Application of UO4. 2H2O prepared from depleted uranium as raw material in selective catalytic oxidation of aniline or derivatives thereof

Abstract

Reasonable utilization of nuclear energy takes an important position in national defense safety consolidation and energy system green transformation processes in China. However, proper management and resource utilization of depleted uranium (especially 238U which does not cause direct radiation threat to a human body) generated along with nuclear energy application become a technical problem to be solved urgently in the fields of environmental protection and sustainable development. Particularly, U3O8 prepared by depleting UF6 is used as a raw material, UO4. 2H2O prepared by a simple dissolution and re-precipitation method is used as a catalyst, and aniline is catalytically oxidized to synthesize 1-diphenyl oxide diazene or derivatives thereof. On the other hand, a bridge from aniline and derivatives thereof to a high value-added chemical namely 1-diphenyl oxide diazene or derivatives thereof is ingeniously erected, and the method shows extraordinary value in environmental, economic and social benefits. The method has extremely important significance from the aspects of environmental friendliness and sustainable development and from the perspective of synthesis of products with higher added values.

Description

Technical Field

[0001] The present invention relates to a novel technology for utilizing depleted uranium, in particular to preparing a UO4·2H2O catalyst using depleted UF6 as a raw material for selectively catalytically oxidizing aniline or its derivatives to prepare 1-diphenyldiazene oxide or its derivatives. Technical Background

[0002] The effective use of nuclear energy plays a vital role in the stable enhancement of my country's national defense and the long-term sustainable development of the energy system. However, along with its widespread application, a series of complex and severe problems and challenges also come. In various links such as nuclear weapons research and development, efficient operation and maintenance of nuclear energy facilities, practical application of nuclear equipment, and in-depth exploration of nuclear technology, a large amount of uranium-rich waste is inevitably produced, among which the tail material produced in the uranium enrichment process - depleted uranium is the most significant. As a by-product of the nuclear energy utilization process, the safe management and proper disposal of this type of depleted uranium waste has become a major issue in the current field of pollution prevention and control, and we urgently need to pay high attention and effectively solve it.

[0003] It is particularly noteworthy that the uniqueness of uranium is not only reflected in the distinct difference in its own properties, but also in the complementary relationship between it and the d-block transition elements in chemical reactivity. The d-block transition elements are known for their rich electronic configurations and variable reactivity, while uranium is characterized by its special contribution of f orbitals and complex coordination environment. The two can complement each other in chemical reactions, making uranium oxides easy to form oxygen vacancies, which is conducive to enhancing catalytic oxidation ability. In recent years, research on uranium oxides has continued to increase. SVChong used UO2 to convert formic acid into formaldehyde (see "Surface Science", 2002, Vol. 504, No. 20, 145-148.). SVChong et al. used UO2 to convert ethanol into high-value-added ethylene (see "Surface Science", 2000, Vol. 444, No. 1, 187-198.). Gupta et al. fixed uranyl ions in MCM-41 and photocatalytically converted methanol into carbon dioxide (see Applied Catalysis B-Environmental, 2004, No. 54, No. 3, 145-154).

[0004] 1-diphenyldiazene oxide is not only a key component of natural compounds and functional materials, but is also often used as a therapeutic agent, indicator, dye, pigment, chemical sensor, polymer, soft material and photochemical switch, etc., showing extremely high application value (see "Acs Catalysis", 2013, Vol. 3, No. 4, 478-486.). The traditional method for synthesizing 1-diphenyldiazene oxide or its derivatives is to use nitrobenzene and its derivatives as raw materials. The research progress reported on green oxidants includes: a cobalt oxide-loaded silica catalyst, using H2O2 as an oxidant, and selectively catalyzing aniline oxidation to synthesize 1-diphenyldiazene oxide at a relatively high temperature (see "Journal of Molecular Catalysis A: Chemical", 2009, Vol. 299, No. 1-2, 121-126.). It can be seen that the current optimal synthesis method of 1-diphenyldiazene oxide or its derivatives is to use aniline or its derivatives as raw materials and H2O2 as an oxidant for direct oxidation synthesis.

[0005] Based on the above background and combined with our previous work, we proposed that uranium-based catalysts be used to catalyze the synthesis of traditional fine chemicals. The present invention uses U3O8 as a raw material, dissolves it and then precipitates it to synthesize a UO4·2H2O catalyst, which is used to catalyze the oxidation of aniline and its derivatives to synthesize 1-diphenyldiazene oxide or its derivatives. The innovative method of using UO4·2H2O in the field of thermal catalysis is proposed. The preparation process of the catalyst is simple and convenient, the reaction activity is high, and the method of directly catalyzing aniline to synthesize 1-diphenyldiazene oxide or its derivatives with UO4·2H2O has not been reported so far. From the strategic perspective of environmental friendliness and sustainable development, the present invention creatively solves the problem of safe disposal and efficient reuse of depleted uranium materials, which not only significantly reduces the potential threat to the natural environment, but also promotes the recycling and value-added utilization of resources. At the same time, from the innovative dimension of organic synthesis, it has opened up an unprecedented path and demonstrated its broad application prospects as a bridge between advanced materials and technologies. Summary of the invention

[0006] The present invention finds that the UO4·2H2O catalyst prepared by using U3O8 obtained from depleted UF6 as raw material can catalytically oxidize aniline or its derivatives to form 1-diphenyldiazene oxide or its derivatives. Therefore, the present invention not only provides a new way to utilize depleted uranium, but also proposes a low-cost, green and efficient method for preparing 1-diphenyldiazene oxide or its derivatives. The method is simple, low-cost, and highly safe, and is more in line with the concept of green and friendly chemistry. Specifically, it includes the following contents:

[0007] In a first aspect, the present invention provides a method for preparing a UO4·2H2O catalyst by using U3O8 obtained from depleted UF6 as a raw material through simple dissolution and reprecipitation.

[0008] Preferably, the catalyst preparation method comprises the following steps:

[0009] (1) Preparation of UO4·2H2O: Weigh a specific mass of U3O8 prepared from depleted UF6, place it in a container, add an appropriate amount of concentrated nitric acid or concentrated hydrochloric acid while heating and stirring, and add an appropriate amount of deionized water to completely dissolve the U3O8 to form a transparent uranyl salt solution, then add an appropriate amount of hydrogen peroxide, continue stirring for several hours, separate the solid product, wash and dry it to obtain UO4·2H2O. Its XRD crystal structure is shown in the attached figure. Figure 1 The transmission electron microscope image is shown in the attached Figure 2 The scanning electron microscope image is shown in the attached Figure 3 The nitrogen isothermal adsorption and desorption pore size distribution diagram is shown in the attached figure. Figure 4 shown.

[0010] Preferably, the structural formula of the aniline or its derivative is as shown in the following formula (I), and the structural formula of the 1-diphenyldiazene oxide or its derivative is as shown in the following formula (II):

[0011]

[0012] Wherein, R1-R5 are independently selected from any one of hydrogen, halogen, hydroxyl, sulfonic acid, nitro, substituted or unsubstituted straight or branched alkyl, alkoxy, carbonyl, alkenyl, alkynyl, substituted or unsubstituted aryl, acylamino, and cyano, but are not limited to the above substituents.

[0013] Preferably, R1-R5 are independently selected from hydrogen, methyl and chlorine.

[0014] Preferably, the aniline or its derivatives include: aniline, o-methylaniline, p-methylaniline, p-chloroaniline, o-chloroaniline, and m-chloroaniline.

[0015] In a second aspect, the present invention provides a method for preparing 1-diphenyldiazene oxide or its derivatives, the method comprising: using aniline or its derivatives as a raw material, mesitylene or a mixed solvent of mesitylene and an organic solvent as a reaction solvent, using UO4·2H2O as a catalyst, and using hydrogen peroxide as an oxidant, to catalyze an oxidation reaction to synthesize 1-diphenyldiazene oxide or its derivatives as a formula (II), wherein the organic solvent comprises methanol, ethanol, or n-butanol;

[0016]

[0017] Among them, R1-R5 are independently selected from any one of hydrogen, halogen, hydroxyl, sulfonic acid, nitro, substituted or unsubstituted straight or branched alkyl, alkoxy, carbonyl, alkenyl, alkynyl, substituted or unsubstituted aryl, acylamino, and cyano, but are not limited to the above substituents.

[0018] Preferably, R1-R5 are independently selected from hydrogen, methyl and chlorine.

[0019] Preferably, the aniline or its derivatives include: aniline, o-methylaniline, p-methylaniline, p-chloroaniline, o-chloroaniline, and m-chloroaniline.

[0020] Preferably, the ratio of the catalyst to aniline or its derivatives is 1-50 mg:1 mmol.

[0021] Preferably, the ratio of the catalyst to aniline or its derivatives is 10-40 mg:1 mmol.

[0022] Preferably, the ratio of the catalyst to aniline or its derivatives is 15-35 mg:1 mmol.

[0023] Preferably, the ratio of the catalyst to aniline or its derivatives is 30 mg:1 mmol.

[0024] Preferably, the mass ratio of the reaction solvent to aniline or its derivatives is 1-40:1.

[0025] Preferably, the mass ratio of the reaction solvent to aniline or its derivatives is 5-35:1.

[0026] Preferably, the mass ratio of the reaction solvent to aniline or its derivatives is 28:1.

[0027] Preferably, the reaction solvent is mesitylene.

[0028] Preferably, the catalyst is UO4·2H2O.

[0029] Preferably, the method comprises the following steps:

[0030] (1) adding aniline or its derivatives and UO4·2H2O into a reaction tube containing a reaction solvent;

[0031] (2) Add 1.0 mL of hydrogen peroxide to the reaction tube and react at 95°C for 12 h;

[0032] (3) filtering, distilling and recrystallizing to obtain 1-diphenyldiazene oxide or its derivatives.

[0033] Preferably, the volume of the hydrogen peroxide solution is 0.1-1.5 mL.

[0034] Preferably, the volume of the hydrogen peroxide is 0.3-1.2 mL

[0035] Preferably, the volume of the hydrogen peroxide solution is 1.0 mL.

[0036] Preferably, the reaction temperature is 50-155°C.

[0037] Preferably, the reaction temperature is 80-110°C.

[0038] Preferably, the reaction temperature is 95°C.

[0039] Preferably, the reaction time is 1-20h.

[0040] Preferably, the reaction time is 5-15h.

[0041] Preferably, the reaction time is 12 h.

[0042] Compared with the prior art, the technical solution of the present invention has the following advantages:

[0043] (1) The present invention uses depleted uranium waste as raw material to prepare the catalyst, which effectively solves the problem of safe disposal and reuse of depleted uranium in my country's nuclear energy utilization;

[0044] (2) Aniline or its derivatives used in the present invention are basic raw materials commonly used in industry and have low cost;

[0045] (3) The present invention uses cheap and readily available hydrogen peroxide as an oxidant, which greatly reduces the cost of the oxidant compared to the traditional method using peracetic acid, Pb(OAc)4, Hg(OAc)2, BaMnO4 and hydrogen peroxide as an oxidant, and solves the problems of toxic substance emissions and production safety generated by the use of oxidants;

[0046] (4) The method of the present invention can catalytically oxidize aniline or its derivatives to the corresponding 1-diphenyldiazene oxide or its derivatives with good specificity and a high yield of the target product. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 X-ray diffraction crystal structure of the prepared UO4·2H2O catalyst;

[0048] Figure 2 Transmission electron microscopy image of the prepared UO4·2H2O catalyst;

[0049] Figure 3 Scanning electron microscopy image of the prepared UO4·2H2O catalyst;

[0050] Figure 4Pore ​​size distribution diagram of nitrogen isothermal adsorption and desorption of the prepared UO4·2H2O catalyst;

[0051] Figure 5 Mass spectrum of the product 1-diphenyldiazene oxide synthesized by the method described in Example 1;

[0052] Figure 6 Mass spectrum of the product 1-diphenyldiazene oxide synthesized by the method described in Example 2;

[0053] Figure 7 Mass spectrum of the product 1-diphenyldiazene oxide synthesized by the method described in Example 3;

[0054] Figure 8 Mass spectrum of the product 1-diphenyldiazene oxide synthesized by the method described in Example 4;

[0055] Fig. 9 Mass spectrum of the product 1-diphenyldiazene oxide synthesized by the method described in Example 5;

[0056] Fig.10 Mass spectrum of the product 1-diphenyldiazene oxide synthesized by the method described in Example 6;

[0057] Fig.11 Mass spectrum of the product 2,2'-dimethyl-1-diphenyldiazene oxide synthesized by the method described in Example 7;

[0058] Fig.12 Mass spectrum of the product 3,3'-dimethyl-1-diphenyldiazene oxide synthesized by the method described in Example 7;

[0059] Fig.13 Mass spectrum of the product 4,4'-dimethyl-1-diphenyldiazene oxide synthesized by the method described in Example 7;

[0060] Fig.14 Mass spectrum of the product 4,4'-dichloro-1-diphenyldiazene oxide synthesized by the method described in Example 7;

[0061] Fig.15 Mass spectrum of the product 4,4'-dibromo-1-diphenyldiazene oxide synthesized by the method described in Example 7;

[0062] Fig.16 Mass spectrum of the product 4,4'-dimethoxy-1-diphenyldiazene oxide synthesized by the method described in Example 7. DETAILED DESCRIPTION

[0063] The present invention is further described in detail below in conjunction with specific examples, but the protection scope of the present invention is not limited thereto. The raw materials used in the following examples are all commercially available unless otherwise specified.

[0064] Example 1 Synthesis of 1-diphenyldiazene oxide using different reaction solvents

[0065] 1. Add 30.0 mg of UO4·2H2O catalyst to a 25 mL reaction tube, then add 0.093 g of aniline and 0.867 g of mesitylene, add 1.0 mL of hydrogen peroxide at 95 °C, react for 12 h, then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0066] 2. Add 30.0 mg of UO4·2H2O catalyst to a reaction tube with a volume of 25 mL, then add 0.093 g of aniline, 0.867 g of mesitylene and methanol (mass ratio 1:1), add 1.0 mL of hydrogen peroxide at 95°C, react for 12 hours, and then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0067] 3. Add 30.0 mg of UO4·2H2O catalyst to a reaction tube with a volume of 25 mL, then add 0.093 g of aniline, 0.867 g of mesitylene and ethanol (mass ratio 1:1), add 1.0 mL of hydrogen peroxide at 95°C, react for 12 hours, and then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0068] 4. Add 30.0 mg of UO4·2H2O catalyst to a reaction tube with a volume of 25 mL, then add 0.093 g of aniline, 0.867 g of mesitylene and n-butanol (mass ratio 1:1), add 1.0 mL of hydrogen peroxide at 95°C, react for 12 hours, and then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0069] The product yield of 1-diphenyldiazene oxide obtained by the preparation method described in 1-4 above was calculated, and the results are shown in Table 1 below:

[0070] Table 1 Process parameters of the preparation method described in Example 1 and the yield of the product 1-diphenyldiazene oxide

[0071]

[0072]

[0073] The mass spectrum of the main product synthesized by the above reaction is as follows Figure 5As shown (the mass spectra of the main products of the above four reactions are the same, so only one mass spectrum is provided). The structural formula of the product is shown in Formula 1. The above results show that using mesitylene or a mixed solvent of mesitylene and an organic solvent (mesitylene + methanol, mesitylene + ethanol, mesitylene + n-butanol) as a reaction solvent and UO4·2H2O as a catalyst, aniline can be catalyzed to synthesize 1-diphenyldiazene oxide; and using mesitylene as a reaction solvent, the yield of 1-diphenyldiazene oxide obtained can reach up to 95%.

[0074]

[0075] Example 2 Synthesis of 1-diphenyldiazene oxide with different amounts of reaction solvent

[0076] 1. Add 30.0 mg of UO4·2H2O catalyst to a 25 mL reaction tube, then add 0.093 g of aniline and 0.434 g of mesitylene, add 1.0 mL of hydrogen peroxide at 95 °C, react for 12 h, then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0077] 2. Add 30.0 mg of UO4·2H2O catalyst to a reaction tube with a volume of 25 mL, then add 0.093 g of aniline and 0.867 g of mesitylene, add 1.0 mL of hydrogen peroxide at 95°C, react for 12 hours, and then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0078] 3. Add 30.0 mg of UO4·2H2O catalyst to a reaction tube with a volume of 25 mL, then add 0.093 g of aniline and 1.301 g of mesitylene, add 1.0 mL of hydrogen peroxide at 95°C, react for 12 hours, and then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0079] 4. Add 30.0 mg of UO4·2H2O catalyst to a reaction tube with a volume of 25 mL, then add 0.093 g of aniline and 1.734 g of mesitylene, add 1.0 mL of hydrogen peroxide at 95°C, react for 12 hours, and then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0080] 5. Add 30.0 mg of UO4·2H2O catalyst to a reaction tube with a volume of 25 mL, then add 0.093 g of aniline and 2.168 g of mesitylene, add 1.0 mL of hydrogen peroxide at 95°C, react for 12 hours, and then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0081] 6. Add 30.0 mg of UO4·2H2O catalyst to a 25 mL reaction tube, then add 0.093 g of aniline and 2.592 g of mesitylene, add 1.0 mL of hydrogen peroxide at 95°C, react for 12 h, and then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0082] 7. Add 30.0 mg of UO4·2H2O catalyst to a reaction tube with a volume of 25 mL, then add 0.093 g of aniline and 3.024 g of mesitylene, add 1.0 mL of hydrogen peroxide at 95°C, react for 12 hours, and then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0083] 8. Add 30.0 mg of UO4·2H2O catalyst to a reaction tube with a volume of 25 mL, then add 0.093 g of aniline and 3.456 g of mesitylene, add 1.0 mL of hydrogen peroxide at 95°C, react for 12 hours, and then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0084] The product yield of 1-diphenyldiazene oxide obtained by the preparation method described in 1-8 above was calculated, and the results are shown in Table 2 below:

[0085] Table 2 Process parameters of the preparation method described in Example 2 and the yield of the product 1-diphenyldiazene oxide

[0086]

[0087] The mass spectrum of the main product obtained from the above reaction is as follows 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 structural formula is shown in Formula 1. The above results show that using mesitylene as a reaction solvent (the mass ratio of mesitylene to aniline is 1-40:1), hydrogen peroxide as an oxidant, and UO4·2H2O as a catalyst, aniline can be catalyzed to synthesize 1-diphenyldiazene oxide; at the same time, when the mass ratio of the reaction solvent mesitylene to aniline is 10-20:1, the yield of 1-diphenyldiazene oxide obtained by the reaction is more than 80%, and when the mass ratio of the reaction solvent mesitylene to aniline is 28:1, the yield of 1-diphenyldiazene oxide obtained by the reaction is as high as 96%.

[0088]

[0089] Example 3 Synthesis of 1-diphenyldiazene oxide at different reaction temperatures

[0090] 1. Add 30.0 mg of UO4·2H2O catalyst to a 25 mL reaction tube, then add 0.093 g of aniline and 0.867 g of mesitylene, add 1.0 mL of hydrogen peroxide at 50°C, react for 12 h, then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0091] 2. Add 30.0 mg of UO4·2H2O catalyst to a reaction tube with a volume of 25 mL, then add 0.093 g of aniline and 0.867 g of mesitylene, add 1.0 mL of hydrogen peroxide at 65°C, react for 12 hours, and then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0092] 3. Add 30.0 mg of UO4·2H2O catalyst to a reaction tube with a volume of 25 mL, then add 0.093 g of aniline and 0.867 g of mesitylene, add 1.0 mL of hydrogen peroxide at 80°C, react for 12 hours, and then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0093] 4. Add 30.0 mg of UO4·2H2O catalyst to a reaction tube with a volume of 25 mL, then add 0.093 g of aniline and 0.867 g of mesitylene, add 1.0 mL of hydrogen peroxide at 95°C, react for 12 hours, and then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0094] 5. Add 30.0 mg of UO4·2H2O catalyst to a reaction tube with a volume of 25 mL, then add 0.093 g of aniline and 0.867 g of mesitylene, add 1.0 mL of hydrogen peroxide at 110°C, react for 12 hours, and then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0095] 6. Add 30.0 mg of UO4·2H2O catalyst to a reaction tube with a volume of 25 mL, then add 0.093 g of aniline and 0.867 g of mesitylene, add 1.0 mL of hydrogen peroxide at 125°C, react for 12 hours, and then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0096] 7. Add 30.0 mg of UO4·2H2O catalyst to a reaction tube with a volume of 25 mL, then add 0.093 g of aniline and 0.867 g of mesitylene, add 1.0 mL of hydrogen peroxide at 140°C, react for 12 hours, and then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0097] 8. Add 30.0 mg of UO4·2H2O catalyst to a reaction tube with a volume of 25 mL, then add 0.093 g of aniline and 0.867 g of mesitylene, add 1.0 mL of hydrogen peroxide at 155°C, react for 12 hours, and then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0098] The product yield of 1-diphenyldiazene oxide obtained by the preparation method described in 1-8 above was calculated, and the results are shown in Table 3 below:

[0099] Table 3 Process parameters of the preparation method described in Example 3 and the yield of the product 1-diphenyldiazene oxide

[0100]

[0101]

[0102] The mass spectrum of the main product obtained from the above reaction is as follows Figure 7 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 structural formula is shown in Formula 1. The above results show that at a reaction temperature of 50-155°C, with mesitylene as the reaction solvent, hydrogen peroxide as the oxidant, and UO4·2H2O

[0103] The catalyst can catalyze aniline to synthesize 1-diphenyldiazene oxide; when the reaction temperature is 80-155°C, the yield of 1-diphenyldiazene oxide obtained by the reaction is above 80%; and when the reaction temperature is above 95°C, the yield of 1-diphenyldiazene oxide obtained by the reaction can reach up to 95%.

[0104]

[0105] Example 4 Synthesis of 1-diphenyldiazene oxide with different reaction times

[0106] 1. Add 30.0 mg of UO4·2H2O catalyst to a 25 mL reaction tube, then add 0.093 g of aniline and 0.867 g of mesitylene, add 1.0 mL of hydrogen peroxide at 95 °C, react for 1 h, then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0107] 2. Add 30.0 mg of UO4·2H2O catalyst to a reaction tube with a volume of 25 mL, then add 0.093 g of aniline and 0.867 g of mesitylene, add 1.0 mL of hydrogen peroxide at 95°C, react for 2 h, and then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0108] 3. Add 30.0 mg of UO4·2H2O catalyst to a reaction tube with a volume of 25 mL, then add 0.093 g of aniline and 0.867 g of mesitylene, add 1.0 mL of hydrogen peroxide at 95°C, react for 4 hours, and then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0109] 4. Add 30.0 mg of UO4·2H2O catalyst to a 25 mL reaction tube, then add 0.093 g of aniline and 0.867 g of mesitylene, add 1.0 mL of hydrogen peroxide at 95°C, react for 6 h, and then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0110] 5. Add 30.0 mg of UO4·2H2O catalyst to a reaction tube with a volume of 25 mL, then add 0.093 g of aniline and 0.867 g of mesitylene, add 1.0 mL of hydrogen peroxide at 95°C, react for 8 hours, and then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0111] 6. Add 30.0 mg of UO4·2H2O catalyst to a reaction tube with a volume of 25 mL, then add 0.093 g of aniline and 0.867 g of mesitylene, add 1.0 mL of hydrogen peroxide at 95°C, react for 10 hours, and then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0112] 7. Add 30.0 mg of UO4·2H2O catalyst to a reaction tube with a volume of 25 mL, then add 0.093 g of aniline and 0.867 g of mesitylene, add 1.0 mL of hydrogen peroxide at 95°C, react for 12 hours, and then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0113] 8. Add 30.0 mg of UO4·2H2O catalyst to a reaction tube with a volume of 25 mL, then add 0.093 g of aniline and 0.867 g of mesitylene, add 1.0 mL of hydrogen peroxide at 95°C, react for 14 hours, and then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0114] 9. Add 30.0 mg of UO4·2H2O catalyst to a reaction tube with a volume of 25 mL, then add 0.093 g of aniline and 0.867 g of mesitylene, add 1.0 mL of hydrogen peroxide at 95°C, react for 16 hours, and then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0115] 10. Add 30.0 mg of UO4·2H2O catalyst to a 25 mL reaction tube, then add 0.093 g of aniline and 0.867 g of mesitylene, add 1.0 mL of hydrogen peroxide at 95°C, react for 18 h, and then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0116] 11. Add 30.0 mg of UO4·2H2O catalyst to a 25 mL reaction tube, then add 0.093 g of aniline and 0.867 g of mesitylene, add 1.0 mL of hydrogen peroxide at 95°C, react for 20 h, then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0117] The product yield of 1-diphenyldiazene oxide obtained by the preparation method described in 1-11 above was calculated, and the results are shown in Table 4 below:

[0118] Table 4 Process parameters of the preparation method described in Example 4 and the yield of the product 1-diphenyldiazene oxide

[0119]

[0120]

[0121] The mass spectrum of the main product obtained from the above reaction is as follows Figure 8 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 structural formula is shown in Formula 1. The above results show that when the reaction time is 1-20h, mesitylene is used as the reaction solvent, hydrogen peroxide is used as the oxidant, and UO4·2H2O is used as the catalyst, aniline can be catalyzed to synthesize 1-diphenyldiazene oxide; when the reaction time is 6-20h, the yield of 1-diphenyldiazene oxide obtained by the reaction is above 80%; and when the reaction time is 12h, the yield of 1-diphenyldiazene oxide obtained by the reaction can reach up to 96%.

[0122]

[0123] Example 5 Synthesis of 1-diphenyldiazene oxide with different volumes of hydrogen peroxide

[0124] 1. Add 30.0 mg of UO4·2H2O catalyst to a 25 mL reaction tube, then add 0.093 g of aniline and 0.867 g of mesitylene, add 0.1 mL of hydrogen peroxide at 95 °C, react for 12 h, then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0125] 2. Add 30.0 mg of UO4·2H2O catalyst to a reaction tube with a volume of 25 mL, then add 0.093 g of aniline and 0.867 g of mesitylene, add 0.2 mL of hydrogen peroxide at 95°C, react for 12 hours, and then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0126] 3. Add 30.0 mg of UO4·2H2O catalyst to a reaction tube with a volume of 25 mL, then add 0.093 g of aniline and 0.867 g of mesitylene, add 0.3 mL of hydrogen peroxide at 95°C, react for 12 hours, and then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0127] 4. Add 30.0 mg of UO4·2H2O catalyst to a reaction tube with a volume of 25 mL, then add 0.093 g of aniline and 0.867 g of mesitylene, add 0.5 mL of hydrogen peroxide at 95°C, react for 12 hours, and then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0128] 5. Add 30.0 mg of UO4·2H2O catalyst to a reaction tube with a volume of 25 mL, then add 0.093 g of aniline and 0.867 g of mesitylene, add 0.8 mL of hydrogen peroxide at 95°C, react for 12 hours, and then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0129] 6. Add 30.0 mg of UO4·2H2O catalyst to a reaction tube with a volume of 25 mL, then add 0.093 g of aniline and 0.867 g of mesitylene, add 1.0 mL of hydrogen peroxide at 95°C, react for 12 hours, and then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0130] 7. Add 30.0 mg of UO4·2H2O catalyst to a reaction tube with a volume of 25 mL, then add 0.093 g of aniline and 0.867 g of mesitylene, add 1.2 mL of hydrogen peroxide at 95°C, react for 12 hours, and then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0131] 8. Add 30.0 mg of UO4·2H2O catalyst to a reaction tube with a volume of 25 mL, then add 0.093 g of aniline and 0.867 g of mesitylene, add 1.4 mL of hydrogen peroxide at 95°C, react for 12 hours, and then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0132] 9. Add 30.0 mg of UO4·2H2O catalyst to a 25 mL reaction tube, then add 0.093 g of aniline and 0.867 g of mesitylene, add 1.5 mL of hydrogen peroxide at 95°C, react for 12 h, then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0133] The product yield of 1-diphenyldiazene oxide obtained by the preparation method described in 1-9 above was calculated, and the results are shown in Table 5 below:

[0134] Table 5 Process parameters of the preparation method described in Example 5 and the yield of the product 1-diphenyldiazene oxide

[0135]

[0136] The mass spectrum of the main product obtained from the above reaction is as follows Fig. 9 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 structural formula is shown in Formula 1. The above results show that when the volume of hydrogen peroxide is 0.1-1.5 mL, mesitylene is used as the reaction solvent, hydrogen peroxide is used as the oxidant, and UO4·2H2O is used as the catalyst, aniline can be catalyzed to synthesize 1-diphenyldiazene oxide; when the volume of hydrogen peroxide is 0.3-1.5 mL, the yield of 1-diphenyldiazene oxide obtained by the reaction is above 70%; and when the volume of hydrogen peroxide is 1.0 mL, the yield of 1-diphenyldiazene oxide obtained by the reaction can reach up to 96%.

[0137]

[0138] Example 6 Synthesis of 1-diphenyldiazene oxide with different catalyst addition amounts

[0139] 1. Add 5.0 mg of UO4·2H2O catalyst to a 25 mL reaction tube, then add 0.093 g of aniline and 0.867 g of mesitylene, add 1.0 mL of hydrogen peroxide at 95 °C, react for 12 h, then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0140] 2. Add 10.0 mg of UO4·2H2O catalyst to a reaction tube with a volume of 25 mL, then add 0.093 g of aniline and 0.867 g of mesitylene, add 1.0 mL of hydrogen peroxide at 95°C, react for 12 hours, and then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0141] 3. Add 15.0 mg of UO4·2H2O catalyst to a reaction tube with a volume of 25 mL, then add 0.093 g of aniline and 0.867 g of mesitylene, add 1.0 mL of hydrogen peroxide at 95°C, react for 12 hours, and then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0142] 4. Add 20.0 mg of UO4·2H2O catalyst to a 25 mL reaction tube, then add 0.093 g of aniline and 0.867 g of mesitylene, add 1.0 mL of hydrogen peroxide at 95°C, react for 12 h, and then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0143] 5. Add 25.0 mg of UO4·2H2O catalyst to a reaction tube with a volume of 25 mL, then add 0.093 g of aniline and 0.867 g of mesitylene, add 1.0 mL of hydrogen peroxide at 95°C, react for 12 hours, and then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0144] 6. Add 30.0 mg of UO4·2H2O catalyst to a reaction tube with a volume of 25 mL, then add 0.093 g of aniline and 0.867 g of mesitylene, add 1.0 mL of hydrogen peroxide at 95°C, react for 12 hours, and then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0145] 7. Add 35.0 mg of UO4·2H2O catalyst to a reaction tube with a volume of 25 mL, then add 0.093 g of aniline and 0.867 g of mesitylene, add 1.0 mL of hydrogen peroxide at 95°C, react for 12 hours, and then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0146] 8. Add 40.0 mg of UO4·2H2O catalyst to a 25 mL reaction tube, then add 0.093 g of aniline and 0.867 g of mesitylene, add 1.0 mL of hydrogen peroxide at 95°C, react for 12 h, and then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0147] 9. Add 45.0 mg of UO4·2H2O catalyst to a reaction tube with a volume of 25 mL, then add 0.093 g of aniline and 0.867 g of mesitylene, add 1.0 mL of hydrogen peroxide at 95°C, react for 12 hours, and then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0148] 10. Add 50.0 mg of UO4·2H2O catalyst to a 25 mL reaction tube, then add 0.093 g of aniline and 0.867 g of mesitylene, add 1.0 mL of hydrogen peroxide at 95°C, react for 12 h, and then filter, distill and recrystallize to obtain the product 1-diphenyldiazene oxide.

[0149] The product yield of 1-diphenyldiazene oxide obtained by the preparation method described in 1-10 above was calculated, and the results are shown in Table 6 below:

[0150] Table 6 Process parameters of the preparation method described in Example 6 and the yield of the product 1-diphenyldiazene oxide

[0151]

[0152] The mass spectrum of the main product obtained from the above reaction is as follows Fig.10 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 structural formula is shown in Formula 1. The above results show that when mesitylene is used as the reaction solvent, hydrogen peroxide is used as the oxidant, UO4·2H2O is used as the catalyst, and the ratio of the catalyst to aniline or its derivatives is 1-50 mg:1 mmol, aniline can be catalyzed to synthesize 1-diphenyldiazene oxide; and when the ratio of the catalyst to aniline or its derivatives is 10-50 mg:1 mmol, the yield of 1-diphenyldiazene oxide obtained by the reaction is higher than 70%; at the same time, when the ratio of the catalyst to aniline or its derivatives is 25-40 mg:1 mmol, the yield of 1-diphenyldiazene oxide obtained by the reaction is as high as more than 90%.

[0153]

[0154] Example 7 Synthesis of 1-Oxydiphenyldiazene Derivatives Using Different Aniline Derivatives

[0155] 1. Add 30.0 mg of UO4·2H2O catalyst to a 25 mL reaction tube, then add 0.107 g of o-methylaniline and 0.867 g of mesitylene, add 1.0 mL of hydrogen peroxide at 95°C, react for 12 h, then filter, distill and recrystallize to obtain the product 2,2'-dimethyl-1-diphenyldiazene oxide. The mass spectrum of the product is shown in Fig.11 As shown, the structural formula is as follows

[0156] As shown in formula 2.

[0157]

[0158] 2. Add 30.0 mg of UO4·2H2O catalyst to a 25 mL reaction tube, then add 0.107 g of m-methylaniline and 0.867 g of mesitylene, add 1.0 mL of hydrogen peroxide at 95°C, react for 12 h, then filter, distill and recrystallize to obtain the product 3,3'-dimethyl-1-diphenyldiazene oxide. The mass spectrum of the product is shown in Fig.12 As shown, the structural formula is as follows

[0159] As shown in formula 3.

[0160]

[0161] 3. Add 30.0 mg of UO4·2H2O catalyst to a 25 mL reaction tube, then add 0.107 g of p-methylaniline and 1.30 g of mesitylene, add 1.0 mL of hydrogen peroxide at 95°C, react for 12 h, then filter, distill and recrystallize to obtain the product 4,4'-dimethyl-1-diphenyldiazene oxide. The mass spectrum of the product is shown in Fig.13 As shown, the structural formula is as follows

[0162] As shown in formula 4.

[0163]

[0164] 4. Add 30.0 mg of UO4·2H2O catalyst to a 25 mL reaction tube, then add 0.127 g of p-chloroaniline and 1.30 g of mesitylene, add 1.0 mL of hydrogen peroxide at 95°C, react for 12 h, then filter, distill and recrystallize to obtain the product 4,4'-dichloro-1-diphenyldiazene oxide. The mass spectrum of the product is shown in Fig.14 As shown, the structural formula is shown in Formula 5.

[0165]

[0166] 5. Add 30.0 mg of UO4·2H2O catalyst to a 25 mL reaction tube, then add 0.172 g of p-bromoaniline and 2.601 g of mesitylene, add 1.0 mL of hydrogen peroxide at 95°C, react for 12 h, then filter, distill and recrystallize to obtain the product 4,4'-dibromo-1-diphenyldiazene oxide. The mass spectrum of the product is shown in Fig.15 As shown, the structural formula is shown in Formula 6.

[0167]

[0168] 6. Add 30.0 mg of UO4·2H2O catalyst to a 25 mL reaction tube, then add 0.123 g of p-methoxyaniline and 2.601 g of mesitylene, add 1.0 mL of hydrogen peroxide at 95°C, react for 12 h, then filter, distill and recrystallize to obtain the product 4,4'-dibromo-1-diphenyldiazene oxide. The mass spectrum of the product is shown below: Fig.16 As shown, the structural formula is shown in Formula 7.

[0169]

[0170] The product yield of the 1-diphenyldiazene oxide derivative obtained by the preparation method described in 1-5 above was calculated, and the results are shown in Table 7 below:

[0171] Table 7 Process parameters and product yields of the preparation method described in Example 7

[0172]

[0173] The mass spectra of the main products in the above reactions 1-6 are as follows: Figure 11-16 shown. The above results show that, with mesitylene as the reaction solvent, hydrogen peroxide as the oxidant and UO4·2H2O as the catalyst, o-methylaniline can be catalyzed to synthesize 2,2'-dimethyl-1-diphenyldiazene oxide with a yield of 76%; m-methylaniline can be catalyzed to synthesize 3,3'-dimethyl-1-diphenyldiazene oxide with a yield of 81%; p-methylaniline can be catalyzed to synthesize 4,4'-dimethyl-1-diphenyldiazene oxide with a yield of 92%; p-chloroaniline can be catalyzed to synthesize 4,4'-dichloro-1-diphenyldiazene oxide with a yield of 95%; p-bromoaniline can be catalyzed to synthesize 4,4'-dibromo-1-diphenyldiazene oxide with a yield of 97%; and p-methoxyaniline can be catalyzed to synthesize 4,4'-dimethoxy-1-diphenyldiazene oxide with a yield of 96%. Therefore, the method of the present invention can catalyze the synthesis of 1-diphenyldiazene oxide or its derivatives from aniline or its derivatives, and the yield of the target product obtained is high.

[0174] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. Preparation method of depleted uranium-based UO4·2H2O and its application in catalytic synthesis of 1-diphenyldiazene oxide or its derivatives.

2. As claimed in claim 1, a method for preparing a UO4·2H2O heterogeneous catalyst, characterized in that: U3O8 made from depleted UF6 is used as the starting material, concentrated acid is used as the solvent, a specific precipitant is used as the auxiliary, and deionized water is used as the diluent. The specific operation steps are as follows: Preparation of UO4·2H2O: Weigh a specific mass of U3O8 prepared with depleted UF6 as raw material, place it in a container, add an appropriate amount of concentrated acid while heating and stirring, so that U3O8 is completely dissolved, then add an appropriate amount of deionized water to form a transparent uranyl salt solution, and then add an appropriate amount of oxidant. After continuous stirring for several hours, separate the solid product, wash and dry it to obtain UO4·2H2O.

3. A method for preparing UO4·2H2O according to claims 1 and 2, characterized in that: The concentrated acid described in claim 2 is concentrated nitric acid with a mass fraction greater than 65% or concentrated hydrochloric acid with a mass fraction greater than 37%, the oxidant is hydrogen peroxide with a mass fraction greater than 25%, the uranyl salt is uranyl nitrate or uranyl chloride, and the stirring time is 2-25h.

4. A method for preparing UO4·2H2O according to claims 1 and 2, characterized in that: The drying temperature described in claim 2 is 60-240° C. and the drying time is 2-8 hours.

5. Use of the catalytic synthesis of 1-diphenyldiazene oxide or its derivatives as claimed in claim 1. Features: The structural formula of the 1-diphenyldiazene oxide or its derivatives is shown in the following formula (II). The raw material for synthesizing the 1-diphenyldiazene oxide or its derivatives is aniline or its derivatives, and the structural formula thereof is shown in the following formula (I): Wherein, R1-R5 are selected from any one of hydrogen, halogen, hydroxyl, sulfonic acid, nitro, substituted or unsubstituted straight or branched alkyl, alkoxy, carbonyl, alkenyl, alkynyl, substituted or unsubstituted aryl, acylamino, and cyano. R1-R5 are selected from any one of hydrogen, methyl, and chlorine.

6. A method for preparing 1-diphenyldiazene oxide or a derivative thereof as claimed in claims 1 and 5, the method comprising: A method for preparing 1-diphenyldiazene oxide or its derivatives, comprising: using aniline or its derivatives as a raw material, mesitylene or a mixed solvent of mesitylene and other organic solvents as a reaction solvent, using UO4·2H2O as a catalyst, and using hydrogen peroxide as an oxidant, to catalyze an oxidation reaction to synthesize 1-diphenyldiazene oxide or its derivatives as a formula (II), wherein the organic solvent comprises methanol, ethanol, and n-butanol; Among them, R1-R5 are independently selected from any one of hydrogen, halogen, hydroxyl, sulfonic acid, nitro, substituted or unsubstituted straight or branched alkyl, alkoxy, carbonyl, alkenyl, alkynyl, substituted or unsubstituted aryl, acylamino, and cyano.

7. The synthesis method according to claims 1, 5 and 6, characterized in that The dosage ratio of the catalyst to aniline or its derivative is 1-50 mg:1 mmol; the mass ratio of the reaction solvent to aniline or its derivative is 1-80:1; the volume of the hydrogen peroxide is 0.1-1.5 mL; the reaction temperature is 50-155° C.; and the reaction time is 1-20 h.

8. The synthesis method according to claims 5-7, characterized in that The R1-R5 are selected from hydrogen, methyl and chlorine respectively. The aniline or its derivatives include: aniline, o-methylaniline, p-methylaniline, p-chloroaniline, n-chloroaniline and m-chloroaniline.

9. The synthesis method according to any one of claims 5 to 8, characterized in that: Aniline or its derivatives, UO4·2H2O (the amount ratio of UO4·2H2O to aniline or its derivatives is 30 mg:1 mmol), and hydrogen peroxide (the molar ratio of UO4·2H2O to aniline or its derivatives is 10:1) are added to mesitylene (the mass ratio of UO4·2H2O to aniline or its derivatives is 40:1), and reacted at 95° C. for 12 hours; 1-diphenyldiazene oxide or its derivatives is obtained by filtration, distillation, and recrystallization.

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