阅读说明：本技术 一种偶氮化合物及其合成方法和应用 (Azo compound and synthesis method and application thereof ) 是由 庞韬 章超 于 2021-01-28 设计创作，主要内容包括：本发明涉及有机合成技术领域,具体为一种偶氮化合物——N＝N(氮氮双键)及其合成方法和应用。本发明基于苯乙酮衍生物和1,3-二氨基胍盐酸盐(及肼类化合物)为底物,通过简单的一锅合成法制备得到N＝N双键化合物,本发明制备得到的偶氮化合物的氮氮双键连接在脂肪族碳上,且本发明的原料简单,反应条件温和,反应体系绿色环保,本发明得到的偶氮化合物可以应用于染料、光学材料等领域。(The invention relates to the technical field of organic synthesis, in particular to an azo compound, namely N ═ N (nitrogen-nitrogen double bond), and a synthesis method and application thereof. The preparation method is based on that acetophenone derivatives and 1, 3-diaminoguanidine hydrochloride (and hydrazine compounds) are used as substrates, an N ═ N double-bond compound is prepared by a simple one-pot synthesis method, nitrogen-nitrogen double bonds of the azo compound prepared by the preparation method are connected to aliphatic carbon, the raw materials are simple, the reaction conditions are mild, the reaction system is green and environment-friendly, and the azo compound prepared by the preparation method can be applied to the fields of dyes, optical materials and the like.)

1. An azo compound having the structural formula:

wherein R is₁～R₅Independently of one another is hydrogenOne of a hydroxyl group and a methoxy group.

2. The azo compound of claim 1, having the formula:

3. a process for the synthesis of azo compounds according to claim 1 or 2, comprising the following steps:

reacting the substrate a and the substrate b in a solvent to obtain the azo compound;

the structural formula of the substrate a is as follows:

wherein R is₁～R₅Independently is one of hydrogen, hydroxyl and methoxy;

the substrate b is selected from the following compounds:

4. the method for synthesizing an azo compound according to claim 3, wherein the ratio of the amounts of the substances of the substrate a and the substrate b is 1 to 3: 0.5 to 1.5.

5. The method for synthesizing an azo compound according to claim 4, wherein the reaction temperature is 80 to 180 ℃ and the reaction time is 1.5 to 2.5 hours.

6. The method for synthesizing an azo compound according to any one of claims 3 to 5, wherein the solvent is one or more of dimethylacetamide, triethylamine, dimethylsulfoxide, and water.

7. The method for synthesizing an azo compound according to claim 6, wherein a catalyst for the reaction is ferrous oxide and/or terbium nitrate;

the dosage of the catalyst for the reaction is 5-10 mg.

8. Use of the azo compound according to any one of claims 1 to 2 and the azo compound obtained by the method for synthesizing an azo compound according to any one of claims 3 to 7 in dyes and optical materials.

Technical Field

The invention relates to the technical field of organic synthesis, in particular to an azo compound and a synthesis method and application thereof.

Background

There are few reports on the synthesis of nitrogen-nitrogen double bonds based on different substrates, and as summarized in the literature at present, there are several methods:

(1) diazotization reaction

Hagh-ben K et al are based on diazonium salts and ortho-methoxyphenol substrates, in K₂CO₃The solution system reacts to synthesize the aromatic azobenzene. Because the nitro group on the diazonium salt is an electron withdrawing group, the reaction is easy to carry out.

Haghbeen K,Tan E W.Synthesis of catechol azo dyes[J].The Journal of Organic Chemistry,1998,63(19):4503-4505.

(2) Mils reaction

Herges R takes zinc powder as a catalyst under the alkaline condition to reduce the aromatic nitro compound into a corresponding nitroso compound, and the intermediate and arylamine continue to react to successfully prepare the azo derivative.

Kubitschke J,Nather C,Herges R.Synthesis of functionalized triazatriangulenes for application in photo-switchable self-assembled monolayers[J].European Journal of Organic Chemistry,2010,(26):5041-5055.

(3) Oxidation of amines

Noureldin NA starting from aromatic amines in KMnO₄(adsorbed on copper sulfate pentahydrate) to prepare an azobenzene compound.

Noureldin N A,Bellegarde J W.A novel method.The synthesis of ketones and azobenzenes using supported permanganate[J].Synthesis,1999,(6):939-942.

(4) Oxidation of arylhydrazines

Wang C L et al with FeCl₃The catalyst is used for oxidizing arylhydrazine in acetone to synthesize azobenzene.

Wang C L,Wang X X，Wang X Y,et al.A convenient method for dehydrogenation of symmetric hydrazo compounds[J].Synthetic Communications,1999,29(19):3435-3438.

(5) Reductive coupling reaction of nitro compound

Wang J Q in the presence of hydrogen, using Pd (acac)₂Reducing nitrobenzene derivatives to aromatic azo compounds in the presence of an isometalated salt as catalystA compound (I) is provided. The method can generate Pb nano particles in situ in the process of synthesizing the product, and the Pb nano particles are also used as catalysts for the reaction, thereby omitting the preparation step of the nano particles.

Wang J Q,Hu L,Cao X Q,et al.Catalysis by Pd nanoclusters generated in situ ofhigh-efficiency synthesis of aromatic azo compounds from nitroaromatics under H2 atmosphere[J].RSC Advances,2013,3(15):4899-4902.

(6) Pyrolysis of azides

In the presence of both copper salts and acids, the dimerization of diazonium salts synthesizes azo compounds, which are influenced by the nature of the aromatic ring substituents: when the aromatic ring contains an electron-withdrawing substituent, C-C coupling is carried out to generate a biphenyl compound; azo compounds being formed only when the aromatic ring contains electron-donating substituents, when Cu⁺When the concentration is reduced, the synthesis of the azo compound is facilitated.

Smith M B,March J.Advanced Organic Chemistry[M].Americal:JohnWiley&Sons,5th edn,2001.

(7) Other reactions

Ziegler T reports an example of the synthesis of azobenzene derivatives by reacting benzotriazole derivatives with phenol compounds under the action of NaH.

Mico X A,Ziegler T,Subramanian L R.A versatile direct approach to ortho-substituted azobenzenes from benzotriazoles[J].Angewandte Chemie International Edition,2004,43(11):1400-1403.

Therefore, the azo compound constructed by the reaction has N ═ N double bonds directly connected with benzene rings, and some reaction catalysts are expensive and substrates need to be prepared.

Disclosure of Invention

The invention aims to provide a novel method for preparing an azo compound with a nitrogen-nitrogen double bond connected with aliphatic carbon by an economic, green and efficient one-pot method.

In order to achieve the above object, the present invention provides the following technical solutions:

the invention provides an azo compound, which has a structural formula as follows:

wherein R is₁～R₅Independently one of hydrogen, hydroxy and methoxy.

Further, the structural formula of the azo compound is as follows:

the invention provides a synthesis method of an azo compound, which comprises the following steps:

reacting the substrate a and the substrate b in a solvent to obtain the azo compound;

the structural formula of the substrate a is as follows:

wherein R is₁～R₅Independently is one of hydrogen, hydroxyl and methoxy;

the substrate b is selected from the following compounds:

further, the ratio of the amount of the substances of the substrate a to the substrate b is 1-3: 0.5 to 1.5.

Further, the reaction temperature is 80-180 ℃, and the reaction time is 1.5-2.5 h.

Further, the solvent is one or more of dimethylacetamide, triethylamine, dimethyl sulfoxide and water.

Further, the catalyst for the reaction is ferrous oxide and/or terbium nitrate. The dosage of the catalyst for the reaction is 5-10 mg.

The invention provides an application of azo compounds in dyes and optical materials.

The invention has the beneficial effects that:

the invention aims to explore a new method for preparing N ═ N double bonds by an economic, green and efficient one-pot method:

the outstanding characteristics are as follows:

(1) the synthesis method of the invention has the advantages that the yield of the azo compound obtained under the action of the specific reaction solvent and the catalyst is over 80 percent;

(2) the nitrogen-nitrogen double bond of the azo compound synthesized by different substrates is connected with aliphatic carbon;

(3) the method has the advantages of simple raw materials, mild reaction conditions and green and environment-friendly reaction system.

Drawings

FIG. 1 is a hydrogen spectrum of Compound 1 obtained in example 1;

FIG. 2 is a carbon spectrum of Compound 1 obtained in example 1;

FIG. 3 is a hydrogen spectrum of Compound 2 obtained in example 2;

FIG. 4 is a carbon spectrum of Compound 2 obtained in example 2;

FIG. 5 is a hydrogen spectrum of Compound 3 obtained in example 3;

FIG. 6 is a carbon spectrum of Compound 3 obtained in example 3;

FIG. 7 is a hydrogen spectrum of Compound 4 obtained in example 4;

FIG. 8 is a carbon spectrum of Compound 4 obtained in example 4;

FIG. 9 is a hydrogen spectrum of Compound 5 obtained in example 5;

FIG. 10 is a carbon spectrum diagram of Compound 5 obtained in example 5;

FIG. 11 is a single crystal structural diagram of Compound 1 obtained in example 1.

Detailed Description

The invention provides an azo compound, which has a structural formula as follows:

wherein R is₁～R₅Independently one of hydrogen, hydroxy and methoxy.

In the present invention, the azo compound is preferably the following compound:

the invention provides a synthesis method of an azo compound, which comprises the following steps:

reacting the substrate a and the substrate b in a solvent to obtain the azo compound;

the structural formula of the substrate a is as follows:

wherein R is₁～R₅Independently is one of hydrogen, hydroxyl and methoxy;

the substrate b is selected from the following compounds:

in the present invention, the substrate a is preferably:

one kind of (1).

In the present invention, the substrate b is preferably:

one kind of (1).

In the present invention, the ratio of the amounts of the substrate a and the substrate b is 1 to 3: 0.5 to 1.5, preferably 2: 1.

in the invention, the reaction temperature is 80-180 ℃, preferably 90 ℃, and the reaction time is 1.5-2.5 h, preferably 2 h.

In the invention, the solvent is one or more of dimethylacetamide, triethylamine, dimethyl sulfoxide and water, and is preferably dimethylacetamide or water.

In the present invention, the catalyst for the reaction is ferrous oxide and/or terbium nitrate, preferably ferrous oxide. The dosage of the catalyst for the reaction is 5-10 mg, preferably 6-9 mg, and more preferably 7.5 mg.

In the present invention, the synthesis method of the azo compound is preferably a one-pot synthesis method.

The invention provides an application of azo compounds in dyes and optical materials.

The technical solutions provided by the present invention are described in detail below with reference to examples, but they should not be construed as limiting the scope of the present invention.

Example 1

And (3) putting 0.2mmol of substrate 1-a, 0.1mmol of substrate 1-b and 5mg of ferrous chloride catalyst into water for reaction, controlling the reaction temperature at 90 ℃, and finishing the reaction after 2 hours to obtain the compound 1.

Wherein the substrate 1-a has the structural formula:the substrate 1-b has the formulaThe structural formula of the compound 1 isThe yield thereof was found to be 81%.

Example 2

And (3) putting 0.2mmol of substrate 2-a, 0.05mmol of substrate 2-b and 7.5mg of ferrous chloride catalyst into water for reaction, controlling the reaction temperature at 90 ℃, and finishing the reaction after 2 hours to obtain the compound 2.

Wherein the substrate 2-a has the structural formula:the substrate 2-b has the structural formulaThe structural formula of the compound 2 isThe yield thereof was found to be 82.5%.

Example 3

And (3) putting 0.2mmol of substrate 3-a, 0.15mmol of substrate 3-b and 6mg of ferrous chloride catalyst into water for reaction, controlling the reaction temperature at 90 ℃, and finishing the reaction after 2 hours to obtain the compound 3.

Wherein the substrate 3-a has the structural formula:the substrate 3-b has the structural formulaThe structural formula of the compound 3 isThe yield thereof was found to be 82%.

Example 4

And (3) putting 0.3mmol of substrate 4-a, 0.1mmol of substrate 4-b and 10mg of ferrous chloride catalyst into water for reaction, controlling the reaction temperature at 90 ℃, and finishing the reaction after 2 hours to obtain the compound 4.

Wherein the substrate 4-a has the structural formula:the substrate 4-b has the structural formulaThe structural formula of the compound 4 isThe yield thereof was found to be 80.5%.

Example 5

And (3) putting 0.2mmol of substrate 5-a, 0.1mmol of substrate 5-b and 8mg of ferrous chloride catalyst into water for reaction, controlling the reaction temperature at 90 ℃, and finishing the reaction after 2 hours to obtain the compound 5.

Wherein the substrate 5-a has the structural formula:the substrate 5-b has the structural formulaThe structural formula of the compound 5 isThe yield thereof was found to be 82.5%.

Example 6

And (3) putting 0.5mmol of substrate 6-a, 0.5mmol of substrate 1-b and 10mg of terbium nitrate catalyst into a mixed solvent of dimethylformamide and water for reaction, controlling the reaction temperature at 180 ℃, and finishing the reaction after 2 hours to obtain the compound 6.

Wherein the substrate 6-a has the structural formula:the structural formula of the compound 6 isThe yield thereof was found to be 70%.

Test example 1

The crystal structure of compound 1 obtained in example 1 of the present application was verified:

culturing: the compound obtained in example 1 was subjected to a solvent natural evaporation method in the presence of chloroform: culturing in a culture solution of a 1:1 system of anhydrous methanol, standing, slowly volatilizing, and culturing to obtain crystal.

And (3) testing: selecting transparent crystals with moderate particles, regular shapes, no cracks and no impurities attached. The structure is synthesized and solved by combining a direct method with Fourier, all hydrogen atom coordinates are determined by theoretical hydrogenation, and a Riding mode is adopted for correction; all atomic scattering factors were taken from International Tables.

The instrument comprises the following steps: the crystal structure is measured by using a German Bruker Smart Apex CCD single crystal diffractometer, adopting Mo-Kalpha rays subjected to graphite monochromatization as incident light and having the wavelength ofThe conditions for the diffraction experiments were: T296K.

And (3) verification: the crystal structure of the obtained compound 1 is shown in figure 11 and is consistent with the structure of the obtained compound.

From the above examples, it can be seen that the present invention provides an azo compound having a double bond linked to an aliphatic carbon, and the structural formula of the azo compound is confirmed to match the structural formula of the compound obtained by nuclear magnetic resonance spectroscopy.

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 principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.