Preparation method of silverton type uranium molybdenum oxygen cluster and application thereof in synthesis of quinazolinone

Abstract

The application discloses a preparation method of a Silverton type uranium molybdenum oxygen cluster and application of the Silverton type uranium molybdenum oxygen cluster in catalytic synthesis of quinazolinone, and belongs to the technical field of polyacid chemistry and catalytic chemistry. 24 The method is to dissolve Fe2(SO4)3 or CoSO4.7H2O or NiSO4.7H2O and (NH4)6Mo7O The Silverton type uranium molybdenum oxygen cluster has high stability and can keep stable in aqueous solutions with pH values of 1-13 and various organic solvents; the Silverton type uranium molybdenum oxygen cluster exhibits excellent catalytic activity in a reaction of synthesizing quinazolinone compounds by dehydration condensation of o-aminobenzamide compounds and aldehyde compounds, and the yield of a target product is as high as 93%. The preparation method of the Silverton type uranium molybdenum oxygen cluster is simple, the Silverton type uranium molybdenum oxygen cluster has high stability and good catalytic activity, the method provides a reference for structure research of uranium-containing poly-molybdenum oxygen clusters, and has a good application prospect in the field of catalytic chemistry.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of polyacid chemistry and catalytic chemistry, in particular to a preparation method of Silverton type uranium molybdenum oxygen clusters and application thereof in synthesis of quinazolinone. BACKGROUND

[0002] It is very important to study the chemical behavior of uranium compounds for the utilization of nuclear resources, environmental protection and the development of actinide chemistry. Polyoxometalates (POMs) are a class of polynuclear metal-oxygen cluster compounds formed by high oxidation state early transition metals (W, Mo, V, Nb, Ta, etc.) through oxygen bridges, which are also called polyacids. POMs can assemble most of the metal elements in the periodic table into their structures. Since the 1990s, research on the use of POMs to sequester uranium and other radionuclides has been rising. There are about 70 uranium-containing POMs with clear structures, mainly concentrated in uranium-containing polytungsten clusters, and there are very few studies on other types of uranium-containing POMs. The first uranium-containing polymolybdenum cluster has been synthesized for 50 years, but there are only 11 uranium-containing polymolybdenum clusters, of which 8 are simple isomorphic Silverton type zero-dimensional structures, 1 is a one-dimensional chain structure, 1 is a two-dimensional planar structure, and only 1 is a non-classical three-dimensional structure. The number of compounds is small, the structure type is very monotonous, and there is no other performance report except the structure. In addition, most of the uranium-containing POMs are synthesized in aqueous solution using conventional solution method, and only one uranium-containing polytungsten cluster is synthesized using hydrothermal method, so most of the uranium-containing POMs are easily soluble in water, which is not conducive to the fixation of radionuclides and the development of other properties, such as catalytic properties. In recent years, the research focus of POMs has developed from structure-oriented research to performance-oriented research. However, the research on uranium-containing POMs is far behind other POMs, the structure research of uranium-containing polymolybdenum clusters is still very scarce, and the performance research is even blank. Therefore, based on the current research status of uranium-containing polymolybdenum clusters, developing a new preparation method of uranium-containing polymolybdenum clusters and studying their catalytic properties is of great significance for enriching and developing polyacid chemistry, actinide chemistry, environmental chemistry and other disciplines.

[0003] Quinazolinone is a kind of diazacyclic compound containing carbonyl, is a variety of alkaloid skeleton, widely exists in natural products and synthetic products, shows a wide range of biological activities, such as antifungal, anti-inflammatory, antimicrobial, etc. For example, the current widely studied in the treatment of cancer halofuginine has antimalarial effect, doxazosin has the effect of antihypertensive. Uranium-containing polyoxomolybdate combines the unique catalytic properties of polyoxometalate, and can combine the Lewis acidity of polyoxometalate and transition metal after introducing transition metal ions into its structure, and can play a unique role in the catalytic synthesis of quinazolinone compounds. Therefore, the catalytic synthesis of quinazolinone compounds by using Silverton type uranium molybdenum oxide cluster synthesized by hydrothermal synthesis can be used as an application outlet to promote the research of uranium-containing polyoxomolybdate, and also provides a new way for the synthesis of quinazolinone. SUMMARY

[0004] In view of the lack of research on the structure and performance of uranium-containing polyoxomolybdate, the application provides a preparation method of Silverton type uranium molybdenum oxide cluster and applies it to the reaction of synthesizing quinazolinone compounds from o-aminobenzamide compounds and aldehyde compounds. The method uses Silverton type uranium molybdenum oxide cluster crystals as catalyst, has high stability, is easy to recover, has high catalytic yield, no toxic by-products are generated, and meets the requirements of green production.

[0005] The application aims to at least solve one of the problems in the prior art, and provides a preparation method and application of Silverton type uranium molybdenum oxide cluster.

[0006] The technical solution of the application is as follows:

[0007] A Silverton type uranium molybdenum oxide cluster has the following chemical formula: H x Na y (H2O)9[M z UMo 12 O 42 ]·4.5H2O, wherein M=Fe(II), Co(II), Ni(II), x+y+2z=8.

[0008] Preferably, the Silverton type uranium molybdenum oxide cluster is compound 1 and / or compound 2 and / or compound 3.

[0009] The chemical formula of compound 1 is H3Na3(H2O)9[FeUMo 12 O 42 ]·4.5H2O,

[0010] The chemical formula of compound 2 is H 1.92 Na 4.08 (H2O)9[CoUMo 12 O42 ]·4.5H2O,

[0011] The chemical formula of compound 3 is H 2.60 Na 4.24 (H2O)9[Ni 0.58 UMo 12 O 42 ]·4.5H2O.

[0012] Preferably, the crystal system of compound 1 is an orthorhombic system, the space group is Ia-3, and the unit cell parameters are a= 13. 1 A, b= 13. 1 A, and c= 13. 1 A. α = β = γ = 90°, Z = 16.

[0013] The crystal system of compound 2 is an orthorhombic system, the space group is Ia-3, and the unit cell parameters are a= 13. 1 A, b= 13. 1 A, and c= 13. 1 A. α = β = γ = 90°, Z = 16.

[0014] The crystal system of compound 3 is an orthorhombic system, the space group is Ia-3, and the unit cell parameters are a= 13. 1 A, b= 13. 1 A, and c= 13. 1 A. α = β = γ = 90°, Z = 16.

[0015] The application discloses a preparation method of a Silverton type uranium molybdenum oxygen cluster, and the compound 1 is obtained by using a hydrothermal method, and the specific steps of the preparation method are as follows: Fe2(SO4)3, (NH4)6Mo7O 24 4H2O is dissolved in an aqueous solution to obtain solution A, then Na2S2O4 is dissolved in an aqueous solution to obtain solution B, B is added drop by drop into A, then UO2(NO)2·6H2O is added, stirring is performed until complete dissolution, then dilute H2SO4 is used to adjust the pH to 4.2, the mixed solution is stirred at room temperature for 30 minutes, then is added to a reaction kettle and sealed, and after reaction at 120 DEG C for five days, black crystals of the compound 1 are obtained.

[0016] In the preparation method, the compound 2 is obtained by changing transition metal salts, and the specific steps of the preparation method are as follows: CoSO4·7H2O, (NH4)6Mo7O 24 4H2O is dissolved in an aqueous solution to obtain solution A, then Na2S2O4 is dissolved in an aqueous solution to obtain solution B, B is added drop by drop into A, then UO2(NO)2·6H2O is added, stirring is performed until complete dissolution, then dilute H2SO4 is used to adjust the pH to 4.2, the mixed solution is stirred at room temperature for 30 minutes, then is added to a reaction kettle and sealed, and after reaction at 120 DEG C for five days, brown crystals of the compound 2 are obtained.

[0017] In the above preparation method, the transition metal salt and solution are changed to obtain compound 3, and the specific steps are as follows: NiSO4·7H2O, (NH4)6Mo7O 24 ·4H2O is dissolved in a lithium acetate buffer solution with pH = 4.8 to obtain solution A, then Na2S2O4 is dissolved in an aqueous solution to obtain solution B, B is added dropwise into A, then UO2(NO)2·6H2O is added, stirring is performed until complete dissolution, then dilute H2SO4 is used to adjust the pH to 4.2, the mixed solution is stirred at room temperature for 30 minutes, then is added to a reaction kettle and sealed, and brown crystals of compound 3 are obtained after reaction at 120 DEG C for five days.

[0018] The application further discloses application of any one of the above-mentioned Silverton type uranium molybdenum oxygen clusters in catalytic synthesis of quinazolinone compounds, and the specific steps are as follows: in a 4ml reaction bottle, an ortho-aminobenzamide compound, an aldehyde compound, a Silverton type uranium molybdenum oxygen cluster and acetonitrile are added, then a screw cap with a Teflon gasket is used for sealing, reaction is carried out at 70-90 DEG C for 1-2 hours, and the obtained solution after reaction is purified by column chromatography (petroleum ether / ethyl acetate) to obtain a quinazolinone compound. The reaction general formula is as follows: (catalyst: Silverton type uranium molybdenum oxygen cluster), and it can be seen that the by-product is only water, which is green and environmentally friendly.

[0019]

[0020] The application has the advantages that the method developed in the application can synthesize a new type of Silverton type uranium molybdenum oxygen cluster, the synthesis steps are simple and easy to operate, the prepared Silverton type uranium molybdenum oxygen cluster can be used as a green and efficient catalyst for catalyzing dehydration of an ortho-aminobenzamide compound and an aldehyde compound to synthesize a quinazolinone compound, a new way for synthesis of the quinazolinone compound is opened up, the raw material cost is low, the reaction time is short, the catalytic yield is high, the catalyst stability is high and the catalyst is easy to recycle and reuse, the experimental operation is simple, and the only by-product is water. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 It is a unit structure diagram of compounds 1, 2 and 3 in Example 1.

[0022] Figure 2 It is a three-dimensional structure diagram of compounds 1, 2 and 3 in Example 1.

[0023] Figure 3 It is an infrared spectrum diagram of compounds 1, 2 and 3 in Example 1.

[0024] Figure 4 It is a PXRD diffraction spectrum of compound 1 in Example 1.

[0025] Figure 5 The PXRD diffraction pattern of compound 2 in Example 1;

[0026] Figure 6 The PXRD diffraction pattern of compound 3 in Example 1;

[0027] Figure 7 The PXRD diffraction patterns of compound 3 in Example 1 after heating and soaking in different organic solvents;

[0028] Figure 8 The PXRD diffraction patterns of compound 3 in Example 1 after immersion in aqueous solutions at different pH values ​​are shown.

[0029] Figure 9 The PXRD diffraction pattern of compound 3 in Example 1 after 7 cycles of catalytic reaction is shown. Detailed Implementation

[0030] The technical solution of the present invention will be further described below by way of specific embodiments.

[0031] It should be noted that the yield rates mentioned below are the actual mass of the separated product divided by the theoretical mass of the product.

[0032] Example 1

[0033] Fe2(SO4)3 (0.25 mmol, 0.0997 g) and (NH4)6Mo7O 24 Solution A was obtained by dissolving 0.5 mmol (0.1179 g) of 4H₂O in 10 mL of aqueous solution. Solution B was obtained by dissolving 0.5 mmol (0.0871 g) of Na₂S₂O₄ in 5 mL of aqueous solution. Solution B was added dropwise to solution A, followed by the addition of 0.1 mmol (0.0502 g) of UO₂(NO)₂·6H₂O. The mixture was stirred until completely dissolved, and the pH was adjusted to 4.2 with dilute H₂SO₄ (1 mol / L). The mixture was stirred at room temperature for 30 minutes, then added to a reaction vessel and sealed. After reacting at 120 °C for five days, black crystals of compound 1 were obtained. The crystal structure was characterized by X-ray single-crystal diffraction (see attached diagram for details). Figure 1 ),Depend on Figure 1 It can be seen that the polyanion of compound 1 has a typical Silverton-type structure. The central uranium atom has a +4 valence and is 12-coordinated. Each polyanion is also coordinated with two Fe(II) ions to form its one-dimensional chain-like structural unit {FeUMo 12 The three-dimensional spatial structure is further expanded by the connection of the surrounding disordered sodium ions and coordinated water molecules. Figure 2The three-dimensional spatial structure of compound 1 is shown, and seven directions of {FeUMo 12} one-dimensional chains are connected to each other by disordered sodium ions and coordinated water molecules, and densely packed to form a stable three-dimensional structure. Compounds 1, 2 and 3 are isomorphic.

[0034] Example 2

[0035] In a 4-milliliter reaction bottle, o-aminobenzamide (0.2 mmol), benzaldehyde (0.2 mmol), compound 3 (0.006 mmol) and acetonitrile (1 mL) were added. Then it was sealed with a screw cap with a Teflon gasket and reacted at 90°C for 2 hours. After the reaction was completed, the target product was separated by column chromatography, and the yield was 91% after weighing and calculation.

[0036] The specific structure of the target product and the data results of detecting the target product by nuclear magnetic resonance are as follows:

[0037]

[0038] 1 H NMR (500 MHz, DMSO-d6) δ = 8.48 (s, 1H), 7.76 (d, J = 7.6, 1H), 7.61 (d, J = 7.4, 2H), 7.41 (dt, J = 23.3, 7.0, 3H), 7.32 (t, J = 7.5, 1H), 7.25 (s, 1H), 6.89 (d, J = 8.1, 1H), 6.76 (t, J = 7.4, 1H), 5.88 (s, 1H). 13 C NMR (126 MHz, DMSO-d6) δ = 164.38, 148.47, 142.07, 133.95, 129.05, 128.89, 127.99, 127.44, 117.77, 115.48, 115.02, 67.24.

[0039] The above test results show that the target product belongs to quinazolinone compounds, that is, quinazolinone compounds can be synthesized by the method of the embodiment.

[0040] Example 3

[0041] In a 4-milliliter reaction bottle, o-aminobenzamide (0.2 mmol), benzaldehyde (0.2 mmol), compound 3 (0.006 mmol) and acetonitrile (1 mL) were added. Then it was sealed with a screw cap with a Teflon gasket and reacted at 90°C for 2 hours. After the reaction was completed, the target product was separated by column chromatography, and the yield was 93% after weighing and calculation.

[0042] The specific structure of the target product and the data results of detecting the target product by nuclear magnetic resonance are as follows:

[0043]

[0044] 1 H NMR (500 MHz, DMSO-d6) δ = 7.71 (d, J = 6.8, 1H), 7.33 (ddd, J = 22.7, 18.1, 7.2, 6H), 7.21-7.16 (m, 1H), 6.71-6.63 (m, 2H), 5.87 (d, J = 2.2, 1H), 3.97-3.83 (m, 1H), 2.82-2.69 (m, 1H), 1.62-1.41 (m, 2H), 1.21 (s, 6H), 0.82 (t, J = 6.7, 3H). 13 C NMR (126 MHz, DMSO-d6) δ = 162.73, 146.77, 141.69, 133.52, 128.93, 128.79, 127.92, 126.66, 117.52, 115.52, 114.70, 70.71, 44.88, 31.48, 27.86, 26.51, 22.53, 14.35.

[0045] The above test results show that the target product belongs to quinazolinone compounds, that is, quinazolinone compounds can be synthesized by using the method of the embodiment.

[0046] Example 4

[0047] In a 4-milliliter reaction bottle, 2-amino-4-methylbenzamide (0.2 mmol), benzaldehyde (0.2 mmol), compound 3 (0.006 mmol) and acetonitrile (1 mL) were added. Then it was sealed with a screw cap with a Teflon gasket, and reacted at 90°C for 2 hours. After the reaction was completed, the target product was separated by column chromatography, and the yield was 90% after weighing and calculation.

[0048] The specific structure of the target product and the data results of detecting the target product by nuclear magnetic resonance are as follows:

[0049]

[0050] 1H NMR (500 MHz, DMSO-d6) δ = 8.29 (s, 1H), 7.54 (dd, J = 14.3, 7.6, 3H), 7.42 - 7.34 (m, 3H), 7.10 (s, 1H), 6.60 (s, 1H), 6.53 (d, J = 7.9, 1H), 5.77 (s, 1H), 2.22 (s, 3H). 13 C NMR (126 MHz, DMSO-d6) δ = 164.22, 148.33, 143.90, 142.30, 128.88, 128.81, 127.93, 127.30, 118.96, 114.91, 113.16, 67.04, 21.88.

[0051] The above test results show that the target product is a quinazolinone compound, i.e. quinazolinone compounds can be synthesized by using the method of the present embodiment.

[0052] Example 5

[0053] In a 4-milliliter reaction bottle, o-aminobenzamide (0.2 mmol), p-fluorobenzaldehyde (0.2 mmol), compound 3 (0.006 mmol) and acetonitrile (1 mL) were added. Then it was sealed with a screw cap with a Teflon gasket and reacted at 90°C for 2 hours. After the reaction was completed, the target product was separated by column chromatography, and the yield was 90% after weighing and calculation.

[0054] The specific structure of the target product and the data results of detecting the target product by nuclear magnetic resonance are as follows:

[0055]

[0056] 1 H NMR (500 MHz, DMSO-d6) δ = 8.33 (s, 1H), 7.62 (d, J = 6.8, 1H), 7.55 (dd, J = 8.6, 5.6, 2H), 7.29 - 7.20 (m, 3H), 7.13 (s, 1H), 6.76 (d, J = 8.1, 1H), 6.69 (t, J = 7.4, 1H), 5.79 (s, 1H). 13 C NMR (126 MHz, DMSO-d6) δ = 164.07, 162.59 (d, J = 244.2 Hz), 148.29, 138.23 (d, J = 2.8 Hz), 133.85, 129.53 (d, J = 8.4 Hz), 127.84, 117.74, 115.58 (d, J = 21.5 Hz), 115.41, 114.92, 66.40.

[0057] The test results above indicate that the target product is 2-(4-fluorophenyl)quinazolinone, meaning that quinazolinone compounds can be synthesized using the method described in this embodiment.

[0058] Example 6

[0059] In a 4 mL reaction flask, o-aminobenzamide (0.2 mmol), 2-naphthaldehyde (0.2 mmol), compound 3 (0.006 mmol), and acetonitrile (1 mL) were added. The flask was then sealed with a screw cap fitted with a Teflon gasket and reacted at 90 °C for 2 hours. After the reaction was complete, the target product was obtained by column chromatography, and the yield was calculated to be 86%.

[0060] The specific structure of the target product and the data results of its detection using nuclear magnetic resonance are as follows:

[0061]

[0062] 1 H NMR (500MHz, DMSO-d6) δ = 8.43 (s, 1H), 8.01–7.91 (m, 4H), 7.72 (d, J = 8.5, 1H), 7.67 (d, J = 6.8, 1H), 7.54(dd,J=6.2,3.2,2H),7.30–7.22(m,2H),6.79(d,J=8.0,1H),6.70(t,J=7.4,1H),5.96(s,1H). 13 C NMR (126MHz, DMSO-d6)δ=164.12,148.39,139.32,133.86,133.48,132.94,128.62,128 .46,128.07,127.88,126.92,126.88,126.37,125.34,117.68,115.42,114.91,67.32.

[0063] The test results above indicate that the target product is 2-(2-naphthyl)quinazolinone, meaning that quinazolinone compounds can be synthesized using the method described in this embodiment.

[0064] Comparative Example 1

[0065] In a 4 mL reaction flask, o-aminobenzamide (0.1 mmol), benzaldehyde (0.11 mmol), catalyst [Cu(IBA)₂]·2DMF 5 mol% (IBA = 4-(1H-imidazol-1-yl)benzoic acid), MgSO₄ (0.1 mmol, 0.012 g), and methanol (1 mL) were added. The flask was then sealed with a screw cap fitted with a Teflon gasket and reacted at 70 °C for 12 hours. After the reaction was complete, the target product was obtained by column chromatography in 79% yield, with the highest yield of 94% obtained after ultrasonic exfoliation of the catalyst.

[0066] As can be seen from the yield values, the Silverton-type uranium-molybdenum-oxygen cluster catalyst used in Examples 2-6 achieved a yield of up to 93% for the synthesis of the target product (quinazolinone compounds). In contrast, Comparative Example 1, using a metal-organic framework as a catalyst, achieved a maximum yield of 94%, but this catalyst required further ultrasonic treatment after synthesis, making the process complex. The highest yield of the catalyst without ultrasonic treatment was only 79%. Furthermore, this catalyst required the addition of MgSO4 as an additive for catalysis, and the catalyst could not be recycled, resulting in resource waste and environmental pollution. The reaction time was 12 hours, indicating low efficiency. In comparison, the target product of this invention maintains a high yield, with a simple catalyst synthesis process, no need for additional additives to avoid waste and pollution, a short reaction time, extremely high catalyst stability, and the ability to be recycled at least 7 times without significant activity reduction.

[0067] The results of infrared spectroscopy and PXED diffraction pattern analysis of Example 1 are shown in the figure. Figures 3-9 .

[0068] The infrared spectra of compounds 1-3 are as follows Figure 3 As shown, 3300cm -1 The characteristic peak at 1100-500 cm⁻¹ is the stretching vibration peak of the OH group in water molecules. -1 The vibrational peak at that location corresponds to a characteristic peak of polyacids. This indicates that the synthesized Silverton uranium-molybdenum-oxygen cluster structure contains a polyacid structure.

[0069] The PXRD diffraction patterns of compounds 1-3 are as follows: Figures 4-6 As shown, the positions of the key diffraction peaks measured experimentally match those calculated theoretically, indicating that compounds 1-3 prepared by the method in Example 1 have high purity and are single-phase. The differences in diffraction peak intensities may be due to changes in the preferred orientation of the powder during the data collection process.

[0070] The PXRD diffraction patterns of compound 3 after being heated (90°C) and soaked in different organic solvents for one day are shown below. Figure 7As shown, the positions of the key diffraction peaks measured in the experiment hardly changed, indicating that compound 3 has high stability and can remain stable in the listed solvents.

[0071] The PXRD diffraction patterns of compound 3 after soaking in aqueous solutions at different pH values ​​at room temperature for one day are shown below. Figure 8 As shown, the positions of the key diffraction peaks measured in the experiment hardly changed, indicating that compound 3 has high stability and can remain stable over a wide pH range.

[0072] The PXRD diffraction pattern of compound 3 after 7 catalytic cycles is shown below. Figure 9 As shown, the positions of the key diffraction peaks measured in the experiment hardly changed, indicating that compound 3 has high stability and good reusability.

[0073] The above-described embodiments are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that any equivalent substitutions or partial improvements made by those skilled in the art within the spirit and principles of the present invention will be considered within the protection scope of the present invention.

Claims

1. A method for preparing Silverton-type uranium-molybdenum-oxygen clusters, characterized in that: Fe2(SO4)3, (NH4)6Mo7O 24 ·4H2O was dissolved in an aqueous solution to obtain solution A. Then, Na2S2O4 was dissolved in an aqueous solution to obtain solution B. Solution B was added dropwise to solution A, followed by the addition of UO2(NO)2·6H2O. The mixture was stirred until completely dissolved, and then the pH was adjusted to 4.2 with dilute H2SO4. The mixed solution was stirred at room temperature for 30 minutes and then added to a reaction vessel and sealed. After reacting at 120°C for five days, black crystals of compound 1 were obtained. The chemical formula of compound 1 is H3Na3(H2O)9[FeUMo] 12 O 42 ]·4.5H2O.

2. The method for preparing a Silverton-type uranium-molybdenum-oxygen cluster according to claim 1, characterized in that: The crystal system of compound 1 is orthorhombic, and the space group is [space group missing]. I a-3, with unit cell parameters a=b=c=26.0130(3)Å, V=17602.4(4)Å 3 Z=16.

3. A method for preparing Silverton-type uranium-molybdenum-oxygen clusters, characterized in that: CoSO4·7H2O and (NH4)6Mo7O 24 ·4H2O was dissolved in an aqueous solution to obtain solution A. Then, Na2S2O4 was dissolved in an aqueous solution to obtain solution B. Solution B was added dropwise to solution A, followed by the addition of UO2(NO)2·6H2O. The mixture was stirred until completely dissolved, and then the pH was adjusted to 4.2 with dilute H2SO4. The mixed solution was stirred at room temperature for 30 minutes, then added to a reaction vessel and sealed. After reacting at 120°C for five days, compound 2, a brown crystal, was obtained. The chemical formula of compound 2 is H2O. 1.92 Na 4.08 (H2O)9[CoUMo 12 O 42 ]·4.5H2O.

4. The method for preparing a Silverton-type uranium-molybdenum-oxygen cluster according to claim 3, characterized in that: The crystal system of compound 2 is orthorhombic, and the space group is [space group missing]. I a-3, with unit cell parameters a=b=c=25.9609(3)Å, V=17496.8(6)Å 3 Z=16.

5. A method for preparing Silverton-type uranium-molybdenum-oxygen clusters, characterized in that: NiSO4·7H2O, (NH4)6Mo7O 24 Solution A was obtained by dissolving 4H₂O in a lithium acetate buffer solution at pH 4.

8. Then, solution B was obtained by dissolving Na₂S₂O₄ in an aqueous solution. Solution B was added dropwise to solution A, followed by the addition of UO₂(NO)₂·6H₂O. The mixture was stirred until completely dissolved, and the pH was adjusted to 4.2 with dilute H₂SO₄. The mixed solution was stirred at room temperature for 30 minutes and then added to a reaction vessel and sealed. After reacting at 120°C for five days, brown crystals of compound 3 were obtained. The chemical formula of compound 3 is H₂O. 2.60 Na 4.24 (H2O)9[Ni 0.58 UMo 12 O 42 ]·4.5H2O.

6. The method for preparing a Silverton-type uranium-molybdenum-oxygen cluster according to claim 5, characterized in that: The crystal system of compound 3 is orthorhombic, and the space group is [space group missing]. I a-3, with unit cell parameters a=b=c=25.9532(8)Å, V=17481.3(16)Å 3 Z=16.

7. An application of a Silverton-type uranium-molybdenum oxide cluster in the synthesis of quinazolinones, characterized in that, The reaction involves the following steps: In a container, an o-aminobenzamide compound, an aldehyde compound, a Silverton-type uranium-molybdenum oxide cluster, and acetonitrile are added. The container is then sealed, and the reaction is carried out at 70-90°C for 1-2 hours. The resulting solution is purified by column chromatography to obtain a quinazolinone compound. The general reaction formula is as follows: The catalyst is a Silverton-type uranium-molybdenum-oxygen cluster; the byproduct is water. The Silverton-type uranium-molybdenum-oxygen cluster has the following chemical formula: H x Na y (H2O)9[M z UMo 12 O 42 ] 4.5H2O, where M=(Fe(II), Co(II), Ni(II)), x+y+2z=8.

8. The application of the Silverton-type uranium-molybdenum oxide cluster according to claim 7 in the synthesis of quinazolinones, characterized in that: The solvent used in the column chromatography method is a combination solvent of petroleum ether and ethyl acetate.

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