A method for preparing uranium-depleted α-UO3 and its application in the catalytic synthesis of nitrosamines or their derivatives.
By preparing α-UO3 catalysts using depleted UF6 as raw materials, the problem of safe disposal of depleted uranium was solved. Furthermore, nitrosobenzene was synthesized through a low-cost oxidation reaction, realizing an efficient and green method for synthesizing nitrosobenzene and solving the problems of high cost and toxic emissions in existing technologies.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- LANZHOU UNIV
- Filing Date
- 2024-03-25
- Publication Date
- 2026-07-24
AI Technical Summary
How to safely dispose of and reuse the large amount of depleted uranium produced after a nuclear reaction, and the fact that existing methods for synthesizing nitrosobenzene are costly and that the emission of toxic oxidants has not been effectively addressed.
Using U3O8 obtained from depleted UF6 as raw material, an α-UO3 catalyst was prepared by a simple dissolution and precipitation method. The α-UO3 catalyst was then used to oxidize aniline or its derivatives in the presence of hydrogen peroxide to synthesize nitrosobenzene or its derivatives.
This approach enables the safe utilization of depleted uranium, reduces oxidant costs, decreases toxic emissions, and improves the specificity and yield of nitrosobenzene synthesis.
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Abstract
Description
Technical Field
[0001] This invention relates to a novel technology for the utilization of depleted uranium, particularly the preparation of α-UO3 from depleted UF6 as a raw material for the selective catalytic oxidation of aniline or its derivatives to prepare nitrosobenzene or its derivatives. Technical Background
[0002] The rational use of nuclear energy is of paramount importance to the stability of my country's national defense and the sustainable development of its energy system. However, with the expansion of nuclear energy utilization, the safe disposal and reuse of the large amounts of depleted uranium generated after nuclear reactions has become an urgent issue in pollution prevention and control.
[0003] Uranium is a naturally occurring radioactive element. Many of its current applications are based on its unique nuclear properties. Natural isotopes of uranium include... 238 U (99.275%) 235 U (0.720%) and very small amounts 234 U (0.0050%) (see *Physical Review Journals Archive*, 1939, Vol. 5, pp. 150-153). Due to its large radius, the coordination number resulting from the f-orbital participation in bonding interactions, and its unique coordination structure, uranium possesses stable high oxidation states, including uranium(V) and uranium(VI), making its oxidation capacity higher than that of common lanthanide catalysts, including lanthanum oxide and cerium oxide-based catalysts. Furthermore, due to the participation of electrons in the f-orbital, uranium oxide readily forms oxygen vacancies, which further enhances its catalytic oxidation capacity. Therefore, uranium oxide catalysts (abbreviated as UO) x ) or uranium-doped metal oxide catalysts (abbreviated as U-MO) y Both are expected to exhibit high catalytic activity in organic oxidation reactions. Taylor et al. used uranium oxide to break down short-chain alkanes, achieving the treatment of volatile organic compounds (VOCs) (see *Applied Catalysis B: Environmental*, 2000, Vol. 25, pp. 137-149). Ismagilov et al. prepared Al / UO by impregnating alumina with an aqueous solution of uranyl nitrate. x This makes the catalyst perform well in the methane oxidation reaction (see Catalysis Today, 2010, Vol. 157, pp. 217-222).
[0004] Nitrosene or its derivatives are extremely important fine chemicals and chemical intermediates, widely used in the synthesis of polymers, pharmaceuticals, dyes, and perfumes. Existing research on the synthesis of nitrosene involves using excess unstable acids (such as peracetic acid and perbenzoic acid) to oxidize aniline and its derivatives (see *Synthesis*, 2004, Vol. 5, 706-710). In addition, some researchers have used Au / TiO2 as a catalyst and hydrogen peroxide as an oxidant to catalyze the oxidation of aniline to synthesize nitrosene or its derivatives (see *Advanced Synthesis & Catalysis*, 2016, Vol. 358, No. 9, 1500-1508). It can be seen that the optimal existing method for synthesizing nitrosene and its derivatives is direct oxidation using aniline or its derivatives as raw materials and H2O2 as an oxidant.
[0005] Because uranium oxides readily form oxygen vacancies, which enhance catalytic oxidation capabilities, and considering that the storage and application of depleted uranium remains one of the most pressing issues for the nuclear industry, developing the remaining uranium... 238 U is needed in industry, so we are considering designing a uranium-based catalyst prepared from U3O8 obtained by depleting UF6 as a raw material for the catalytic oxidation of aniline and its derivatives to synthesize nitrosobenzene and its derivatives.
[0006] In summary, we have innovatively proposed a scheme using α-UO3 as a catalyst. The preparation process of this catalyst is simple and convenient, using U3O8 obtained from depleted UF6 as a raw material, and can be prepared through a simple precipitation method. More importantly, the method of directly catalyzing the synthesis of nitrosamines and their derivatives from aniline using α-UO3 has not been reported to date. This innovation not only solves the problem... 238 This approach offers a novel solution to the problem of difficult-to-process residual U, and also enables the low-cost synthesis of high-value-added fine chemicals, demonstrating enormous application potential. Summary of the Invention
[0007] This invention discovers that an α-UO3 catalyst prepared using U3O8 obtained from depleted UF6 as a raw material can catalytically oxidize aniline or its derivatives to form nitrosamine or its derivatives. Therefore, this invention not only provides a novel method for utilizing depleted uranium, but also proposes a low-cost, green, and efficient method for preparing nitrosamine or its derivatives. This method is simple, low-cost, and highly safe, aligning well with green and friendly chemistry principles. Specifically, it includes the following:
[0008] In a first aspect, the present invention provides a method for preparing an α-UO3 catalyst by simply dissolving and reprecipitating U3O8 obtained from depleted UF6 as a raw material.
[0009] Preferably, the catalyst preparation method includes the following steps:
[0010] (1) Preparation of UO4·2H2O: Weigh a specific mass of U3O8 prepared from depleted UF6 as raw material, place it in a container, heat and stir, add an appropriate amount of concentrated nitric acid or concentrated hydrochloric acid, and after U3O8 is completely dissolved, add an appropriate amount of deionized water to form a transparent uranyl salt solution, then add an appropriate amount of hydrogen peroxide, stir continuously for several hours, separate the solid product, wash and dry it to obtain UO4·2H2O.
[0011] (2) Preparation of α-UO3: The precursor UO4·2H2O was thoroughly ground in a mortar, then transferred to a clean porcelain boat and placed in a muffle furnace. It was then calcined at 560℃ for 3 hours at a heating rate of 5℃ / min to obtain α-UO3. Its XRD crystal structure is shown in the attached figure. Figure 1 As shown.
[0012] Preferably, the aniline or its derivative has the structural formula shown in formula (I) below, and the nitrosobenzene or its derivative has the structural formula shown in formula (II) below:
[0013]
[0014] R1-R5 are selected from any one of hydrogen, halogen, hydroxyl, sulfonic acid group, nitro group, substituted or unsubstituted straight-chain or branched alkyl, alkoxy, carbonyl, alkenyl, alkynyl, substituted or unsubstituted aryl, amide, and cyano groups.
[0015] Preferably, R1-R5 are selected from hydrogen, methyl, chlorine, bromine, and methoxy, respectively.
[0016] Preferably, the aniline or its derivatives include: aniline, o-methylaniline, m-methylaniline, p-methylaniline, p-chloroaniline, p-bromoaniline, and p-methoxyaniline.
[0017] Secondly, the present invention provides a method for preparing nitrosobenzene or its derivatives, the method comprising: using aniline or its derivatives as shown in formula (I) as raw material, using an organic solvent as a reaction solvent, using α-UO3 as a catalyst, and using hydrogen peroxide as an oxidant, catalytic oxidation reaction to synthesize nitrosobenzene as shown in formula (II), wherein the organic solvent comprises one or a combination of several of isoalkanes, n-pentane, n-octane, n-heptane, cyclohexane, n-hexane, and petroleum ether;
[0018]
[0019] R1-R5 are selected from any one of hydrogen, halogen, hydroxyl, sulfonic acid group, nitro group, substituted or unsubstituted straight-chain or branched alkyl, alkoxy, carbonyl, alkenyl, alkynyl, substituted or unsubstituted aryl, amide, and cyano groups.
[0020] Preferably, R1-R5 are selected from hydrogen, methyl, chlorine, bromine, and methoxy, respectively.
[0021] Preferably, the aniline or its derivatives include: aniline, o-methylaniline, m-methylaniline, p-methylaniline, p-chloroaniline, p-bromoaniline, and p-methoxyaniline.
[0022] Preferably, the catalyst is α-UO3.
[0023] Preferably, the ratio of the catalyst to aniline or its derivative is 1-30 mg: 1 mmol.
[0024] Preferably, the ratio of the catalyst to aniline or its derivative is 2-25 mg: 1 mmol.
[0025] Preferably, the ratio of the catalyst to aniline or its derivative is 5-15 mg: 1 mmol.
[0026] Preferably, the ratio of the catalyst to aniline or its derivative is 10 mg: 1 mmol.
[0027] Preferably, the molar ratio of hydrogen peroxide to aniline or its derivative is 1-10:1.
[0028] Preferably, the molar ratio of hydrogen peroxide to aniline or its derivative is 2-5:1.
[0029] Preferably, the molar ratio of hydrogen peroxide to aniline or its derivative is 3:1.
[0030] Preferably, the reaction solvent is isopentane.
[0031] Preferably, the mass ratio of the reaction solvent to aniline or its derivative is 1-50:1.
[0032] Preferably, the mass ratio of the reaction solvent to aniline or its derivative is 2-30:1.
[0033] Preferably, the mass ratio of the reaction solvent to aniline or its derivative is 3-20:1.
[0034] Preferably, the mass ratio of the reaction solvent to aniline or its derivative is 5-10:1.
[0035] Preferably, the mass ratio of the reaction solvent to aniline or its derivative is 6:1.
[0036] Preferably, the method includes: adding aniline or its derivatives, α-UO3, and hydrogen peroxide to a reaction solvent, reacting at 10-50°C for 1-8 hours; filtering, distilling, and recrystallizing to obtain nitrosobenzene or its derivatives.
[0037] Preferably, the reaction temperature is 10-50°C.
[0038] Preferably, the reaction temperature is 15-35°C.
[0039] Preferably, the reaction temperature is 25°C.
[0040] Preferably, the reaction time is 1-8 hours.
[0041] Preferably, the reaction time is 2-7 hours.
[0042] Preferably, the reaction time is 3-6 hours.
[0043] Preferably, the reaction time is 5 hours.
[0044] Compared with the prior art, the technical solution of the present invention has the following advantages:
[0045] (1) The present invention uses U3O8 obtained by depleting UF6 as raw material to prepare catalyst, which effectively solves the problem of safe disposal and reuse of depleted uranium in my country’s nuclear energy utilization.
[0046] (2) The aniline or its derivatives used in this invention are common basic raw materials in industry, and are inexpensive and readily available;
[0047] (3) This invention uses inexpensive and readily available hydrogen peroxide as an oxidant and has a low reaction temperature. Compared with traditional methods that use oxidants such as peracetic acid and perbenzoic acid, it significantly reduces the cost of oxidants and solves the problem of toxic emissions generated by the use of oxidants.
[0048] (4) The method described in this invention can catalytically oxidize aniline or its derivatives to the corresponding nitrosobenzene or its derivatives, with good specificity and high yield of the target product. Detailed Implementation
[0049] The present invention will be further described in detail below with reference to specific embodiments. The scope of protection of the present invention is not limited thereto. Unless otherwise specified, all raw materials used in the following embodiments can be purchased commercially. Attached Figure Description
[0050] Figure 1 Here are X-ray diffraction crystal structure diagrams of α-UO3;
[0051] Figure 2 Mass spectrum of nitrosobenzene synthesized by the method described in Example 1;
[0052] Figure 3 Mass spectrum of nitrosobenzene synthesized by the method described in Example 2;
[0053] Figure 4 Mass spectrum of nitrosobenzene synthesized by the method described in Example 3;
[0054] Figure 5 Mass spectrum of nitrosobenzene synthesized by the method described in Example 4;
[0055] Figure 6 Mass spectrum of nitrosobenzene synthesized by the method described in Example 5;
[0056] Figure 7 Mass spectrum of nitrosobenzene synthesized by the method described in Example 6;
[0057] Figure 8 Mass spectrum of the product o-methylnitrosobenzene synthesized by the method described in Example 7;
[0058] Figure 9 Mass spectrum of the product m-methylnitrosobenzene synthesized by the method described in Example 7;
[0059] Figure 10 Mass spectrum of p-methylnitrosobenzene synthesized by the method described in Example 7;
[0060] Figure 11 Mass spectrum of p-chloronitrosobenzene synthesized by the method described in Example 7;
[0061] Figure 12 Mass spectrum of p-bromonitrosobenzene synthesized by the method described in Example 7;
[0062] Figure 13 Mass spectrum of the product p-methoxynitrosobenzene synthesized by the method described in Example 7.
[0063] Example 1: Synthesis of nitrosobenzene using different reaction solvents
[0064] 1. Add 10.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.093 g of aniline and 2.049 g of n-octane. While stirring at 25 °C, add 0.3 mmol of hydrogen peroxide (i.e., 0.3 mL of 30% hydrogen peroxide aqueous solution). React for 5 h, then filter, distill, and recrystallize to obtain the product nitrosobenzene.
[0065] 2. Add 10.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.093 g of aniline and 1.878 g of n-pentane. While stirring at 25 °C, add 0.3 mmol of hydrogen peroxide (i.e., 0.3 mL of 30% hydrogen peroxide aqueous solution). React for 5 h, then filter, distill, and recrystallize to obtain the product nitrosobenzene.
[0066] 3. Add 10.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.093 g of aniline and 2.109 g of n-octane. While stirring at 25 °C, add 0.3 mmol of hydrogen peroxide (i.e., 0.3 mL of 30% hydrogen peroxide aqueous solution). React for 5 h, then filter, distill, and recrystallize to obtain the product nitrosobenzene.
[0067] 4. Add 10.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.093 g of aniline and 1.860 g of isopentane. While stirring at 25 °C, add 0.3 mmol of hydrogen peroxide (i.e., 0.3 mL of 30% hydrogen peroxide aqueous solution). React for 5 h, then filter, distill, and recrystallize to obtain the product nitrosobenzene.
[0068] 5. Add 10.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.093 g aniline and 2.340 g cyclohexane. While stirring at 25 °C, add 0.3 mmol of hydrogen peroxide (i.e., 0.3 mL of 30% hydrogen peroxide aqueous solution). React for 5 h, then filter, distill, and recrystallize to obtain the product nitrosobenzene.
[0069] 6. Add 10.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.093 g aniline and 1.977 g n-hexane. While stirring at 25 °C, add 0.3 mmol of hydrogen peroxide (i.e., 0.3 mL of 30% hydrogen peroxide aqueous solution). React for 5 h, then filter, distill, and recrystallize to obtain the product nitrosobenzene.
[0070] 7. Add 10.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.093 g of aniline and 1.950 g of n-hexane. While stirring at 25 °C, add 0.3 mmol of hydrogen peroxide (i.e., 0.3 mL of 30% hydrogen peroxide aqueous solution). React for 5 h, then filter, distill, and recrystallize to obtain the product nitrosobenzene.
[0071] The yields of nitrosobenzene products obtained by the preparation methods described in 1-7 above were calculated, and the results are shown in Table 1 below:
[0072] Table 1. Process parameters and yield of nitrosobenzene as described in Example 1.
[0073]
[0074] The mass spectrum of the product synthesized by the above reaction is shown below. Figure 1As shown (the mass spectra of the main products of the above 7 reactions are the same, so only one mass spectrum is provided). The above results indicate that aniline can be catalytically synthesized into nitrosamine using organic solvents (isopentane, n-pentane, n-octane, n-heptane, cyclohexane, n-hexane, petroleum ether or combinations thereof) as reaction solvents, hydrogen peroxide as oxidant, and α-UO3 as catalyst; among them, the yield of nitrosamine synthesis is as high as 97% when isopentane is used as the reaction solvent.
[0075] Example 2: Synthesis of nitrosobenzene with different amounts of reaction solvent
[0076] 1. Add 10.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.093 g of aniline and 0.620 g of isopentane. While stirring at 25 °C, add 0.3 mmol of hydrogen peroxide (i.e., 0.3 mL of 30% hydrogen peroxide aqueous solution). React for 5 h, then filter, distill, and recrystallize to obtain the product nitrosobenzene.
[0077] 2. Add 10.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.093 g aniline and 1.240 g isopentane. While stirring at 25 °C, add 0.3 mmol of hydrogen peroxide (i.e., 0.3 mL of a 30% hydrogen peroxide aqueous solution). React for 5 h, then filter, distill, and recrystallize to obtain the product nitrosobenzene.
[0078] 3. Add 10.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.093 g of aniline and 1.860 g of isopentane. While stirring at 25 °C, add 0.3 mmol of hydrogen peroxide (i.e., 0.3 mL of 30% hydrogen peroxide aqueous solution). React for 5 h, then filter, distill, and recrystallize to obtain the product nitrosobenzene.
[0079] 4. Add 10.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.093 g aniline and 2.480 g isopentane. While stirring at 25 °C, add 0.3 mmol of hydrogen peroxide (i.e., 0.3 mL of 30% hydrogen peroxide aqueous solution). React for 5 h, then filter, distill, and recrystallize to obtain the product nitrosobenzene.
[0080] 5. Add 10.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.093 g of aniline and 3.10 g of isopentane. While stirring at 25 °C, add 0.3 mmol of hydrogen peroxide (i.e., 0.3 mL of 30% hydrogen peroxide aqueous solution). React for 5 h, then filter, distill, and recrystallize to obtain the product nitrosobenzene.
[0081] 6. Add 10.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.093 g of aniline and 3.72 g of isopentane. While stirring at 25 °C, add 0.3 mmol of hydrogen peroxide (i.e., 0.3 mL of 30% hydrogen peroxide aqueous solution). React for 5 h, then filter, distill, and recrystallize to obtain the product nitrosobenzene.
[0082] The yields of nitrosobenzene products obtained by the preparation methods described in 1-6 above were calculated, and the results are shown in Table 2 below:
[0083] Table 2. Process parameters and yield of nitrosobenzene as described in Example 2.
[0084]
[0085] The mass spectrum of the main product obtained from the above reaction is shown below. Figure 2 As shown (the mass spectra of the main products of the above 6 reactions are the same, so only one mass spectrum is provided). The above results indicate that aniline can be catalytically synthesized into nitrosamines using isopentane as the reaction solvent (mass ratio of isopentane to aniline is 2-20:1), hydrogen peroxide as the oxidant, and α-UO3 as the catalyst; at the same time, when the mass ratio of isopentane to aniline is 5-35:1, the yield of nitrosamines obtained from the reaction is above 80%, and when the mass ratio of isopentane to aniline is 15-30:1, the yield of nitrosamines obtained from the reaction is as high as 90% or more, and can reach up to 98%.
[0086] Example 3: Synthesis of nitrosobenzene at different reaction temperatures
[0087] 1. Add 10.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.093 g of aniline and 1.860 g of isopentane. While stirring at 10 °C, add 0.3 mmol of hydrogen peroxide (i.e., 0.3 mL of 30% hydrogen peroxide aqueous solution). React for 5 h, then filter, distill, and recrystallize to obtain the product nitrosobenzene.
[0088] 2. Add 10.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.093 g of aniline and 1.860 g of isopentane. While stirring at 15 °C, add 0.3 mmol of hydrogen peroxide (i.e., 0.3 mL of 30% hydrogen peroxide aqueous solution). React for 5 h, then filter, distill, and recrystallize to obtain the product nitrosobenzene.
[0089] 3. Add 10.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.093 g of aniline and 1.860 g of isopentane. While stirring at 20 °C, add 0.3 mmol of hydrogen peroxide (i.e., 0.3 mL of 30% hydrogen peroxide aqueous solution). React for 5 h, then filter, distill, and recrystallize to obtain the product nitrosobenzene.
[0090] 4. Add 10.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.093 g of aniline and 1.860 g of isopentane. While stirring at 25 °C, add 0.3 mmol of hydrogen peroxide (i.e., 0.3 mL of 30% hydrogen peroxide aqueous solution). React for 5 h, then filter, distill, and recrystallize to obtain the product nitrosobenzene.
[0091] 5. Add 10.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.093 g of aniline and 1.860 g of isopentane. While stirring at 30 °C, add 0.3 mmol of hydrogen peroxide (i.e., 0.3 mL of 30% hydrogen peroxide aqueous solution). React for 5 h, then filter, distill, and recrystallize to obtain the product nitrosobenzene.
[0092] 6. Add 10.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.093 g of aniline and 1.860 g of isopentane. While stirring at 35 °C, add 0.3 mmol of hydrogen peroxide (i.e., 0.3 mL of 30% hydrogen peroxide aqueous solution). React for 5 h, then filter, distill, and recrystallize to obtain the product nitrosobenzene.
[0093] 7. Add 10.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.093 g of aniline and 1.860 g of isopentane. While stirring at 40 °C, add 0.3 mmol of hydrogen peroxide (i.e., 0.3 mL of 30% hydrogen peroxide aqueous solution). React for 5 h, then filter, distill, and recrystallize to obtain the product nitrosobenzene.
[0094] 8. Add 10.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.093 g of aniline and 1.860 g of isopentane. While stirring at 45 °C, add 0.3 mmol of hydrogen peroxide (i.e., 0.3 mL of 30% hydrogen peroxide aqueous solution). React for 5 h, then filter, distill, and recrystallize to obtain the product nitrosobenzene.
[0095] 9. Add 10.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.093 g of aniline and 1.860 g of isopentane. While stirring at 50 °C, add 0.3 mmol of hydrogen peroxide (i.e., 0.3 mL of 30% hydrogen peroxide aqueous solution). React for 5 h, then filter, distill, and recrystallize to obtain the product nitrosobenzene.
[0096] The yields of nitrosobenzene products obtained by the preparation methods described in 1-9 above were calculated, and the results are shown in Table 3 below:
[0097] Table 3. Process parameters and yield of nitrosobenzene as described in Example 3.
[0098]
[0099] The mass spectrum of the main product obtained from the above reaction is shown below. Figure 3 As shown (the mass spectra of the main products of the above 9 reactions are the same, so only one mass spectrum is provided). The above results indicate that aniline can be catalytically synthesized into nitrosamines at reaction temperatures of 10-50℃, using hydrogen peroxide as the oxidant, isopentane as the reaction solvent, and α-UO3 as the catalyst; at reaction temperatures of 15-30℃, the yield of nitrosamines obtained is above 80%; and at reaction temperatures of 20-25℃, the yield of nitrosamines obtained can reach above 90%.
[0100] Example 4: Synthesis of nitrosobenzene with different reaction times
[0101] 1. Add 10.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.093 g of aniline and 1.860 g of isopentane. While stirring at 25 °C, add 0.3 mmol of hydrogen peroxide (i.e., 0.3 mL of 30% hydrogen peroxide aqueous solution). React for 1 h, then filter, distill, and recrystallize to obtain the product nitrosobenzene.
[0102] 2. Add 10.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.093 g of aniline and 1.860 g of isopentane. While stirring at 25 °C, add 0.3 mmol of hydrogen peroxide (i.e., 0.3 mL of 30% hydrogen peroxide aqueous solution). React for 2 h, then filter, distill, and recrystallize to obtain the product nitrosobenzene.
[0103] 3. Add 10.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.093 g of aniline and 1.860 g of isopentane. While stirring at 25 °C, add 0.3 mmol of hydrogen peroxide (i.e., 0.3 mL of 30% hydrogen peroxide aqueous solution). React for 3 h, then filter, distill, and recrystallize to obtain the product nitrosobenzene.
[0104] 4. Add 10.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.093 g of aniline and 1.860 g of isopentane. While stirring at 25 °C, add 0.3 mmol of hydrogen peroxide (i.e., 0.3 mL of 30% hydrogen peroxide aqueous solution). React for 4 h, then filter, distill, and recrystallize to obtain the product nitrosobenzene.
[0105] 5. Add 10.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.093 g aniline and 1.860 g isopentane. While stirring at 25 °C, add 0.3 mmol of hydrogen peroxide (i.e., 0.3 mL of 30% hydrogen peroxide aqueous solution). React for 5 h, then filter, distill, and recrystallize to obtain the product nitrosobenzene.
[0106] 6. Add 10.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.093 g of aniline and 1.860 g of isopentane. While stirring at 25 °C, add 0.3 mmol of hydrogen peroxide (i.e., 0.3 mL of 30% hydrogen peroxide aqueous solution). React for 6 h, then filter, distill, and recrystallize to obtain the product nitrosobenzene.
[0107] 7. Add 10.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.093 g of aniline and 1.860 g of isopentane. While stirring at 25 °C, add 0.3 mmol of hydrogen peroxide (i.e., 0.3 mL of 30% hydrogen peroxide aqueous solution). React for 7 h, then filter, distill, and recrystallize to obtain the product nitrosobenzene.
[0108] 8. Add 10.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.093 g of aniline and 1.860 g of isopentane. While stirring at 25 °C, add 0.3 mmol of hydrogen peroxide (i.e., 0.3 mL of 30% hydrogen peroxide aqueous solution). React for 8 h, then filter, distill, and recrystallize to obtain the product nitrosobenzene.
[0109] The yields of nitrosobenzene products obtained by the preparation methods described in 1-8 above were calculated, and the results are shown in Table 4 below:
[0110] Table 4. Process parameters and yield of nitrosobenzene as described in Example 4.
[0111]
[0112]
[0113] The mass spectrum of the main product obtained from the above reaction is shown below. Figure 4 As shown (the mass spectra of the main products of the above 8 reactions are the same, so only one mass spectrum is provided). The above results indicate that, with a reaction time of 1-8 h, using hydrogen peroxide as the oxidant, isopentane as the reaction solvent, and α-UO3 as the catalyst, aniline can be catalytically synthesized into nitrosamines; at a reaction time of 2-8 h, the yield of nitrosamines obtained is above 80%; and at a reaction time of 4-8 h, the yield of nitrosamines obtained can reach above 98%.
[0114] Example 5: Synthesis of nitrosobenzene with different amounts of hydrogen peroxide added.
[0115] 1. Add 10.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.093 g of aniline and 1.860 g of isopentane. While stirring at 25 °C, add 0.1 mmol of hydrogen peroxide (i.e., 0.1 mL of 30% hydrogen peroxide aqueous solution). React for 5 h, then filter, distill, and recrystallize to obtain the product nitrosobenzene.
[0116] 2. Add 10.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.093 g of aniline and 1.860 g of isopentane. While stirring at 25 °C, add 0.2 mmol of hydrogen peroxide (i.e., 0.2 mL of 30% hydrogen peroxide aqueous solution). React for 5 h, then filter, distill, and recrystallize to obtain the product nitrosobenzene.
[0117] 3. Add 10.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.093 g of aniline and 1.860 g of isopentane. While stirring at 25 °C, add 0.3 mmol of hydrogen peroxide (i.e., 0.3 mL of 30% hydrogen peroxide aqueous solution). React for 5 h, then filter, distill, and recrystallize to obtain the product nitrosobenzene.
[0118] 4. Add 10.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.093 g of aniline and 1.860 g of isopentane. While stirring at 25 °C, add 0.4 mmol of hydrogen peroxide (i.e., 0.4 mL of 30% hydrogen peroxide aqueous solution). React for 5 h, then filter, distill, and recrystallize to obtain the product nitrosobenzene.
[0119] 5. Add 10.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.093 g of aniline and 1.860 g of isopentane. While stirring at 25 °C, add 0.5 mmol of hydrogen peroxide (i.e., 0.5 mL of 30% hydrogen peroxide aqueous solution). React for 5 h, then filter, distill, and recrystallize to obtain the product nitrosobenzene.
[0120] 6. Add 10.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.093 g of aniline and 1.860 g of isopentane. While stirring at 25 °C, add 0.6 mmol of hydrogen peroxide (i.e., 0.6 mL of 30% hydrogen peroxide aqueous solution). React for 5 h, then filter, distill, and recrystallize to obtain the product nitrosobenzene.
[0121] The yields of nitrosobenzene products obtained by the preparation methods described in 1-6 above were calculated, and the results are shown in Table 5 below:
[0122] Table 5. Process parameters and yield of nitrosobenzene as described in Example 5.
[0123]
[0124] The mass spectrum of the main product obtained from the above reaction is shown below. Figure 5 As shown (the mass spectra of the main products of the above 6 reactions are the same, so only one mass spectrum is provided). The above results indicate that when the molar ratio of hydrogen peroxide to aniline is 1-6:1, isopentane is used as the reaction solvent, and α-UO3 is used as the catalyst, aniline can be catalytically synthesized into nitrosamines; at the same time, when the molar ratio of hydrogen peroxide to aniline is 2-5:1, the yield of nitrosamines obtained from the reaction is above 80%; and when the molar ratio of hydrogen peroxide to aniline is 3-4:1, the yield of nitrosamines obtained from the reaction is as high as 92% or more.
[0125] Example 6: Synthesis of nitrosobenzene with different catalyst addition amounts
[0126] 1. Add 1.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.093 g of aniline and 1.860 g of isopentane. While stirring at 25 °C, add 0.3 mmol of hydrogen peroxide (i.e., 0.3 mL of 30% hydrogen peroxide aqueous solution). React for 5 h, then filter, distill, and recrystallize to obtain the product nitrosobenzene.
[0127] 2. Add 2.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.093 g of aniline and 1.860 g of isopentane. While stirring at 25 °C, add 0.3 mmol of hydrogen peroxide (i.e., 0.3 mL of 30% hydrogen peroxide aqueous solution). React for 5 h, then filter, distill, and recrystallize to obtain the product nitrosobenzene.
[0128] 3. Add 3.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.093 g of aniline and 1.860 g of isopentane. While stirring at 25 °C, add 0.3 mmol of hydrogen peroxide (i.e., 0.3 mL of 30% hydrogen peroxide aqueous solution). React for 5 h, then filter, distill, and recrystallize to obtain the product nitrosobenzene.
[0129] 4. Add 5.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.093 g of aniline and 1.860 g of isopentane. While stirring at 25 °C, add 0.3 mmol of hydrogen peroxide (i.e., 0.3 mL of 30% hydrogen peroxide aqueous solution). React for 5 h, then filter, distill, and recrystallize to obtain the product nitrosobenzene.
[0130] 5. Add 8.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.093 g of aniline and 1.860 g of isopentane. While stirring at 25 °C, add 0.3 mmol of hydrogen peroxide (i.e., 0.3 mL of 30% hydrogen peroxide aqueous solution). React for 5 h, then filter, distill, and recrystallize to obtain the product nitrosobenzene.
[0131] 6. Add 10.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.093 g aniline and 1.860 g isopentane. While stirring at 25 °C, add 0.3 mmol of hydrogen peroxide (i.e., 0.3 mL of 30% hydrogen peroxide aqueous solution). React for 5 h, then filter, distill, and recrystallize to obtain the product nitrosobenzene.
[0132] 7. Add 11.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.093 g of aniline and 1.860 g of isopentane. While stirring at 25 °C, add 0.3 mmol of hydrogen peroxide (i.e., 0.3 mL of 30% hydrogen peroxide aqueous solution). React for 5 h, then filter, distill, and recrystallize to obtain the product nitrosobenzene.
[0133] 8. Add 12.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.093 g of aniline and 1.860 g of isopentane. While stirring at 25 °C, add 0.3 mmol of hydrogen peroxide (i.e., 0.3 mL of 30% hydrogen peroxide aqueous solution). React for 5 h, then filter, distill, and recrystallize to obtain the product nitrosobenzene.
[0134] The yields of nitrosobenzene products obtained by the preparation methods described in 1-6 above were calculated, and the results are shown in Table 6 below:
[0135] Table 6 shows the process parameters and yield of the product nitrosobenzene for the preparation method described in Example 6.
[0136]
[0137] The mass spectrum of the main product obtained from the above reaction is shown below. Figure 6 As shown (the mass spectra of the main products of the above 8 reactions are the same, so only one mass spectrum is provided). The above results indicate that when hydrogen peroxide is used as the oxidant, mesitylene as the reaction solvent, zirconium hydroxide as the catalyst, and the ratio of catalyst to aniline or its derivative is 1-12 mg:1 mmol, aniline can be catalytically synthesized into nitrosamine; and when the ratio of catalyst to aniline or its derivative is 5-12 mg:1 mmol, the yield of nitrosamine obtained is higher than 80%; while when the ratio of catalyst to aniline or its derivative is 8-11 mg:1 mmol, the yield of nitrosamine obtained is as high as 90% or more.
[0138] Example 7: Synthesis of nitrosobenzene derivatives using different aniline derivatives
[0139] 1. Add 10.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.107 g of o-methylaniline and 1.860 g of isopentane. While stirring at 25 °C, add 0.3 mmol of hydrogen peroxide (i.e., 0.3 mL of 30% hydrogen peroxide aqueous solution). React for 5 h, then filter, distill, and recrystallize to obtain the product o-methylnitrosobenzene.
[0140] 2. Add 10.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.107 g of m-methylaniline and 1.860 g of isopentane. While stirring at 25 °C, add 0.3 mmol of hydrogen peroxide (i.e., 0.3 mL of 30% hydrogen peroxide aqueous solution). React for 5 h, then filter, distill, and recrystallize to obtain the product m-methylnitrosobenzene.
[0141] 3. Add 10.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.107 g of p-methylaniline and 1.860 g of isopentane. While stirring at 25 °C, add 0.3 mmol of hydrogen peroxide (i.e., 0.3 mL of 30% hydrogen peroxide aqueous solution). React for 5 h, then filter, distill, and recrystallize to obtain the product p-methylnitrosobenzene.
[0142] 4. Add 10.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.127 g of p-chloroaniline and 1.860 g of isopentane. While stirring at 25 °C, add 0.3 mmol of hydrogen peroxide (i.e., 0.3 mL of 30% hydrogen peroxide aqueous solution). React for 5 h, then filter, distill, and recrystallize to obtain the product p-chloronitrosobenzene.
[0143] 5. Add 10.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.172 g of p-bromoaniline and 1.860 g of isopentane. While stirring at 25 °C, add 0.3 mmol of hydrogen peroxide (i.e., 0.3 mL of a 30% hydrogen peroxide aqueous solution). React for 5 h, then filter, distill, and recrystallize to obtain the product p-bromonitrosobenzene.
[0144] 6. Add 10.0 mg of α-UO3 catalyst to a 10 mL reaction tube, then add 0.123 g of p-chloroaniline and 1.860 g of isopentane. While stirring at 25 °C, add 0.3 mmol of hydrogen peroxide (i.e., 0.3 mL of a 30% hydrogen peroxide aqueous solution). React for 5 h, then filter, distill, and recrystallize to obtain the product p-methoxynitrosobenzene.
[0145] The yields of the nitrosobenzene derivatives obtained by the preparation methods described in 1-6 above were calculated, and the results are shown in Table 7 below:
[0146] Table 7. Process parameters and product yield of the preparation method described in Example 7.
[0147]
[0148]
[0149] The mass spectra of the main products in reactions 1-6 above are as follows: Figure 7-12As shown above, the results indicate that using isopentane as the reaction solvent, hydrogen peroxide as the oxidant, and α-UO3 as the catalyst, o-methylaniline can be catalytically synthesized into o-methylnitrosobenzene with a yield of 90%; m-methylaniline can be catalytically synthesized into m-methylnitrosobenzene with a yield of 92%; p-methylaniline can be catalytically synthesized into p-methylnitrosobenzene with a yield of 92%; p-chloroaniline can be catalytically synthesized into p-chloronitrosobenzene with a yield of 86%; p-bromoaniline can be catalytically synthesized into p-bromonitrosobenzene with a yield of 82%; and p-methoxyaniline can be catalytically synthesized into p-methoxynitrosobenzene with a yield of 95%. Therefore, the method of the present invention can catalytically synthesize nitrosobenzene or its derivatives from aniline or its derivatives, and the yield of the target product is high.
[0150] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.
Claims
1. A method for preparing nitrosobenzene or its derivatives using a uranium-depleted α-UO3 catalyst, characterized in that, Includes the following steps: (1) Preparation of α-UO3 catalyst: Step 1, Preparation of UO4·2H2O: Weigh a specific mass of U3O8 prepared from depleted UF6 as raw material, place it in a container, heat and stir while adding an appropriate amount of concentrated nitric acid to completely dissolve U3O8, then add an appropriate amount of deionized water to form a transparent uranyl salt solution, then add an appropriate amount of hydrogen peroxide, stir continuously for several hours, separate the solid product, wash and dry it to obtain UO4·2H2O; Step 2, Preparation of α-UO3: The precursor UO4·2H2O was ground thoroughly in a mortar, then transferred to a clean porcelain boat, placed in a muffle furnace, and calcined at 560℃ for 3h at a heating rate of 5℃ / min to obtain the α-UO3 catalyst. (2) Using aniline or its derivatives as shown in formula (I) as raw material, an organic solvent as reaction solvent, α-UO3 obtained in step (1) as catalyst, and hydrogen peroxide as oxidant, a catalytic oxidation reaction is carried out to synthesize nitrosobenzene or its derivatives as shown in formula (II); wherein R1-R5 are selected from any one of hydrogen, halogen, nitro, substituted or unsubstituted straight-chain or branched alkyl, alkoxy, carbonyl, alkenyl, alkynyl, substituted or unsubstituted aryl, and amide, respectively. 。 2. The method according to claim 1, characterized in that, In step (2), the organic solvent is selected from one or a combination of several of the following: isopentane, n-pentane, n-octane, n-heptane, cyclohexane, n-hexane, and petroleum ether.
3. The method according to claim 1 or 2, characterized in that, The catalyst is used in an amount of 1-30 mg: 1 mmol aniline or its derivative.
4. The method according to claim 1 or 2, characterized in that, In the catalytic oxidation reaction, the molar ratio of hydrogen peroxide to aniline or its derivatives is 1-10:
1.
5. The method according to claim 1 or 2, characterized in that, The mass ratio of the reaction solvent to aniline or its derivative is 1-50:
1.
6. The method according to claim 1, characterized in that, R1-R5 are selected from hydrogen, methyl, chlorine, bromine, and methoxy, respectively.
7. The method according to claim 6, characterized in that, The aniline or its derivatives include: aniline, o-methylaniline, m-methylaniline, p-methylaniline, p-chloroaniline, p-bromoaniline, and p-methoxyaniline.
8. The method according to claim 1, characterized in that, Aniline or its derivatives, α-UO3, and hydrogen peroxide are added to the reaction solvent and reacted at 10-50℃ for 1-8 h. Nitrobenzene or its derivatives are obtained by filtration, distillation, and recrystallization.
9. The method according to claim 8, characterized in that, The reaction temperature was 25 °C and the reaction time was 5 h.