CN104987346A - Method for preparing fluorescence polyamino compound - Google Patents

Abstract

The invention relates to a method for treating polybasic acid with thionyl chloride and reacting with amino compound to prepare polyamido compound with fluorescence. Including dissolving polybasic acid in tetrahydrofuran, adding thionyl chloride solution in tetrahydrofuran drop by drop, removing thionyl chloride after reaction to obtain mixture I; adding amino compound to mixture I to obtain mixture II, and washing mixture II three times with petroleum ether , separate the tetrahydrofuran layer with a separatory funnel, distill off the tetrahydrofuran under reduced pressure to obtain the crude product III; dissolve the polyamide compound in the crude product III with chloroform, and evaporate the chloroform under reduced pressure after centrifugation or filtration to finally obtain the fluorescent polyamido compounds. The reason why the compound obtained by the method of the present invention has fluorescence is that the molecular structure contains polyamide groups, and by changing different amino compounds, the fluorescence quantum intensity and fluorescence color of the product are different. The organic solvent used in the preparation process can be recycled and reused.

Description

A kind of preparation method of polyamido compound with fluorescence

technical field

The invention relates to a preparation method of a fluorescent polyamide compound, in particular to a method for using carboxylic acid as a reaction substrate and thionyl chloride as an acid chloride reagent to react with an amino compound to generate a fluorescent polyamide compound.

Background technique

Small organic molecules have fluorescent properties, mostly because they contain conjugated heterocyclic rings and various chromophores, and their conjugation length can be changed by introducing unsaturated groups such as ethylenic bonds and benzene rings and various chromophores. As a result, the photoelectric properties of the compound are changed. Among them, amide bonds are commonly used to connect conjugated heterocyclic rings and chromophore functional groups, but there are no compounds with fluorescent properties that only generate multiple amide bonds at home and abroad.

Contents of the invention

In order to solve the above technical problems, the present invention provides a method for preparing a fluorescent polyamide-based compound. The polyamide-based compound can be used to test the concentration of mercury ions in water.

Technical scheme of the present invention is as follows:

A kind of preparation method of polyamido compound with fluorescence, the steps are as follows:

1) Dissolve the carboxylic acid in tetrahydrofuran under the condition of blowing nitrogen gas, add the thionyl chloride solution diluted in tetrahydrofuran drop by drop, add amino compound (primary amine or secondary amine) to react after stirring. After the reaction is completed, excess thionyl chloride is steamed out to obtain a mixture I whose main component is polyacyl chloride;

2) Dissolving mixture I with tetrahydrofuran, adding amino compound and stirring to obtain mixture II whose main component is polyamide compound;

3) After the mixture II was washed three times with petroleum ether, the tetrahydrofuran layer was separated with a separatory funnel, and the tetrahydrofuran in the mixture was distilled off under reduced pressure to obtain the crude product III;

4) The crude product III was dissolved in chloroform, and after filtration, the chloroform in the chloroform solution was distilled off under reduced pressure to obtain a fluorescent polyamide compound.

The carboxylic acid in the above step 1) is selected from polybasic acid, the preferred polybasic acid is citric acid, and the quantum yield of its product is generally higher;

In the above step 1), the preferred mass ratio of polybasic acid to tetrahydrofuran is about 1:25~1:30. In this ratio, the reaction is mild and the amount of solvent used is moderate;

The molar ratio of polybasic acid to thionyl chloride in the above step 1) is about ( 1:n)~(1:1.05n) ;

The volume ratio of tetrahydrofuran to thionyl chloride in the above step 1) is about ( 5:1)~(50:1) ; (there is also a need for the ratio of the two in the thionyl chloride solution diluted with tetrahydrofuran)

The preferred reaction temperature range in the above step 1) is 0°C~30°C, and the reaction time is 1~4hr;

The amino compound in the above step 2) is preferably aminoethylaminopropyldimethoxysilane and acrylamine. When the reaction substrate is citric acid and N-(β-aminoethyl-γ-aminopropyl)methyldimethoxysilane, the quantum yield of the product is 10.7%. Under the irradiation of 365nm ultraviolet lamp, the fluorescence The color is blue-white. When the amino compound is diethylamine, the fluorescent color is yellow-green under the irradiation of 365nm ultraviolet light.

The molar ratio of the polyacid to the amino compound in the above step 2) is preferably ( 1:n) ~ (1:1.1n) , where n is the number of -COOH in the polyacid.

In the above step 2), the reaction temperature is preferably in the range of 30-50°C, which is easy to control, and there are few by-products in this temperature range. The reaction time is preferably 30 min to 1 hr, and the reaction efficiency is high within this reaction time.

In the above step 3), the preferred ratio of mixture II to the total volume of petroleum ether is about (75-150):750. Under this ratio, the amount of petroleum ether is moderate, and the unreacted amino compounds in the reaction system can be cleaned.

In the above step 4), the preferred volume ratio of the crude product III to chloroform is 1: (25-35). Under this ratio, the amount of chloroform is moderate and can completely dissolve the fluorescent polyamide compound in the crude product II.

The specific chemical reaction is as follows:

.

The excellent result effect of the inventive method is as follows:

1. The preparation method involved in the present invention is easy to operate. Polyamide-based compounds with higher fluorescence quantum yield and various fluorescent colors can be obtained only by lower temperature and shorter time.

2. The polyamide group compound quantum yield that the present invention obtains is higher. By adopting the preparation method of the invention, the quantum yield of the polyamide group compound is as high as 40.7%.

3. The preparation method involved in the present invention has obvious economic effect, and the solvent in each preparation step can be recycled and reused.

Description of drawings

Fig. 1 is the absorption spectrum, excitation spectrum and emission spectrum of the polyamido compound with fluorescence prepared in Example 1.

FIG. 2 is the emission spectrum of the fluorescent polyamide-based compound prepared in Example 1 at different excitation wavelengths.

3 is a product characterization diagram of the fluorescent polyamide-based compound prepared in Example 2.

Detailed ways

The present invention will be further described below in conjunction with example, but not limited thereto.

The raw materials used in the examples are anhydrous citric acid, glyceric acid, malic acid, diethylamine, ethylenediamine, diethylamine, allylamine, N-(β-aminoethyl-γ-aminopropyl)methyl Dimethoxysilane, thionyl chloride, tetrahydrofuran, petroleum ether, and chloroform (chloroform) are all commercially available.

Example 1

The preparation of fluorescent citric acid amide, the steps are as follows:

1. Take 2g of citric acid and put it into a three-necked flask, add 30ml of tetrahydrofuran to dissolve, slowly pass nitrogen gas, take 2.7ml of thionyl chloride (the molar ratio of citric acid and thionyl chloride is 1:3.2) and put it in a constant pressure funnel, and then use Dilute with 2.3 ml tetrahydrofuran, then add dropwise to the dissolved citric acid, stir the device evenly at 40°C for 12 hours, evaporate excess thionyl chloride to obtain transparent liquid I,

2. Take 2ml of tetrahydrofuran to dilute the transparent liquid I, add 10 ml of N-(β-aminoethyl-γ-aminopropyl)methyldimethoxysilane, and stir vigorously for half an hour to obtain mixture II;

3. The mixture II was washed three times with 35 mL of petroleum ether, the tetrahydrofuran layer was separated by a separatory funnel, and then the tetrahydrofuran was evaporated under reduced pressure to obtain about 2 g of the crude product III;

4. The product in the crude product III was extracted with 50 mL of chloroform, centrifuged or filtered, and then the chloroform was distilled off under reduced pressure to obtain a fluorescent polyamide compound CA-Si.

Fluorescence test was performed on the polyamide compound with fluorescence obtained above. Fig. 1 is the absorption spectrum, excitation spectrum and emission spectrum of polyamide compounds with fluorescence. The insert picture is a photo of fluorescent small molecule solution under natural light (left) and ultraviolet light (right). Figure 2 shows its emission spectra at different excitation wavelengths (the excitation wavelength difference is 20nm). Taking quinine sulfate as a reference substance, the fluorescence quantum yield of polyamide compound was 40.7%.

Example 2

The preparation of fluorescent citric acid amide, the steps are as follows:

1. Take 2g of citric acid and add it to a three-necked flask, add 30ml of tetrahydrofuran to dissolve it, slowly pass nitrogen gas, take 1.45ml of thionyl chloride (the molar ratio of citric acid and thionyl chloride is 1:2) and put it in a constant pressure funnel, Then dilute it with 1.55 ml tetrahydrofuran, then add it dropwise to the dissolved citric acid, put the device at 0°C and stir evenly for 12 hours, then add 20 ml of n-hexane and filter under reduced pressure three times, and distill the remaining thionyl chloride, namely Obtain transparent liquid I;

2. Take 2ml tetrahydrofuran to dilute the transparent liquid, add 10ml diethylamine, stir vigorously for half an hour to obtain mixture II;

3. The mixture II was washed three times with 35 mL of petroleum ether, the tetrahydrofuran layer was separated by a separatory funnel, and then the tetrahydrofuran was evaporated under reduced pressure to obtain about 1.25 g of crude product III.

4. Use 50mL tetrachloromethane to extract the product in the crude product III, centrifuge or filter and then steam the tetrachloromethane under reduced pressure to obtain a fluorescent polyamide compound CA;

The characterization diagram of the obtained product is shown in Figure 3, the UV absorbance, excitation and emission spectra of the fluorescent small molecule CA solution; and the photos of the fluorescent small molecule under natural light (right) and ultraviolet light (left). Taking quinine sulfate as a reference substance, the fluorescence quantum yield of polyamide compound was 37.6%.

Example 3

The preparation of fluorescent trisamide, the steps are as follows:

1. Take 2g of glyceric acid and add it to a three-necked flask, add 30ml of tetrahydrofuran to dissolve it, slowly blow in nitrogen, take 2.5ml of thionyl chloride (the molar ratio of citric acid and thionyl chloride is 1:2) and place it in a constant pressure funnel , then dilute with 1.5 ml tetrahydrofuran, then add dropwise to the dissolved citric acid, put the device at 0°C and stir evenly for 12 hours, then add 20 ml of n-hexane and filter under reduced pressure for three times, distill off the remaining thionyl chloride, Obtain transparent liquid I;

2. Take 2ml of tetrahydrofuran to dilute the transparent liquid, add diethylamine and N-(β-aminoethyl-γ-aminopropyl)methyldimethoxysilane 10 ml, stir vigorously for half an hour to obtain mixture II;

3. The mixture II was washed three times with 35mL petroleum ether, the tetrahydrofuran layer was separated by a separatory funnel, and then the tetrahydrofuran was evaporated under reduced pressure to obtain about 0.7g of the crude product III;

4. Use 50mL of chloroform to extract the product in the crude product III, centrifuge or filter, and then distill off the chloroform under reduced pressure to obtain a fluorescent polyamide compound.

The characterization of the obtained product is similar to Example 1, and the fluorescence quantum yield is 10.5%.

Example 4

The preparation of fluorescent trisamide, the steps are as follows:

1. Take 2g of glyceric acid and add it to a three-necked flask, add 30ml of tetrahydrofuran to dissolve it, slowly blow in nitrogen, take 1.4ml of thionyl chloride (the molar ratio of citric acid and thionyl chloride is 1:2.2) and place it in a constant pressure funnel , and then diluted with 2.6ml of tetrahydrofuran, and then added dropwise to the dissolved citric acid. After the device was uniformly stirred at 0°C for 12 hours, 20ml of n-hexane was added to filter under reduced pressure three times, and the excess thionyl chloride was distilled off. Obtain transparent liquid I;

2. Take 2ml tetrahydrofuran to dilute the transparent liquid, add an appropriate amount of N-(β-aminoethyl-γ-aminopropyl)methyldimethoxysilane 10ml, and stir vigorously for half an hour to obtain mixture II;

3. The mixture II was washed three times with 35 mL of petroleum ether, the tetrahydrofuran layer was separated by a separatory funnel, and then the tetrahydrofuran was evaporated under reduced pressure to obtain about 2.05 g of the crude product III.

4. Use 50mL of dichloromethane to extract the product in the crude product III, centrifuge or filter, and then distill off the dichloromethane under reduced pressure to obtain a fluorescent polyamide compound.

Example 5

The preparation of fluorescent citric acid amide, the steps are as follows:

1. Take 2g of malic acid and add it to a three-necked flask, add 30ml of tetrahydrofuran to dissolve it, slowly blow in nitrogen, take 2.7ml of thionyl chloride (the molar ratio of citric acid and thionyl chloride is 1:2.2) and put it in a constant pressure funnel, Then dilute with 2.3ml of tetrahydrofuran, then add dropwise into the dissolved citric acid, put the device at 0°C and stir evenly for 12 hours, add 20ml of n-hexane and filter under reduced pressure for three times, distill off excess thionyl chloride, namely Obtain transparent liquid I;

2. Take 2ml of tetrahydrofuran to dilute the transparent liquid, add 10ml of acrylamine, and stir vigorously for half an hour to obtain mixture II;

3. The mixture II was washed three times with 35mL petroleum ether, the tetrahydrofuran layer was separated by a separatory funnel, and then the tetrahydrofuran was evaporated under reduced pressure to obtain about 1.45g of crude product III.

4. Use 50mL of dichloromethane to extract the product in the crude product III, centrifuge or filter, and then distill off the dichloromethane under reduced pressure to obtain a fluorescent polyamide compound.

Example 6

The preparation of fluorescent citric acid amide, the steps are as follows:

1. Take 2g of citric acid and add it to a three-necked flask, add 30ml of tetrahydrofuran to dissolve it, slowly blow in nitrogen, take 1.45ml of thionyl chloride (the molar ratio of citric acid and thionyl chloride is 1:2.2) and place it in a constant pressure funnel, Then dilute with 1.55ml of tetrahydrofuran, then add dropwise into the dissolved citric acid, put the device at 0°C and stir evenly for 12 hours, add 20ml of n-hexane and filter under reduced pressure three times, distill off excess thionyl chloride, namely Obtain transparent liquid I;

2. Take 2ml of tetrahydrofuran to dilute the transparent liquid, add 10ml of acrylamine, and stir vigorously for half an hour to obtain mixture II;

3. The mixture II was washed three times with 35 mL of petroleum ether, the tetrahydrofuran layer was separated by a separatory funnel, and then the tetrahydrofuran was evaporated under reduced pressure to obtain about 0.9 g of the crude product III.

4. Use 50mL of chloroform to extract the product in the crude product III, centrifuge or filter, and then distill off the chloroform under reduced pressure to obtain a fluorescent polyamide compound.

Claims (10)

1. there is a preparation method for the multiamide based compound of fluorescence, it is characterized in that, comprise the steps:

1) under the condition passing into nitrogen, dissolve carboxylic acid with tetrahydrofuran (THF), after dropwise instilling the thionyl chloride solution of tetrahydrofuran (THF) dilution, after stirring, add aminocompound reaction, steam unnecessary thionyl chloride after reacting completely, obtain the mixture I that main component is polynary acyl chlorides;

2) with tetrahydrofuran (THF) dissolving mixt I, after adding aminocompound stirring, the mixtures II that main component is polynary amide compound is obtained;

3) after mixtures II being washed three times with sherwood oil, isolate tetrahydrofuran (THF) layer with separating funnel, the decompression tetrahydrofuran (THF) steamed in mixture obtains crude product III;

4) dissolve crude product III with chloroform, after filtration, chloroform decompression in chloroformic solution is steamed, finally obtain the multiamide based compound with fluorescence.

2. preparation method according to claim 1, is characterized in that, the carboxylic acid in step 1) is polyprotonic acid.

3. preparation method according to claim 2, is characterized in that, described polyprotonic acid is citric acid.

4. preparation method according to claim 1, is characterized in that, in step 1), carboxylic acid and tetrahydrofuran (THF) mass ratio are 1:25 ~ 1:30; Carboxylic acid acid is 1:(1-1.05 with thionyl chloride mol ratio) n, wherein n is the number of-COOH in polyprotonic acid; Tetrahydrofuran (THF) and thionyl chloride volume ratio are (5-50): 1.

5. preparation method according to claim 1, is characterized in that, in step 1), range of reaction temperature is 0 DEG C ~ 30 DEG C, and the reaction times is 1 ~ 4hr.

6. preparation method according to claim 1, is characterized in that, step 2) in, described aminocompound is the one in aminoethylaminopropyl dimethoxysilane, allylamine.

7. preparation method according to claim 1, is characterized in that, step 2) in, the mol ratio of polyprotonic acid and aminocompound is 1:(1-1.1) n, wherein n is the number of-COOH in polyprotonic acid.

8. preparation method according to claim 1, is characterized in that, step 2) in, range of reaction temperature is 30 ~ 50 DEG C,

Reaction times is 30min ~ 1hr.

9. preparation method according to claim 1, is characterized in that, in step 3), mixtures II is (1 ~ 2) with the ratio of sherwood oil cumulative volume: 10.

10. preparation method according to claim 1, is characterized in that, in step 4), crude product III is 1:(25 ~ 35 with the ratio of the volume of chloroform).