A pyridine-pyrimidine thiohydrazide Al 3+ and Zr 4+ fluorescent probe

Abstract

The present application relates to a kind of pyridopyrimidine thiohydrazine class Al 3+ And Zr 4+ Fluorescent probe, its preparation method is first 3- (dimethylamino) -1- (pyridine-4-yl) -2-propylene-1-ketone and thiourea are reacted to obtain intermediate 1, after again with ethyl bromoacetate reaction obtains intermediate 2, intermediate 2 and hydrazine hydrate carry out amidation reaction to obtain the intermediate 3 with 2-hydroxy-1-naphthaldehyde carries out amine aldehyde condensation, and pyridopyrimidine thiohydrazine class Al 3+ And Zr 4+ Fluorescent probe.The present application fluorescent probe is a kind of raw material cheap and easy to obtain, yield is high, pH applicable range is wide and the high selectivity chemical sensor of strong anti-interference ability, can be used for the qualitative and trace detection of Al 3+ And Zr 4+ In natural water body and environment, has good practical value and popularization value.

Description

Technical Field

[0001] This invention relates to a pyridopyrimidine thiohydrazide Al 3+ and Zr 4+ Fluorescent probes specifically belong to the field of organic chemical fluorescent functional materials technology. Background Technology

[0002] Aluminum is one of the most abundant metallic elements in the Earth's crust, ranking third in abundance. Due to its excellent electrical conductivity, corrosion resistance, and malleability, it is widely used in various industries, including aerospace, automotive manufacturing, materials, food packaging, aluminum tableware, and pharmaceutical production. However, aluminum is not an essential trace element for the human body, and excessive intake can lead to diseases such as Parkinson's disease, Alzheimer's disease, and osteoporosis. High levels of aluminum ions in the environment can easily cause water pollution and plant death. Therefore, trace detection of aluminum ions in the environment is particularly important.

[0003] Zirconium, as a transition metal element, is widely used in mining, electronics, and ceramics due to its excellent high-temperature resistance and corrosion resistance. While zirconium and its compounds have low toxicity, zirconium-containing compounds can damage multiple organs in animals, including the kidneys, liver, and brain. High concentrations of zirconium salts, when inhaled, can cause various respiratory diseases and immune system disorders. High concentrations of zirconium ions can also pollute water and soil environments. However, there are very few reports on fluorescent probes for detecting zirconium ions. Therefore, designing and synthesizing a fluorescent probe capable of rapidly and sensitively detecting zirconium ions in the environment and water is of significant practical importance.

[0004] Currently, methods for metal ion detection mainly include spectrophotometry, inductively coupled plasma atomic absorption spectrometry, and atomic absorption spectrometry. However, these methods are relatively complex to operate, expensive, and have slow signal response. Fluorescence analysis has gained widespread attention due to its advantages of high sensitivity, ease of operation, and low cost. Currently, for the detection of Zr... 4+ There is very little research on fluorescent probes for Zr, and the ones that have been reported are... 4+ Most identification probes suffer from drawbacks such as poor anti-interference ability and a narrow pH range. However, a fluorescent probe based on pyridine-thiophene-rhodamine, developed by Mahappatraa et al. in 2013, can detect Zr... 4+Identification was performed, but due to its ring-opening phenomenon, the applicable pH range was small, and only 14 metal ions were compared and detected (AKMahapatraa, SK Mannaa, SK Mukhopadhyay, A. Banik, First rhodamine-based “off-on” chemosensor with high selectivity and sensitivity for Zr). 4+ and its imaging in living cells. [J]. Sensors and Actuators B: Chemical. 2013, 183, 350-355). Currently, there is no technology capable of simultaneously detecting Al. 3+ and Zr 4+ Report on dual-channel fluorescent probes.

[0005] Therefore, the pH range designed in this invention is wide, the anti-interference ability is strong, and it can specifically identify Al. 3+ and Zr 4+ The dual-channel fluorescent probe has significant practical importance and application value. Summary of the Invention

[0006] This invention aims to provide pyridine-pyrimidine thiohydrazides Al 3+ and Zr 4+ Fluorescent probes and their preparation methods, including pyridopyrimidine thiohydrazides of the present invention. 3+ and Zr 4+ Fluorescent probes are characterized by biselectivity, strong anti-interference ability, wide pH range, convenient and fast detection, and significant recognition effect.

[0007] This invention relates to a pyridopyrimidine thiohydrazide Al 3+ and Zr 4+ The chemical structural formula of the fluorescent probe is:

[0008] .

[0009] The pyridine-pyrimidine thiohydrazide Al 3+ and Zr 4+ The preparation method of the fluorescent probe is as follows:

[0010] Step 1: 3-(dimethylamino)-1-(pyridin-4-yl)-2-propen-1-one, thiourea and KOH were heated under reflux in anhydrous ethanol for 6 to 8 hours, cooled to room temperature and the pH was adjusted to neutral. The precipitated orange solid was filtered to obtain intermediate 1.

[0011] Step 2: Under an argon atmosphere, intermediate 1 and sodium hydride were reacted in DMF (N,N-dimethylformamide) at room temperature for 1 h, followed by the addition of ethyl bromoacetate and the reaction continued overnight. The product was extracted with ethyl acetate, and the resulting organic phase was separated by brine extraction, drying with anhydrous sodium sulfate, and column chromatography to obtain intermediate 2.

[0012] Step 3: Intermediate 2 and hydrazine hydrate were heated under reflux in anhydrous ethanol for 5-6 hours, then cooled to room temperature and filtered to obtain intermediate 3.

[0013] Step 4: Intermediate 3 and 2-hydroxy-1-naphthaldehyde were heated under reflux in anhydrous ethanol for 4-6 h, then cooled to room temperature and filtered to obtain pyridinoid pyrimidine thiohydrazide Al. 3+ and Zr 4+ Fluorescent probe.

[0014] The equivalent ratio of 3-(dimethylamino)-1-(pyridin-4-yl)-2-propen-1-one, thiourea, and KOH is 1:1.2:1.1.

[0015] The equivalent ratio of intermediate 1, sodium hydride, and ethyl bromoacetate is 1:1:1.8.

[0016] The eluent used in the column chromatography separation is petroleum ether / ethyl acetate in a volume ratio of 1:3.

[0017] The material ratio of intermediate 2, hydrazine hydrate and anhydrous ethanol is 0.6 g: 0.5 ml: 6 ml, wherein the mass concentration of hydrazine hydrate is 40% to 50%.

[0018] The equivalent ratio of intermediate 3 and 2-hydroxy-1-naphthaldehyde is 1:1.

[0019] This invention Al 3+ and Zr 4+ The reaction equation for the fluorescent probe is as follows:

[0020] ;

[0021] NNS is the target fluorescent probe molecule.

[0022] The beneficial effects of this invention are:

[0023] 1. The fluorescent probe of this invention is prepared by adding Al to a DMSO / H2O solution (dimethyl sulfoxide and aqueous solution). 3+ A strong blue fluorescence was subsequently produced upon the addition of Zr. 4+ The fluorescence then turns bright green, which can be clearly distinguished from other metal ions. It has high sensitivity and good anti-interference ability.

[0024] 2. In practical applications, the fluorescent probe of this invention can be used for qualitative and quantitative detection by fluorescent lamp and fluorescence spectrometer. It is simple to operate, inexpensive, and has strong anti-interference ability. It can realize dual-channel detection of aluminum ions and zirconium ions, and the identification effect is significant.

[0025] 3. The fluorescent probe of this invention is effective for Al 3+ and Zr 4+ The detection limits are as low as 1.26 × 10⁻⁶. -7 M and 1.33×10 -7 M can be used in natural environments such as soil and water bodies. 3+ and Zr 4+ Trace analysis and detection of ion concentration has certain practical and promotional value. Attached Figure Description

[0026] Figure 1 This is the fluorescence emission spectrum of the fluorescent probe NNS of this invention;

[0027] Figure 2 Different concentrations of Al were added to the fluorescent probe NNS of this invention. 3+ Fluorescence emission spectrum after treatment;

[0028] Figure 3 Al was added to the fluorescent probe NNS of this invention. 3+ Fluorescence intensity working curve;

[0029] Figure 4 The fluorescent probe NNS of this invention binds to Al 3+ Job's Plot curve;

[0030] Figure 5 The fluorescent probe NNS of this invention binds to Al 3+ Ion competition columnar spectra;

[0031] Figure 6 The fluorescent probes NNS and NNS-Al of this invention 3+ Fluorescence changes at different pH values;

[0032] Figure 7 Different concentrations of Zr were added to the fluorescent probe of this invention. 4+ Fluorescence emission spectrum after treatment;

[0033] Figure 8 Adding Zr to the fluorescent probe of this invention 4+ Fluorescence intensity working curve;

[0034] Figure 9 The fluorescent probe NNS of this invention binds to Zr 4+ Job's Plot curve;

[0035] Figure 10 The fluorescent probe NNS of this invention binds to Zr 4+ Ion competition columnar spectra;

[0036] Figure 11 The fluorescent probes NNS and NNS-Zr of this invention 4+ Fluorescence changes at different pH values;

[0037] Figure 12 This is the chemical structural formula of the fluorescent probe of the present invention. Detailed Implementation

[0038] Example 1

[0039] Pyridine-pyrimidine thiohydrazides Al 3+ and Zr 4+ Synthesis of fluorescent probes

[0040] Synthesis of intermediate 1:

[0041] 3-(dimethylamino)-1-(pyridin-4-yl)-2-propen-1-one (3.5244 g, 20 mmol), thiourea (1.6747 g, 22 mmol), and KOH (1.1782 g, 21 mmol) were dissolved in 20 mL of anhydrous ethanol and heated under reflux for 6 h at 80 °C. The reaction was monitored by TLC. After the reaction was complete, the mixture was cooled to room temperature and the pH of the solution was adjusted to neutral with hydrochloric acid (37%). An orange solid precipitated and was filtered. The solid was washed once with anhydrous ethanol and once with distilled water, and then dried to obtain 2.9887 g of yellow powder (intermediate 1), with a yield of 84.8%.

[0042] Synthesis of intermediate 2:

[0043] Intermediate 1 (1.8924 g, 10 mmol) and sodium hydride (0.2790 g, 11 mmol) were dissolved in 10 mL of DMF. The mixture was reacted at room temperature for 1 h under argon protection. Ethyl bromoacetate (2.0 mL, 18 mmol) was then added to continue the reaction. The reaction progress was monitored by TLC. After the reaction was complete, the product was extracted with ethyl acetate. The resulting organic phase was washed with saturated brine, dried over anhydrous sodium sulfate, and the ethyl acetate solvent was removed by rotary evaporation. The product was then separated by column chromatography with petroleum ether:ethyl acetate = 1:3 as the eluent to give 1.1855 g of a pale yellow solid (intermediate 2), with a yield of 62.6%.

[0044] Synthesis of intermediate 3:

[0045] Intermediate 2 (0.5507 g, 2 mmol) and 0.5 mL of hydrazine hydrate (40% ~ 50% by mass) were added to a 50 mL round-bottom flask, followed by 6 mL of anhydrous ethanol. The mixture was heated under reflux for 6 h at 80 °C. After the reaction was completed by TLC monitoring, the reactants were cooled to room temperature and filtered to obtain 0.4932 g of white solid product (intermediate 3), with a yield of 89.6%.

[0046] Synthesis of probe NNS:

[0047] Intermediate 3 (0.2613 g, 1 mmol) and 2-hydroxy-1-naphthaldehyde (0.1722 g, 1 mmol) were dissolved in 8 mL of anhydrous ethanol and heated under reflux for 6 h at a reaction temperature of 80 °C. After the reaction was completed by TLC monitoring, the solution was cooled to room temperature and filtered to obtain 0.3754 g of the target probe compound NNS, with a yield of 86.6%.

[0048] 1 H NMR (500 MHz, DMSO- d 6 ) δ 9.29 (s, 1H), 8.79 (dd, J = 12.8, 4.9 Hz, 2H), 8.48 (d, J = 7.9 Hz, 1H), 8.28 (d, J = 8.6 Hz, 1H), 8.06 (d, J = 5.0 Hz, 1H), 7.91 (q, J = 6.8 Hz, 3H), 7.58 (t, J = 7.8 Hz, 1H), 7.56 - 7.48 (m, 2H), 7.40 (t, J = 7.5 Hz, 1H), 7.20 (d, J = 8.9 Hz, 1H), 4.60 (s, 1H), 4.16 (s, 2H).

[0049] Example 2

[0050] Pyridine-pyrimidine thiohydrazides Al 3+ and Zr 4+ Determination of fluorescence selectivity of the fluorescent probe NNS.

[0051] Weigh 0.0208 g of fluorescent probe NNS, dissolve it in DMSO solvent and dilute to 50 mL in a volumetric flask to prepare a 1 mmol / L solution, which is the fluorescent probe NNS stock solution.

[0052] The test was conducted in a DMSO:H2O = 1:1 (v / v) solution system. Twenty-two 5 mL centrifuge tubes were used, and 60 μL of the fluorescent probe NNS stock solution, 1400 μL of DMSO solution, and 1200 μL of pure aqueous solution were added to each tube, respectively. One centrifuge tube was used as a blank control without metal ion solution. The remaining 21 centrifuge tubes were each added with 300 μL of a 1 mol / L metal ion solution containing Li. + Na + Mg 2+ Al 3+ , K + Ca 2+ , Cr 3+ , Mn 2+ Fe 2+ Fe 3+ Co 2+ Ni 2 + Cu 2+ Zn 2+ Ag + Cd 2+ Ba 2+ Hg 2+ , Pb 2+ Ce 3+ Zr 4+ After mixing thoroughly, the fluorescence spectrum was measured.

[0053] Al was measured at an excitation wavelength of 393 nm. 3+ The detection solution exhibited a very significant fluorescence enhancement at 455 nm, displaying blue fluorescence. Zr... 4+ Two fluorescence emission peaks appeared in the detection solution, at 485 nm and 512 nm, respectively, producing green fluorescence. This indicates that the fluorescent probe NNS can specifically recognize Al. 3+ and Zr 4+ Its fluorescence spectrum is as follows Figure 1 As shown.

[0054] Example 3

[0055] Pyridine-pyrimidine thiohydrazides Al 3+ and Zr 4+ Fluorescent probe NNS for Al 3+ Quantitative fluorescence detection.

[0056] The test was conducted in a DMSO:H2O = 1:1 (v / v) solution system. Fourteen 5 mL centrifuge tubes were used, and 60 μL of fluorescent probe NNS stock solution and 1400 μL of DMSO solution were added to each tube, followed by the addition of 1 eq to 10 eq of Al. 3+ Prepare a solution (60 μL ~ 600 μL), then add 1440 μL ~ 900 μL of aqueous solution.

[0057] like Figure 2 As shown, the probe moves with Al at an excitation wavelength of 393 nm. 3+ Fluorescence spectra showing changes in solubility. Furthermore, the fluorescence intensity at 455 nm is related to Al. 3+ A linear fit was performed, and the resulting scatter plot of the linear fit is shown below. Figure 3 As shown. Based on its slope, the lowest detection limit is calculated to be 1.26 × 10⁻⁶. -7 M.

[0058] Example 4

[0059] Pyridine-pyrimidine thiohydrazides Al 3+ and Zr 4+ Fluorescent probe NNS for Al 3+ Job's Plot curve.

[0060] The test was conducted in a DMSO : H2O = 1 : 1 (v / v) solution system. Nine 5 mL centrifuge tubes were used, and fluorescent probes NNS and Al were added to the tubes. 3+ The concentration ratios were 1:9, 2:8, 3:7, 4:6, 5:5, 6:4, 7:3, 8:2, and 9:1, with the initial concentration of the probe NNS being 30 μM.

[0061] like Figure 4 As shown, the fluorescence intensity at 455 nm under excitation at a wavelength of 393 nm by a fluorescence spectrometer is [NNS] / {[NNS]+[Al] 3+ The fluorescence intensity is highest at 0.5, therefore it can be inferred that the probe NNS and Al... 3+ The complexation ratio is 1:1.

[0062] Example 5

[0063] Pyridine-pyrimidine thiohydrazides Al 3+ and Zr 4+ Fluorescent probe NNS for Al 3+ Ion competition detection.

[0064] The test was conducted in a DMSO:H2O = 1:1 (v / v) solution system, divided into two groups. In the first group, 21 5 mL centrifuge tubes were used. 60 μL of the fluorescent probe NNS stock solution, 1400 μL of DMSO solution, and 1200 μL of pure aqueous solution were added to each tube, respectively. One centrifuge tube was used as a blank control without adding the metal ion solution. The remaining 20 centrifuge tubes were each added with 300 μL of a 1 mol / L metal ion solution, including:

[0065] Li + Na + Mg 2+ Al 3+ , K + Ca 2+ , Cr 3+ , Mn 2+ Fe 2+ Fe 3+ Co 2+ Ni 2+ Cu 2+ Zn 2 + Ag + Cd 2+ Ba 2+ Hg 2+ , Pb 2+ Ce 3+ The second group consisted of 19 5 mL centrifuge tubes. To each tube, 60 μL of the fluorescent probe NNS stock solution, 1400 μL of DMSO solution, 900 μL of pure water, and 300 μL of Al were added. 3+ The solution and 300 μL of other metal ions (Li) + Na + Mg 2+ , K + Ca 2+ , Cr 3+ , Mn 2+ Fe 2+ Fe 3+ Co 2+ Ni 2+ Cu 2+ ,Zn 2+ Ag + Cd 2+ Ba 2+ Hg 2+ , Pb 2+ Ce 3+ ).

[0066] like Figure 5 The bar chart illustrates the effect of the fluorescent probe NNS on Al. 3+ It has strong anti-interference ability, and other metal ions do not affect the NNS probe's recognition of Al. 3+ ion.

[0067] Example 6

[0068] Pyridine-pyrimidine thiohydrazide Al at different pH levels 3+ and Zr 4+ Fluorescent probes NNS probes and Al 3+ Fluorescence changes upon binding.

[0069] The test was conducted in a DMSO:H2O = 1:1 (v / v) solution system, with pH measurements performed in two groups. Eleven centrifuge tubes were used in each group. In the first group, 60 μL of probe NNS stock solution and 1440 μL of DMSO solution were added to each of the eleven centrifuge tubes, followed by the addition of 1500 μL of a solution with a pH ranging from 2 to 12. In the second group, 60 μL of probe NNS stock solution and 300 μL of Al were added to each of the eleven centrifuge tubes. 3+ The solution consisted of 1440 μL of DMSO solution, followed by the addition of 1200 μL of solutions with pH values ​​between 2 and 12.

[0070] like Figure 6 As shown in the figure, the fluorescence value of the fluorescent probe at 455 nm was measured at an excitation wavelength of 393 nm. Based on this figure, the fluorescence value of Al detected by the fluorescent probe can be determined. 3+ The applicable pH range is 4 to 10.

[0071] Example 7

[0072] Pyridine-pyrimidine thiohydrazides Al 3+ and Zr 4+ Fluorescent probe NNS for Zr 4+ Quantitative fluorescence detection.

[0073] The test was conducted in a DMSO:H2O = 1:1 (v / v) solution system. Fourteen 5 mL centrifuge tubes were used, and 60 μL of fluorescent probe NNS stock solution, 1400 μL of DMSO solution, and then 1 eq ~ 10 eq of Zr were added to each tube. 4+ Prepare a solution (60 μL ~ 600 μL), then add 1440 μL ~ 900 μL of aqueous solution.

[0074] like Figure 7 As shown, the probe moves with Zr at an excitation wavelength of 393 nm. 4+Fluorescence spectra showing changes in solubility. Furthermore, the ratio of fluorescence intensity at 485 nm and 512 nm is compared with that of Zr. 4+ A linear fit was performed, and the resulting scatter plot of the linear fit is shown below. Figure 8 As shown. Based on its slope, the lowest detection limit is calculated to be 1.33 × 10⁻⁶. -7 M.

[0075] Example 8

[0076] Pyridine-pyrimidine thiohydrazides Al 3+ and Zr 4+ Fluorescent probe NNS for Zr 4+ Job's Plot curve.

[0077] The test was conducted in a DMSO : H2O = 1 : 1 (v / v) solution system. Nine 5 mL centrifuge tubes were used, and fluorescent probes NNS and Zr were added to the tubes. 4+ The concentration ratios were 1:9, 2:8, 3:7, 4:6, 5:5, 6:4, 7:3, 8:2, and 9:1, with the initial concentration of the probe NNS being 30 μM.

[0078] like Figure 9 As shown, at an excitation wavelength of 393 nm, the ratio of fluorescence intensity at 485 nm and 512 nm is [NNS] / {[NNS]+[Zr] 4+ The fluorescence intensity is highest at 0.5, therefore it can be inferred that the probe NNS and Zr... 4+ The complexation ratio is 1:1.

[0079] Example 9

[0080] Pyridine-pyrimidine thiohydrazides Al 3+ and Zr 4+ Fluorescent probe NNS for Zr 4+ Ion competition detection.

[0081] The test was conducted in a DMSO:H2O = 1:1 (v / v) solution system, divided into two groups. In the first group, 21 5 mL centrifuge tubes were used. 60 μL of the fluorescent probe NNS stock solution, 1400 μL of DMSO solution, and 1200 μL of pure water were added to each tube, respectively. One centrifuge tube was used as a blank control without adding the metal ion solution. The remaining 20 centrifuge tubes were each added with 300 μL of a 1 mol / L metal ion solution, including:

[0082] Li + Na + Mg2+ , K + Ca 2+ , Cr 3+ , Mn 2+ Fe 2+ Fe 3+ Co 2+ Ni 2+ Cu 2+ Zn 2+ Ag + Cd 2+ Ba 2+ Hg 2+ , Pb 2+ Ce 3+ Zr 4+ The second group consisted of 19 5 mL centrifuge tubes. To each tube, 60 μL of the fluorescent probe NNS stock solution, 1400 μL of DMSO solution, 900 μL of pure water, and 300 μL of Zr were added. 4+ The solution and 300 μL of other metal ions (Li) + Na + Mg 2+ , K + Ca 2+ , Cr 3+ , Mn 2+ Fe 2+ Fe 3+ Co 2+ Ni 2+ Cu 2+ Zn 2+ Ag + Cd 2+ Ba 2+ Hg 2+ , Pb 2+ Ce 3+ ).

[0083] like Figure 10 The bar chart shows that the fluorescent probe NNS is effective against Zr. 4+ It has strong anti-interference ability, and other metal ions can recognize Zr by the probe NNS. 4+ It has almost no impact.

[0084] Example 10

[0085] Pyridine-pyrimidine thiohydrazides Al 3+ and Zr 4+ Fluorescent probe NNS at different pH values ​​and probe Zr 4+ Fluorescence changes.

[0086] The test was conducted in a DMSO:H2O = 1:1 (v / v) solution system, with pH measurements performed in two groups. Eleven centrifuge tubes were used in each group. In the first group, 60 μL of probe NNS stock solution and 1440 μL of DMSO solution were added to each of the eleven centrifuge tubes, followed by the addition of 1500 μL of a solution with a pH ranging from 2 to 12. In the second group, 60 μL of probe NNS stock solution and 300 μL of Zr were added to each of the eleven centrifuge tubes. 4+ The solution consisted of 1440 μL of DMSO solution, followed by the addition of 1200 μL of solutions with pH values ​​between 2 and 12.

[0087] like Figure 11 As shown in the figure, the fluorescence value of the fluorescent probe at 455 nm was measured at an excitation wavelength of 393 nm. Based on this figure, the fluorescence value of the fluorescent probe for detecting Zr can be determined. 4+ The applicable pH range is 4 to 10.

Claims

1. A pyridopyrimidine thiohydrazide Al 3+ and Zr 4+ Fluorescent probe, characterized in that: The aforementioned pyridine-pyrimidine thiohydrazide Al 3+ and Zr 4+ The chemical structural formula of the fluorescent probe is: 。 2. The pyridopyrimidine thiohydrazide Al according to claim 1 3+ and Zr 4+ Fluorescent probe, characterized in that: The pyridine-pyrimidine thiohydrazide Al 3+ and Zr 4+ The preparation method of the fluorescent probe is as follows: Step 1: 3-(dimethylamino)-1-(pyridin-4-yl)-2-propen-1-one, thiourea and KOH were heated under reflux in anhydrous ethanol for 6 to 8 hours, cooled to room temperature and the pH was adjusted to neutral. The precipitated orange solid was filtered to obtain intermediate 1. Step 2: Under an argon atmosphere, intermediate 1 and sodium hydride were reacted in DMF (N,N-dimethylformamide) at room temperature for 1 h, followed by the addition of ethyl bromoacetate and the reaction continued overnight. The product was extracted with ethyl acetate, and the resulting organic phase was separated by brine extraction, drying with anhydrous sodium sulfate, and column chromatography to obtain intermediate 2. Step 3: Intermediate 2 and hydrazine hydrate were heated under reflux in anhydrous ethanol for 5-6 hours, then cooled to room temperature and filtered to obtain intermediate 3. Step 4: Intermediate 3 and 2-hydroxy-1-naphthaldehyde were heated under reflux in anhydrous ethanol for 4-6 h, then cooled to room temperature and filtered to obtain pyridinoid pyrimidine thiohydrazide Al. 3+ and Zr 4+ Fluorescent probe.

3. A pyridopyrimidine thiohydrazide Al according to claim 2 3+ and Zr 4+ Fluorescent probe, characterized in that: The equivalent ratio of 3-(dimethylamino)-1-(pyridin-4-yl)-2-propen-1-one, thiourea and KOH is 1:1.2:1.

1.

4. A pyridopyrimidine thiohydrazide Al according to claim 2 3+ and Zr 4+ A fluorescent probe, characterized in that: The equivalent ratio of intermediate 1, sodium hydride, and ethyl bromoacetate is 1:1:1.

8.

5. A pyridopyrimidine thiohydrazide Al according to claim 2 3+ and Zr 4+ A fluorescent probe, characterized in that: The eluent used in the column chromatography separation is petroleum ether / ethyl acetate in a volume ratio of 1:

3.

6. A pyridopyrimidine thiohydrazide Al according to claim 2 3+ and Zr 4+ A fluorescent probe, characterized in that: The material ratio of intermediate 2, hydrazine hydrate and anhydrous ethanol is 0.6 g: 0.5 ml: 6 ml, wherein the mass concentration of hydrazine hydrate is 40% to 50%.

7. A pyridopyrimidine thiohydrazide Al according to claim 2 3+ and Zr 4+ A fluorescent probe, characterized in that: The equivalent ratio of intermediate 3 and 2-hydroxy-1-naphthaldehyde is 1:1.

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