A pyridinoisocoumarin compound, a preparation method and application thereof

Abstract

The present application relates to the field of organic synthetic chemistry, and particularly relates to a pyridine and isochromenol compound and a preparation method and application thereof, the preparation method is that 7-quinoline carboxylic acid and alkyne compound are used as raw materials, an oxidizing agent, a base and a catalyst are added, reaction is carried out in an organic solvent under air condition, the reaction temperature is 80 DEG C, the reaction time is 12 h, after the reaction is completed, the reaction liquid is concentrated, and the pyridine and isochromenol compound is obtained by using column chromatography separation. The preparation method provided by the present application does not need the protection condition of inert gas, the synthesis of the pyridine and isochromenol compound can be completed by simply stirring and mixing the raw materials under air environment at room temperature, and the preparation method has the advantages of simple operation, mild reaction condition and low energy consumption, and is beneficial to large-scale preparation and production.

Description

Technical Field

[0001] This invention relates to the field of organic synthetic chemistry, specifically to a pyridoisocoumarin compound, its preparation method, and its application. Background Technology

[0002] The information disclosed in the background section of this invention is intended only to enhance the understanding of the overall background of the invention and is not necessarily to be regarded as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] Isocromuels are a class of lactone compounds, scientifically known as 1-hydro-2-benzopyran-1-one, belonging to the benzopyranone class of compounds. They form the parent nucleus from which a wide variety of isocromuel compounds are derived. Currently, nearly 400 compounds with isocromuel structures have been extracted from nature. Isocromuels possess antibacterial, antitumor, and electroluminescent properties and are widely used in biomedical and organic light-emitting materials research fields, such as agrimonylactone, artemisinin, and cassia lactone.

[0004] Typical methods for synthesizing isocomonasin compounds include the Diels-Alder reaction and the HWE reaction to construct the isocomonasin structure. However, these methods are complex, requiring multiple steps and demanding reaction conditions. Alkyne-mediated CH activation is a simpler and more efficient method for synthesizing isocomonasin compounds. This method utilizes the unsaturation of alkynes, using them as coupling cyclization complexes to participate in the cyclization reaction, yielding isocomonasin compounds in one step.

[0005] While existing techniques have reported methods for synthesizing isocoumarin compounds involving alkynes, current research primarily utilizes benzene-based aromatic compounds as substrates. For the synthesis of isocoumarin derivatives from non-benzene aromatic compounds, such as pyrido-isocoumarins, efficient preparation processes are currently lacking. Therefore, there is an urgent need for research into new synthetic methodologies to provide novel, concise, and efficient synthetic methods for isocoumarin compounds with specific structures. Summary of the Invention

[0006] To address the shortcomings and deficiencies of the prior art, the first objective of this invention is to provide a pyridoisocoumarin compound that exhibits good electroluminescence properties.

[0007] A second objective of this invention is to provide a method for preparing the above-mentioned compound, wherein the preparation method does not require an inert gas protective condition and the compound can be synthesized at room temperature.

[0008] A third object of the present invention is to provide applications of the above-mentioned compounds.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0010] A pyridoisocoumarin compound, the general structural formula of which is shown below:

[0011]

[0012] Wherein, R1 is phenyl, p-chlorophenyl, p-bromophenyl, p-methylphenyl, o-fluorophenyl, m-fluorophenyl, o-methoxyphenyl, or m-methoxyphenyl; R2 is the same as R1.

[0013] Furthermore, the pyridoisocoumarin compound has any one of the following structural formulas:

[0014]

[0015] The above-mentioned method for preparing pyridoisocoumarin compounds involves using 7-quinoline carboxylic acid and an alkyne compound of formula (II) as reactants, adding an oxidant, a base, and a catalyst respectively, and reacting them in an organic solvent under air conditions to obtain pyridoisocoumarin of formula (I); the reaction formula is shown below:

[0016]

[0017] The alkyne compounds are diphenylacetylene, 4,4'-dichlorodiphenylacetylene, di(4-bromophenyl)acetylene, 1,2-bis(2-fluorophenyl)acetylene, 1,2-bis(4-methylphenyl)acetylene, 1,2-bis(3-fluorophenyl)acetylene, 1,2-bis(2-methoxyphenyl)acetylene, or 1,2-bis(3-methoxyphenyl)acetylene.

[0018] Further, the molar volume ratio of the 7-quinoline carboxylic acid, alkyne compound, oxidant, base, catalyst and organic solvent is 0.1 mmol: 0.2 mmol: 0.1 mmol: 0.05 mmol: 0.005 mmol: 1 mL.

[0019] Furthermore, the reaction conditions are a temperature of 80°C and a time of 12 hours.

[0020] Furthermore, the oxidant is AgNTf2 (silver bis(trifluoromethanesulfonyl)imide).

[0021] Furthermore, the organic solvent is 1,4-dioxane.

[0022] Furthermore, the base is Pr3N (tripropylamine).

[0023] Furthermore, the catalyst is [Cp*RhCl2]2 (dichloro(pentamethylcyclopentadienyl)rhodium(III) dimer).

[0024] Furthermore, after the reaction is complete, elution and purification are required.

[0025] The above-mentioned pyridoisocoumarin compound can be used to prepare electroluminescent devices.

[0026] Furthermore, the elution was performed using petroleum ether and ethyl acetate, and the product was purified by silica gel column chromatography.

[0027] Beneficial effects

[0028] This invention provides a compound, its preparation method, and its application. Using 7-quinolinecarboxylic acid and diphenylacetylene as reactants, an oxidant, a base, and a catalyst are added respectively. The reaction is carried out in an organic solvent under air conditions to achieve the synthesis of the compound. The preparation method does not require inert gas protection and the compound is synthesized at room temperature. The preparation method has the advantages of simple operation, mild reaction conditions, and low energy consumption, which is beneficial for large-scale preparation and production. Attached Figure Description

[0029] Figure 1 The fluorescence spectrum of the compound prepared in Example 1; Figure 1 A is the absorption wavelength diagram of the compound prepared in Example 1; Figure 1 B is the emission wavelength diagram of the compound prepared in Example 1. Detailed Implementation

[0030] The following description further sets forth specific details of the invention to provide a thorough understanding of it. The terminology used in this specification is for illustrative purposes only and is not intended to limit the scope of the invention.

[0031] Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as understood by one of ordinary skill in the art. Unless otherwise specified, the pharmaceuticals or reagents used in this invention are used in accordance with the product instructions or conventional methods in the relevant field. The process of this invention is now further described with reference to the accompanying drawings and specific embodiments.

[0032] Example 1

[0033]

[0034] At room temperature, 7-quinolinecarboxylic acid 1a (0.1 mmol), diphenylacetylene 2a (0.2 mmol), [Cp*RhCl2]2 (0.005 mmol), AgNTf2 (0.1 mmol), Pr3N (0.05 mmol), and 1,4-dioxane (1 mL) were added sequentially to a 15 mL reaction tube and mixed thoroughly. The mixture was then reacted under air at 80 °C with stirring for 12 h. After the reaction was completed, the reaction solution was concentrated under vacuum and then washed with a mixture of petroleum ether and ethyl acetate as eluent. The solution was then subjected to rapid silica gel column chromatography to obtain product 3a of this example, which was a yellow solid with a yield of 71%.

[0035] The NMR results of product 3a are as follows: ¹H NMR (400MHz, CDCl₃) δ 8.46 (d, J = 8.6Hz, ¹H), 8.40 (dd, J = 4.1, 1.9Hz, ¹H), 8.14 (dd, J = 8.3, 1.9Hz, ¹H), 7.90 (d, J = 8.6Hz, ¹H), 7.37 (dd, J = 8.2, 4.0Hz, ¹H), 7.33–7.28 (m, 2H), 7.28–7.24 (m, 3H), 7.23–7.15 (m, 5H).

[0036] Example 2

[0037]

[0038] At room temperature, 7-quinolinecarboxylic acid 1a (0.1 mmol), 4,4'-dichlorodiphenylacetylene 2b (0.2 mmol), [Cp*RhCl2]2 (0.005 mmol), AgNTf2 (0.1 mmol), Pr3N (0.05 mmol), and 1,4-dioxane (1 mL) were added sequentially to a 15 mL reaction tube and mixed thoroughly. The mixture was then reacted under air at 80 °C with stirring for 12 h. After the reaction was completed, the reaction solution was concentrated under vacuum and then washed with a mixture of petroleum ether and ethyl acetate as eluent. The solution was then subjected to rapid silica gel column chromatography to obtain product 3b, a yellow solid with a yield of 36%.

[0039]

[0040] The NMR results of product 3b are as follows: ¹H NMR (400MHz, CDCl₃) ppm: δ 8.49–8.42 (m, 2H), 8.16 (dd, J = 8.3, 1.9Hz, 1H), 7.93 (d, J = 8.3, 4.1Hz, 1H), 7.41 (dd, J = 8.3, 4.1Hz, 1H), 7.30–7.24 (m, 3H), 7.25–7.18 (m, 3H), 7.14–7.19 (m, 2H).

[0041] Example 3

[0042]

[0043] At room temperature, 7-quinolinecarboxylic acid 1a (0.1 mmol), bis(4-bromophenyl)acetylene 2e (0.2 mmol), [Cp*RhCl2]2 (0.005 mmol), AgNTf2 (0.1 mmol), Pr3N (0.05 mmol), and 1,4-dioxane (1 mL) were added sequentially to a 15 mL reaction tube and mixed thoroughly. The mixture was then reacted under air at 80 °C with stirring for 12 h. After the reaction was completed, the reaction solution was concentrated under vacuum and then washed with a mixture of petroleum ether and ethyl acetate as eluent. The solution was then subjected to rapid silica gel column chromatography to obtain product 3c, a yellow solid with a yield of 35%.

[0044]

[0045] The NMR results for product 3c are as follows: ¹H NMR (400MHz, CDCl₃) ppm: δ 8.51–8.33 (m, 2H), 8.16 (dd, J = 8.3, 1.9Hz, 1H), 7.93 (d, J = 8.6Hz, 1H), 7.41 (dd, J = 8.3, 3.9Hz, 3H), 7.39–7.34 (m, 2H), 7.21–7.14 (m, 2H), 7.10–7.03 (m, 2H).

[0046] Example 4

[0047]

[0048] At room temperature, 7-quinolinecarboxylic acid 1a (0.1 mmol), 1,2-bis(4-methylbenzene)acetylene 2d (0.2 mmol), [Cp*RhCl2]2 (0.005 mmol), AgNTf2 (0.1 mmol), Pr3N (0.05 mmol), and 1,4-dioxane (1 mL) were added sequentially to a 15 mL reaction tube and mixed thoroughly. The mixture was then reacted under air at 80 °C with stirring for 12 h. After the reaction was completed, the reaction solution was concentrated under vacuum and then washed with a mixture of petroleum ether and ethyl acetate as eluent. The solution was then subjected to rapid silica gel column chromatography to obtain product 3d, a yellow solid with a yield of 51%.

[0049]

[0050] The 3d NMR results of the product are as follows: ¹H NMR (400MHz, CDCl₃) δ 8.48–8.40 (m, 2H), 8.12 (dd, J = 8.2, 1.9 Hz, 1H), 7.87 (d, J = 8.6 Hz, 1H), 7.36 (dd, J = 8.2, 4.1 Hz, 1H), 7.23–7.17 (m, 2H), 7.07 (s, 4H), 7.00 (d, J = 8.2 Hz, 2H), 2.40 (s, 3H), 2.29 (s, 3H).

[0051] Example 5

[0052]

[0053] At room temperature, 7-quinolinecarboxylic acid 1a (0.1 mmol), 1,2-bis(2-fluorophenyl)acetylene 2e (0.2 mmol), [Cp*RhCl2]2 (0.005 mmol), AgNTf2 (0.1 mmol), Pr3N (0.05 mmol), and 1,4-dioxane (1 mL) were added sequentially to a 15 mL reaction tube and mixed thoroughly. The mixture was then reacted under air at 80 °C with stirring for 12 h. After the reaction was completed, the reaction solution was concentrated under vacuum and then washed with a mixture of petroleum ether and ethyl acetate as eluent. The solution was then subjected to rapid silica gel column chromatography to obtain product 3e, a yellow solid with a yield of 62%.

[0054]

[0055] The NMR results for product 3e are as follows: ¹H NMR (400MHz, CDCl₃) δ 8.52–8.42 (m, 2H), 8.17 (dd, J = 8.3, 1.8Hz, 1H), 7.94 (d, J = 8.6Hz, 1H), 7.41 (dd, J = 8.3, 4.1Hz, 1H), 7.32–7.25 (m, 2H), 7.23–7.17 (m, 1H), 7.09–7.02 (m, 1H), 7.02–6.98 (m, 1H), 6.98–6.88 (m, 3H).

[0056] Example 6

[0057]

[0058] At room temperature, 7-quinolinecarboxylic acid 1a (0.1 mmol), 1,2-bis(3-fluorophenyl)acetylene 2f (0.2 mmol), [Cp*RhCl2]2 (0.005 mmol), AgNTf2 (0.1 mmol), Pr3N (0.05 mmol), and 1,4-dioxane (1 mL) were added sequentially to a 15 mL reaction tube and mixed thoroughly. The mixture was then reacted under air at 80 °C with stirring for 12 h. After the reaction was completed, the reaction solution was concentrated under vacuum and then washed with a mixture of petroleum ether and ethyl acetate as eluent. The solution was then subjected to rapid silica gel column chromatography to obtain product 3f, a yellow solid with a yield of 45%.

[0059]

[0060] The NMR results for product 3f are as follows: ¹H NMR (400MHz, CDCl₃) δ 8.50–8.41 (m, 2H), 8.17 (dd, J = 8.3, 1.9Hz, 1H), 7.94 (d, J = 8.7Hz, 1H), 7.41 (dd, J = 8.3, 4.1Hz, 1H), 7.27–7.22 (m, 1H), 7.22–7.15 (m, 1H), 7.09 (m, 1H), 7.06–7.02 (m, 1H), 7.02–6.90 (m, 4H).

[0061] Example 7

[0062]

[0063] At room temperature, 7-quinolinecarboxylic acid 1a (0.1 mmol), 1,2-bis(2-methoxyphenyl)acetylene 2 g (0.2 mmol), [Cp*RhCl2]2 (0.005 mmol), AgNTf2 (0.1 mmol), Pr3N (0.05 mmol), and 1,4-dioxane (1 mL) were added sequentially to a 15 mL reaction tube and mixed thoroughly. The mixture was then reacted under air at 80 °C with stirring for 12 h. After the reaction was completed, the reaction solution was concentrated under vacuum and then washed with a mixture of petroleum ether and ethyl acetate as eluent. The solution was then subjected to rapid silica gel column chromatography to obtain 3 g of the product of this example, which was a yellow emulsion with a yield of 62%.

[0064]

[0065] The NMR results of 3g of product are as follows: ¹H NMR (400MHz, CDCl₃) δ 8.45 (d, J = 8.7Hz, ¹H), 8.42 (dd, J = 4.0, 1.9Hz, ¹H), 8.12 (dd, J = 8.3, 1.9Hz, ¹H), 7.86 (d, J = 8.7Hz, ¹H), 7.36 (dd, J = 8.2, 4.1Hz, ¹H), 7.24–7.19 (m, ¹H), 7.18–7.12 (m, 2H), 6.95 (dd, J = 7.4, 1.8Hz, ¹H), 6.80–6.64 (m, 4H), 3.77–3.62 (s, 3H), 3.50 (s, 3H).

[0066] Example 8

[0067]

[0068] At room temperature, 7-quinolinecarboxylic acid 1a (0.1 mmol), 1,2-bis(3-methoxyphenyl)acetylene 2h (0.2 mmol), [Cp*RhCl2]2 (0.005 mmol), AgNTf2 (0.1 mmol), Pr3N (0.05 mmol), and 1,4-dioxane (1 mL) were added sequentially to a 15 mL reaction tube and mixed thoroughly. The mixture was then stirred at 80 °C under air for 12 h. After the reaction was completed, the reaction solution was concentrated under vacuum and then washed with a mixture of petroleum ether and ethyl acetate as eluent. The solution was then subjected to rapid column chromatography on a silica gel column to obtain the product 3h of this example, which was a yellow emulsion with a yield of 42%.

[0069]

[0070] The NMR results of the product after 3 hours are as follows: ¹H NMR (400MHz, CDCl₃) δ 8.48–8.43 (m, 2H), 8.14 (dd, J = 8.2, 1.9Hz, 1H), 7.90 (d, J = 8.6Hz, 1H), 7.38 (dd, J = 8.3, 4.1Hz, 1H), 7.17 (dt, J = 21.2, 7.9Hz, 2H), 7.02 (m, 1H), 6.87–6.75 (m, 5H), 3.69 (s, 3H), 3.61 (s, 3H).

[0071] Performance testing

[0072] The fluorescence spectrum of the compound prepared in Example 1 of this invention was tested, and the results are as follows: Figure 1 As shown, Figure 1 Results A show that the target compound has a broad absorption peak in the range of 250 nm to 420 nm, with a maximum absorption wavelength of 277 nm. Figure 1Results B show that its emission peak is in the range of 400 nm to 800 nm, with a maximum emission wavelength of 449 nm. The results indicate that the compound prepared in this invention has good electroluminescence properties and can be used to prepare electroluminescent devices.

Claims

1. A pyridoisocoumarin compound, characterized in that, The pyridoisocoumarin compound has any of the following structural formulas: 。 2. A method for preparing the pyridoisocoumarin compound according to claim 1, characterized in that, The preparation method involves using 7-quinoline carboxylic acid and an alkyne compound of formula (II) as reactants, adding an oxidant, a base, and a catalyst, and reacting in an organic solvent under air conditions to obtain pyridoisocoumarin of formula (I); the reaction formula is shown below: ； The alkyne compounds are selected from 1,2-diphenylacetylene, 1,2-bis(4-chlorophenyl)acetylene, 1,2-bis(4-bromophenyl)acetylene, 1,2-bis(2-fluorophenyl)acetylene, 1,2-bis(4-methylphenyl)acetylene, 1,2-bis(3-fluorophenyl)acetylene, 1,2-bis(2-methoxyphenyl)acetylene, or 1,2-bis(3-methoxyphenyl)acetylene; The oxidant is bis(trifluoromethanesulfonyl)imide silver, and the catalyst is dichloro(pentamethylcyclopentadienyl)rhodium(III) dimer.

3. The preparation method according to claim 2, characterized in that, The molar volume ratio of the 7-quinoline carboxylic acid, alkyne compound, oxidant, base, catalyst and organic solvent is 0.1 mmol: 0.2 mmol: 0.1 mmol: 0.05 mmol: 0.005 mmol: 1 mL.

4. The preparation method according to claim 2, characterized in that, The reaction conditions were a temperature of 80°C and a time of 12 hours.

5. The preparation method according to claim 2, characterized in that, The organic solvent is 1,4-dioxane; the base is tripropylamine.

6. The preparation method according to claim 2, characterized in that, After the reaction is complete, elution and purification are required.

7. The preparation method according to claim 6, characterized in that, The elution was performed using petroleum ether and ethyl acetate, and the product was purified by silica gel column chromatography.

8. The application of the pyridoisocoumarin compound of claim 1, characterized in that, The pyridoisocoumarin compound can be used to prepare electroluminescent devices.

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