A green preparation method of diphenyl sulfide and its derivatives

Abstract

The invention belongs to the field of catalytic organic synthesis and relates to a green preparation method of diphenyl sulfide and its derivatives. The invention first uses zeolite molecular sieve to load metallic iron to prepare a catalyst in which divalent Fe and trivalent Fe coexist, namely, Fe(II) / Fe(III)-ZSM-5 catalyst, and then uses the catalyst in the desulfurization reaction of diphenyl disulfide and its derivatives, wherein the ZSM-5 zeolite carrier plays a role in activating Fe atoms and reactants, and the iron atoms have catalytic oxidation properties on the surface of the zeolite, and can efficiently and greenly realize the reaction in a heterogeneous phase, without the participation of halogenated substances and without the participation of ligands, so as to prepare diphenyl sulfide and its derivatives, increase the atomic economy of the synthesis process, reduce the separation difficulty of the system, and finally obtain a catalyst that can achieve a very high conversion rate and excellent product selectivity under the catalytic conditions of using air and oxygen as oxidants and without the participation of ligands.

Description

Technical Field

[0001] The invention belongs to the field of catalytic organic synthesis, and specifically relates to a catalyst using zeolite molecular sieve to load metallic iron, and application of the catalyst in catalytic oxidation synthesis of diphenyl sulfide. Background Art

[0002] Aryl sulfide compounds are widely present in drug molecules, natural products and synthetic material molecules, and have wide application value in many important fields. In the field of drug synthesis, diaryl sulfide and aryl-heteroaryl sulfide are therapeutic drugs for treating diseases such as cancer, AIDS, Alzheimer's disease and Parkinson's disease. Moreover, diaryl sulfide is the precursor of the corresponding sulfoxide and sulfone, and can also show excellent biological activity in the human body.

[0003] In general, the coupling reaction of halogenated aromatics and thiophenol thiol catalyzed by transition metals (palladium, copper, etc.) is the main way to synthesize diaryl sulfides (Organic letters, 2020, 22 (19): 7433-7438, Synthesis, 2022, 54 (01): 184-198), but it requires the participation of organic ligands and organic / inorganic bases to participate in the reaction to achieve the reaction. This conventional synthesis route also has obvious disadvantages: the use of transition metal catalysts (especially precious metal catalysts) is relatively expensive; and metal salts and ligands are homogeneous catalysts and cannot be easily recovered from the reaction system, and the generated metal ions are not easy to separate from the reaction system, which increases the cost of later purification; secondly, the reaction of halogenated aromatics with thiophenols not only has poor atom economy, but also thiophenols as reactants are highly toxic and have an unpleasant odor. Therefore, it is very necessary to develop a simple and efficient thioether synthesis route.

[0004] In recent years, researchers have discovered a new method for synthesizing sulfides with high atom economy, namely, desulfurization of disulfides to prepare sulfides. Earlier reports have shown that aromatic disulfides can remove two sulfur atoms under catalysis to obtain biaryl hydrocarbon products (Synlett, 2014, 25 (13): 1869-1872.). In recent years, there have also been reports on the removal of one atom of sulfur from disulfides to obtain sulfides (ACS Catalysis, 2020, 10 (4): 2707-2712.). In this article, cuprous iodide and 1,10-phenanthroline were used as catalysts to achieve the desulfurization reaction of disulfide substrates with different structures. Compared with thiophenols and thiols, disulfides have the advantages of being odorless and non-toxic. This reaction pathway for preparing sulfides has incomparable advantages over traditional methods. However, organic ligands are still required in the reaction system. The reaction solution will not only produce serious metal residues, but also the catalyst cannot be recovered, and the production cost is high. If zeolite or other solid catalyst carriers are used to replace homogeneous organic ligand compounds, the economy of the reaction can be greatly improved.

[0005] In view of the above problems, the present invention synthesizes and utilizes a Fe-loaded zeolite catalyst to catalyze the desulfurization of disulfide, and synthesizes a phenylene sulfide compound. In this catalyst, iron has an electron-deficient characteristic, which is easy to electrostatically interact with the charged oxygen atoms in the acidic zeolite framework to form a new catalytic active center structure. In the process of catalyzing the desulfurization of disulfide, the ZSM-5 zeolite carrier plays a key role in activating Fe atoms and reactants. The iron atoms have catalytic oxidation properties on the surface of the zeolite, and can efficiently and greenly realize the reaction in a heterogeneous phase, without the participation of halogenated substances, and without the participation of ligands, to prepare diphenyl sulfide, increase the atomic economy of the synthesis process, reduce the separation difficulty of the system, and effectively avoid the shortcomings of the above-mentioned prior art. Summary of the invention

[0006] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and provide a green method for preparing diphenyl disulfide and its derivatives by desulfurization of diphenyl disulfide and its derivatives, with mild reaction conditions and simple operation.

[0007] A method for preparing diphenyl sulfide compounds and derivatives thereof comprises the following steps:

[0008] A certain amount of diphenyl disulfide and its derivatives are added to a reaction tube, and the catalyst Fe(II) / Fe(III)-ZSM-5 prepared by the present invention is added, and then a base is added, and then an organic solvent is added. The reaction tube is sealed in an air or oxygen atmosphere and reacted at 110-150° C. After reacting for 3-12 hours, it is cooled to room temperature, the reaction liquid is filtered to remove the catalyst, and the product diphenyl sulfide and its derivatives can be obtained by silica gel column chromatography.

[0009] The reaction formula is:

[0010]

[0011] Wherein, in the structural formula of diphenyl disulfide, R is independently selected from H, methyl, ethyl, methoxy, fluorine, chlorine, bromine, nitro, and trifluoromethyl.

[0012] Furthermore, the base is potassium hydroxide, cesium carbonate, or potassium tert-butoxide, preferably potassium hydroxide.

[0013] Furthermore, the molar ratio of diphenyl disulfide to the base is 0.4 to 1:1.

[0014] Furthermore, the organic solvent is any one of dimethyl sulfoxide and N,N-dimethylformamide, preferably dimethyl sulfoxide.

[0015] The catalyst is a ZSM-5 zeolite-loaded iron catalyst, and the preparation process is as follows:

[0016] A certain amount of solid ferric nitrate is added to a suspension containing ZSM-5 zeolite, and then ion exchange is carried out in a water bath at 70-90°C for 4-6 hours. The exchanged solution is placed in an ice bath at 0-7°C and stirred for 30 minutes. An aqueous sodium carbonate solution is added to adjust the pH value of the system to 9-11. Thereafter, ascorbic acid solution is added for reduction, the suspension is centrifuged, and dried to obtain a catalyst in which divalent Fe and trivalent Fe coexist, which is calculated as Fe(II) / Fe(III)-ZSM-5 catalyst.

[0017] Furthermore, the ratio of the mass of iron in the ferric nitrate to the mass of the ZSM-5 zeolite is 0.04 to 0.1.

[0018] Furthermore, the concentration of the sodium carbonate aqueous solution is 0.01-0.05 mol / L, the concentration of the ascorbic acid aqueous solution is 0.4-0.7 mol / L, and the amount of ascorbic acid added is equivalent to 6-13 moles of iron.

[0019] Furthermore, the carrier is a ZSM-5 zeolite carrier, and the silicon-aluminum ratio is 20-100.

[0020] Furthermore, the mass ratio of the catalyst to the substrate diphenyl disulfide is 100-200:1 g / mol.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] a) The Fe(II) / Fe(III)-ZSM-5 catalyst synthesized for the first time in the present invention is used for the desulfurization of diphenyl disulfide to prepare diphenyl sulfide. The catalyst preparation method of the present invention is simple, does not require cumbersome post-processing steps, and has mild reaction conditions, which is conducive to large-scale production and industrial application. The carrier used is ZSM-5 zeolite, which is widely used in industry and has very good thermal stability and hydrothermal stability, so that the catalyst can be recycled and reused many times after the reaction, which further reduces production costs and environmental pollution compared with conventional homogeneous catalysis.

[0023] b) The catalyst of the present invention is used in the desulfurization of diphenyl disulfide to prepare diphenyl sulfide, and can achieve very high conversion rate and product selectivity under catalytic conditions with air and oxygen as oxidants and no ligand participation; in terms of substrate expansion, it can also achieve high yields of a variety of different substrates, indicating that the catalyst has excellent substrate universality. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is the XPS spectrum of Fe in the catalyst prepared in Example 1.

[0025] Figure 2 The compound synthesized in Example 1 1 H NMR.

[0026] Figure 3The compound synthesized in Example 9 1 H NMR.

[0027] Figure 4 The compound synthesized in Example 10 1 H NMR.

[0028] Figure 5 The compound synthesized in Example 11 1 H NMR.

[0029] Figure 6 The compound synthesized in Example 12 1 H NMR.

[0030] Figure 7 The compound synthesized in Example 13 1 H NMR.

[0031] Figure 8 The compound synthesized in Example 14 1 H NMR.

[0032] Fig. 9 The compound synthesized in Example 15 1 H NMR.

[0033] Fig.10 The compound synthesized in Example 16 1 H NMR. DETAILED DESCRIPTION

[0034] The following examples are only listed as examples of embodiments of the present invention and do not constitute any limitation to the present invention. It can be understood by those skilled in the art that modifications within the scope of the essence and concept of the present invention fall within the scope of protection of the present invention. Unless otherwise specified, the reagents and instruments used in the following examples are all commercially available products.

[0035] Example 1: Preparation of catalyst: Preparation of ZSM-5 zeolite-supported Fe catalyst by ion exchange: The catalyst was prepared by ion exchange method, 0.5 g of ferric nitrate nonahydrate solid was weighed and dissolved in 10 g of water, 1 g of ZSM-5 zeolite carrier was added, ultrasonic dispersion was performed for 10 min, and then ion exchange was performed at 80 ° C for 5 hours. The exchanged solution was placed in an ice bath and stirred for 30 min, and 0.01 mol / L sodium carbonate solution was added to adjust the pH value of the system to 10.0; then 20 mL of 0.1 g / mL ascorbic acid solution was added for reduction, and the suspension was centrifuged to obtain a catalyst Fe(II) / Fe(III)-ZSM-5 catalyst in which divalent Fe and trivalent Fe coexisted.

[0036] Figure 1The XPS spectrum of Fe 2p in Fe(II) / Fe(III)-ZSM-5 catalyst shows that the binding energies of 710.1 and 711.9 eV are respectively 2+ and Fe 3+ The characteristic peaks of Fe and Fe indicate that both divalent Fe and trivalent Fe exist in the catalyst.

[0037] 30mg Fe(II) / Fe(III)-ZSM-5 catalyst was added to the reaction tube, and then 0.2mmol diphenyl disulfide, 0.4mmol potassium hydroxide, and 1.0mL DMSO were added under oxygen atmosphere. After sealing, the reaction was carried out at 120°C. After 12 hours of reaction, it was cooled to room temperature, the reaction liquid was filtered, and the conversion rate and selectivity were measured by gas chromatography, and separated by silica gel column chromatography. The final calculation showed that the conversion rate of diphenyl disulfide was 91% and the selectivity was 99%; (diphenylsulfane: colorless oil 1 HNMR(400MHz, CDCl3)δ7.34(m,4H),7.28(m,4H),7.23(dd,2H).)

[0038] Example 2: 30 mg of Fe(II) / Fe(III)-ZSM-5 catalyst was added to a reaction tube, and then 0.2 mmol of diphenyl disulfide, 0.4 mmol of cesium carbonate, and 1.0 mL of DMSO were added under an oxygen atmosphere, and the reaction was carried out at 120° C. after sealing. After the reaction lasted for 12 hours, the reaction solution was cooled to room temperature, and the reaction solution was filtered, and the conversion rate and selectivity were measured by gas chromatography, and the silica gel column was used for separation. The final calculation showed that the conversion rate of diphenyl disulfide was 55.6%, and the selectivity was 49.9%.

[0039] Example 3: 30 mg of Fe(II) / Fe(III)-ZSM-5 catalyst was added to a reaction tube, and then 0.2 mmol of diphenyl disulfide, 0.4 mmol of potassium tert-butoxide, and 1.0 mL of DMSO were added under an oxygen atmosphere, and the reaction was carried out at 120° C. after sealing. After the reaction for 12 hours, the reaction solution was cooled to room temperature, and the reaction solution was filtered, and the conversion rate and selectivity were measured by gas chromatography, and separated by silica gel column chromatography. The final calculation showed that the conversion rate of diphenyl disulfide was 43.1%, and the selectivity was 47.6%.

[0040] Example 4: 30 mg of Fe(II) / Fe(III)-ZSM-5 catalyst was added to a reaction tube, and then 0.2 mmol of diphenyl disulfide, 0.4 mmol of potassium hydroxide, and 1.0 mL of DMSO were added under an oxygen atmosphere, and the reaction was carried out at 110° C. after sealing. After reacting for 12 hours, the reaction solution was cooled to room temperature, and the reaction solution was filtered, and the conversion rate and selectivity were measured by gas chromatography, and separated by silica gel column chromatography. The final calculation showed that the conversion rate of diphenyl disulfide was 65% and the selectivity was 93%.

[0041] Example 5: 30 mg of Fe(II) / Fe(III)-ZSM-5 catalyst was added to a reaction tube, and then 0.2 mmol of diphenyl disulfide, 0.4 mmol of potassium hydroxide, and 1.0 mL of DMSO were added under an oxygen atmosphere, and the reaction was carried out at 150° C. after sealing. After the reaction lasted for 12 hours, the reaction solution was cooled to room temperature, and the reaction solution was filtered, and the conversion rate and selectivity were measured by gas chromatography, and separated by silica gel column chromatography. The final calculation showed that the conversion rate of diphenyl disulfide was 96% and the selectivity was 75%.

[0042] Example 6: 30 mg of Fe(II) / Fe(III)-ZSM-5 catalyst was added to a reaction tube, and then 0.2 mmol of diphenyl disulfide, 0.4 mmol of potassium hydroxide, and 1.0 mL of DMSO were added under an oxygen atmosphere, and the reaction was carried out at 120° C. after sealing. After reacting for 3 hours, the reaction solution was cooled to room temperature, and the reaction solution was filtered, and the conversion rate and selectivity were measured by gas chromatography, and separated by silica gel column chromatography. The final calculation showed that the conversion rate of diphenyl disulfide was 15% and the selectivity was 99%.

[0043] Example 7: The reaction was completed according to the steps in Example 1, and the Fe(II) / Fe(III)-ZSM-5 catalyst used in Example 1 was recovered, washed with dichloromethane for multiple times, and dried, and marked as Fe(II) / Fe(III)-ZSM-5 recovered once. 30 mg of Fe(II) / Fe(III)-ZSM-5-recovered once catalyst was added to the reaction tube, and then 0.2 mmol of diphenyl disulfide, 0.4 mmol of potassium hydroxide, and 1.0 mL of DMSO were added under an oxygen atmosphere. After sealing, the reaction was carried out at 120°C. After reacting for 12 hours, it was cooled to room temperature, the reaction solution was filtered, and the conversion selectivity was determined by gas chromatograph sampling, and separated by silica gel column chromatography. The final calculation showed that the conversion rate of diphenyl disulfide was 86% and the selectivity was 96%.

[0044] Example 8: The reaction was completed according to the steps in Example 1, and the Fe(II) / Fe(III)-ZSM-5-recovered primary catalyst used in Example 10 was recovered, washed with dichloromethane for multiple times, and dried, and marked as Fe(II) / Fe(III)-ZSM-5 recovered secondary catalyst. 30 mg of Fe(II) / Fe(III)-ZSM-5-recovered secondary catalyst was added to the reaction tube, and then 0.2 mmol of diphenyl disulfide, 0.4 mmol of potassium hydroxide, and 1.0 mL of DMSO were added under an oxygen atmosphere. After sealing, the reaction was carried out at 120°C. After reacting for 12 hours, it was cooled to room temperature, the reaction solution was filtered, and the conversion selectivity was determined by sampling gas chromatograph, and separated by silica gel column chromatography. The final calculation showed that the conversion rate of diphenyl disulfide was 80% and the selectivity was 81%.

[0045] Example 9: 30 mg of Fe(II) / Fe(III)-ZSM-5 catalyst was added to the reaction tube, and then 0.2 mmol of di(4-methylphenyl) disulfide, 0.4 mmol of potassium hydroxide, and 1.0 mL of DMSO were added under an oxygen atmosphere. After sealing, the reaction was carried out at 120°C. After reacting for 12 hours, it was cooled to room temperature, the reaction liquid was filtered, and the conversion rate and selectivity were determined by gas chromatography, and separated by silica gel column chromatography. The final calculation showed that the conversion rate of di(4-methylphenyl) disulfide was 83% and the selectivity was 98%; (Diptolylsulfane: white solid 1 H NMR (400MHz, CDCl3) δ7.24(d,J=8.2Hz,4H),7.11(d,J=7.9Hz,4H),2.33(s,6H).)

[0046] Example 10: 30 mg of Fe(II) / Fe(III)-ZSM-5 catalyst was added to the reaction tube, and then 0.2 mmol of bis(4-methoxyphenyl) disulfide, 0.4 mmol of potassium hydroxide, and 1.0 mL of DMSO were added under an oxygen atmosphere. After sealing, the reaction was carried out at 120°C. After reacting for 12 hours, it was cooled to room temperature, the reaction liquid was filtered, and the conversion rate and selectivity were determined by gas chromatography, and separated by silica gel column chromatography. The final calculation showed that the conversion rate of bis(4-methoxyphenyl) disulfide was 64% and the selectivity was 97%; (bis(4-methoxyphenyl)sulfane: white solid 1 HNMR(400MHz, CDCl3)δ7.28(m,4H),6.84(m,4H),3.79(s,6H).)

[0047] Example 11: 30 mg of Fe(II) / Fe(III)-ZSM-5 catalyst was added to the reaction tube, and then 0.2 mmol of bis(4-fluorophenyl) disulfide, 0.4 mmol of potassium hydroxide, and 1.0 mL of DMSO were added under an oxygen atmosphere. After sealing, the reaction was carried out at 120°C. After reacting for 12 hours, it was cooled to room temperature, the reaction liquid was filtered, and the conversion rate and selectivity were determined by gas chromatography, and separated by silica gel column chromatography. The final calculation showed that the conversion rate of bis(4-fluorophenyl) disulfide was 57% and the selectivity was 84%; (bis(4-fluorophenyl)sulfane: white solid 1 H NMR (400MHz, CDCl3) δ7.31(m,4H),7.01(m,4H).)

[0048] Example 12: 30 mg of Fe(II) / Fe(III)-ZSM-5 catalyst was added to the reaction tube, and then 0.2 mmol of bis(4-chlorophenyl) disulfide, 0.4 mmol of potassium hydroxide, and 1.0 mL of DMSO were added under an oxygen atmosphere. After sealing, the reaction was carried out at 120°C. After reacting for 12 hours, it was cooled to room temperature, the reaction liquid was filtered, and the conversion rate and selectivity were determined by gas chromatography, and separated by silica gel column chromatography. The final calculation showed that the conversion rate of bis(4-chlorophenyl) disulfide was 86%, and the selectivity was 87%; (bis(4-chlorophenyl)sulfane: white solid 1 H NMR (400MHz, CDCl3) δ7.42(m,4H),7.37(m,4H).)

[0049] Example 13: 30 mg of Fe(II) / Fe(III)-ZSM-5 catalyst was added to the reaction tube, and then 0.2 mmol of bis(4-bromophenyl) disulfide, 0.4 mmol of potassium hydroxide, and 1.0 mL of DMSO were added under an oxygen atmosphere. After sealing, the reaction was carried out at 120°C. After reacting for 12 hours, it was cooled to room temperature, the reaction liquid was filtered, and the conversion rate and selectivity were determined by gas chromatography, and separated by silica gel column chromatography. The final calculation showed that the conversion rate of bis(4-bromophenyl) disulfide was 96% and the selectivity was 79%; (bis(4-bromophenyl)sulfane: white solid 1 H NMR (400MHz, CDCl3) δ7.43(m,4H),7.19(m,4H).)

[0050] Example 14: 30 mg of Fe(II) / Fe(III)-ZSM-5 catalyst was added to the reaction tube, and then 0.2 mmol of bis(4-ethylphenyl) disulfide, 0.4 mmol of potassium hydroxide, and 1.0 mL of DMSO were added under an oxygen atmosphere. After sealing, the reaction was carried out at 120°C. After reacting for 12 hours, the reaction solution was cooled to room temperature, the reaction solution was filtered, and the conversion rate and selectivity were determined by gas chromatography, and separated by silica gel column chromatography. The final calculation showed that the conversion rate of bis(4-ethylphenyl) disulfide was 78% and the selectivity was 97%; (bis(4-ethylphenyl)sulfane: white solid 1 HNMR (400MHz, CDCl3): δ7.21(d,4H), δ7.07(d,4H), δ2.62-2.52(m,4H), δ1.26(t,6H).)

[0051] Example 15: 30 mg of Fe(II) / Fe(III)-ZSM-5 catalyst was added to the reaction tube, and then 0.2 mmol of bis(3-nitrophenyl) disulfide, 0.4 mmol of potassium hydroxide, and 1.0 mL of DMSO were added under an oxygen atmosphere. The reaction was carried out at 120°C after sealing. After 12 hours of reaction, the reaction solution was cooled to room temperature, the reaction solution was filtered, and the conversion rate and selectivity were determined by gas chromatography, and separated by silica gel column chromatography. The final calculation showed that the conversion rate of bis(3-nitrophenyl) disulfide was 48% and the selectivity was 67%; (bis(3-nitrophenyl)sulfane: brown solid 1 H NMR (400MHz, CDCl3): δ8.19-8.15(m,4H), δ7.65(d,2H), δ7.55(t,2H))

[0052] Example 16: 30 mg of Fe(II) / Fe(III)-ZSM-5 catalyst was added to the reaction tube, and then 0.2 mmol of bis(4-trifluoromethylphenyl) disulfide, 0.4 mmol of potassium hydroxide, and 1.0 mL of DMSO were added under an oxygen atmosphere. After sealing, the reaction was carried out at 120°C. After reacting for 12 hours, it was cooled to room temperature, the reaction liquid was filtered, and the conversion rate and selectivity were determined by gas chromatography, and separated by silica gel column chromatography. The final calculation showed that the conversion rate of bis(4-trifluoromethylphenyl) disulfide was 48%, and the selectivity was 72%; (bis(3-nitrophenyl)sulfane:colorlessoil 1 HNMR(400MHz, CDCl3): δ7.80-7.34(m,8H).)

[0053] Comparative Example 1: 6 mg of ferric nitrate was added to the reaction tube as a catalyst, and then 0.2 mmol of diphenyl disulfide, 0.4 mmol of potassium hydroxide and 1.0 mL of DMSO were added under an oxygen atmosphere. The tube was sealed and reacted at 120°C. After 12 hours of reaction, the tube was cooled to room temperature, the reaction solution was filtered, and the conversion selectivity was determined by gas chromatography. No conversion of diphenyl disulfide occurred and no target product was generated.

[0054] Comparative Example 2: 6 mg of ferric oxide was added to a reaction tube, and then 0.2 mmol of diphenyl disulfide, 0.4 mmol of potassium hydroxide and 1.0 mL of DMSO were added under an oxygen atmosphere. The tube was sealed and reacted at 120°C. After 12 hours of reaction, the tube was cooled to room temperature, the reaction solution was filtered, and the conversion selectivity was determined by gas chromatography. No conversion of diphenyl disulfide occurred and no target product was generated.

[0055] Comparative Example 3: 30 mg of ZSM-5 zeolite was added to a reaction tube, and then 0.2 mmol of diphenyl disulfide, 0.4 mmol of potassium hydroxide and 1.0 mL of DMSO were added under an oxygen atmosphere. The tube was sealed and reacted at 120° C. After reacting for 12 hours, the tube was cooled to room temperature, the reaction liquid was filtered, and the conversion selectivity was determined by sampling with a gas chromatograph. No conversion of diphenyl disulfide occurred, and no target product was generated.

[0056] Comparative Example 4: Preparation of trivalent Fe catalyst supported by ZSM-5 zeolite by ion exchange method: The catalyst was prepared by ion exchange method, 0.5g of solid ferric nitrate nine hydrate was weighed and dissolved in 10g of water, 1g of ZSM-5 zeolite carrier was added, ultrasonic dispersion was performed for 10min, and then ion exchange was carried out by stirring at 80°C for 3 hours. After the completion, the mixture was filtered and dried at 100°C after multiple washings, and then calcined at 550 degrees in an air flow for 3 hours. The obtained powder was marked as Fe(III) / ZSM-5-IE. 30mg of Fe(III) / ZSM-5-IE catalyst was added to the reaction tube, and then 0.2mmol of diphenyl disulfide, 0.4mmol of potassium hydroxide, and 1.0mL of DMSO were added under an oxygen atmosphere. After sealing, the reaction was carried out at 120°C. After reacting for 12 hours, the reaction was cooled to room temperature, the reaction solution was filtered, and the conversion selectivity was determined by gas chromatograph sampling, and separated by silica gel column chromatography. It was finally calculated that diphenyl disulfide was not converted and no target product was generated;

[0057] Comparative Example 5: Preparation of ZSM-5 zeolite-supported Fe catalyst by impregnation: Weigh 0.2164g of ferric nitrate nine hydrate solid and dissolve it in 1g of water, impregnate an equal volume on 1g of ZSM-5 carrier, dry it in an oven at 100℃ for 12h after natural drying, and then calcine it in an air flow at 550 degrees for 3 hours to prepare a 3% Fe / ZSM-5-D catalyst, where the valence of Fe is trivalent. 30mgFe / ZSM-5-D catalyst was added to the reaction tube, and then 0.2mmol diphenyl disulfide, 0.4mmol potassium hydroxide, and 1.0mLDMSO were added under an oxygen atmosphere. After sealing, the reaction was carried out at 120℃. After reacting for 12 hours, it was cooled to room temperature, the reaction solution was filtered, and the conversion selectivity was determined by gas chromatograph sampling, and separated by silica gel column chromatography. It was finally calculated that diphenyl disulfide was not converted and no target product was generated.

[0058] Comparative Example 6:

[0059] 0.6g of ferric nitrate solid was added to a suspension containing 1g of ZSM-5 zeolite, and then ion exchange was performed in a water bath at 70-90℃ for 4-6h. The exchanged solution was placed in an ice bath and stirred, and 0.01mol / L sodium carbonate aqueous solution was added to adjust the pH value of the system to 10; then 20mL of 0.75mol / L ascorbic acid aqueous solution was added for reduction, and the suspension was centrifuged to obtain a divalent Fe catalyst Fe(II)-ZSM-5 catalyst. 30mg of Fe(II)-ZSM-5 catalyst was added to a reaction tube, and then 0.2mmol of diphenyl disulfide, 0.4mmol of potassium hydroxide, and 1.0mL of DMSO were added under an oxygen atmosphere. After sealing, the reaction was carried out at 120℃. After 12 hours of reaction, it was cooled to room temperature, the reaction solution was filtered, and a sample was taken for gas chromatography to determine the conversion selectivity, and silica gel column chromatography was used for separation. Finally, it was calculated that diphenyl disulfide was not converted and no target product was generated.

Claims

1. A green preparation method of diphenyl sulfide and its derivatives, characterized in that: Add diphenyl disulfide and its derivatives into a reaction container, add Fe(II) / Fe(III)-ZSM-5 catalyst, then add alkali and organic solvent, heat to react in an oxidizing atmosphere and sealed conditions, cool to room temperature after the reaction, filter the reaction solution to remove the catalyst, and obtain diphenyl sulfide and its derivatives after silica gel column chromatography; ； R is independently selected from H, methyl, ethyl, methoxy, fluorine, chlorine, bromine, nitro, trifluoromethyl; The preparation method of the Fe(II) / Fe(III)-ZSM-5 catalyst is as follows: adding solid ferric nitrate to a suspension containing ZSM-5 zeolite, then performing ion exchange in a water bath at 70-90°C for 4-6 hours, placing the exchanged solution in an ice bath for stirring, and adjusting the pH value of the system to 9-11; adding ascorbic acid solution for reduction, centrifuging the suspension, and drying to obtain a catalyst in which divalent Fe and trivalent Fe coexist, which is calculated as Fe(II) / Fe(III)-ZSM-5 catalyst; the ratio of the mass of iron in the ferric nitrate to the mass of the ZSM-5 zeolite is 0.04-0.1; the concentration of the ascorbic acid aqueous solution is 0.4-0.7 mol / L, and the amount of ascorbic acid added is equivalent to 6-13 moles of iron.

2. The green preparation method of diphenyl sulfide and its derivatives according to claim 1, characterized in that: The silicon-aluminum ratio of the ZSM-5 zeolite carrier is 20~100.

3. The green preparation method of diphenyl sulfide and its derivatives according to claim 1, characterized in that: The base is a mixture of one or more of potassium hydroxide, cesium carbonate and potassium tert-butoxide; the molar ratio of diphenyl disulfide to the base is 0.4-1:

1.

4. The green preparation method of diphenyl sulfide and its derivatives according to claim 3, characterized in that: The base is potassium hydroxide.

5. The green preparation method of diphenyl sulfide and its derivatives according to claim 1, characterized in that: The organic solvent is one of dimethyl sulfoxide and N,N-dimethylformamide.

6. The green preparation method of diphenyl sulfide and its derivatives according to claim 5, characterized in that: The organic solvent is dimethyl sulfoxide.

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