1. A novel NH-sulfoxide imine compound is characterized in that the structural formula is shown as formula 1:

in the formula 1, R1 is selected from one of alkyl or aryl, and R2 is selected from one of alkyl or aryl.

2. The method for synthesizing a novel NH-sulfoximine compound according to claim 1, characterized in that a thioether compound (shown in formula 2), an ammonium source compound, an electrolyte, a low-valence iodine catalyst and a solvent are sequentially added into a three-necked flask, then an anode and a cathode of an electrode are respectively inserted into a reaction solution, a constant current of 7-10 mA is switched on, the reaction solution is stirred and reacted for 5-8 hours at 20-30 ℃, and after the reaction is finished, the NH-sulfoximine compound (shown in formula 1) is obtained by column chromatography separation, and the reaction general formula is as follows:

in the formula 2, R1 is selected from one of alkyl or aryl, and R2 is selected from one of alkyl or aryl.

3. The method for synthesizing a novel NH-sulfoximine compound according to claim 2, wherein the molar charge ratio of the thioether compound, the ammonium source compound, the electrolyte and the low-valence iodine catalyst is 1: 1.5-3: 1-2: 0.1-0.2, preferably 1: 2: 1: 0.1.

4. The method for synthesizing a novel NH-sulfoximine compound according to claim 2, wherein the ammonium source compound is ammonium acetate.

5. The method for synthesizing a novel NH-sulfoximine compound according to claim 2, wherein the low-valence iodine catalyst is one of para-iodoaniline and para-iodoanisole.

6. The method for synthesizing a novel NH-sulfoximine compound according to claim 2, wherein the electrolyte is one of tetrabutylammonium hexafluorophosphate and tetrabutylammonium acetate, and the concentration of the electrolyte in the reaction system is 0.1 to 0.3mol/L, preferably 0.2 mol/L.

7. The method for synthesizing a novel NH-sulfoximine compound according to claim 2, wherein the solvent is a mixture of hexafluoroisopropanol and methanol at a volume ratio of 1: 1; or the solvent is a mixed solution of tetrahydrofuran and methanol, and the volume ratio of the tetrahydrofuran to the methanol is 1: 1.

8. The method for synthesizing a novel NH-sulfoximine compound according to claim 2, wherein the anode is a graphite electrode and the cathode is a platinum electrode.

Background

NH-sulfoximine is one of sulfone nitrogen heterocyclic compounds, the skeleton of which has unique structure and properties, and the skeleton is widely applied to drug molecules, such as suloxifen (shown as a in figure 1) and Ru31156 (shown as b in figure 1) (RU 31156.Arch. int. Pharmacokyn. Ther,1978,231(2): 328-339.); the drug BAY 1000394 for treating cancer has entered the clinical stage (as shown in c of fig. 1) (mol. cancer. ther.,2012,11(10): 2265. su. 2573.); L-Buthionine Sulfoximine (BSO) is able to restore the capacity of tumor cells to become sensitive to Melphalan (shown in d of FIG. 1) (J.Bio.chem.,1979,254(25):1205-1209), L-methionine sulfoximine has a catalytic effect on the biosynthesis of glutathione (shown in e of FIG. 1) (R.Proc.Soc.Lond.B,1950,137(888): 402-17.); the vitamin D3 analogue has an inhibitory effect on cytochrome P450C24 (shown as f in figure 1) (J.Med.chem.,2004,47(27): 6854-6863). Therefore, the synthesis of the NH-sulfoxide imine compound has very important medicinal research value.

At present, known reports are methods for directly synthesizing NH-sulfoximine compounds by adopting sulfides under the condition of no metal catalyst. In 2017, Luisi and Bull achieved highly chemoselective N-and O-group transfer of thioethers to sulfides in methanol solvent (shown in a of FIG. 2) by using excess diacetoxyiodobenzene as oxidant, 2 equivalents of ammonium carbamate as nitrogen source, 25 ℃ (chem. Commun.,2017,53(2): 348-351); in the same year, the Li project group reports that direct thioether synthesis of sulfoximine compounds (shown in b of fig. 2) is realized by using 2.3 equivalents of diacetoxyiodobenzene as a reaction catalyst to provide a large amount of high-valent iodine reagent, 1.5 equivalents of ammonium carbonate to provide a nitrogen source, and methanol as a solvent (chemistry select, 2017,2(4): 1620-; in 2018, the Reboul group used thioether as a substrate raw material, 2.1 equivalents of diacetyloxyiodobenzene as a reaction catalyst, 1.5 equivalents of ammonium carbamate as a nitrogen source, and methanol as a solvent to synthesize the NH-sulfoximine compound (as shown in c of fig. 2) in one step (chem. eur. j.,2018,24(64): 17006-.

The methods for directly synthesizing the NH-sulfoximine compounds from the thioether all need a large amount of excessive high-valence iodine reagent, and because the solubility of high-valence iodine in an organic solvent is very high, the existing treatment method generally needs to carry out chromatographic column separation on reaction mixed liquid after the reaction is finished, so that the method not only causes difficulty in product separation and recycling of iodobenzene, but also consumes a large amount of organic solvent, and is not environment-friendly. Therefore, the above-mentioned method for directly synthesizing NH-sulfoximine compounds from thioethers is greatly limited, and the preparation cost of reagents used in the reaction and treatment processes is generally high or harmful over-oxidizing agents are required, and in order to solve these problems, a new method for synthesizing NH-sulfoximine compounds must be developed.

Electrochemical is an attractive method for realizing sustainable development, and because an oxidant, a reducing agent or a metal catalyst with high toxicity is not required to be additionally added in the reaction process, less waste is generated in the reaction process, electrons can be continuously used relative to a chemical oxidant, the provided redox reagent is cleaner, the price is not high, and the redox reagent can be recycled, so that the beneficial effects are expected in the current synthetic reaction. At present, there are many electrochemical methods for aryl iodides that can generate high-valence lambda³The report of iodide shows that anodic oxidation of aryl iodide to generate high-valence iodine in situ is an environment-friendly and efficient method for synthesizing high-valence iodine reagent. However, no method for directly synthesizing NH-sulfoximine compounds by electrochemical synthesis has been reported.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provide a novel NH-sulfoxide imine compound and a synthesis method thereof, wherein the novel NH-sulfoxide imine compound expands the variety of the NH-sulfoxide imine compound and lays a foundation for the synthesis of a medicament containing an NH-sulfoxide imine skeleton; the invention discloses a synthesis method of a novel NH-sulfoximine compound, which is essentially electrochemical synthesis, namely a method for preparing the NH-sulfoximine compound by oxidizing aryl iodine by using current as a unique oxidant to generate a catalytic amount of high-valence iodine reagent in situ for catalytic reaction, wherein the high-selectivity one-pot transfer of NH-and O-is realized by a simple ammonia source and a catalytic amount of iodo aromatic hydrocarbon; the high-efficiency electrochemical synthesis method can directly synthesize and obtain the NH-sulfoxide imine compound from the easily obtained sulfide, and the yield reaches more than 80 percent; the electrochemical synthesis method has the characteristics of simple operation, convenient treatment, higher yield and the like, simultaneously avoids the use of a large amount of high-price iodine reagent, reduces the environmental pollution, meets the currently advocated green concept, and has more ecological footprint than the traditional method.

In order to achieve the above purpose, one of the technical scheme purposes of the invention is to design a novel NH-sulfoxide imine compound, the structural formula of which is shown as formula 1:

in the formula 1, R1 is selected from one of alkyl or aryl, and R2 is selected from one of alkyl or aryl.

The second technical scheme of the invention is to provide a method for synthesizing the novel NH-sulfoximine compound, which comprises the steps of sequentially adding a thioether compound (shown as a formula 2), an ammonium source compound, an electrolyte, a low-valence iodine catalyst and a solvent into a three-neck flask, respectively inserting an anode and a cathode of an electrode into a reaction solution, switching on a constant current of 7-10 mA, stirring and reacting for 5-8 hours at 20-30 ℃, and after the reaction is finished, performing column chromatography separation to obtain the NH-sulfoximine compound (shown as a formula 1), wherein the reaction general formula is as follows:

in the formula 2, R1 is selected from one of alkyl or aryl, and R2 is selected from one of alkyl or aryl.

Further preferably, the molar charge ratio of the thioether compound, the ammonium source compound, the electrolyte and the low-valence iodine catalyst is 1: 1.5-3: 1-2: 0.1-0.2, and preferably 1: 2: 1: 0.1.

Further preferably, the ammonium source compound is ammonium acetate

Further preferably, the low-valence iodine catalyst is one of p-iodoaniline and p-iodoanisole.

Further preferably, the electrolyte is one of tetrabutylammonium hexafluorophosphate and tetrabutylammonium acetate, and the concentration of the electrolyte in the reaction system is 0.1-0.3 mol/L, preferably 0.2 mol/L.

Further preferably, the solvent is a mixed solution of hexafluoroisopropanol and methanol, and the volume ratio of the hexafluoroisopropanol to the methanol is 1: 1; or the solvent is a mixed solution of tetrahydrofuran and methanol, and the volume ratio of the tetrahydrofuran to the methanol is 1: 1.

Further, according to a preferable technical scheme, the anode is a graphite electrode, and the cathode is a metal platinum electrode.

The invention has the advantages and beneficial effects that:

1. the novel NH-sulfoxide imine compound disclosed by the invention is a sulfone mono-nitrogen isoelectric compound, has special activity, expands the variety of the NH-sulfoxide imine compound, lays a foundation for the synthesis of a medicament containing an NH-sulfoxide imine skeleton, particularly has great research value in the fields of medicines and pesticides, and is an important intermediate for constructing a heterocyclic compound in the synthesis of the pesticides and medicines. At present, no good synthesis way and an efficient and simple synthesis method exist, so that the synthesis of the sulfoximine compound at other positions is limited in the application of the sulfoximine compound in the biological and medical fields, and the sulfoximine compound synthesized at other positions becomes a primary research object.

2. The invention discloses a synthesis method of a novel NH-sulfoximine compound, which is essentially electrochemical synthesis, namely a method for preparing the NH-sulfoximine compound by oxidizing aryl iodine by using current as a unique oxidant to generate a catalytic amount of high-valence iodine reagent in situ for catalytic reaction, wherein the high-selectivity one-pot transfer of NH-and O-is realized by a simple ammonia source and a catalytic amount of iodo aromatic hydrocarbon; the high-efficiency electrochemical synthesis method can directly synthesize and obtain the NH-sulfoxide imine compound from the easily obtained sulfide, and the yield reaches more than 80 percent; the electrochemical synthesis method has the characteristics of simple operation, convenient treatment, higher yield and the like, simultaneously avoids the use of a large amount of high-price iodine reagent, reduces the environmental pollution, meets the currently advocated green concept, and has more ecological footprint than the traditional method.

Drawings

FIG. 1 is a structural formula of a currently reported NH-sulfoximine compound;

FIG. 2 is a process for the direct synthesis of NH-sulfoximines from currently reported thioethers;

FIG. 3 is a schematic structural diagram of the novel NH-sulfoximine compound of the present invention;

FIG. 4 is a reaction scheme of the novel NH-sulfoximine compound synthesis method of the invention.

Detailed Description

The following description of the embodiments of the present invention will be made with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.

Example 1

The (S-methylsulfoximido) benzene synthesized by the synthesis method has a structure shown as 2a in figure 3, and comprises the following specific operation steps:

24.83mg (0.2mmol) of methyl phenyl sulfide, 30.84mg (0.4mmol) of ammonium acetate and 60.30mg (0.2mmol) of electrolyte tetrabutylammonium acetate are weighed and added into a clean 10mL three-neck flask in sequence; then, the iodoanisole solution was sucked up by a 100. mu.L microinjector and weighed on an analytical balance to obtain 4.683mg (0.02mmol) to be injected into the three-necked flask; 2mL of hexafluoroisopropanol and methanol are respectively taken by a 5mL measuring cylinder, poured into a 10mL beaker and uniformly mixed to obtain a mixed solvent, and then the mixed solvent is poured into the three-mouth flask; respectively connecting graphite serving as an anode and metal platinum serving as a cathode into interfaces at two sides of the three-mouth flask, connecting the three-mouth flask to a direct-current stabilized voltage power supply, connecting an electronic stirrer into a middle interface of the three-mouth flask, after the three-mouth flask is installed, turning on a power switch, keeping the current stable at 8mA, stirring for an electrolytic reaction at 25 ℃ for 6 hours, dipping a little of the mixture after the reaction into a capillary tube, dripping the mixture onto a high-efficiency thin-layer chromatography silica gel plate, placing the chromatography silica gel plate into a reagent bottle containing a small amount of petroleum ether/ethyl acetate eluent (the volume ratio of the petroleum ether to the ethyl acetate is 5:1), taking out the chromatography silica gel plate, drying, placing the chromatography silica gel plate into a dark box three-purpose ultraviolet analyzer, and when an analysis result shows that the electrolytic reaction is completed, namely, the methyl phenyl sulfide completely disappears; putting the completely reacted mixed solution on a rotary evaporator, carrying out rotary evaporation to remove the solvent, pouring the residue into saturated sodium thiosulfate aqueous solution (reducing high-valence iodine into low-valence iodine), transferring the residue into a 250mL separating funnel, extracting the residue with Dichloromethane (DCM) solvent for three times, and pouring 20mL of DCM for each time; putting the lower layer liquid into a 200mL beaker, pouring a proper amount of anhydrous sodium sulfate for drying, filtering by using a funnel to obtain a clean solution, transferring the solution into a 100mL round-bottom flask, carrying out reduced pressure distillation on a rotary evaporator, and obtaining dry powder after the solvent is completely evaporated; adding a proper amount of chromatographic silica gel into the dried powder, adding a small amount of Dichloromethane (DCM) for dissolution, removing the solvent through rotary evaporation, and taking out a little sample for sample reservation when the sample is in a dry state as the added chromatographic silica gel; after the chromatographic column is fixed, putting the mixed solution of the chromatographic silica gel and the petroleum ether into the chromatographic column, and lightly beating the chromatographic silica gel and the petroleum ether by using an aurilave to compact the filler; finally, slowly pouring the mixed sample powder above a chromatographic column, separating a large amount of impurities by using a small amount of petroleum ether solution, separating and purifying by using petroleum ether/ethyl acetate eluent (the volume ratio of the petroleum ether to the ethyl acetate is 5:1), analyzing the obtained solution by using a Thin Layer Chromatography (TLC) to obtain eluent containing a target compound, and distilling the eluent containing the target compound under reduced pressure to obtain dry pure (S-methyl sulfoxide imino) benzene with the mass of 26.2mg, the yield of 84% (calculated by methyl phenyl sulfide), and the nuclear magnetic detection purity of more than 95%, wherein the nuclear magnetic data are as follows:

¹H NMR(400MHz,Chloroform-d)δ7.97–7.90(m,2H),7.58–7.52(m,1H),7.51–7.44(m,2H),3.04(s,3H),2.92(s,1H).¹³C NMR(125MHz,CDCl₃)δ143.32,133.07,129.25,127.63,46.05.HRMS(ESI):calcd.for C₇H₁₀NOS([M+H]⁺)156.0483,found 156.0490.

example 2

The structure of the benzyl (imino) (naphthalene-2-yl) -16-sulfoketone synthesized by the synthesis method is shown as 2p in figure 3, and the specific operation steps are as follows:

weighed 50.07mg (0.2mmol) of benzyl (naphthalen-2-yl) sulfane, 30.84mg (0.4mmol) of ammonium acetate, and 60.30mg (0.2mmol) of electrolyte tetrabutylammonium acetate were sequentially added to a clean 10mL three-necked flask; then, the iodoanisole solution was sucked up by a 100. mu.L microinjector and weighed on an analytical balance to obtain 4.683mg (0.02mmol) to be injected into the three-necked flask; 2mL of tetrahydrofuran and methanol are respectively taken by a 5mL measuring cylinder, poured into a 10mL beaker and uniformly mixed to obtain a mixed solvent, and then the mixed solvent is poured into the three-mouth flask; respectively connecting graphite serving as an anode and metal platinum serving as a cathode into interfaces at two sides of the three-mouth flask, connecting the three-mouth flask to a direct-current stabilized voltage power supply, connecting an electronic stirrer into a middle interface of the three-mouth flask, after the three-mouth flask is installed, turning on a power switch, keeping the current stable at 8mA, stirring for an electrolytic reaction at 25 ℃ for 6 hours, dipping a little of the mixture after the reaction into a capillary tube, dripping the mixture onto a high-efficiency thin-layer chromatography silica gel plate, placing the chromatography silica gel plate into a reagent bottle containing a small amount of petroleum ether/ethyl acetate eluent (the volume ratio of the petroleum ether to the ethyl acetate is 5:1), taking out the chromatography silica gel plate, drying, placing the chromatography silica gel plate into a dark box three-purpose ultraviolet analyzer, and when an analysis result shows that the electrolytic reaction is completed, namely, the methyl phenyl sulfide completely disappears; putting the completely reacted mixed solution on a rotary evaporator, carrying out rotary evaporation to remove the solvent, pouring the residue into saturated sodium thiosulfate aqueous solution (reducing high-valence iodine into low-valence iodine), transferring the residue into a 250mL separating funnel, extracting the residue with Dichloromethane (DCM) solvent for three times, and pouring 20mL of DCM for each time; putting the lower layer liquid into a 200mL beaker, pouring a proper amount of anhydrous sodium sulfate for drying, filtering by using a funnel to obtain a clean solution, transferring the solution into a 100mL round-bottom flask, carrying out reduced pressure distillation on a rotary evaporator, and obtaining dry powder after the solvent is completely evaporated; adding a proper amount of chromatographic silica gel into the dried powder, adding a small amount of Dichloromethane (DCM) for dissolution, removing the solvent through rotary evaporation, and taking out a little sample for sample reservation when the sample is in a dry state as the added chromatographic silica gel; after a chromatographic column is fixed, mixed chromatographic silica gel and petroleum ether are put into the chromatographic column, an aurilave is used for beating lightly to compact the filler, finally, mixed sample powder is slowly poured above the chromatographic column, then a small amount of petroleum ether solution is used for separating a large amount of impurities, then petroleum ether/ethyl acetate eluent (the volume ratio of the petroleum ether to the ethyl acetate eluent is 5:1) is used for separation and purification, the obtained solution is analyzed by Thin Layer Chromatography (TLC) to obtain eluent containing a target compound, and the eluent containing the target compound is subjected to reduced pressure distillation to obtain dry pure benzyl (imino) (naphthalene-2-yl) -16-sulfoketone, the mass of the dry pure benzyl (imino) (naphthalene-2-yl) -16-sulfoketone is 45.58mg, the yield is 81 percent (calculated by benzyl (naphthalene-2-yl) sulfane), and the nuclear magnetic data are as follows:

¹H NMR(400MHz,Chloroform-d)δ8.26(d,J＝1.9Hz,1H),7.83(ddd,J＝7.9,4.7,1.9Hz,3H),7.67(dd,J＝8.7,1.9Hz,1H),7.58(ddd,J＝8.2,6.8,1.3Hz,1H),7.52(ddd,J＝8.2,6.9,1.3Hz,1H),7.28–7.22(m,1H),7.21–7.14(m,3H),7.08–7.02(m,2H),4.45–4.31(m,2H),2.45(s,1H).¹³C NMR(126MHz,CDCl₃)δ135.04,132.11,131.09,130.53,129.34,129.02,128.99,128.81,128.50,127.85,127.44,123.72,64.58.HRMS(ESI):calcd.for C₁₇H₁₅NOS([M+H]⁺):282.0953,found 282.0966.

similarly, the synthesis method of the novel NH-sulfoximine compounds can be used for preparing NH-sulfoximine compounds shown as 2 b-2 o and 2 q-2 v in figure 3, and the yield of the NH-sulfoximine compounds is over 80 percent.

The reaction mechanism in example 1 is as follows:

as shown in the attached figure 4, iodoarene A generates a high-valence iodine catalyst B (phenyl iodide (III) diacetate) in situ in anodic oxidation by constant current electrolysis in hexafluoroisopropanol rich in acetate, and the phenyl iodide (III) diacetate is directly mixed with NH₃Reacting to obtain a key nitrene intermediate C; then, the nitrene intermediate C is captured by a thioether compound (compound 1) to react to obtain a sulfilimine intermediate D, the sulfilimine intermediate D is subjected to nucleophilic attack through acetate anions or methanol to obtain a sulfilitrile intermediate E, iodoarene A is regenerated, and the sulfilitrile intermediate E is attacked by MeOH to obtain an NH-sulfoximine compound (compound 2).

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the technical principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.