阅读说明：本技术 一种水杨醛基荧光化合物的制备方法 (Preparation method of salicylaldehyde-based fluorescent compound ) 是由 李淑君 戴慧超 郑芷伊 赵翘楚 王游 于 2020-06-02 设计创作，主要内容包括：本发明属于有机合成领域,特别涉及一种水杨醛基荧光化合物的制备方法。本发明利用天然产物和席夫碱反应的特点,制备的荧光化合物生物相容性好,不易溶于水,且固态下为橙色(或黄色)荧光发射。方法：(1)按摩尔体积比将40～80mmol水合肼(质量分数85％)溶解于10～20ml无水乙醇,升温至60～70℃,在不断搅拌的条件下,将40mmol水杨醛缓慢滴加至反应容器中,回流2～3h,趁热过滤得到黄色粉状固体,用无水乙醇洗涤后烘干,得到水杨醛腙；(2)按摩尔体积比将水杨醛腙与20～30mmol 1,4-苯二醛溶解于20～30ml DMF中,加入0.8～1.2ml乙酸做催化剂,加热回流4～6h后,冰水浴结晶过滤后获得沉淀,并用乙醇洗涤三次,干燥得荧光化合物1。本发明使用的原料价格低廉,环境友好,制备的荧光化合物产率高达58～72％。(The invention belongs to the field of organic synthesis, and particularly relates to a preparation method of a salicylaldehyde-based fluorescent compound. The invention utilizes the characteristic of the reaction of natural products and Schiff base, and the prepared fluorescent compound has good biocompatibility, is not easy to dissolve in water, and has orange (or yellow) fluorescence emission in a solid state. The method comprises the following steps: (1) dissolving 40-80 mmol of hydrazine hydrate (mass fraction 85%) in 10-20 ml of absolute ethyl alcohol according to a molar volume ratio, heating to 60-70 ℃, slowly dropwise adding 40mmol of salicylaldehyde into a reaction container under the condition of continuous stirring, refluxing for 2-3 h, filtering while hot to obtain yellow powdery solid, washing with absolute ethyl alcohol, and drying to obtain salicylaldehyde hydrazone; (2) dissolving salicylaldehyde hydrazone and 20-30 mmol 1, 4-benzaldehyde in 20-30 ml DMF according to a molar volume ratio, adding 0.8-1.2 ml acetic acid as a catalyst, heating and refluxing for 4-6 h, crystallizing in an ice water bath, filtering to obtain a precipitate, washing with ethanol for three times, and drying to obtain the fluorescent compound 1. The raw materials used in the invention are low in price and environment-friendly, and the yield of the prepared fluorescent compound is up to 58-72%.)

1. The preparation method of the salicylaldehyde-based fluorescent compound is characterized by comprising the following steps of:

(1) dissolving 40-80 mmol of hydrazine hydrate (mass fraction 85%) in 10-20 ml of absolute ethyl alcohol according to a molar volume ratio, heating to 60-70 ℃, slowly dropwise adding 40mmol of salicylaldehyde into a reaction container under the condition of continuous stirring, refluxing for 2-3 h, filtering while hot to obtain yellow powdery solid, washing with absolute ethyl alcohol, and drying to obtain salicylaldehyde hydrazone;

(2) dissolving salicylaldehyde hydrazone and 20-30 mmol 1, 4-benzaldehyde in 20-30 ml DMF according to molar volume ratio, adding 0.8-1.2 ml acetic acid as a catalyst, heating and refluxing for 4-6 h, crystallizing in an ice water bath, filtering to obtain a precipitate, washing with ethanol for three times, and drying to obtain a fluorescent compound 1 with the molecular formula of C₂₂H₁₈N₄O₂The concrete structure is as follows:

2. the preparation method according to claim 1, wherein in the step (1), the ratio of the hydrazine hydrate to the absolute ethyl alcohol is 40-80 mmol: 10 to 20 ml.

3. The preparation method according to claim 1, wherein in the step (1), the ratio of the hydrazine hydrate to the salicylaldehyde is 40-80 mmol: 40 mmol.

4. The preparation method according to claim 1, wherein in the step (1), the reaction temperature is 60-70 ℃ and the reflux time is 2-3 h.

5. The preparation method according to claim 1, wherein in the step (2), the ratio of the amount of 1, 4-benzenedialdehyde to DMF is 20-30 mmol: 20-30 ml.

6. The preparation method according to claim 1, wherein in the step (2), the ratio of the amount of the 1, 4-benzenedialdehyde to the amount of the acetic acid is 20-30 mmol: 0.8 to 1.2 ml.

7. The preparation method according to claim 1, wherein in the step (2), the reaction temperature is 40-50 ℃ and the reflux time is 4-6 h.

8. The method according to claim 1, wherein in the step (2), the residual ethanol is removed by vacuum drying after ethanol washing to obtain the fluorescent compound 1.

Technical Field

The invention belongs to the field of organic synthesis, and particularly relates to a preparation method of a salicylaldehyde-based fluorescent compound.

Background

Salicylaldehyde is a natural product of colorless to yellow oily liquid, can be used as a spice, a food additive and the like, can be used as an organic synthesis intermediate with extremely wide application, and is commonly used for synthesizing gypenzine, benzbromarone, acetominophenidone and the like in the synthesis of medicaments. The aldehyde group in the salicylaldehyde is an important functional group in organic synthesis, can react with amino to increase the length of a carbon chain, introduces a carbon-nitrogen double bond with bioactivity, can expand a conjugated system of the salicylaldehyde through the reaction, and expands the application of the salicylaldehyde in other fields.

Aggregation-induced emission (AIE) was proposed in 2001 by tangzhizhong et al, which solves the problem of aggregation-induced quenching of the conventional fluorescent materials, has stable chemical properties, very strong fluorescence in high water content, strong environmental adaptability, and excellent application prospects in the fluorescence detection field, can realize very sensitive detection of heavy metals and the like, and can also be applied to the related fields of biological imaging and the like. It is known that a fluorescent compound with a longer emission wavelength is more beneficial to biological imaging, and because the long emission wavelength has less photodamage to biological tissues and small interference to biological tissue autofluorescence, but at present, a fluorescent substance with a long emission wavelength is synthesized by complex chemical reactions, so that not only is the production cost high, but also due to the complex structure, the fluorescent substance has the disadvantages of high toxicity to biological tissues, poor biocompatibility and the like.

Disclosure of Invention

The invention aims to provide a preparation method of a fluorescent compound prepared by taking a natural product salicylaldehyde as a raw material, wherein the prepared fluorescent compound can emit orange or yellow fluorescence in a solid state.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a method for preparing a fluorescent compound by using a natural product salicylaldehyde as a raw material comprises the following steps:

(1) dissolving 40-80 mmol of hydrazine hydrate (mass fraction 85%) in 10-20 ml of absolute ethyl alcohol according to a molar volume ratio, heating to 60-70 ℃, slowly dropwise adding 40mmol of salicylaldehyde into a reaction container under the condition of continuous stirring, refluxing for 2-3 h, filtering while hot to obtain yellow powdery solid, washing with absolute ethyl alcohol, and drying to obtain salicylaldehyde hydrazone;

(2) dissolving salicylaldehyde hydrazone and 20-30 mmol 1, 4-benzaldehyde in 20-30 ml DMF according to a molar volume ratio, adding 0.8-1.2 ml acetic acid as a catalyst, heating and refluxing for 4-6 h, crystallizing in an ice water bath, filtering to obtain a precipitate, washing with ethanol for three times, and drying to obtain the fluorescent compound 1.

The salicylaldehyde, the hydrazine hydrate (the mass fraction is 85%) and the 1, 4-benzenedialdehyde are directly purchased by an alatin reagent company.

Preferably, in step (2), the residual ethanol is removed by vacuum drying after ethanol washing to obtain fluorescent compound 1.

The invention has the beneficial effects that:

(1) the used raw materials are low in price and environment-friendly;

(2) a simple and green synthesis path is used, so that the energy consumption is low;

(3) the yield of the fluorescent compound prepared by the invention is up to 58-72%;

(4) the invention utilizes the characteristic of the reaction of natural products and Schiff base, and the prepared fluorescent compound has good biocompatibility, is not easy to dissolve in water, and has orange (or yellow) fluorescence emission in a solid state.

Drawings

FIG. 1 is an infrared spectrum of a fluorescent compound 1 prepared according to the present invention, and the structures of the functional groups of the fluorescent compound 1 are determined.

FIG. 2 shows the NMR spectrum of fluorescent compound 1 prepared according to the present invention, and the structure of fluorescent compound 1 is determined.

FIG. 3 is a fluorescence spectrum of fluorescent compound 1 prepared according to the present invention, and it can be seen that the maximum excitation wavelength of fluorescent compound 1 is 410nm and the maximum emission wavelength is 580 nm.

Detailed Description

The first embodiment is as follows: dissolving 40mmol of hydrazine hydrate (85 mass percent) in 10ml of absolute ethyl alcohol, heating to 60 ℃, slowly dropwise adding 40mmol of salicylaldehyde into a reactor under the condition of continuous stirring, refluxing for 2 hours, filtering while hot to obtain yellow powdery solid, washing with absolute ethyl alcohol, putting into an oven for drying to obtain salicylaldehyde hydrazone, dissolving the obtained salicylaldehyde hydrazone and 30mmol of 1, 4-benzaldehyde in 30ml of DMF, adding 1.2ml of acetic acid as a catalyst, heating to 60 ℃, refluxing for 6 hours, crystallizing in an ice water bath, filtering to obtain precipitate, washing with ethanol for three times, and drying in vacuum to obtain a yellow powdery fluorescent compound 1 with the yield of 58%, wherein the fluorescent compound emits orange light under the irradiation of an ultraviolet lamp.

The second embodiment is as follows: dissolving 60mmol of hydrazine hydrate (85 mass percent) in 15ml of absolute ethyl alcohol, heating to 65 ℃, slowly dropwise adding 40mmol of salicylaldehyde into a reactor under the condition of continuous stirring, refluxing for 2.5 hours, filtering while hot to obtain a yellow powdery solid, washing with absolute ethyl alcohol, putting into an oven for drying to obtain salicylaldehyde hydrazone, dissolving the obtained salicylaldehyde hydrazone and 30mmol of 1, 4-benzaldehyde in 30ml of DMF, adding 1.2ml of acetic acid as a catalyst, heating to 60 ℃, refluxing for 6 hours, crystallizing in an ice water bath, filtering to obtain a precipitate, washing with ethanol for three times, drying in vacuum to obtain a yellow powdery fluorescent compound 1 with the yield of 60%, and emitting orange light by irradiating an ultraviolet lamp with the fluorescent compound.

The third concrete implementation mode: dissolving 80mmol of hydrazine hydrate (85 mass percent) in 20ml of absolute ethyl alcohol, heating to 70 ℃, slowly dripping 40mmol of salicylaldehyde into a reactor under the condition of continuous stirring, refluxing for 3 hours, filtering while the salicylaldehyde is hot to obtain yellow powdery solid, washing with the absolute ethyl alcohol, putting into an oven for drying to obtain salicylaldehyde hydrazone, dissolving the obtained salicylaldehyde hydrazone and 30mmol of 1, 4-benzaldehyde in 30ml of DMF, adding 1.2ml of acetic acid as a catalyst, heating to 60 ℃, refluxing for 6 hours, crystallizing in an ice water bath, filtering to obtain precipitate, washing with ethanol for three times, and drying in vacuum to obtain a yellow powdery fluorescent compound 1 with the yield of 63%, wherein the fluorescent compound emits orange light under the irradiation of an ultraviolet lamp.

The fourth concrete implementation mode: dissolving 40mmol of hydrazine hydrate (85 mass percent) in 10ml of absolute ethyl alcohol, heating to 60 ℃, slowly dropwise adding 40mmol of salicylaldehyde into a reactor under the condition of continuous stirring, refluxing for 2 hours, filtering while hot to obtain yellow powdery solid, washing with absolute ethyl alcohol, putting into an oven for drying to obtain salicylaldehyde hydrazone, dissolving the obtained salicylaldehyde hydrazone and 20mmol of 1, 4-benzaldehyde in 20ml of DMF, adding 0.8ml of acetic acid as a catalyst, heating to 60 ℃, refluxing for 4 hours, crystallizing in an ice water bath, filtering to obtain precipitate, washing with ethanol for three times, and drying in vacuum to obtain a yellow powdery fluorescent compound 1 with the yield of 65%, wherein the fluorescent compound emits orange light under the irradiation of an ultraviolet lamp.

The fifth concrete implementation mode: dissolving 60mmol of hydrazine hydrate (85 mass percent) in 15ml of absolute ethyl alcohol, heating to 65 ℃, slowly dropwise adding 40mmol of salicylaldehyde into a reactor under the condition of continuous stirring, refluxing for 2.5 hours, filtering while hot to obtain a yellow powdery solid, washing with absolute ethyl alcohol, putting into an oven for drying to obtain salicylaldehyde hydrazone, dissolving the obtained salicylaldehyde hydrazone and 20mmol of 1, 4-benzaldehyde in 20ml of DMF, adding 0.8ml of acetic acid as a catalyst, heating to 60 ℃, refluxing for 4 hours, crystallizing in an ice water bath, filtering to obtain a precipitate, washing with ethanol for three times, drying in vacuum to obtain a yellow powdery fluorescent compound 1, wherein the yield is 67%, and the fluorescent compound emits orange light under the irradiation of an ultraviolet lamp.

The sixth specific implementation mode: dissolving 80mmol of hydrazine hydrate (85 mass percent) in 20ml of absolute ethyl alcohol, heating to 70 ℃, slowly dripping 40mmol of salicylaldehyde into a reactor under the condition of continuous stirring, refluxing for 3 hours, filtering while the salicylaldehyde is hot to obtain yellow powdery solid, washing with the absolute ethyl alcohol, putting the yellow powdery solid into an oven for drying to obtain salicylaldehyde hydrazone, dissolving the obtained salicylaldehyde hydrazone and 20mmol of 1, 4-benzaldehyde in 20ml of DMF, adding 0.8ml of acetic acid as a catalyst, heating to 60 ℃, refluxing for 4 hours, crystallizing in an ice water bath, filtering to obtain precipitate, washing with ethanol for three times, and drying in vacuum to obtain a yellow powdery fluorescent compound 1 with the yield of 70%, wherein the fluorescent compound emits orange light under the irradiation of an ultraviolet lamp.

The seventh embodiment: dissolving 80mmol of hydrazine hydrate (85 mass percent) in 20ml of absolute ethyl alcohol, heating to 70 ℃, slowly dripping 40mmol of salicylaldehyde into a reactor under the condition of continuous stirring, refluxing for 3 hours, filtering while the salicylaldehyde is hot to obtain yellow powdery solid, washing with the absolute ethyl alcohol, putting the yellow powdery solid into an oven for drying to obtain salicylaldehyde hydrazone, dissolving the obtained salicylaldehyde hydrazone and 20mmol of 1, 4-benzaldehyde in 20ml of DMF, adding 0.8ml of acetic acid as a catalyst, heating to 70 ℃, refluxing for 6 hours, crystallizing in an ice water bath, filtering to obtain precipitate, washing with ethanol for three times, and drying in vacuum to obtain a yellow powdery fluorescent compound 1 with the yield of 72%, wherein the fluorescent compound emits orange light under the irradiation of an ultraviolet lamp.