Dihydronaphthalene bridged ring compound as well as preparation method and application thereof

Abstract

The invention provides a dihydronaphthalene bridged ring compound and a preparation method and application thereof.The dihydronaphthalene bridged ring compound is prepared from a tetrayne compound and methylbenzene under the heating condition, and the tetrayne compound generates a benzyne intermediate; the benzyne intermediate and methylbenzene are subjected to a [4 + 2] cycloaddition reaction, a cyclic transition state of the dihydronaphthalene bridged ring compound is generated, and the dihydronaphthalene bridged ring compound is finally formed through old bond breakage and new bond formation. Compared with the prior art, the dihydronaphthalene bridged ring compound provided by the invention has the advantages that the dihydronaphthalene bridged ring compound has multiple rings, so that the dihydronaphthalene bridged ring compound is more complex in structure and has a wider application prospect, the maximum absorption wavelength of the dihydronaphthalene bridged ring compound in ethanol is 300nm, and Abs can reach 2.0 or above, which indicates that the dihydronaphthalene bridged ring compound is good in absorbance and can be better used for preparing optical materials.

Description

Technical Field

[0001] The invention belongs to the technical field of organic compound synthesis, and specifically relates to a dihydronaphthalene bridged ring compound and a preparation method and application thereof. Background Art

[0002] Naphthalene is the simplest condensed aromatic hydrocarbon, which is formed by two benzene rings sharing two adjacent carbon atoms. It is widely used as a raw material for preparing dyes, resins, solvents, etc., and is also used as an insect repellent. It is a white or colorless flaky crystalline solid at room temperature and pressure, with a strong coal tar smell, and is easily soluble in solvents such as anhydrous ethanol, ether, and benzene.

[0003] Naphthalene is an important organic chemical raw material with a wide range of applications. For example, naphthalene can be used as a key raw material for the production of chemical intermediates such as phthalic anhydride, various naphthols, and naphthylamines. These intermediates are then used in synthetic resins, plasticizers, dyes, surfactants, synthetic fibers, pesticides, and pharmaceuticals. Naphthalene and its derivatives are used as stabilizers and processing aids in the plastics and rubber industries, helping to improve the properties of the final product.

[0004] The patent with publication number CN 115246761 A published on October 28, 2022 discloses a method for preparing polysubstituted naphthalene derivatives by converting acetylene compounds into After mixing with p-toluenesulfonyl chloride and solvent, add React with a catalyst to obtain a polysubstituted naphthalene ring derivative However, as people's demand for hydrogenated naphthalene derivatives increases, more complex structures and more uses are gradually showing their advantages. Summary of the invention

[0005] The object of the present invention is to provide a dihydronaphthalene bridged ring compound and a preparation method thereof, wherein toluene is used as a reaction solvent, a tetraacetylene compound is added and a benzene acetylene intermediate is generated under heating conditions, and the benzene acetylene intermediate reacts with toluene to generate a naphthalene bridged ring compound. The preparation method is simple and efficient, and a dihydronaphthalene bridged ring compound with a higher yield and a more complex structure can be obtained by controlling the reaction temperature. Moreover, the preparation method is mild, simple and green.

[0006] Another object of the present invention is to provide an application of a dihydronaphthalene bridged ring compound for use in optical materials.

[0007] The specific technical solutions of the present invention are as follows:

[0008] The present invention provides a method for preparing a dihydronaphthalene bridged ring compound, which is specifically:

[0009] The tetraacetylene compound is added into toluene, heated for reaction, and separated and purified after the reaction to obtain a dihydronaphthalene bridged ring compound.

[0010] The concentration of the tetraacetylene compound in toluene is 0.2 mol / L.

[0011] The heating reaction refers to reacting at 105-110° C. for 12 h to 14 h.

[0012] The separation and purification method comprises the following steps: drying the crude product under reduced pressure, loading the crude product into a wet column, and performing column chromatography separation and purification using ethyl acetate:petroleum ether in a volume ratio of 1:40 as an eluent to obtain a white solid product, namely a dihydronaphthalene bridged ring compound.

[0013] The tetraacetylene compound is prepared by the following steps:

[0014] 1) Add malonic acid ester and propargyl bromide to anhydrous acetonitrile in an ice-water bath, use sodium hydride as a base, react, and then purify and separate to obtain compound 1;

[0015] 2) Compound 1 prepared in step 1) is mixed with phenylethynyl bromide or chlorophenylethynyl bromide in a CuCl anhydrous and oxygen-free catalytic system, an aqueous solution of n-butylamine and hydroxylamine hydrochloride are added, the mixture is stirred under ice bath for reaction, and a tetraacetylene compound is obtained after separation and purification.

[0016] In step 1), the molar ratio of sodium hydride, malonic acid ester, propargyl bromide and anhydrous acetonitrile is 4-5:1:2.1-2.4:20-23.

[0017] The reaction in step 1) is carried out in an ice-water bath at a temperature of 0-5°C and a reaction time of more than 8 hours; the preferred reaction time is 8.5 hours;

[0018] The structural formula of compound 1 in step 1) is: Wherein E1 and E2 are the same, namely CO2R, R is a straight-chain alkyl, branched alkyl or unsaturated hydrocarbon with less than six carbon atoms, and preferably, the structural formula of the compound 1 is

[0019] The purification and separation in step 1) is specifically as follows: the product is washed with a saturated sodium chloride aqueous solution, extracted with ethyl acetate, dried under reduced pressure, and subjected to column chromatography using a mixed solvent of ethyl acetate: petroleum ether in a volume ratio of 1:80 to obtain the product, namely compound 1.

[0020] In step 2), the molar ratio of the compound 1 in step 1): phenylethynyl bromide or chlorophenylethynyl bromide: CuCl: hydroxylamine hydrochloride is 1: 2-2.5: 0.15-0.16: 0.07-0.08.

[0021] In step 2), the n-butylamine aqueous solution is used as a solvent, and its mass concentration is 30%.

[0022] In step 2), the dosage ratio of compound 1 to the aqueous solution of n-butylamine is 0.4-0.5 mol / L;

[0023] In step 2), the reaction is stirred in an ice bath for at least 12 hours;

[0024] In step 2), the preparation method of the chlorophenylethynyl bromide is as follows: phenylacetylene or chlorophenylacetylene and N-bromosuccinimide are reacted in acetone solvent under the catalysis of AgNO3 catalyst at room temperature for 3 hours, the crude product is washed with saturated sodium chloride aqueous solution, and extracted with n-hexane to obtain chlorophenylethynyl bromide; wherein the molar ratio of phenylacetylene or chlorophenylacetylene: N-bromosuccinimide and AgNO3 is 1:1-1.2:0.05.

[0025] In step 2), the separation and purification refers to: washing the product with a saturated sodium chloride solution, extracting with dichloromethane, drying under reduced pressure, and separating by column chromatography with a volume ratio of ethyl acetate: petroleum ether = 1:100 to obtain a solid product, i.e., a tetraacetylene compound.

[0026] Preferably, the tetraacetylene compound has the structural formula

[0027] The invention provides a dihydronaphthalene bridged ring compound, which is prepared by the above method.

[0028] The structural formula of the dihydronaphthalene bridged ring compound is: R is a straight-chain alkyl group with less than six carbon atoms, a branched-chain alkyl group or an unsaturated hydrocarbon, preferably a methyl group; R1 is hydrogen, a straight-chain alkyl group with less than six carbon atoms, a branched-chain alkyl group, an ester group, an alkoxy group or a halogen, preferably Cl; R2 is hydrogen, a straight-chain alkyl group with less than six carbon atoms, a branched-chain alkyl group, an ester group, an alkoxy group or a halogen, preferably Cl.

[0029] Preferably, the dihydronaphthalene bridged ring compound has the structural formula:

[0030] The invention provides an application of a dihydronaphthalene bridged ring compound for optical materials.

[0031] The maximum absorption wavelength of the dihydronaphthalene bridged ring compound in ethanol is 300 nm, indicating that the substance has good absorbance and can be well used in the preparation of optical materials.

[0032] The present invention uses tetraacetylene compounds and toluene as raw materials, reacts in toluene solvent at 105-110°C for 12h-14h, under which the benzene acetylene intermediate undergoes a [4+2] cycloaddition reaction with toluene, and the mechanism diagram is as follows: Figure 6 shown. Figure 6The tetrayne compounds undergo a [4+2] HDDA reaction at high temperature to generate benzyne compounds. The benzyne compounds undergo a [4+2] cycloaddition reaction in toluene solvent under heating conditions to generate a cyclic transition state of a dihydronaphthalene bridged ring compound. After the old bond breaks and the new bond is formed, a dihydronaphthalene bridged ring compound is finally formed.

[0033] Compared with the prior art, the dihydronaphthalene bridged ring compound provided by the present invention has a more complex structure due to the presence of multiple rings, and has a broader application prospect. The maximum absorption wavelength in ethanol is 300nm, and the Abs can reach above 2.0, indicating that the substance has good absorbance and can be well used for the preparation of optical materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is the general structural formula of dihydronaphthalene bridged ring compound;

[0035] Figure 2 The hydrogen nuclear magnetic resonance spectrum of the dihydronaphthalene bridged ring compound prepared in Example 1;

[0036] Figure 3 The carbon NMR spectrum of the dihydronaphthalene bridged ring compound prepared in Example 1;

[0037] Figure 4 Example 1 Preparation process equation;

[0038] Figure 5 The diagram is a mechanism for the preparation of tetrayne compounds;

[0039] Figure 6 The reaction mechanism diagram of dihydronaphthalene bridged ring compounds;

[0040] Figure 7 This is the IUCr structure detection diagram of the dihydronaphthalene bridged ring compound prepared in Example 1;

[0041] Figure 8 This is the UV spectrum of the dihydronaphthalene bridged ring compound prepared in Example 1. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] Unless otherwise specified, the test materials and reagents used in the following examples can be obtained from commercial sources.

[0044] If no specific techniques or conditions are specified in the examples, they can be carried out according to the techniques or conditions described in the literature in the art or according to the product instructions.

[0045] Example 1

[0046] A dihydronaphthalene bridged ring compound, the structural formula of which is:

[0047]

[0048] The preparation method of the dihydronaphthalene bridged ring compound comprises the following steps:

[0049] 1) Using 830 mmol of sodium hydride as a catalyst, 200 mmol of dimethyl malonate and 440 mmol of propargyl bromide were added to 210 mL of anhydrous acetonitrile, and the mixture was stirred mechanically in an ice-water bath at 0-5°C for 8 hours. The product was washed with a saturated sodium chloride aqueous solution, extracted with ethyl acetate, and dried under reduced pressure. Column chromatography was performed using a mixed solvent of ethyl acetate: petroleum ether in a volume ratio of 1:80 to obtain a product, namely compound 1, with the structural formula

[0050] 2) 100 mmol of chlorophenylacetylene and 120 mmol of N-bromosuccinimide were placed in a two-necked flask, and acetone solvent was added until the solid reactant was submerged by 0.5 cm. 5 mmol of AgNO3 catalyst was added, and the reaction was carried out under magnetic stirring at room temperature for 3 hours. The crude product was washed with a saturated sodium chloride aqueous solution and extracted with n-hexane to obtain chlorophenylacetylene bromide.

[0051] 3) In a 500ml three-necked flask, 40mmol of compound 1 and 2.88mmol of hydroxylamine hydrochloride as a base are mixed in a 6mmolCuCl anhydrous and oxygen-free catalytic system (a vacuum device for evacuating and releasing argon is used, evacuating first and then releasing, and this is repeated 3 times), and then 100ml of a 30% by mass aqueous solution of n-butylamine (63g water + 27g n-butylamine) is used as a solvent. First, half of the solvent is poured in, and then 90mmol of chlorophenylacetylene bromide prepared in step 3) is poured in, and finally the remaining solvent is poured in. Under an ice bath, the reaction is stirred magnetically for 12 hours. The product is washed with a saturated sodium chloride solution and extracted with dichloromethane. The organic phase is collected, dried under reduced pressure, and chromatographed with a volume ratio of ethyl acetate: petroleum ether = 1:100 to obtain a white solid product, i.e., a tetraacetylene compound, with a structural formula of

[0052]

[0053] 4) Under the condition of 110°C, 1 mmol of the tetraacetylene compound prepared in step 3) was reacted in 5 mL of toluene. After 12 hours, the reaction was stopped and the plate was spotted with TCL (volume ratio of petroleum ether: ethyl acetate = 8:1), and the spot analysis was performed under ultraviolet light. By comparing with the tetraacetylene compound spot, it was found that the tetraacetylene compound spot was basically reacted completely, and a new purple fluorescent spot was generated below the tetraacetylene compound spot. The crude product was decompressed and dried, wet loaded on a column, and separated by column chromatography with a volume ratio of ethyl acetate: petroleum ether = 1:40 to obtain a white solid product, i.e., a dihydronaphthalene bridged ring compound, and the column chromatography yield was about 75%.

[0054] According to Example 1, a set of comparative experiments was conducted: the solvent was changed from toluene to acetonitrile, and the other conditions were the same. The prepared 1mmol tetraacetylene compound was heated and reacted in 5mL acetonitrile only. After 12 hours, the reaction was stopped and the plate was spotted with TCL (petroleum ether: ethyl acetate = 8:1), and the spot analysis was performed under ultraviolet light. By comparing with the tetraacetylene compound spot, it was found that the tetraacetylene compound spot had basically no reaction, and no obvious new spot was generated. This shows that the toluene solvent has a significant effect on the reaction.

[0055] Example 1 The product is a white powder. 1 H NMR, 13 C NMR was used to determine the results, and the results are as follows:

[0056] 13 C NMR (101MHz, CDCl3) δ172.1, 172.0, 149.7, 145.3, 143.4, 140.0, 138.6, 138.6, 137.2, 135.1, 133.9, 133.2, 1 32.4, 132.2, 131.8, 131.7, 128.6, 128.0, 122.0, 113.1, 93.9, 88.5, 59.6, 53.2, 52.0, 46.1, 40.9, 38.9, 19.7;

[0057] 1 H NMR (400MHz, CDCl3) δ7.48(d,J=8.7Hz,2H),7.37-7.29(m,2H),7.27-7.23(m,2H),7.16-7.09(m,2H),6.91(t,J=6.1Hz,1H) ,6.81(t,J=5.7Hz,1H),6.28-6.22(m,1H),4.77-4.65(m,2H),3.82(d,J=2.4Hz,6H),3.80-3.73(m,4H),1.98-1.81(m,3H).

[0058] The product of Example 1 is dissolved in ethanol at a concentration of 3.90 mg / ml. From its UV-visible absorption spectrum data, it can be concluded that its maximum absorption wavelength in ethanol is 300 nm and Abs can reach above 2.0, indicating that the substance has good absorbance and can be well used in the preparation of optical materials.

[0059] The description of the above embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the protection scope of the present invention.

Claims

1. A method for preparing a dihydronaphthalene bridged ring compound, characterized in that: The preparation method is specifically: The tetraacetylene compound is added into toluene, heated for reaction, and separated and purified after the reaction to obtain a dihydronaphthalene bridged ring compound.

2. The preparation method according to claim 1, characterized in that: The concentration of the tetraacetylene compound in toluene is 0.2 mol / L.

3. The preparation method according to claim 1 or 2, characterized in that: The heating reaction refers to reacting at 105-110° C. for 12 h to 14 h.

4. The preparation method according to claim 1, characterized in that: The separation and purification method comprises the following steps: drying the crude product under reduced pressure, loading the crude product into a wet column, and performing column chromatography separation and purification using ethyl acetate:petroleum ether in a volume ratio of 1:40 as an eluent to obtain a white solid product, namely a dihydronaphthalene bridged ring compound.

5. The preparation method according to claim 1, characterized in that: The tetraacetylene compound is prepared by the following steps: 1) Add malonic acid ester and propargyl bromide to anhydrous acetonitrile in an ice-water bath, use sodium hydride as a base, react, and then purify and separate to obtain compound 1; 2) Compound 1 prepared in step 1) is mixed with phenylethynyl bromide or chlorophenylethynyl bromide in a CuCl anhydrous and oxygen-free catalytic system, an aqueous solution of n-butylamine and hydroxylamine hydrochloride are added, the mixture is stirred under ice bath for reaction, and a tetraacetylene compound is obtained after separation and purification.

6. The preparation method according to claim 5, characterized in that: In step 1), the molar ratio of sodium hydride, malonic acid ester, propargyl bromide and anhydrous acetonitrile is 4-5:1:2.1-2.4:20-23.

7. The preparation method according to claim 5, characterized in that: In step 2), the molar ratio of the compound 1 in step 1): phenylethynyl bromide or chlorophenylethynyl bromide: CuCl: hydroxylamine hydrochloride is 1: 2-2.5: 0.15-0.16: 0.07-0.

08.

8. A dihydronaphthalene bridged ring compound prepared by the preparation method according to any one of claims 1 to 7, characterized in that: The structural formula of the dihydronaphthalene bridged ring compound is: R is a straight-chain alkyl group with less than 6 carbon atoms, a branched-chain alkyl group or an unsaturated hydrocarbon; R1 is hydrogen, a straight-chain alkyl group with less than 6 carbon atoms, a branched-chain alkyl group, an ester group, an alkoxy group or a halogen; R2 is hydrogen, a straight-chain alkyl group with less than 6 carbon atoms, a branched-chain alkyl group, an ester group, an alkoxy group or a halogen.

9. The dihydronaphthalene bridged ring compound according to claim 8, characterized in that: The structural formula of the dihydronaphthalene bridged ring compound is:

10. Use of the dihydronaphthalene bridged ring compound according to claim 8 or 9, characterized in that: The dihydronaphthalene bridged ring compound is used for optical materials.

Images