O,o'-monothiocarbonic acid ester compound and method for preparing the same

Abstract

This invention provides an O,O'-monothiocarbonate compound and its preparation method, belonging to the field of organic chemical synthesis technology. This invention discloses a multi-component reaction of a silicon ether, elemental sulfur, and a difluorocarbene reagent under the action of an organic base to synthesize O,O'-monothiocarbonate compounds. Furthermore, the preparation method disclosed in this invention uses readily available and commercially available reactants, avoiding the use of hazardous and scarce reagents. The reaction conditions disclosed in this invention are mild, easy to operate, and yield a high quantity of O,O'-monothiocarbonates.

Description

Technical Field

[0001] This invention relates to the field of organic chemical synthesis technology, and in particular to an O,O′-monothiocarbonate compound and its preparation method. Background Technology

[0002] O,O′-monothiocarbonates, characterized by their -OC(=S)O- structural units, are a class of versatile compounds with important applications in organic synthesis and materials science. Their unique reactivity stems from the varying electrophilicity of carbon atoms and the different nucleophilicity and leaving group capabilities of sulfur atoms. This unique property makes them valuable intermediates for constructing various sulfur-containing molecules (including thioethers, thioesters, and cyclic thiocarbonates). Furthermore, due to the strong coordination ability of sulfur atoms with various metal ions, they have significant applications in constructing organometallic complexes.

[0003] Currently, the common methods for synthesizing O,O′-monothiocarbonates include: 1. reacting phenolic monomers with phosgene in an alkaline solution; 2. reacting thioacyl chlorides with bisphenol monomers; 3. reacting thiocarbonyl imidazoles with bisphenols, etc. These methods suffer from drawbacks such as the high toxicity of the organic reagents used, difficulty in storage, and high cost. Elemental sulfur, as a byproduct of the petrochemical industry, has advantages such as abundant reserves, low price, easy storage, and non-corrosiveness. Using it directly as the sulfur source for synthesizing O,O′-monothiocarbonates not only avoids the use of highly toxic phosgene but also improves the utilization rate of elemental sulfur. Therefore, developing simple and efficient organic reactions for synthesizing O,O′-monothiocarbonates based on elemental sulfur, using non-toxic or low-toxic reagents, has significant scientific and industrial value. Summary of the Invention

[0004] The purpose of this invention is to provide an O,O′-monothiocarbonate compound and its preparation method, in order to solve the technical problems of high toxicity and high cost of raw materials in the current synthesis of O,O′-monothiocarbonate.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0006] This invention provides a method for preparing O,O′-monothiocarbonate compounds, comprising the following steps:

[0007] Silyl ether, elemental sulfur, and difluorocarbene reagent were reacted in the presence of an organic base, and the reaction solution was extracted and subjected to column chromatography to obtain O,O′-monothiocarbonate compounds.

[0008] The silyl ether is selected from any of the following compounds:

[0009]

[0010] Where k is an integer from 2 to 20, R 1 It is an alkyl or aryl substituent.

[0011] Furthermore, the molar ratio of the silyl ether, elemental sulfur, difluorocarbene reagent, and organic base is 2:2-6:1-3:0.05-0.5.

[0012] Furthermore, the reaction is carried out in a protective atmosphere, which includes nitrogen and / or argon.

[0013] Furthermore, the reaction is carried out in an organic solvent comprising one or more of N,N-dimethylformamide, N,N-dimethylacetamide, tetrahydrofuran, dichloromethane, and trichloromethane;

[0014] The concentration of the silyl ether in the reaction system is 0.2–2 mol / L.

[0015] Furthermore, the reaction temperature is 40–100°C, and the reaction time is 0.1–3 h.

[0016] Furthermore, the organic base is selected from one or more of the following compounds:

[0017]

[0018] Furthermore, the difluorocarbene reagent contains Ph3P. + CF2COO - One of BrCF2COONa and ClCF2COONa.

[0019] This invention provides an O,O′-monothiocarbonate compound, wherein the O,O′-monothiocarbonate compound has one of the following general structural formulas:

[0020]

[0021] Where R 2 R 3 R 4 Independently, they are alkyl or aryl.

[0022] The beneficial effects of this invention are:

[0023] (1) The reaction raw materials used in the preparation method of the present invention are readily available and the preparation is simple;

[0024] (2) The reaction conditions for synthesizing monothiocarbonates in this invention are mild, the process is simple, and the efficiency is high.

[0025] (3) The preparation method of the present invention has strong group tolerance and can introduce a variety of functional groups into the monomer. Attached Figure Description

[0026] Figure 1 The structure characterization NMR spectrum of O,O′-monothiocarbonate 3a;

[0027] Figure 2 High-resolution mass spectrum of O,O′-monothiocarbonate 3a;

[0028] Figure 3 For O,O′-monothiocarbonate 3b 1 H NMR spectrum;

[0029] Figure 4 For O,O′-monothiocarbonate 3b 13 C NMR spectrum;

[0030] Figure 5 High-resolution mass spectrum of O,O′-monothiocarbonate 3a;

[0031] Figure 6 For O,O′-monothiocarbonate 3c 1 H NMR spectrum;

[0032] Figure 7 For O,O′-monothiocarbonate 3c 13 C NMR spectrum;

[0033] Figure 8 The high-resolution mass spectrum of O,O′-monothiocarbonate 3c. Detailed Implementation

[0034] This invention provides a method for preparing O,O′-monothiocarbonate compounds, comprising the following steps:

[0035] Silyl ether, elemental sulfur, and difluorocarbene reagent were reacted in the presence of an organic base, and the reaction solution was extracted and subjected to column chromatography to obtain O,O′-monothiocarbonate compounds.

[0036] The silyl ether is selected from any of the following compounds:

[0037]

[0038] Where k is an integer from 2 to 20, R 1 It is an alkyl or aryl substituent.

[0039] In this invention, k is preferably 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20.

[0040] In this invention, elemental sulfur is sublimed sulfur.

[0041] In this invention, the molar ratio of the silyl ether, elemental sulfur, difluorocarbene reagent and organic base is 2:2-6:1-3:0.05-0.5, preferably 2:2.6-5.5:1.3-2.5:0.1-0.4, and more preferably 2:3.0:1.5:0.2.

[0042] In this invention, the reaction is carried out in a protective atmosphere, which includes nitrogen and / or argon, preferably nitrogen.

[0043] In this invention, the reaction is carried out in an organic solvent containing one or more of N,N-dimethylformamide, N,N-dimethylacetamide, tetrahydrofuran, dichloromethane, and chloroform, preferably one or more of N,N-dimethylacetamide, tetrahydrofuran, and dichloromethane, and more preferably N,N-dimethylacetamide.

[0044] In this invention, the concentration of the silyl ether in the reaction system is 0.2 to 2 mol / L, preferably 0.25 to 0.5 mol / L, and more preferably 0.5 mol / L.

[0045] In this invention, the reaction temperature is 40–100°C, preferably 50–90°C, and more preferably 60–80°C; the reaction time is 0.1–3 h, preferably 0.5–2 h, and more preferably 1–1.5 h.

[0046] In this invention, the reaction is carried out under stirring at a speed of 200-600 rpm, preferably 300-500 rpm, and more preferably 400 rpm.

[0047] In this invention, the organic base is preferably one or more of the following compounds:

[0048] MTBD is further preferred.

[0049] In this invention, the difluorocarbene reagent is preferably Ph3P. + CF2COO - One of BrCF2COONa and ClCF2COONa, wherein Ph3P + CF2COO - The structural formula is:

[0050]

[0051] This invention provides an O,O′-monothiocarbonate compound, wherein the O,O′-monothiocarbonate compound has one of the following general structural formulas:

[0052]

[0053] Where R 2 R 3 R 4 Independently, they are alkyl or aryl.

[0054] In this invention, the O,O′-monothiocarbonate compound is preferably one of the following compounds:

[0055]

[0056] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0057] Example 1

[0058] An O,O′-monothiocarbonate compound, the structural formula of which is shown in 3a:

[0059]

[0060] The O,O′-monothiocarbonate compound is prepared by direct reaction of phosphonium difluoroacetate, elemental sulfur, and disilyl ether, as shown in formula (I):

[0061]

[0062] The synthesis method of reactant 1a is referenced in Nature Chemistry 2017, 9, 1083-1088. Reactant 2 is phosphonium difluoroacetate salt, which can be purchased from the market. In this example, it was purchased from Shanghai Fluorine Technology Co., Ltd. Elemental sulfur is sublimed sulfur, which can be purchased from the market. In this example, it was purchased from Aladdin Company.

[0063] The synthesis steps of the O,O′-monothiocarbonate compound are as follows: Monomer 1a (0.50 mmol, 125 mg), reactant 2 (0.38 mmol, 137 mg), and elemental sulfur (0.75 mmol, 24 mg) were weighed in a molar ratio of 1.0:3.0:1.5 and added sequentially to a 10 mL Schlenk tube equipped with a magnetic stir bar. Under N2 protection, 1 mL of N,N-dimethylacetamide was injected, followed by 0.05 mmol of organic base MTBD. The temperature was raised to 60 °C and stirred at 300 rpm for 1 h while maintaining the temperature. After the reaction was completed, the reaction solution was cooled to room temperature, 3 mL of deionized water was added, and the mixture was extracted with ethyl acetate. The organic phases were combined and dehydrated by anhydrous sodium sulfate. The mixture was filtered, and the solvent was removed from the filtrate by rotary evaporation to obtain the crude product. The crude product was purified by column chromatography to obtain a white solid with a yield of 87%. 1H NMR (600MHz, d6-DMSO) δ7.36 (d, J = 8.5 Hz, 4H), 7.22 (d, J = 8.6 Hz, 4H), 2.93 (m, 2H), 1.21 (d, J = 6.9 Hz, 12H). 13 C NMR(150MHz,d6-DMSO)δ193.64,152.32,132.79,124.20,119.52.HRMS[M+Na + Calcd. 337.1233, Found 337.1243. See NMR spectrum. Figure 1 High-resolution mass spectrometry can be seen Figure 2 .

[0064] Example 2

[0065] An O,O′-monothiocarbonate compound, the structural formula of which is shown in 3b:

[0066]

[0067] The O,O′-monothiocarbonate compound is prepared by direct reaction of phosphonium difluoroacetate, elemental sulfur, and disilyl ether, as shown in formula (II):

[0068]

[0069] The synthesis steps of the O,O′-monothiocarbonate compound are as follows: Monomer 1b (0.50 mmol, 110 mg), reactant 2 (0.38 mmol, 137 mg), and elemental sulfur (0.75 mmol, 24 mg) were weighed in a molar ratio of 1.0:3.0:1.5 and added sequentially to a 10 mL Schlenk tube equipped with a magnetic stir bar. 1 mL of N,N-dimethylacetamide was injected under N2 protection, followed by 0.05 mmol of the organic base MTBD. The mixture was heated to 60 °C and stirred at 300 rpm for 1 h while maintaining the temperature constant. After the reaction was completed, the reaction solution was cooled to room temperature, 3 mL of deionized water was added, and the mixture was extracted with ethyl acetate. The organic phases were combined and dehydrated using anhydrous sodium sulfate. The mixture was filtered, and the solvent was removed from the filtrate by rotary evaporation to obtain the crude product. The crude product was purified by column chromatography to obtain a white solid with a yield of 93%. The NMR spectrum is shown below. Figure 3 and Figure 4 High-resolution mass spectrometry can be seen Figure 5 . 1 H NMR (600MHz, d6-DMSO) δ7.38(t,J=7.8Hz,2H),7.20-7.16(m,2H),7.14(t,J=2.1Hz,2H),7.12-7.08(m,2H),2.35(s,6H). 13CNMR(150MHz,d6-DMSO)δ194.26,153.17,139.79,129.61,127.60,122.09,118.76,20.82.HRMS[M+Na + ]Calcd.281.0607Found 281.0610.

[0070] Example 3

[0071] An O,O′-monothiocarbonate compound, the structural formula of which is shown in 3c:

[0072]

[0073] The O,O′-monothiocarbonate compound is prepared by direct reaction of phosphonium difluoroacetate, elemental sulfur, and disilyl ether, as shown in formula (III):

[0074]

[0075] The synthesis steps of the O,O′-monothiocarbonate compound are as follows: Monomer 1c (0.50 mmol, 104 mg), reactant 2 (0.38 mmol, 137 mg), and elemental sulfur (0.75 mmol, 24 mg) were weighed in a molar ratio of 1.0:3.0:1.5 and added sequentially to a 10 mL Schlenk tube equipped with a magnetic stir bar. 1 mL of N,N-dimethylacetamide was injected under N2 protection, followed by 0.05 mmol of the organic base MTBD. The mixture was heated to 60 °C and stirred at 300 rpm for 1 h while maintaining the temperature constant. After the reaction was completed, the reaction solution was cooled to room temperature, 3 mL of deionized water was added, and the mixture was extracted with ethyl acetate. The combined organic phases were dehydrated using anhydrous sodium sulfate, filtered, and the solvent was removed by rotary evaporation of the filtrate to obtain the crude product. The crude product was purified by column chromatography to obtain a white solid with a yield of 76%. The NMR spectrum is shown below. Figure 6 and Figure 7 High-resolution mass spectrometry can be seen Figure 8 . 1 H NMR(600MHz,d6-DMSO)δ7.62-7.42(m,4H),7.40-7.27(m,6H). 13 C NMR(150MHz,d6-DMSO)δ194.21,153.16,129.87,126.94,121.76.HRMS[M+Na + ]Calcd.253.0294,Found 253.0291.

[0076] Application example: O,O′-monothiocarbonate compounds, as important organic synthesis intermediates, are often used in the following organic reactions, such as... Reactions, Chugaev elimination reaction, Corey–Winter olefin synthesis reaction, Barton–McCombie dehydroxylation reaction, and free radical substitution reaction.

[0077] As can be seen from the above embodiments, this invention provides an O,O′-monothiocarbonate compound and its preparation method. This invention discloses a multi-component reaction of a silicon ether, elemental sulfur, and a difluorocarbene reagent under the action of an organic base to synthesize O,O′-monothiocarbonate compounds. Furthermore, the preparation method disclosed in this invention uses readily available and commercially available reactants, avoiding the use of hazardous and scarce reagents. The reaction conditions disclosed in this invention are mild, easy to operate, and yield a high quantity of O,O′-monothiocarbonates.

[0078] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing an O,O'-monothiocarbonate compound, characterized in that, Includes the following steps: Silyl ether, elemental sulfur, and difluorocarbene reagent were reacted in the presence of an organic base, and the reaction solution was extracted and subjected to column chromatography to obtain O,O'-monothiocarbonate compounds. The silyl ether is selected from any of the following compounds: Where k is an integer from 2 to 20.

2. The method for preparing O,O'-monothiocarbonate compounds according to claim 1, characterized in that, The molar ratio of the silyl ether, elemental sulfur, difluorocarbene reagent and organic base is 2:2-6:1-3:0.05-0.

5.

3. The method for preparing O,O'-monothiocarbonate compounds according to claim 1, characterized in that, The reaction is carried out in a protective atmosphere, which includes nitrogen and / or argon.

4. The method for preparing O,O'-monothiocarbonate compounds according to claim 1 or 3, characterized in that, The reaction is carried out in an organic solvent containing one or more of N,N-dimethylformamide, N,N-dimethylacetamide, tetrahydrofuran, dichloromethane, and trichloromethane. The concentration of the silyl ether in the reaction system is 0.2–2 mol / L.

5. The method for preparing O,O'-monothiocarbonate compounds according to any one of claims 1 to 3, characterized in that, The reaction temperature is 40–100°C, and the reaction time is 0.1–3 h.

6. The method for preparing O,O'-monothiocarbonate compounds according to claim 5, characterized in that, The organic base is selected from one or more of the following compounds:

7. The method for preparing O,O'-monothiocarbonate compounds according to claim 1, 2, or 6, characterized in that, The difluorocarbene reagent contains Ph3P + CF2COO - One of BrCF2COONa and ClCF2COONa.

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