CN103936682A - Aminemethylene-quinoxaline-1,4-dioxide as well as preparation method and application thereof - Google Patents

Abstract

The invention discloses a preparation method of amine methylene-quinoxaline-1,4-dioxide as follows: acetylmethaquine and bis-(dimethylamine)methane or bis-(diethylamine)methane or bis -(piperidine)methane undergoes a Mannich reaction to produce aminomethylene-quinoxaline-1,4-dioxide. The synthetic amine methylene-quinoxaline-1,4-dioxide (a, b, c) of the present invention is a kind of novel veterinary drug synthesized by the applicant on the basis of quinoline, insoluble in water, soluble in Dioxane and dimethyl sulfoxide, the parent ring of its structure is the same as that of olaquindox (quinetazine). Its activity test shows that it has good antibacterial activity against Escherichia coli C _83-1 , Pseudomonas aeruginosa C _79-6 , Salmonella ₁₀₁₄ , Klebsiella ₂₁₉ and so on. Among them, the piperidinium-quinoxaline-1,4-dioxide (c) prepared by the present invention is the best, and can be used as a new type of veterinary drug in the treatment of bacterial diseases.

Description

A kind of amine methylene-quinoxaline-1,4-dioxide and its preparation method and application

technical field

The invention relates to a quinoxaline compound, a preparation method thereof, and an application in antibacterial drugs.

Background technique

Quinoxaline-1,4-dioxyl derivatives as antibacterial and growth-promoting additives have low toxicity, small side effects, low dosage, and can be used in feed for a long period of time, playing a huge role in animal husbandry. For example, Carbadox, Olaquindox, and Maquindox have good activity on Gram-negative bacteria and positive bacteria, and have nitrogen retention and protein assimilation effects, which are helpful for improving feed conversion. It has a significant effect on rate and growth promotion. Therefore, it is widely used in various animal feeds, mainly used to promote growth, improve feed utilization rate and prevent diarrhea in young animals, improve the survival rate of young animals and poultry, and sometimes it is also used to treat fowl cholera, pullorum, piglet diarrhea and other diseases . Since Haddadin and Issidorides in Beirut, Lebanon published the first article on Beirut reaction in 1965, hundreds of patents using Beirut reaction have been published and no less than a thousand new nitrogen heterocyclic compounds have been synthesized. However, due to the potential "three causes" problem, many countries have conducted a lot of research on the safe application of quinoxaline drugs, successively enacted strict regulations, and made strict regulations on drug production, usage methods, dosage, etc., and continuously The research and development of new livestock and poultry special substitutes. In fact, in the past 50 years, due to the application of quinoxalines in animal feed, the production efficiency has been improved, the cost of livestock products, especially meat, has been reduced, the hygiene of meat has been improved, and a large number of cheap and high-quality livestock products have been provided to humans. .

Contents of the invention

The technical problem to be solved in the present invention is to overcome the existing defects and provide a new quinoxaline compound with medicinal value - aminomethylene-quinoxaline-1,4-dioxide;

Another object of the present invention is to provide the preparation method of above-mentioned compound;

Another object of the present invention is to provide the application of the above compounds.

The purpose of the present invention is specifically achieved through the following technical solutions:

A kind of amine methylene-quinoxaline-1,4-dioxide, its structural formula is as I:

in,

when When, it is compound a, and the name of the compound is: dimethylaminomethylene-quinoxaline-1,4-dioxide;

when When it is compound b, the name of the compound is: diethylamine methylene-quinoxaline-1,4-dioxide;

when , it is compound c, and the name of the compound is: piperidinyl-quinoxaline-1,4-dioxide.

A preparation method of amine methylene-quinoxaline-1,4-dioxide is: acetylmethaquine and bis-(dimethylamine)methane or bis-(diethylamine)methane or bis-(piperidine ) methane undergoes Mannich reaction to generate amine methylene-quinoxaline-1,4-dioxide.

Preferably, the medium of the Mannich reaction is an acidic reaction medium, and pyridine is used as a reaction solvent.

Preferably, the acidic medium is obtained by adding concentrated hydrochloric acid, wherein the ratio of acetylmethaquine: pyridine: bis-(dimethylamine) methane: concentrated hydrochloric acid (W: V: V) is 4.4g: 40mL: 0.15 mL: 0.8mL.

Preferably, the temperature of the Mannich reaction is controlled at 55° C., and the reaction time is controlled at 2 hours.

As a preferred version of the above method, the specific steps are as follows:

Accurately weigh 4.4g of acemetquine and dissolve it in 40ml of pyridine, heat to dissolve, drop into bis-(dimethylamine)methane or bis-(diethylamine)methane or bis-(piperidine)methane 0.15mL and drop 0.8mL Concentrate HCl, stir; control the temperature at 55°C, reflux for 2 hours after the reaction is completed, spin the solvent, wash the concentrated solution with saturated NaCl to a separatory funnel, extract a small amount of ethyl acetate several times, combine the extracts, put them in anhydrous Na2SO4 Dry, filter, spin dry, and evaporate the solvent to obtain a crude product, which is separated with a silica gel column to obtain a dendritic yellow crystal, which is the final product.

Further preferably, when heating and dissolving, liquid paraffin is used as the heating medium.

The bis-(dimethylamine)methane or bis-(diethylamine)methane or bis-(piperidine)methane is prepared according to the following method:

Under cooling in an ice-water bath, add 15ml of 37% HCHO to the reaction flask, and under stirring, use a dropping funnel to add dropwise an aqueous solution containing 0.37mol of dimethylamine or diethylamine or piperidine. After the dropwise addition, stir at room temperature for 30min , and then add solid NaOH until the solution forms two phases, divide the separating funnel into two layers, dry it with solid NaOH, place it for filtration, distill at atmospheric pressure, collect the fraction at 83°C, and obtain that.

Described acemetquine is prepared according to the following method:

Add 18 g of excess acetylacetone to benzofurazan, warm in a water bath until dissolved, add triethylamine under shaking, and warm for several minutes, cool at room temperature, place it, and gradually precipitate crystals, and a large number of yellow crystals precipitate after 10 hours. Suction filtration, collect the crystals, wash with a small amount of water, dry, and recrystallize from absolute ethanol to obtain bright yellow needle crystals, that is, acemetquine.

Use of piperidinium-quinoxaline-1,4-dioxide (c) as a veterinary drug for the treatment of bacterial diseases.

In order to further illustrate the essence of the present invention, the applicant carried out relevant drug efficacy tests on the prepared dimethylamine (diethylamine, piperidine) methylene-quinoxaline-1,4-dioxide.

(1), in vitro antibacterial test of compounds a, b, c

1 Materials and methods

1.1 The experimental drugs quinoxaline (a, b, c) and quinocetone (MBQO) were provided by Lanzhou Institute of Animal Husbandry and Veterinary Medicine, Chinese Academy of Agricultural Sciences, with a purity of over 98%.

1.2 Test strains

Escherichia coliC _83-1 was purchased from China Veterinary Drug Control Institute, SalmonellaC _79-6 was purchased from China Veterinary Drug Control Institute, Pseudomonas qeruginosa ₁₀₁₄ was purchased from Beijing Institute of Biological Drugs, Klebsiella ₂₁₉ was purchased from Beijing Biological Drug Laboratory.

1.3 Test method

1.3.1 Comparison of antibacterial effect in vitro: Cool the melted agar medium to 50°C by cup and saucer method, add an appropriate amount of test bacteria solution and mix with the agar medium, draw 15ml and place it in a plate. After solidification, put Place the Oxford cup on the bacterial layer of the petri dish, add 0.2ml of liquid medicine to each cup, cover the petri dish, incubate at a constant temperature of 37°C for 18-24h, measure the diameter of the antibacterial zone with a vernier caliper. Judgment criteria for antibacterial effect: D≤8mm is not sensitive, 8mm<D≤13 is low sensitivity, 13mm<D≤19 is moderately sensitive, and 19mm<D is highly sensitive.

1.4 Optimization of synthesis conditions of piperidinium-quinoxaline-1,4-dioxide (c)

In this experiment, the material ratio of acemequine:bis-(piperidine)methane (X ₁ ) was 1:2-1:5.5, the reaction time (X ₂ ) was 0.5-3.5h, the reaction temperature (X ₃ ) was 0-65°C and Catalyst amount (X ₄ ) 0.5-2.0ml 4 factors and 8 levels were tested, and U ₈ ×(8 ⁴ ) table design was proposed.

2 Results and Discussion

2.1 In vitro antibacterial test results of 3-methyl-2-(aminostyryl)-quinoxaline-1,4-dioxide (a, b, c) and quinocetone are shown in Table 1.

Table 1. Comparison (mm) of the in vitro bacteriostatic effect of the target compound

x±s,n=5,p<0.05Vs control

It can be seen from Table 1 that quinocetone and compounds a, b, and c have different degrees of enhancement of the four kinds of bacteria used in the experiment, especially the inhibition zone of c on Escherichia coli is significantly increased. See Figures 7 and 8.

2.2 Physicochemical properties of compound c

Piperidinium-quinoxaline-1,4-dioxide (c) is a new compound, and its physical and chemical properties have not been reported yet. In this paper, its solubility and melting point were determined. This product is yellow powder, odorless, soluble in pyridine, tetrahydrofuran, dimethyl sulfoxide, slightly soluble in dioxane, acetone, insoluble in water, chloroform, benzene. The melting point is 203-205°C.

2.3 Uniform design to optimize the synthesis conditions of "compound c"

According to the single factor test, this experiment selects the material ratio of acemetquine: bis-(dipiperidine) methane (X1) 1:2.0-1:5.5, reaction time (X2) 1-4h, reaction temperature (X3) 0-65℃ And catalyst amount (X4) 0.4-1.8ml 4 factors and 8 levels were tested, and the U8×(84) table design was proposed, and the factors and levels are shown in Table 1.

Table 1. Factors and levels of compound c chemical synthesis uniform design

It can be seen from the table that the optimal reaction conditions are, acetylmequine: pyridine: bis-(piperidine) methane: concentrated hydrochloric acid (W: V: V) is 4.4g: 40mL: 0.15mL: 0.8mL. Stir at 55°C for 2h.

Beneficial effects of the present invention:

The amine methylene-quinoxaline-1,4-dioxide (a, b, c) synthesized by the present invention is a new type of veterinary drug synthesized by the applicant on the basis of quinone, which is insoluble in water and soluble in Dioxane and dimethyl sulfoxide have the same parent ring as that of olaquindox (quinetazine). Its activity test shows that it has good antibacterial activity against Escherichia coli C _83-1 , Pseudomonas aeruginosa C _79-6 , Salmonella ₁₀₁₄ , Klebsiella ₂₁₉ and so on. Among them, the piperidinium-quinoxaline-1,4-dioxide (c) prepared by the present invention is the best, and can be used as a new type of veterinary drug in the treatment of bacterial diseases. The synthesis method of the invention is simple and easy, has few by-products, high yield and mild conditions, and is suitable for large-scale industrial production.

Description of drawings

The accompanying drawings are used to provide a further understanding of the present invention, and constitute a part of the description, and are used together with the embodiments of the present invention to explain the present invention, and do not constitute a limitation to the present invention. In the attached picture:

Fig. 1 is the plate photo of cup and saucer method antibacterial experiment;

Fig. 2 is the photograph that vernier caliper measures the antibacterial circle diameter in the cup and saucer method antibacterial experiment;

Fig. 3 is compound a proton nuclear magnetic resonance spectrogram;

Fig. 4 is compound a carbon nuclear magnetic resonance spectrogram;

Fig. 5 is compound b proton nuclear magnetic resonance spectrogram;

Fig. 6 is compound b carbon nuclear magnetic resonance spectrogram;

Fig. 7 is compound c proton nuclear magnetic resonance spectrogram;

Figure 8 is a carbon nuclear magnetic resonance spectrum of compound c.

Detailed ways

The preferred embodiments of the present invention will be described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described here are only used to illustrate and explain the present invention, and are not intended to limit the present invention.

Example 1: Dimethylamine (diethylamine, piperidine) methylene-quinoxaline-1,4-dioxide

Preparation of dimethylaminomethylene-quinoxaline-1,4-dioxide (a)

1) Synthesis of bis-(dimethylamino)methane

Under cooling in an ice-water bath, add 15ml of 37% HCHO into the reaction flask, and under stirring, add 0.37mol NH(CH ₃ ) ₂ aqueous solution (50ml, 33wt%) dropwise with a dropping funnel. After the addition is complete, stir at room temperature for 30min, then Add solid NaOH until the solution forms two phases, divide the separating funnel into two layers, dry with solid NaOH, place and filter, distill at atmospheric pressure, and collect 83 ° C fractions.

2) Synthesis of Acetyl Mequin

Benzofurazan (10g, 73.5mmol), add excess acetylacetone 18g, warm in a water bath until dissolved, add 40ml of triethylamine under shaking, then warm for several minutes, cool at room temperature, place, and gradually precipitate crystallization, 10 hours A large number of yellow crystals precipitated out. The crystals were collected by suction filtration, washed with a small amount of water, and dried to give a yield of 11 g. Recrystallized from absolute ethanol to obtain bright yellow needle crystals with a yield of 68%.

3) Synthesis of the final product

Accurately weigh 4.4g of acemethaquine and dissolve it in 40ml of pyridine, heat the liquid paraffin to dissolve, add two drops of bis-(dimethylamine)methane and 10 drops of concentrated HCl, stir, reflux, TLC tracking until the end of the reaction, spin to dry the solvent , wash the concentrated solution with saturated NaCl to a separatory funnel, extract a small amount of ethyl acetate several times, combine the extracts, put them in anhydrous Na ₂ SO ₄ for drying, filter, spin dry, and evaporate the solvent to obtain a crude product. The crude product was separated by a silica gel column to obtain dendritic yellow crystals, namely compound a. See Figures 3 and 4 for its NMR spectra.

Example 2:

Preparation of diethylaminemethylene-quinoxaline-1,4-dioxide (b)

Its preparation method is the same as in Example 1, referring to Example 1, the difference is that in Step 1, diethylamine is used instead of dimethylamine to finally obtain compound b. See Figures 5 and 6 for its NMR spectrum.

Embodiment 3:

Preparation of piperidinium-quinoxaline-1,4-dioxide (c)

Its preparation method is basically the same as that of Example 1, the difference is that in step 1, piperidine is used to replace dimethylamine, and compound c is finally obtained. See Figures 7 and 8 for its NMR spectra.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still understand the foregoing embodiments The recorded technical solutions are modified, or some of the technical features are equivalently replaced. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (10)

1. An aminomethylene-quinoxaline-1, 4-dioxide having the formula:

（Ⅰ）

wherein,

。

2. a method for preparing aminomethylene-quinoxaline-1, 4-dioxide, characterized in that: the mequindox and the bis- (dimethylamine) methane or the bis- (diethylamine) methane or the bis- (piperidine) methane have Mannich reaction to generate aminomethylene-quinoxaline-1, 4-dioxide.

3. The process for the preparation of aminomethylene-quinoxaline-1, 4-dioxide according to claim 2, characterized in that: the Mannich reaction medium is an acidic reaction medium, and pyridine is used as a reaction solvent.

4. The process for the preparation of aminomethylene-quinoxaline-1, 4-dioxide according to claim 3, characterized in that: the acidic medium is obtained by adding concentrated hydrochloric acid, wherein the mequindox: pyridine: bis- (dimethylamine) methane or bis- (diethylamine) methane or bis- (piperidine) methane: concentrated hydrochloric acid 4.4 g: 40mL of: 0.15 mL: 0.8 mL.

5. The process for the preparation of aminomethylene-quinoxaline-1, 4-dioxide according to any of claims 2 to 4, characterized in that: the temperature of the Mannich reaction is controlled to be 55 ℃, and the reaction time is controlled to be 2 h.

6. The process for preparing aminomethylene-quinoxaline-1, 4-dioxide according to claim 5, characterized in that: the specific operation steps are as follows:

precisely weighing 4.4g of mequindox, dissolving the mequindox in 40mL of pyridine, heating to dissolve the mequindox, dripping 0.15mL of bis- (dimethylamine) methane or bis- (diethylamine) methane or bis- (piperidine) methane and 0.8mL of concentrated HCl, and stirring; controlling the temperature at 55 ℃, refluxing for 2 hours, finishing the reaction, spin-drying the solvent, washing the concentrated solution to a separating funnel by using saturated NaCl, extracting a small amount of ethyl acetate for multiple times, combining the extract liquor, and adding anhydrous Na₂SO₄Drying, filtering, spin-drying, and volatilizing solvent to obtain crude product, and separating the crude product with silica gel column to obtain dendritic yellow crystal as final product.

7. The process for preparing aminomethylene-quinoxaline-1, 4-dioxide according to claim 6, characterized in that: when heating and dissolving, liquid paraffin is adopted as a heating medium.

8. The process for producing aminomethylene-quinoxaline-1, 4-dioxide according to claim 6 or 7, characterized in that: the bis- (dimethylamine) methane or bis- (diethylamine) methane or bis- (piperidine) methane is prepared by the following method:

adding 15ml of 37% HCHO into a reaction bottle under the cooling of ice-water bath, dropwise adding an aqueous solution containing 0.37mol of dimethylamine or diethylamine or piperidine by using a dropping funnel under stirring, stirring at room temperature for 30min after the dropwise adding is finished, then adding solid NaOH until the solution forms two phases, separating the two phases by using a separating funnel, drying by using the solid NaOH, standing, filtering, distilling at normal pressure, and collecting 83 ℃ fractions to obtain the final product.

9. The process for producing aminomethylene-quinoxaline-1, 4-dioxide according to claim 6 or 7, characterized in that: the mequindox is prepared by the following method:

adding 18g of excessive acetylacetone into benzofurazan, heating in a water bath until the materials are dissolved, adding triethylamine under shaking, heating for a plurality of minutes, cooling at room temperature, standing, gradually precipitating crystals, precipitating a large amount of yellow crystals after 10 hours, performing suction filtration, collecting the crystals, washing with a small amount of water, drying, and recrystallizing with absolute ethyl alcohol to obtain fresh yellow needle-shaped crystals, namely mequindox.

10. Use of piperidine methylene-quinoxaline-1, 4-dioxide as a veterinary drug for the treatment of bacterial diseases.