a single variable was controlled to change the metal loading to 0.5wt%, 2wt%, 4wt%, 6wt%, 8wt% and 10wt%. Nitrobenzene was completely converted within 100 min, and the selectivity of N-hydroxyaniline was greater than 98%.

[0118] Comparative Examples 12-16

[0119] While keeping other reaction conditions in Example 73 unchanged, the single variable was controlled to change the reaction temperature to 60°C, 50°C, 40°C, 30°C and 20°C. Nitrobenzene was completely converted within 40 minutes, and the selectivity of N-hydroxyaniline was less than 90% as the time went on. The selectivity at different temperatures was as follows: Fig.18 shown.

[0120] Examples 96-125

[0121] While keeping other reaction conditions in Example 73 unchanged, control a single variable and change the type of substrate. Examples 96-125 use p-methylnitrobenzene, m-methylnitrobenzene, o-methylnitrobenzene, p-chloronitrobenzene, m-chloronitrobenzene, o-chloronitrobenzene, p-fluoronitrobenzene, m-fluoronitrobenzene, o-fluoronitrobenzene, p-bromonitrobenzene, p-iodonitrobenzene, p-ethylnitrobenzene, p-propylnitrobenzene, p-tert-butylnitrobenzene, p-nitrobenzaldehyde, p-nitroacetophenone, p-nitrobenzenenitrile, p-nitrostyrene, p-nitrophenylacetylene, p-nitrobenzamide, p-nitrobenzoyl chloride, p-nitroaniline, p-nitrophenol, 2,3-dichloronitrobenzene, 2,4-dichloronitrobenzene, 2,5-dichloronitrobenzene, 2,6-dichloronitrobenzene, 2,3,4-trichloronitrobenzene, 2,4,6-trichloronitrobenzene and 3,4,5-trichloronitrobenzene as substrates, respectively. The nitro group can be completely converted within 80 minutes, the selectivity of N-hydroxyaniline is greater than 98%, and other substituents can be retained.

[0122] Examples 126-136

[0123] Keeping the other conditions in Example 73 unchanged, only changing the catalyst to one of Pt / Fe2O3, Pt / Fe3O4, Pt / FeO, Pt / Co3O4, Pt / TiO2, Pt / MnO2, Pt / CuO, Pt / ZnO, Pt / Ga2O3, Pt / In2O3 and Pt / GeO2, the reaction was carried out for 100 min, the conversion rate of nitrobenzene was close to 100%, the selectivity of N-hydroxyaniline was greater than 98%, and the conversion rate and selectivity were shown in Table 7. Fig. 20 .

[0124] Catalytic hydrogenation of nitroaromatics to prepare aromatic amines

[0125] Embodiment 137

[0126] The catalyst was the catalyst used in Example 1.

[0127] Preparation of aniline: 19.5 mg of Pt NPs / SnO2 catalyst with a metal loading of 1 wt% was uniformly dispersed in 4.9 mL of ethanol containing 0.1 mL of ethylenediamine, and added to a 48 mL thick-walled glass pressure bottle. The reaction bottle was heated and maintained at 60°C, 102 μL of nitrobenzene and 2 mg of VO(acac)2 were added, and 0.1 MPa of hydrogen was introduced. The air in the bottle was purged for 1 min, and the pressure bottle was sealed to retain 0.1 MPa of hydrogen. The reaction was carried out under sufficient stirring. Under anaerobic conditions, the reaction was carried out by 1 H NMR was used to detect the conversion rate and selectivity of the reaction process. Fig.15 As shown, nitrobenzene was completely converted within 30 min, and the product was aniline, without any other products being generated.

[0128] Examples 138-143

[0129] While keeping other reaction conditions in Example 137 unchanged, a single variable was controlled, the ethanol solvent was changed to one of water, methanol, acetonitrile, toluene, n-hexane and cyclohexane, and the reaction was carried out under sufficient stirring. Nitrobenzene was completely converted within 40 minutes, and the product was aniline, and no other products were generated.

[0130] Examples 144-150

[0131] While keeping other reaction conditions in Example 137 unchanged, a single variable was controlled, and the reaction temperature was changed to 50° C., 40° C., 30° C., 20° C., 10° C., 0° C. and −10° C. Nitrobenzene was completely converted within 100 min, and the product was aniline, without generating other products.

[0132] Examples 151-158

[0133] While keeping other reaction conditions in Example 137 unchanged, a single variable was controlled to change ethylenediamine to 1,2-propylenediamine, 1,3-propylenediamine, 1,2-butylenediamine, 1,3-butylenediamine, 1,4-butylenediamine, 2,3-butylenediamine, 1,5-pentanediamine and 1,6-hexanediamine. Nitrobenzene was completely converted within 40 minutes, and the product was aniline, without generating other products.

[0134] Examples 159-164

[0135] While keeping other reaction conditions in Example 137 unchanged, a single variable was controlled to change the metal loading to 0.5wt%, 2wt%, 4wt%, 6wt%, 8wt% and 10wt%. Nitrobenzene was completely converted within 100 min, and the product was aniline.

[0136] Examples 165-194

[0137] While keeping other reaction conditions in Example 137 unchanged, a single variable is controlled to change the type of substrate. Examples 165-194 use p-methylnitrobenzene, m-methylnitrobenzene, o-methylnitrobenzene, p-chloronitrobenzene, m-chloronitrobenzene, o-chloronitrobenzene, p-fluoronitrobenzene, m-fluoronitrobenzene, o-fluoronitrobenzene, p-bromonitrobenzene, p-iodonitrobenzene, p-ethylnitrobenzene, p-propylnitrobenzene, p-tert-butylnitrobenzene, p-nitrobenzaldehyde, p-nitroacetophenone, p-nitrobenzenenitrile, p-nitrostyrene, p-nitrophenylacetylene, p-nitrobenzamide, p-nitrobenzoyl chloride, p-nitroaniline, p-nitrophenol, 2,3-dichloronitrobenzene, 2,4-dichloronitrobenzene, 2,5-dichloronitrobenzene, 2,6-dichloronitrobenzene, 2,3,4-trichloronitrobenzene, 2,4,6-trichloronitrobenzene and 3,4,5-trichloronitrobenzene as substrates, respectively. The nitro group can be completely converted within 50 minutes, the product is aniline, no other products are generated, and other substituents can be retained.

[0138] Examples 195-205

[0139] Keeping the other conditions in Example 137 unchanged, only changing the catalyst to one of Pt / Fe2O3, Pt / Fe3O4, Pt / FeO, Pt / Co3O4, Pt / TiO2, Pt / MnO2, Pt / CuO, Pt / ZnO, Pt / Ga2O3, Pt / In2O3 and Pt / GeO2, the reaction was carried out for 30 min, the conversion rate of nitrobenzene was close to 100%, the selectivity of aniline was about 100%, and the conversion rate and selectivity were shown in Table 1. Fig.21 .

[0140] Although the above embodiments have been described, once those skilled in the art know the basic creative concepts, they can make additional changes and modifications to these embodiments. Therefore, the above description is only an embodiment of the present invention and does not limit the patent protection scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the specification and drawings of the present invention, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for preparing nitrosoaromatic hydrocarbons from nitroaromatic hydrocarbons, characterized in that: The method uses metal nanoparticles supported by a reducible carrier as a catalyst, hydrogen as a hydrogen source, and a bidentate amine as an auxiliary agent, wherein the bidentate amine accounts for 40% to 100% of the total volume of the reaction solvent, and prepares nitrosoaromatic hydrocarbons from nitroaromatic hydrocarbons. During the reaction, the hydrogen pressure is maintained at 0.1 to 0.6 MPa and the reaction temperature is 20 to 70°C.

2. The method for preparing nitrosoaromatics from nitroaromatics according to claim 1, characterized in that: The metal includes one or more of Pt, Pd, Ni, Ir, Ru and Rh.

3. The method for preparing nitrosoaromatics from nitroaromatics according to claim 1, characterized in that: The particle size of the metal nanoparticles is less than 5 nm.

4. The method for preparing nitrosoaromatics from nitroaromatics according to claim 1, characterized in that: Based on the total mass of the catalyst, the content of the metal nanoparticles in the catalyst is 0.5-10wt%, and the content of the reducing carrier load is 90-99.5wt%.

5. The method for preparing nitrosoaromatics from nitroaromatics according to claim 1, characterized in that: The reducible carrier includes one or more of SnO2, Fe2O3, Fe3O4, FeO, Co3O4, TiO2, MnO2, CuO, ZnO, Ga2O3, In2O3 and GeO2.

6. The method for preparing nitrosoaromatics from nitroaromatics according to claim 1, characterized in that: The bidentate amine auxiliary agent includes one or more of ethylenediamine, propylenediamine, butylenediamine, pentylenediamine and hexylenediamine.

7. A method for preparing N-hydroxy aromatic amines from nitro aromatics, characterized in that: The method uses metal nanoparticles supported by a reducible carrier as a catalyst, hydrogen as a hydrogen source, and bidentate amine as an auxiliary agent to prepare N-hydroxy aromatic amine from nitro aromatic hydrocarbons. The hydrogen pressure during the reaction is 0.1-0.6 MPa and the reaction temperature is -10-19°C.

8. The method for preparing N-hydroxy aromatic amines from nitro aromatics according to claim 7, characterized in that: The metal includes one or more of Pt, Pd, Ni, Ir, Ru and Rh.

9. The method for preparing N-hydroxy aromatic amines from nitro aromatics according to claim 7, characterized in that: The particle size of the metal nanoparticles is less than 5 nm.

10. The method for preparing N-hydroxy aromatic amines from nitro aromatics according to claim 7, characterized in that: Based on the total mass of the catalyst, the content of the metal nanoparticles in the catalyst is 0.5-10wt%, and the content of the reducing carrier load is 90-99.5wt%.

11. The method for preparing N-hydroxy aromatic amines from nitro aromatics according to claim 7, characterized in that: The reducible carrier includes one or more of SnO2, Fe2O3, Fe3O4, FeO, Co3O4, TiO2, MnO2, CuO, ZnO, Ga2O3, In2O3 and GeO2.

12. The method for preparing N-hydroxy aromatic amines from nitro aromatics according to claim 7, characterized in that: The bidentate amine auxiliary agent includes one or more of ethylenediamine, propylenediamine, butylenediamine, pentylenediamine and hexylenediamine.

13. A method for preparing aromatic amines from nitroaromatic hydrocarbons, characterized in that: The method uses metal nanoparticles supported on a reducible carrier as a catalyst, hydrogen as a hydrogen source, bidentate amines and vanadium-containing compounds as auxiliary agents to prepare aromatic amines from nitroaromatic hydrocarbons. During the reaction, the hydrogen pressure is maintained at 0.1-0.6 MPa and the reaction temperature is -10-70°C.

14. The method for preparing aromatic amines from nitroaromatic hydrocarbons according to claim 13, characterized in that: The metal includes one or more of Pt, Pd, Ni, Ir, Ru and Rh.

15. The method for preparing aromatic amines from nitroaromatic hydrocarbons according to claim 13, characterized in that: The particle size of the metal nanoparticles is less than 5 nm.

16. The method for preparing aromatic amines from nitroaromatic hydrocarbons according to claim 13, characterized in that: Based on the total mass of the catalyst, the content of the metal nanoparticles in the catalyst is 0.5-10wt%, and the content of the reducing carrier load is 90-99.5wt%.

17. The method for preparing aromatic amines from nitroaromatic hydrocarbons according to claim 13, characterized in that: The reducible carrier includes one or more of SnO2, Fe2O3, Fe3O4, FeO, Co3O4, TiO2, MnO2, CuO, ZnO, Ga2O3, In2O3 and GeO2.

18. The method for preparing aromatic amines from nitroaromatic hydrocarbons according to claim 13, characterized in that A method for preparing aromatic amines from nitroaromatic hydrocarbons, wherein the vanadium-containing compound comprises one of NaVO3, NH4VO3, VOSO4, V2O5, VO2, V2O3, VO(acac)2, V(acac)3, VCl4 and VCl3.

19. The method for preparing aromatic amines from nitroaromatic hydrocarbons according to claim 13, characterized in that: The bidentate amine auxiliary agent includes one or more of ethylenediamine, propylenediamine, butylenediamine, pentylenediamine and hexylenediamine.

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