42 results about "Dimethpyrindene" patented technology

The invention relates to application of 2-[(7-hydroxy-8-methyl-2-oxopigmene-4-yl) methylsulphonase]-4, 6-dimethyl pyridine-3-carbonitrile in resisting Ebola virus, and belongs to the technical field of medicine. The invention provides 2-[(7-hydroxy-8-methyl-2-oxopigmene-4-yl) methylsulphonase]-4, 6-dimethylpyridine-3-carbonitrile which can effectively inhibit the replication of Ebola viruses in a non-toxic range in order to solve the technical problem of lack of an effective Ebola virus resisting drug in the prior art, and also provides a preparation method of the 2-[(7-hydroxy-8-methyl-2-oxopigmene-4-yl) methylsulphonase]-4, 6-dimethylpyridine-3-carbonitrile. The compound has a good anti-infection effect on SUDV, BDBV and TAFV viruses, and can be applied to preparation of safe and effective broad-spectrum anti-Ebola virus drugs.

The application of 2-[(7-hydroxy-8-methyl-2-oxochrome-4-yl)methylthiosulfase]-4,6-dimethylpyridine-3-carbamate in the treatment of Ebola virus belongs to the field of pharmaceutical technology. This invention addresses the technical problem of the lack of effective anti-Ebola virus drugs in the prior art by providing 2-[(7-hydroxy-8-methyl-2-oxochrome-4-yl)methylthiosulfase]-4,6-dimethylpyridine-3-carbamate, which can effectively inhibit Ebola virus replication within a non-toxic range. The compound exhibits good anti-infective effects against SUDV, BDBV, and TAFV viruses and can be used to prepare safe and effective broad-spectrum anti-Ebola virus drugs.

The invention belongs to the technical field of fuel additives and clean energy. The invention provides a fuel oil additive, which is prepared from 40 to 60 parts of fatty acid ester, 10 to 20 parts of alcohol ether compounds, 1 to 3 parts of nanometer oxides, 2 to 4 parts of surfactants, 1 to 2 parts of oxidation stabilizers, 2 to 3 parts of sodium benzoate, 1 to 2 parts of 2, 6-dimethyl pyridine, 0.5 to 1 part of metal organic catalytic combustion improvers and 20 to 30 parts of solvent oil. The fuel additive can significantly improve the fuel combustion efficiency, reduce the fuel consumption, reduce the emission of CO, HC, NOx and soot, and improve the combustion stability and storage performance. The additive selects part of bio-based raw materials, has the characteristics of energy conservation, emission reduction, greenness and low carbon, is suitable for the field of combustion-supporting modification of gasoline, diesel oil and biofuel, and has good environmental benefits and application prospects.

The present invention relates to the technical field of preparation of molecular sieves. Disclosed are a ZSM-23 molecular sieve, and a preparation method therefor and the use thereof. The ratio of the 2,6-dimethylpyridine infrared total B acid amount to pyridine infrared total B acid amount of the ZSM-23 molecular sieve is 65-99:100. Moreover, in the 2,6-dimethylpyridine infrared B acid, the ratio of the B acid amount at a desorption temperature lower than 250°C to the 2,6-dimethylpyridine infrared total B acid amount is 64-95:100. The B acid sites of the ZSM-23 molecular sieve of the present invention are predominantly distributed at orifices and on the external surface, and with weak B acid being dominant, the molecular sieve has a high catalytic activity and excellent catalytic reaction performance mainly based on an orifice adsorption mechanism.

A synthesis of bis-oxime heterocycles via reaction of 2,4-dimethyl pyridine or 2,4-dimethylpyrimidine in the presence of a phase transfer catalyst. Such bis-oxime heterocycles provide a more direct route to the synthesis of bis-quaternary pyridinium compounds and their analogues as nerve agent antidotes.

The application discloses a kind of light response porous liquid adsorbents and its preparation method and application.Light response porous liquid adsorbents with the mass fraction of 0.2% to 10% of porous main body and macromolecular ionic liquid space steric solvent are prepared after dissolving.Light response metal organic cage is obtained by the coordination self-assembly of isomolar transition metal salt and mixed m-phenylenediamine derivative ligand with photoresponsive azobenzene derivative ligand and long-chain alkyl ligand under the promotion of 2,6-dimethylpyridine.Azobenzene ligand gives the light response of porous liquid, and long-chain alkyl ligand creates a suitable environment for the isomerization of azobenzene, significantly improving the light response efficiency of porous liquid.The number of external pores and the opening and closing of internal pore windows are adjusted under light conditions using light response molecules, the gas adsorption capacity is changed, and the remote control of material on gas adsorption is realized, so that it can be applied to olefin / alkane separation.

The invention discloses a bridged ring phloroglucinol antibacterial compound as well as a preparation method and application thereof, and belongs to the field of medicinal chemistry and anti-infection pharmacy. The structural general formula of the bridged ring phloroglucinol antibacterial compound is shown in the specification. The preparation method specifically comprises the following steps: (1) preparing a compound B by taking methyl iodide, sodium methoxide and a compound A as raw materials; (2) preparing a compound C by taking diisobutylaluminium hydride, the compound B, 2, 6-dimethyl pyridine and trifluoromethanesulfonic anhydride as raw materials; (3) preparing a compound D by taking palladium acetate, triphenylphosphine, the compound C, triethylamine and formic acid as raw materials; and (4) preparing a target product by taking the compound D, hexafluoroisopropanol, p-toluenesulfonic acid, the compound E, chiral phosphoric acid and ytterbium trifluoromethanesulfonate as raw materials. The compound disclosed by the invention shows high selectivity, low drug resistance risk and a potential new action mechanism, and provides a new leading structure and a technical path for overcoming drug resistance of existing antibacterial drugs.

The invention provides a steel bar corrosion immediate response corrosion inhibition system and a preparation method and application thereof, and belongs to the technical field of corrosion inhibitors. The preparation method disclosed by the invention comprises the following steps: mixing triethanolamine, polyphenols and 4-dimethyl pyridine, and then carrying out a reaction, so as to obtain anti-rust molecules; the preparation method comprises the following steps: mixing aniline, ethylbenzene, a lauryl sodium sulfate aqueous solution and rust-inhibiting molecules, and emulsifying to obtain a microemulsion; and mixing the microemulsion with a polyvinyl alcohol aqueous solution, and dropwise adding an ammonium persulfate aqueous solution to carry out polymerization reaction, thereby obtaining the steel bar corrosion immediate response corrosion inhibition system. The corrosion inhibition molecule (at) PANI corrosion inhibition system can immediately respond to steel bar corrosion, the steel bar corrosion rate can be remarkably controlled within 3 h after active corrosion of steel bars occurs, a stable protection layer is formed within 12 h, and generation of steel bar corrosion products is reduced.

The invention provides a cap reagent, a preparation method, a cap reaction method and application, and relates to the technical field of nucleic acid chemical synthesis. The composition comprises a first composition and a second composition, the first composition comprises acetic anhydride and acetonitrile; the second composition is prepared from 4-dimethylaminopyridine and an organic solvent; the organic solvent comprises a solvent A and a solvent B; the solvent A is 2, 6-dimethyl pyridine; the solvent B is at least one of acetonitrile and tetrahydrofuran.

The application relates to the technical field of catalytic materials, and relates to an organic photocatalytic material and a preparation method thereof.1, comprising the following steps: mixing modified N-hydroxy phthalimide phenylacetate, an aliphatic nitroalkane, 2,6-dimethylpyridine, a photocatalyst and a solvent, then irradiating under visible light, placing in an inert atmosphere, stirring for 2-8 hours, and obtaining a product through post-treatment to obtain a final product; the mass ratio of the modified N-hydroxy phthalimide phenylacetate, the nitro compound, the 2,6-dimethylpyridine, the photocatalyst and the solvent is 2-5:1-2:1-3:1:8-11. The visible light catalysis method can be used to synthesize the nitro compound under mild conditions, and further provides a green and efficient new path for the preparation of a nitrogen-containing drug intermediate.

This invention discloses a triphenylamine-based D-A type AIE molecule targeting STAT3, its preparation method, and its application in the diagnosis and treatment of colorectal cancer. This molecule uses triphenylamine as a donor and pyridinium as an acceptor, linked by a rigid conjugated trans-vinyl group, exhibiting aggregation-induced emission (AIE) properties. The preparation method employs a Knoevenagel condensation reaction, using 4-(diphenylamino)benzaldehyde and 1,4-dimethylpyridinium iodide as raw materials, and proceeds via a nucleophilic addition-dehydration reaction catalyzed by pyrrolidine, with a yield of 50±3% and a purity ≥98%. This molecule exhibits a fluorescence emission wavelength of 640 nm, demonstrates a significant AIE effect, can penetrate the colorectal cancer cell membrane and specifically aggregate, and shows activity against the IC50 of HCT116 and DLD1 cells. 50 The concentrations were 6.41 μM and 11.46 μM, respectively, which exerted anti-tumor effects by inhibiting STAT3 phosphorylation, enabling integrated diagnosis and treatment of colorectal cancer.

The present disclosure provides crystal forms of PARP1 inhibitor 5-(4-((9-fluoro-4-oxo- 4,5-dihydropyrazolo[1,5-a]quinoxalin-7-yl)methyl)piperazin-l-yl)-N,6-dimethylpicolinamide and preparation method thereof. The crystal forms are applicable for the treatment or prevention of diseases or conditions such as cancer that respond to PARP1 activity inhibition.

The application relates to a heat-resistant stainless steel pipe, the chemical composition of which comprises C, Si, Mn, P, S, Cr, Ni, Mo, Nd, Ce, iron and impurities; the surface of the stainless steel pipe is coated with a heat-resistant coating which comprises the following components: thermosetting phenolic resin, 4-chloro phthalic acid, agarose, branched polyethylene imine, a catalyst, a curing agent, 4-N,N-dimethylpyridine and dimethylformamide; and relates to a processing technology of the heat-resistant stainless steel pipe. The thermosetting phenolic resin has good heat resistance, the agarose makes the heat-resistant coating form a compact protective layer, the esterification product of 4-chloro phthalic acid and agarose has a benzene ring rigid group, 4-N,N-dimethylpyridine activates the carboxyl group of 4-chloro phthalic acid, the polymerization product obtained by the reaction of 4-chloro phthalic acid and branched polyethylene imine, and the synergistic effect of the components each containing a rigid group, effectively improve the heat resistance of the coating.

The invention provides a fluorescent probe for high selectivity of iron ions and monitoring of ferrous ions in cells as well as a preparation method and application of the fluorescent probe, and particularly relates to the technical field of analysis and detection. The fluorescent probe provided by the invention has a chemical structure as shown in a formula I. According to the fluorescent probe, halogen bromide ions serve as anions, quaternary ammonium salt serves as cations, a thiophene unit is selected as a pi electron bridge, the solubility and sensitivity of the fluorescent probe can be improved through the quaternary ammonium salt, meanwhile, the alkalization effect of the fluorescent probe can be prevented, and N, N-dimethyl formamide in a quaternary ammonium group can be used as a ligand. N, N-dimethyl, pyridine and piperazine structures tend to promote positioning of the fluorescent probe in lysosome; the thiophene can significantly improve the excitation wavelength of the fluorescent probe and enhance the aggregation effect. The obtained fluorescent probe has good water solubility, and no organic solvent needs to be added when the fluorescent probe is used, so that the fluorescent probe can be directly used for measuring iron ions in a water-based environment containing living organisms.

The invention discloses an intelligent continuous purification method of 2, 3-dimethyl pyridine, relates to the technical field of intelligent continuous purification, and aims to solve the problem of poor purification precision of 2, 3-dimethyl pyridine in raw materials. The water content is strictly controlled through drying treatment, and the shelf life of the product is prolonged. Meanwhile, a circulating treatment mechanism reduces material loss, improves the utilization rate of raw materials and reduces the production cost, human errors are reduced through real-time purity monitoring and automatic parameter adjustment, it is ensured that the product purity stably reaches the standard, the quality consistency is improved, the unqualified product rate is reduced, the water content is reduced to 0.05% or below through accurate vacuum degree and temperature regulation and control, and the production efficiency is improved. The energy waste is reduced by combining nitrogen protection to avoid oxidation, greatly prolonging the quality guarantee period of products, heat tracing and heat preservation of pipelines, linkage adjustment of parameters and other designs, and the production energy consumption and the material cost are further reduced by matching with an accurate metering pump to control the flow.

The application discloses a COF nanosheet for enhancing the flame-retardant property of PVC and PE pipes and a preparation method and application thereof. The nanosheet contains a COF skeleton composed of elements such as N, P and Br; in the preparation, a hydrothermal synthesis method is used to react hexachlorotriphosphazene, 3-bromo-2,6-dimethylpyridine and 4-pyridine formaldehyde at high temperature to obtain a COF crystal nucleus, and the crystal nucleus is subjected to plane growth at a higher temperature to finally generate the COF nanosheet ZR-COF. The ZR-COF nanosheet obtained by the application is applied to PE and PVC pipes as a flame-retardant additive, the synergistic effect of various flame-retardant elements greatly enhances the flame-retardant property of the PE and PVC pipes, the sheet structure can be fully contacted with the PVC and PE, and the mechanical strength of the PVC and PE can be improved.

The invention relates to a preparation method of a supported catalyst and 3, 5-dimethyl pyridine, which comprises the following steps: S1, heating and dissolving iron nitrate nonahydrate, ammonium molybdate tetrahydrate and lanthanum nitrate in deionized water, adding a spherical HY molecular sieve, and soaking; s2, slowly evaporating water under a heating condition, and drying for 12 hours in a drying oven at 120 DEG C; and putting the dried molecular sieve into a fixed bed, and roasting to obtain the required supported catalyst. S3, heating the supported catalyst to 350-380 DEG C, introducing ammonia gas, and feeding propionaldehyde and methanol into the fixed bed according to the mass ratio of 1: 2-10: 1 for reaction; and cooling and collecting the reaction liquid, and rectifying for multiple times to obtain the 3, 5-dimethyl pyridine meeting the requirements. According to the method, propionaldehyde, methanol and ammonia gas are used as raw materials, a high-product-content reaction solution is prepared under a high-temperature condition by using a supported catalyst, and a product is obtained through rectification. Experiments prove that the product content in the obtained reaction liquid is high (up to 90%), the raw material conversion rate is high, and the method has very high industrial value.

The application relates to a photosensitizer for type I photodynamic therapy and a preparation method thereof, and belongs to the photosensitizer field. The photosensitizer is obtained through five-step reactions of phenothiazine, n-bromobutane, phosphorus oxychloride, N-bromosuccinimide, 5-aldehyde-2-thiophene boronic acid, 1,4-dimethylpyridine-1-iodonium and potassium hexafluorophosphate, and can effectively generate type I active oxygen in a small molecule state. The photosensitizer has great prospects in the field of type I photodynamic therapy.

The application discloses an alkyl pyridine salt type aggregation-induced emission compound, a preparation method and application thereof, a molecular structural formula of the alkyl pyridine salt type aggregation-induced emission compound is as follows: the preparation method comprises the following steps: stirring and refluxing raw material D, 1,4-dimethyl pyridine-1-iodide, anhydrous ethanol and piperidine overnight, after the reaction mixture is cooled, vacuum concentration is carried out, and the crude product is purified by elution, so that the alkyl pyridine salt type aggregation-induced emission compound is obtained. The alkyl pyridine salt type aggregation-induced emission compound provided by the application can simultaneously and efficiently kill gram-positive bacteria and gram-negative bacteria.

The application relates to a mercury ion ratio fluorescent probe based on a hemicyanine and preparation and application of the fluorescent probe, the fluorescent probe has a molecular formula of C 26 H 23 INOPS; the preparation of the fluorescent probe comprises the following steps: (1) 4-hydroxybenzaldehyde is reacted with diphenylthiophosphonic dichloride to obtain O-(4-formylphenyl)diphenylthiophosphonate, i.e. compound 3, (2) 4-methylpyridine is reacted with methyl iodide to obtain 1,4-dimethylpyridine iodide, i.e. compound 2, (3) compound 3 is reacted with compound 2 to obtain a mercury ion ratio fluorescent probe 4-(4-(diphenylthiophosphonate)styryl)-1-methylpyridine iodide, i.e. compound 1; the application of the fluorescent probe is that the fluorescent probe is reacted with mercury ions in a buffer solution, and the existence of the mercury ions is detected by using the ratio (F 504nm / F 450nm ) change of the fluorescence intensity at two different emission wavelengths. The probe preparation process of the application is simple, and the fluorescent probe molecule exhibits high selectivity and sensitivity in a coexisting system of mercury ions and other cations.

The invention discloses a method and a system for continuously synthesizing 2, 3-dimethyl-4-nitropyridine-N-oxide based on a microchannel, and belongs to the technical field of organic synthesis. The method comprises the following steps: (1) carrying out oxidation reaction on 2, 3-dimethyl pyridine, hydrogen peroxide and acetic acid in a first micro-channel reactor, and introducing a formaldehyde aqueous solution from an inlet in the last plate of the first micro-channel reactor for quenching to obtain an oxidation reaction solution; (2) feeding the oxidation reaction liquid to a concentration device, separating formaldehyde, part of water and part of acetic acid, and reducing the content of acetic acid to 15 wt% or below; (3) reacting the concentrated reaction solution, concentrated sulfuric acid and nitric acid in a second microchannel reactor to obtain a nitration reaction solution; and (4) carrying out post-treatment on the nitration reaction liquid to obtain the product. According to the method, the crude product can be directly precipitated, the yield of the crude product is 82% or above, and the purity of the crude product is 96% or above. The method significantly reduces the consumption of sulfuric acid, and is safe and suitable for industrial amplification.

The present application provides a diesel hydro-upgrading catalyst, a preparation method and application thereof. The catalyst comprises the following components based on the weight of the catalyst: a) HZSM-23 molecular sieve, content of 2-13 wt%, preferably 4-12 wt%; b) modified Y molecular sieve, content of 3-20 wt%, preferably 5-18 wt%; c) macroporous alumina, content of 30-65 wt%, preferably 35-60 wt%; d) hydrogenation active component selected from group VIB metal and / or group VIII metal, wherein the content of group VIB metal is 10-30 wt% in terms of oxide, preferably 12-25 wt%, and the content of group VIII metal is 2-10 wt% in terms of oxide, preferably 3-8 wt%; in the 2,6-dimethylpyridine infrared B acid of the catalyst, the proportion of weak B acid is 48%-74%, preferably 50%-72%. The B acid sites on the outer surface and the pore mouth of the catalyst are mainly weak B acid, which can significantly improve the cetane number and low-temperature flow performance of diesel product when treating poor-quality diesel, especially poor-quality diesel rich in aromatic hydrocarbons and naphthenes, and at the same time improve the yield of the product.

The application provides a ZSM-22 molecular sieve, a preparation method and application thereof, wherein the total 2,6-dimethylpyridine infrared B acid amount of the ZSM-22 molecular sieve is 0.07-0.51 mmol / g, preferably 0.08-0.49 mmol / g; in the 2,6-dimethylpyridine infrared B acid, the B acid amount with a desorption temperature > 420 DEG C is 0-0.12 mmol / g, preferably 0.01-0.10 mmol / g; preferably, the ratio of the B acid amount with a desorption temperature > 420 DEG C to the total 2,6-dimethylpyridine infrared B acid amount is 0-22:100, preferably 2-20:100. The ZSM-22 molecular sieve has less strong B acid sites on the outer surface and the pore mouth, and when applied to a hydroisomerization reaction process, the yield and quality of the target product can be greatly improved.

This invention belongs to the field of lithium-ion battery material technology, and specifically relates to an iron phosphate material, a lithium iron phosphate cathode material, its preparation method, and its application. The preparation method of the iron phosphate material includes the following steps: mixing N,N-di(3-methylpyridinyl)dicarboxamide benzoyl chloride, m-tetra(1-aminophenyl)porphyrin, a catalyst, and a solvent, stirring to obtain a 1,3,5-tricarboxyamide-linked porphyrin compound; adding an iron source and solvent, heating, and separating to obtain a 1,3,5-tricarboxyamide-linked iron porphyrin solid product; then mixing with N,N',N'-tris(3-methylpyridinyl)trimethylamide, a solvent, a surfactant solution, and a crosslinking agent, separating to prepare a precursor powder; dispersing the precursor powder in a solvent, adding phosphate, mixing, adjusting the pH, heating the mixture under stirring, aging, filtering, and calcining the precipitate to obtain the iron phosphate material.

The application discloses a kind of based on ion exchange membrane's purification method of pentaerythritol, it is related to membrane material preparation technical field.In the application, modified metal organic framework containing pyridine ring and quaternary ammonium salt cation is prepared, and is loaded to the surface of ion exchange membrane, pyridine ring can be protonated and positive, can improve the selective permeability of anion, and have good acid and alkali resistance, can improve the chemical stability of ion exchange membrane in acid and alkali environment, prolong service life, metal framework itself has good hydrophilicity, rigidity and high temperature stability, the side chain methyl of introduced 2,6-dimethylpyridine-4-formaldehyde provides steric hindrance, both synergies, can effectively inhibit ion exchange membrane water absorption swelling, improve dimensional stability and mechanical strength;Quaternary ammonium salt can increase the cation sites on membrane surface, increase ion transport capacity, improve ion conductivity, reduce membrane resistance, improve the flux of ion exchange membrane, conducive to improving separation efficiency.

The invention relates to the technical field of molecular sieve preparation, and discloses a ZSM-23 molecular sieve as well as a preparation method and application thereof. The ratio of the amount of 2, 6-dimethylpyridine infrared total B acid to the amount of pyridine infrared total B acid in the ZSM-23 molecular sieve is (65-99): 100, and in the 2, 6-dimethylpyridine infrared B acid, the ratio of the amount of B acid with the desorption temperature lower than 250 DEG C to the amount of the 2, 6-dimethylpyridine infrared total B acid is (64-95): 100. The B acid sites of the ZSM-23 molecular sieve are mainly distributed on the orifices and the outer surface, and the ZSM-23 molecular sieve is mainly composed of weak B acid, is high in catalytic activity, and has excellent catalytic reaction performance mainly composed of an orifice adsorption mechanism.

The invention discloses a preparation method of 2-chloromethyl-4-methoxy-3, 5-dimethyl pyridine hydrochloride, which comprises the following steps: carrying out oxidation reaction on 3, 5-dimethyl pyridine to obtain 3, 5-dimethyl pyridine nitrogen oxide; the method comprises the following steps: in mixed acid of nitric acid and sulfuric acid, carrying out nitration reaction on 3, 5-dimethyl pyridine nitrogen oxide to obtain 4-nitro-3, 5-dimethyl pyridine nitrogen oxide; the method comprises the following steps: carrying out methoxy reaction on 4-nitro-3, 5-dimethyl pyridine nitrogen oxide to obtain 4-methoxy-3, 5-dimethyl pyridine nitrogen oxide, activating the 4-methoxy-3, 5-dimethyl pyridine nitrogen oxide by using an activating reagent, carrying out chlorination reaction on the 4-methoxy-3, 5-dimethyl pyridine nitrogen oxide and thionyl chloride to obtain free alkali of 2-chloromethyl-4-methoxy-3, 5-dimethyl pyridine, and carrying out reaction on the free alkali of 2-chloromethyl-4-methoxy-3, 5-dimethyl pyridine nitrogen oxide and the free alkali of 2-chloromethyl-4-methoxy-3, 5-dimethyl pyridine nitrogen oxide to obtain the 2-chloromethyl-4-methoxy-3, 5-dimethyl pyridine nitrogen oxide. And carrying out a salt forming reaction in an organic solvent of HCl to obtain the 2-chloromethyl-4-methoxy-3, 5-dimethyl pyridine hydrochloride. According to the invention, the'activation-chlorination 'yield is greater than 93.5%.

The invention relates to a COF nanosheet for enhancing the flame retardant property of PVC (polyvinyl chloride) and PE (polyethylene) pipes as well as a preparation method and application of the COF nanosheet. The nanosheet contains a COF framework composed of elements such as N, P and Br; in the preparation, a hydrothermal synthesis method is used, hexachlorotripolyphosphazene, 3-bromo-2, 6-dimethylpyridine and 4-pyridylaldehyde react at a high temperature to obtain a COF crystal nucleus, and the crystal nucleus is subjected to plane growth at a relatively high temperature to finally generate the COF nanosheet ZR-COF. The ZR-COF nanosheet obtained by the invention is used as a flame retardant additive to be applied to PE and PVC pipes, the flame retardant property of the PE and PVC pipes is greatly enhanced through the synergistic effect of various flame retardant elements, and the sheet structure can be in full contact with PVC and PE and can also improve the mechanical strength of the PE and PVC pipes.

The invention belongs to the technical field of medicine analysis, and particularly relates to a method for analyzing a phosphodiesterase 4 inhibitor and impurities thereof. According to the analysis method for the phosphodiesterase 4 inhibitor and the impurities thereof, the dipotassium phosphate aqueous solution is used as a mobile phase A, acetonitrile is used as a mobile phase B, and gradient elution parameters and chromatographic parameters such as the flowing speed of the mobile phase, the column temperature, the sample size and the detection wavelength are improved, so that the purity of the phosphodiesterase 4 inhibitor is improved. The method can be used for simultaneously detecting and analyzing (E)-1-(3-(tetrahydrothiophene-3-yl) oxy-4-methoxystyryl)-2, 6-dimethyl pyridine-4-(1H)-ketone and seven impurities thereof, and solves the problem that in the prior art, the (E)-1-(3-(tetrahydrothiophene-3-yl) oxy-4-methoxystyryl)-2, 6-dimethyl pyridine-4-(1H)-ketone and seven impurities thereof are lacked. The invention aims to solve the technical problems in the prior art in a conventional method for detecting and analyzing 2, 6-dimethyl pyridine-4-(1H)-ketone and impurities thereof.

The invention discloses a medical examination fluorescent molecular probe and a preparation method thereof in the technical field of medical examination, and the medical examination fluorescent molecular probe is prepared from the following components in parts by weight: 17 to 19 parts of 3, 4-difluorobenzaldehyde, 12 to 15 parts of benzylamine, 10 to 11 parts of piperidine, 24 to 26 parts of 1, 4-dimethyl pyridine iodide, 14 to 15 parts of 1-isopropyl pyrimidine-2, 4, 6 (1H, 3H, 5H)-triketone and 6.2 to 7.1 parts of potassium fluoborate. According to the present invention, the 3, 4-difluorobenzaldehyde is modified with benzylamine, such that the steric hindrance is improved so as to achieve the technical effect of selectivity improvement, and the 1-isopropylpyrimidine-2, 4, 6 (1H, 3H, 5H)-triketone is modified to synthesize the flavin compound so as to obtain the high-sensitivity anti-interference fluorescent molecular probe.