1. A carbazole and dibenzothiophene compound is characterized in that the structural formula is as follows:

wherein X ═ NTs, S; Y-Me, Cl.

2. The process for preparing carbazoles and dibenzothiophenes according to claim 1,

the synthesis steps are as follows: adding the raw materials 1 and 2 and potassium carbonate into tetrahydrofuran/n-hexane (1:2, v/v), heating to 40-60 ℃, reacting for 24-36h, and performing column chromatography separation to obtain the target compound 3.

Background

Carbazole is present in many natural products, drugs and organic functional materials, and additionally, synthetic carbazole derivatives also show potential pharmacological activities such as anticancer, antipsychotic, anti-tuberculosis and the like. Many methods for synthesizing carbazole have been reported in the literature (chem. rev.2012,112,3193-3328), such as Fisher-Borsche synthesis, Graebe-Ullmann synthesis, Cadogan cyclization, iron-mediated synthesis, and the like. However, these methods often have disadvantages such as harsh reaction conditions, complicated substrate preparation steps, and/or use of transition metals. Indole is a raw material which is easy to obtain, so that the preparation of carbazole by taking indole as a synthesis template becomes a high-efficiency and convenient strategy. In the developed method, there are still severe reaction conditions and/or disadvantages of using transition metals and the like (org. biomol. chem.2019,17, 8330-. On the other hand, dibenzothiophene compounds exist in drugs, dyes, liquid crystals, conductive polymers, and the like. Most of the methods for synthesizing dibenzothiophenes reported so far require multi-step synthesis of raw materials (chem. -eur. j 2014,20, 7258-7261).

Based on the important application of carbazole compounds and dibenzothiophene compounds and the defects of the existing synthetic method, in order to efficiently synthesize the compounds, the invention provides a general synthetic method of the carbazole compounds and the dibenzothiophene compounds.

Disclosure of Invention

The invention takes potassium carbonate as alkali, takes tetrahydrofuran/n-hexane (1:2, v/v) as solvent, and synthesizes carbazole compounds and dibenzothiophene compounds under the protection of nitrogen, thereby providing an efficient synthesis method for the carbazole compounds and the dibenzothiophene compounds.

According to the invention, the reaction of the carbazole compound and the dibenzothiophene compound comprises the following main synthesis steps: synthesizing a target compound by taking a 3-nitroindole compound or 3-nitrobenzothiophene and alkylene azlactone as raw materials and taking tetrahydrofuran/n-hexane (1:2, v/v) as a solvent under the action of potassium carbonate under the protection of nitrogen, wherein the synthesis reaction formula of the target compound is as follows:

the specific product structure is as follows:

in the reaction, the feeding molar ratio of 3-nitroindole compounds or 3-nitrobenzothiophene 1 to (Z) -2-phenyl-4- (1-phenylethylene) oxazole-5 (4H) -ketone 2a is 1:1.2, the feeding molar ratio of potassium carbonate to 3-nitroindole compounds or 3-nitrobenzothiophene 1 is 2:1, tetrahydrofuran/n-hexane (1:2, v/v) is used as a solvent, the reaction time is 24-36H under the protection of nitrogen, and the reaction temperature is 40-60 ℃.

And after the reaction is finished, cooling to room temperature, carrying out post-treatment on the reaction system, and purifying by column chromatography to obtain the target product.

The invention has the advantages that: the raw materials are easy to prepare, the reaction conditions are mild, the operation is simple and convenient, and a metal catalyst is not required.

Detailed Description

The present invention will be further described with reference to the following examples, which are only for illustrating the technical solutions of the present invention and are not to be construed as limiting the present invention.

Example 1

To a 25mL dry reaction tube, 1a (0.20mmol), 2a (0.24mmol,1.2equiv), tetrahydrofuran/n-hexane (1:2, v/v,4mL), and magnetite were added under nitrogen. Stirring at room temperature, and adding anhydrous K₂CO₃(0.40mmol,2.0equiv), transferred to a 60 ℃ oil bath and stirred for a further 24 h. After the reaction was completed, the reaction mixture was cooled to room temperature, diluted hydrochloric acid (1M,2mL) was added thereto, stirring was continued for several minutes, and the organic solvent was removed therefrom under reduced pressure. Adding H to the remaining mixture₂O (10mL) with CH₂Cl₂(10 mL. times.3) and the combined organic phases were extracted with anhydrous Na₂SO₄Drying, filtration, removal of the organic solvent under reduced pressure and column chromatography of the residue (DCM: PE ═ 1:1) afforded product 3a in 53% yield.

White colourSolid, 57.9mg, mp 214-.¹H NMR(400MHz,CDCl₃)δ9.85(br s,1H),8.25(d,J＝8.0Hz,1H),8.04(s,1H),7.94(br s,1H),7.63(d,J＝8.4Hz,2H),7.58-7.49(m,8H),7.38(t,J＝7.6Hz,2H),7.35(t,J＝7.8Hz,1H),7.18(d,J＝7.6Hz,1H),7.11(d,J＝8.0Hz,2H),3.02,2.28ppm.¹³C{¹H}NMR(100MHz,CDCl₃)δ167.0,145.9,144.9,139.1,138.3,138.1,135.4,134.7,134.4,132.5,132.2,129.7,129.6,129.2,128.9,128.5,127.5,127.2,126.8,126.5,125.1,119.6,118.3,112.3,108.3,25.1,21.5ppm.HRMS(ESI-TOF)m/z:[M+Na]⁺ Calcd for C₃₃H₂₆N₂NaO₄S⁺ 569.1505；Found 569.1515.

Example 2

To a 25mL dry reaction tube, 1b (0.20mmol), 2a (0.24mmol,1.2equiv), tetrahydrofuran/n-hexane (1:2, v/v,4mL), and magnetite were added under nitrogen. Stirring at room temperature, and adding anhydrous K₂CO₃(0.40mmol,2.0equiv), transferred to a 40 ℃ oil bath and stirred for a further 24 h. After the reaction was completed, the reaction mixture was cooled to room temperature, diluted hydrochloric acid (1M,2mL) was added thereto, stirring was continued for several minutes, and the organic solvent was removed therefrom under reduced pressure. Adding H to the remaining mixture₂O (10mL) with CH₂Cl₂(10 mL. times.3) and the combined organic phases were extracted with anhydrous Na₂SO₄Drying, filtration, removal of the organic solvent under reduced pressure and column chromatography of the residue (DCM: PE ═ 1:1) afforded product 3b in 92% yield.

White solid, 100.5mg, mp 245-.¹H NMR(400MHz,CDCl₃)δ10.34(br s,1H),8.24(s,1H),8.17(d,J＝8.4Hz,1H),7.98(br s,1H),7.88(s,1H),7.66(d,J＝8.4Hz,2H),7.60-7.50(m,8H),7.42-7.38(m,2H),7.29(dd,J＝1.2,8.8Hz,1H),7.11(d,J＝8.0Hz,2H),2.51,2.28ppm.¹³C{¹H}NMR(100MHz,CDCl₃)δ166.7,146.4,144.8,138.2,137.8,136.3,134.9,134.7,133.9,132.5,132.3,129.9,129.6,129.2,128.9,128.5,127.9,127.2,126.4,126.3,123.8,118.7,117.4,114.2,108.3,21.5,21.4ppm.HRMS(ESI-TOF)m/z:[M+Na]⁺Calcd for C₃₃H₂₆N₂NaO₄S⁺ 569.1505；Found 569.1508.

Example 3

To a 25mL dry reaction tube, 1c (0.20mmol), 2a (0.24mmol,1.2equiv), tetrahydrofuran/n-hexane (1:2, v/v,4mL), and magnetite were added under nitrogen. Stirring at room temperature, and adding anhydrous K₂CO₃(0.40mmol,2.0equiv), transferred to a 40 ℃ oil bath and stirred for a further 24 h. After the reaction was completed, the reaction mixture was cooled to room temperature, diluted hydrochloric acid (1M,2mL) was added thereto, stirring was continued for several minutes, and the organic solvent was removed therefrom under reduced pressure. Adding H to the remaining mixture₂O (10mL) with CH₂Cl₂(10 mL. times.3) and the combined organic phases were extracted with anhydrous Na₂SO₄Drying, filtration, removal of the organic solvent under reduced pressure and column chromatography of the residue (DCM: PE ═ 1:1) afforded product 3c in 43% yield.

White solid, 43% yield, mp 232-.¹H NMR(400MHz,CDCl₃)δ10.42(br s,1H),8.34-8.32(m,2H),7.99(br s,1H),7.85(s,1H),7.69(d,J＝8.4Hz,2H),7.60-7.48(m,8H),7.41-7.36(m,3H),7.16(d,J＝8.0Hz,2H),2.31ppm.¹³C{¹H}NMR(100MHz,CDCl₃)δ166.8,146.4,145.3,138.6,138.0,137.6,135.4,134.5,132.6,132.5,132.1,129.8,129.8,129.3,128.9,128.7,127.2,126.5,124.7,124.6,124.4,118.9,116.6,114.7,108.1,21.5ppm.HRMS(ESI-TOF)m/z:[M+Na]⁺ Calcd for C₃₂H₂₃ ³⁵ClN₂NaO₄S 589.0959；Found 589.0964.

Example 4

Protection by nitrogenNext, 1d (0.20mmol), 2a (0.24mmol,1.2equiv), tetrahydrofuran/n-hexane (1:2, v/v,4mL), and magneton were added to a 25mL dry reaction tube. Stirring at room temperature, and adding anhydrous K₂CO₃(0.40mmol,2.0equiv), transferred to a 40 ℃ oil bath and stirred for a further 36 h. After the reaction was completed, the reaction mixture was cooled to room temperature, diluted hydrochloric acid (1M,2mL) was added thereto, stirring was continued for several minutes, and the organic solvent was removed therefrom under reduced pressure. Adding H to the remaining mixture₂O (10mL) with CH₂Cl₂(10 mL. times.3) and the combined organic phases were extracted with anhydrous Na₂SO₄Drying, filtration, removal of the organic solvent under reduced pressure and column chromatography (DCM: PE ═ 1:1) of the residue afforded product 3d in 31% yield.

White solid, 26.1mg, mp 236-.¹H NMR(400MHz,CDCl₃)δ10.48(br s,1H),8.60(d,J＝7.2Hz,1H),8.10(d,J＝8.4Hz,1H),8.02(br s,1H),7.87(s,1H),7.56-7.44(m,10H),7.40(t,J＝7.8Hz,2H),2.98(s,3H),2.87(s,3H)ppm.¹³C{¹H}NMR(100MHz,CDCl₃)δ170.1,166.7,146.4,138.4,138.2,137.9,134.9,132.5,132.4,129.9,129.2,128.9,128.5,127.3,126.5,126.2,123.9,118.6,116.9,115.2,109.8,27.8ppm.HRMS(ESI-TOF)m/z:[M+Na]⁺ Calcd for C₂₇H₂₀N₂NaO₃ ⁺ 443.1366；Found 443.1369.

Example 5

To a 25mL dry reaction tube, 1e (0.20mmol), 2a (0.24mmol,1.2equiv), tetrahydrofuran/n-hexane (1:2, v/v,4mL), and magnetons were added under nitrogen. Stirring at room temperature, and adding anhydrous K₂CO₃(0.40mmol,2.0equiv), transferred to a 40 ℃ oil bath and stirred for a further 24 h. After the reaction was completed, the reaction mixture was cooled to room temperature, diluted hydrochloric acid (1M,2mL) was added thereto, stirring was continued for several minutes, and the organic solvent was removed therefrom under reduced pressure. Adding H to the remaining mixture₂O (10mL) with CH₂Cl₂(10 mL. times.3) extraction and combination of the organic phasesAnhydrous Na₂SO₄Drying, filtration, removal of the organic solvent under reduced pressure and column chromatography of the residue (DCM: PE ═ 1:1) afforded product 3e in 66% yield.

White solid, 63.2mg, mp 215-.¹H NMR(400MHz,CDCl₃)δ10.37(br s,1H),8.56(d,J＝7.2Hz,1H),8.23(d,J＝8.0Hz,1H),8.02(br s,1H),7.95(s,1H),7.57-7.36(m,12H),1.74(s,9H)ppm.¹³C{¹H}NMR(100MHz,CDCl₃)δ166.6,151.0,146.3,138.7,138.1,137.8,134.7,132.4,132.3,129.8,129.0,128.8,128.2,127.2,126.3,125.5,123.5,123.3,117.8,116.4,115.5,109.7,84.0,28.3ppm.HRMS(ESI-TOF)m/z:[M+Na]⁺ Calcd for C₃₀H₂₆N₂NaO₄ ⁺ 501.1785；Found 501.1789.

Example 6

To a 25mL dry reaction tube, 1f (0.20mmol), 2a (0.24mmol,1.2equiv), tetrahydrofuran/n-hexane (1:2, v/v,4mL), and magnetite were added under nitrogen. Stirring at room temperature, and adding anhydrous K₂CO₃(0.40mmol,2.0equiv), transferred to a 60 ℃ oil bath and stirred for a further 36 h. After the reaction was completed, the reaction mixture was cooled to room temperature, diluted hydrochloric acid (1M,2mL) was added thereto, stirring was continued for several minutes, and the organic solvent was removed therefrom under reduced pressure. Adding H to the remaining mixture₂O (10mL) with CH₂Cl₂(10 mL. times.3) and the combined organic phases were extracted with anhydrous Na₂SO₄Drying, filtration, removal of the organic solvent under reduced pressure and column chromatography (DCM: PE ═ 1:1) of the residue afforded 3f in 40% yield.

White solid, 31.3mg, mp 225-.¹H NMR(400MHz,CDCl₃)δ10.44(br s,1H),8.94(d,J＝8.0Hz,1H),8.01(br s,1H),7.84(d,J＝7.2Hz,1H)7.57-7.44(m,10H),7.41-7.38(m,3H).¹³C{¹H}NMR(100MHz,CDCl₃)δ166.9,148.4,139.0,138.8,137.9,135.8,134.8,132.5,132.4,129.7,129.2,128.9,128.5,127.3,126.5,126.0,124.6,122.0,119.4,115.3ppm.HRMS(ESI-TOF)m/z:[M+Na]⁺ Calcd for C₂₅H₁₇NNaO₂S⁺ 418.0872；Found 418.0878.

It should be noted that the above summary and the detailed description are intended to demonstrate the practical application of the technical solutions provided by the present invention, and should not be construed as limiting the scope of the present invention. Various modifications, equivalent substitutions, or improvements may be made by those skilled in the art within the spirit and principles of the invention. The scope of the invention is to be determined by the appended claims.