65 results about "Benzyl bromide" patented technology

The utility model provides a continuous photochemical reaction system for preparing 2, 4-disubstituted benzyl bromide by adopting 2, 4-disubstituted toluene. The continuous photochemical reaction system comprises a photocatalytic reaction device, a feeding device, a post-treatment device, a product receiving device and a heat exchange device. According to the system, 2, 4-disubstituted toluene and dibromohydantoin can be subjected to continuous bromination reaction to realize photochemical reaction, continuous feeding and continuous discharging are realized, and the reaction process is uninterrupted. The structure of the heat exchange device is improved, for example, the heat exchange device is controlled to be a corrugated pipe, the corrugation distance and the pipe diameter of the corrugated pipe are controlled, particularly, baffle plates are arranged on the inner wall of the corrugated pipe at intervals, and the size of the baffle plates and the distance between every two adjacent baffle plates are controlled to be within a certain range value; therefore, the heat transfer coefficient of the heat exchange device is high, the temperature control effect is better, and the efficiency of the continuous photochemical reaction and the purity of the 2, 4-disubstituted benzyl bromide product are improved.

The invention provides a series of polybenzyl bromide or polybenzyl iodide-based monomolecular resin photoresists as well as a preparation method and application thereof. The monomolecular resin can be used as a main body material of the photoresists. The raw materials are cheap and easily available, and the synthesis process is simple. According to the compound disclosed by the invention, adamantane is taken as a core unit, a plurality of benzyl bromide or benzyl iodine groups, adamantane and a benzene ring are externally connected, and bromine atoms or iodine atoms are additionally introduced, so that the sensitivity and the etching resistance of the photoresist can be improved to the maximum extent.

The invention relates to the technical field of benzyl bromide preparation and discloses a benzyl bromide preparation device and method.The benzyl bromide preparation device comprises a stirring kettle, a heating box is fixedly connected to the outer wall of the stirring kettle, an isolation sleeve is fixedly connected to the inner wall of the stirring kettle, a water inlet pipe is fixedly connected to the upper surface of the heating box, and a water outlet pipe is fixedly connected to the lower surface of the heating box; one end of the water inlet pipe penetrates through the surface of the heating box and is fixedly connected with a water pump, a supporting plate is fixedly connected into the heating box, the water pump is installed on the surface of the supporting plate, and the middle of the heating box is connected with a heating assembly. The bottom of the isolation sleeve is connected with a temperature measuring assembly, and the inner wall of the isolation sleeve is connected with a scraping assembly. According to the preparation device and the preparation method of the benzyl bromide, reaction materials in the stirring kettle can be uniformly heated, so that the reaction uniformity is improved, and an overheating or supercooling phenomenon of a local area is avoided.

The application discloses a kind of breathable antibacterial fabric and its preparation process, S1, nylon is used as warp and tension is maintained;S2, spandex is used as weft, and weft and warp are interwoven into grey cloth;S3, the grey cloth is finished by finishing agent, the burr is cut, and the wrinkle is smoothed, to obtain fabric, using hexamethylene diisocyanate, 3-hydroxypropionic acid is reacted to obtain hexamethylene di (carbamate propionic acid), after acyl chloride, and with N-methyl-2,2-diamino diethylamine, benzyl bromide is reacted, to obtain antibacterial finishing agent.It contains a large number of quaternary ammonium salt antibacterial groups, and has inhibitory and killing effect on bacteria such as escherichia coli, and at the same time contains polyamide and urethane structure, and has high affinity and interfacial force between the polyamide molecular chain in the blended fabric and the urethane structure of spandex polyurethane, to improve the firmness of antibacterial finishing agent attached to the surface of fabric and antibacterial time effect.

The invention relates to the technical field of pesticide synthesis processes, in particular to a one-pot multi-component preparation method of a chiral Dufulin compound. The method comprises the following steps: mixing quinine, substituted benzyl bromide and a solvent, and refluxing to obtain a reaction solution; the preparation method comprises the following steps: mixing 2-amino-4-methylbenzothiazole, 2-fluorobenzaldehyde, a solvent and a catalyst, and then refluxing to obtain a reaction system; mixing the reaction system with diethyl phosphite, the reaction liquid and an alkali reagent, and stirring to react, so as to obtain a stirred reaction material; and extracting the stirred reaction material with an extraction liquid, separating the liquid to obtain an organic phase, washing the organic phase with water, and removing the solvent to obtain the chiral Dufulin compound. According to the invention, low-cost clean synthesis of chiral Dufulin is realized; the preparation method disclosed by the invention is reasonable in design, mild in reaction condition, easy to obtain raw materials, convenient to operate, high in product yield, suitable for large-scale production and good in industrial replicability.

The invention belongs to the technical field of chemical synthesis of spices, and particularly relates to a synthetic method of vanillin and ethyl vanillin. Carrying out substitution reaction on catechol and methyl iodide to generate o-dimethoxybenzene 3; 3 and 1, 2-dichloromethyl methyl ether are subjected to formylation reaction to generate 3, 4-dimethoxybenzaldehyde 4; carrying out demethylation reaction on the 3, 4-dihydroxy benzaldehyde 5 and pyridine hydrochloride to generate 3, 4-dihydroxy benzaldehyde 5; carrying out substitution reaction on the 4-benzyloxy-3-hydroxybenzaldehyde 5 and benzyl bromide to generate 4-benzyloxy-3-hydroxybenzaldehyde 6; carrying out substitution reaction on the 4-benzyloxy-3-methoxyl / ethyoxyl benzaldehyde 6 and iodomethane / iodoethane to generate 4-benzyloxy-3-methoxyl / ethyoxyl benzaldehyde 7; 7 is reduced by hydrogen under the catalysis of palladium on carbon to generate vanillin / ethyl vanillin. Cheap catechol is adopted as a raw material, reaction conditions are mild, equipment requirements are not high, energy consumption is low, the problems that raw materials are not suitable to obtain, the price is high, separation is difficult, and three wastes are seriously generated in a traditional vanillin synthesis method are solved, and a new method is provided for synthesis of vanillin.

This invention discloses a cellulose mixed ester and its preparation method, comprising the following steps: S1, dissolving cellulose in a solvent, adding an etherification protecting agent and reacting, then adding benzyl bromide and reacting to obtain a first intermediate product; S2, dissolving the first intermediate product in an organic mixed solution and reacting to obtain a second intermediate product, 3-o-benzyl cellulose; S3, reacting the second intermediate product with an acylation agent A under the action of a catalyst to obtain a third intermediate product; S4, removing the benzyl group from the third intermediate product to obtain a fourth intermediate product; S5, acylating the fourth intermediate product with an acylation agent B under the action of a catalyst to obtain the final product, 3-o-B-acyl-2,6-di-o-A-acyl cellulose. This invention successfully achieves the selective esterification preparation of cellulose mixed esters by constructing a solvent dissolution and etherification protecting system, an organic solution reaction system, and an acylation alkaline composite catalyst system in a synergistic manner. More importantly, it achieves a high product yield and a relatively fast reaction process.

This invention relates to the field of oilfield chemical additives technology, and discloses a method for preparing a 1-benzyl-10-phenylpyrrolo[1,2-a:3,4-b']dipyrazine-1-onium type quaternary ammonium salt high-temperature acidizing corrosion inhibitor. The method uses 2,2'-piperazine as the starting material, which undergoes a quaternization reaction with benzyl bromide to obtain a quaternary ammonium salt intermediate. The obtained intermediate undergoes an oxidative cyclization reaction with benzaldehyde and manganese dioxide in a dichloromethane system. After separation, drying, and purification, the target product is obtained. The preparation process of this invention is simple and easy to control, the product is easy to purify, and it is suitable for industrial production. It exhibits good synergistic effects with additives, excellent water solubility and compatibility, can stabilize and protect steel, reduce construction risks, and is suitable for various high-temperature acidizing operations.

The invention discloses an epoxy resin flame retardant as well as a preparation method and application thereof, and relates to the field of chemical synthesis. The chemical structural formula of the epoxy resin flame retardant is shown as a formula I and a formula II: # imgabs0. The preparation method of the epoxy resin flame retardant comprises the following steps: synthesizing a quaternary ammonium salt intermediate and synthesizing the flame retardant. N, N-dimethylethanolamine, benzyl bromide and phenylphosphonic dichloride are used as raw materials for two-step synthesis of the phosphate gemini quaternary ammonium salt type epoxy resin flame retardant, a quaternary ammonium salt structure is introduced to phosphate, the suffocation effect of phosphate in a gas phase is compensated, organic phosphorus-nitrogen free radicals can fully play a role in capturing free radicals during combustion, and the flame retardant property of the flame retardant is improved. Meanwhile, the phosphorus component takes epoxy resin as a carbon source to effectively form carbon, and the oxidation stability of Br <-> further improves the safety guarantee of the epoxy resin.

There is disclosed a method of preparing a compound of Formula (1), or a salt thereof (1) the method comprising: a) treating a compound of Formula (2) sequentially with o-tolylmagnesium chloride, N-methylpiperazine and iodine, under conditions sufficient to obtain a compound of Formula (3) b) treating the compound of Formula (3) from step a) with 3,5-bis(trifluoromethyl)benzyl bromide and a suitable base, under conditions sufficient to obtain a compound of Formula (1).

The invention discloses a 5-hydroxypyrazole compound as well as a synthesis method and application thereof, and the structural formula of the 5-hydroxypyrazole compound is as follows: 3-phenoxyphenyl-3-oxo-methyl propionate derivative is used as a starting material, the starting material and benzyl bromide derivative are subjected to hydrocarbylation reaction firstly, then the starting material and hydrazine hydrate are subjected to Knorr reaction, and the 5-hydroxypyrazole compound is obtained. Finally, the 5-hydroxy-3-phenoxyphenyl pyrazole ring compound is prepared, and the prepared 5-hydroxypyrazole ring compound shows that the 5-hydroxypyrazole ring compound has a good inhibition effect on HepG2 cells and can be used for further preparing anti-cancer drugs.

The present invention discloses a method for synthesizing aromatic sulfonyl fluoride compounds, belonging to the field of organic chemistry. In the method of the present invention, inexpensive and readily available Na2S2O4 is used as the sulfur dioxide source, and nickel acetate tetrahydrate is used as the nickel source. The substrate has a wide applicability, the raw materials are simple and readily available, and the economic cost is low. In addition, the method of the present invention only needs to react for 15 hours to obtain the target product in a good yield, which is more rapid and efficient. The synthesis method of the present invention converts simple and readily available β-arylvinyl bromide or benzyl bromide into aromatic sulfonyl fluoride under relatively simple conditions, and realizes the sulfofluorination of β-arylvinyl bromide or benzyl bromide in one pot. The target compound has wide applications in the fields of new drug development, new material synthesis, etc.

The application provides a series of monomolecular resin photoresists based on polybenzyl bromide or polybenzyl iodine and a preparation method and application thereof, and the monomolecular resin can be used as a main body material of the photoresist. Raw materials are cheap and easy to obtain, and the synthesis process is simple. The compound provided by the application takes adamantane as a core unit, is externally connected with multiple benzyl bromide or benzyl iodine groups, and the core structure of adamantane and benzene ring and the introduction of bromine atoms or iodine atoms can maximize the sensitivity and etching resistance of the photoresist.

The application belongs to the technical field of chemical industry and relates to a preparation method of a novel chiral bipyridine and application of the chiral bipyridine in catalytic reaction. Various benzyl bromides with 4,5-diazofluorene as a skeleton are reacted to generate a series of chiral bipyridine ligands, then under the participation of the ligands, indolines and quinoline nitrogen-containing heterocyclic compounds are reacted with pinacol diboronic acid under the catalysis of [IrOMe(COD)2] as a metal catalyst, and then a series of phenol compounds are obtained through oxidation of sodium perborate. The novel chiral bipyridine ligand developed by the method has the advantages of good site selectivity and excellent reaction yield without using strong acid and strong base in the process of C-H bond selective boronation.

This invention discloses a method for preparing high-purity quartz sand from quartz ore, relating to the field of high-purity quartz sand processing. First, a quaternized cation reagent is prepared using benzyl bromide and N,N-dimethyldodecylamine as raw materials. The adsorption of this self-made collector on the quartz surface is the result of the combined effects of electrostatic attraction and multiple forms of hydrogen bonding. The addition of quaternary ammonium and polyhydroxy groups allows for strong physical adsorption of quartz without the need for strong acids. Furthermore, a stable filler layer is formed on the quartz surface, thereby improving the collection effect of the quartz sand. Secondly, the preparation process of this invention is as follows: coarse washing – coarse crushing – direct high-temperature bursting water quenching – medium crushing – microwave heating – fine crushing – acid leaching – magnetic separation – flotation – drying. A segmented, step-by-step treatment is adopted, using different treatment methods for different particle sizes of quartz sand, which is beneficial for removing inclusions in the quartz and results in a larger surface area and better effect compared to acid leaching. The quartz sand prepared by this invention exhibits high purity.

The invention provides an ultraviolet light grafting modified UHMWPE fiber, a fiber reinforced composite material and a preparation method and application of the UHMWPE fiber and the fiber reinforced composite material. The preparation method of the ultraviolet light grafting modified UHMWPE fiber comprises the following steps: (1) grafting Diazirine on the UHMWPE fiber: preparing absolute ethyl alcohol and 4-[3-(trifluoromethyl)-3H-bis (aziridin-3-yl) benzyl bromide (Diazirine) into a Diazirine ethanol solution; the UHMWPE fiber is immersed in a Diazirne ethanol solution, the surface of the fiber is fully wetted, the fiber is naturally aired, the two faces of the fiber are irradiated through an ultraviolet light source, and a UHMWPE-Dia fiber is obtained; (2) grafting the UHMWPE-Dia fiber with PEI: dissolving polyethyleneimine (PEI) in a solvent absolute ethyl alcohol to prepare a PEI solution, putting the UHMWPE-Dia fiber obtained in the step (1) and the PEI solution into a sealed container, and carrying out horizontal mechanical shaking for reaction; after the reaction is finished, the fiber is flatly laid and dried to remove the solvent absolute ethyl alcohol, and the UHMWPE-Dia-PEI fiber is obtained. The fiber reinforced composite material comprises epoxy resin, an amine curing agent and ultraviolet grafting modified UHMWPE (Ultra High Molecular Weight Polyethylene) fibers.

There is disclosed a method of preparing a compound of Formula (1), or a salt thereof (1) the method comprising: a) treating a compound of Formula (2) sequentially with o-tolylmagnesium chloride, N-methylpiperazine and iodine, under conditions sufficient to obtain a compound of Formula (3) b) treating the compound of Formula (3) from step a) with 3,5-bis(trifluoromethyl)benzyl bromide and a suitable base, under conditions sufficient to obtain a compound of Formula (1).

The invention discloses a cyclic quaternary ammonium salt N-hydronopyl tetrahydropyrrole compound as well as a synthesis method and antibacterial application thereof, and belongs to the technical field of plant antibiosis. Hydronopyl chloride and tetrahydropyrrole are taken as raw materials, an N-hydronopyl tetrahydropyrrole intermediate is prepared through reaction, and the cyclic quaternary ammonium salt N-hydronopyl tetrahydropyrrole compound is prepared through a one-step reaction. Then, the cyclic quaternary ammonium salt N-hydronopyl tetrahydropyrrole compound and an alpha-bromoacetophenone compound or a benzyl bromide compound are subjected to a quaternization reaction, and the cyclic quaternary ammonium salt N-hydronopyl tetrahydropyrrole compound can be synthesized; the cyclic quaternary ammonium salt N-hydronopyl tetrahydropyrrole compound has excellent broad-spectrum antibacterial activity, and especially has a remarkable inhibition effect on common phytopathogens such as rhizoctonia solani, oxysporum tomentosum, colletotrichum carpopogonum, fusarium oxysporum, tobacco black shank, Fusarium fulvum, coriolus versicolor, fusarium verticillium and the like.

The invention relates to a novel tetrahydro-beta-carboline derivative as well as a synthesis method and application thereof. The method comprises the following steps: by taking novel tetrahydro-beta-carboline as a substrate, firstly adding inorganic alkali NaH under the protection of nitrogen, then adding an anhydrous N, N-dimethylformamide solvent for dissolving, reacting with a series of benzyl bromide or similar compounds under the condition of ice bath, carrying out intermolecular nucleophilic substitution reaction, adding a quenching agent for quenching reaction, and extracting to remove redundant N, N-dimethyl formamide, so as to obtain the novel tetrahydro-beta-carboline derivative. A series of novel tetrahydro-beta-carboline derivatives are obtained through column chromatography analysis in an N, N-dimethylformamide solvent, and the compounds have the application of inhibiting phytopathogen. The phytopathogens comprise rhizoctonia solani, sclerotinia sclerotiorum, botrytis cinerea, fusarium graminearum, colletotrichum capsici and pyricularia oryzae. The synthesis process is simple, and the product purity is high.

The present invention discloses a small molecule inhibitor with a structural general formula (I). Its preparation method is as follows: Using 5-acetyl-2,8-dihydroxyquinoline and benzyl bromide as the original raw materials, a small molecule inhibitor of formula (I) is obtained through eight-step reactions; this small molecule inhibitor synthesizes new compounds by changing R 1 , and has an obvious inhibitory effect on colorectal tumor cells. Acting on the colorectal cancer cell line SW620, its IC 50 is at least 0.965 μM. #imgabs0#

The invention discloses a preparation method of a luminescent compound. The preparation method comprises the following steps: step 1, reducing a raw material a by a reducing agent to generate a compound b; 2, reacting the compound b with benzyl bromide to generate a compound c; 3, reacting the compound c with methyl dithioacetate under photocatalysis to generate a target product compound d; according to the present invention, the reaction conditions are mild, the green reaction modes such as photocatalysis are adopted, the good yield can be obtained while the mild reaction conditions are ensured, the method is suitable for the luminescent substrates with various structures, and the application range is expanded.

The application discloses a selenium-substituted hemicyanine dye precursor and a synthesis method and application thereof, and belongs to the fine chemical field. The structure of the selenium-substituted hemicyanine dye precursor is shown in a general formula I. In the general formula I, R1 is one of H, a phenyl group, a p-phenyl benzyl chloride, a p-phenyl benzyl bromide, SO3R4, COOR4 or C1-C 12 alkyl; R2 is C, S or Se; R3 is one of H, a phenyl group or C1-C 12 alkyl; R4 is H or C1-C 12 alkyl; and Y is Cl, Br or I. The application provides a selenium-substituted hemicyanine dye precursor, which has near-infrared absorption and emission spectral performance and high active oxygen generation capacity, and provides an ideal platform for constructing dye photosensitizers.

The invention provides a fluorine-functionalized super-crosslinking material, a preparation method thereof and application of the fluorine-functionalized super-crosslinking material in cold-assisted solid-phase microextraction. The invention belongs to the technical field of headspace solid-phase microextraction. The fluorine-functionalized super-crosslinked coating is prepared by carrying out a reaction on C-methyl calix [4] hydrocarbon resorcinol, 4-(trifluoromethyl) benzyl bromide, ferric trichloride and dichloroethane in an oil bath at the temperature of 100 DEG C. The fluorine-functionalized super-crosslinking coating can be used for preparing a solid-phase micro-extraction fiber coating, and the solid-phase micro-extraction fiber coating can realize efficient adsorption of polychlorinated naphthalene through F-pi bonds, electrostatic adsorption and other acting forces. The invention further provides a self-made portable cold-assisted solid-phase microextraction device which can assist in extraction of high-boiling-point components in polychlorinated naphthalene. Compared with other solid-phase microextraction cold auxiliary devices, the solid-phase microextraction cold auxiliary device is simple in structure, convenient to operate and convenient to commercialize. The method has a wide application prospect in the aspects of environmental monitoring, food safety and the like.

The invention discloses a method for preparing 4-cyanobenzyl bromide through continuous flow photocatalysis, and belongs to the field of organic synthesis. The preparation method comprises the following steps: by taking p-toluenitrile as a raw material, dissolving the p-toluenitrile in an organic solvent, then adding a bromination reagent, and carrying out photocatalytic bromination reaction to obtain the 4-cyanobenzyl bromide. The method disclosed by the invention is mild in catalytic reaction process condition, simple to operate and few in by-products, and the obtained product is high in purity and stable in performance. The method aims at the defects of a traditional synthesis process, does not need complex operation steps, is suitable for small-scale synthesis in a laboratory, can meet the requirements of industrial large-scale production, and has a wide application prospect.

The invention provides a preparation method of a key intermediate of a gemfibrozil impurity A, and belongs to the technical field of chemical synthesis. According to the invention, a brand-new synthetic route of the gemfibrozil impurity A is designed firstly, and efficient preparation methods of three key intermediates are provided on the basis of the brand-new synthetic route. Specifically, the preparation method comprises the following steps: firstly, reacting with propionyl chloride in a 1, 2-dichloroethane environment under the catalysis of aluminum trichloride, and cooling, layering and drying a product to obtain a first intermediate; taking the first intermediate as a raw material, reacting with benzyl bromide in a DMF (Dimethyl Formamide) environment by taking potassium carbonate as an acid-binding agent, collecting an organic phase, dissolving with methanol, carrying out reduction reaction by using sodium borohydride under the catalysis of cerium chloride heptahydrate, and collecting to obtain a second intermediate; taking the second intermediate as a raw material, dissolving the second intermediate in methylbenzene, and performing dehydration reaction under the catalysis of TsOH.H2O to obtain a third intermediate; on the basis of the three intermediates, efficient synthesis of the gemfibrozil impurity A can be achieved, the synthesis route is short, and the process efficiency is high.

The application provides a fluorescent probe based on a cinnamic acid derivative as well as a synthesis method and application thereof, and relates to the technical field of synthesis of specific probes. The fluorescent probe is prepared by introducing benzyl bromide into the hydroxyl group of a modified structure compound FHA using p-hydroxycinnamic acid as raw material, and a novel bifunctional fluorescent probe capable of specifically detecting Al 3＋ and N2H4 is developed. The application overcomes the defects of the prior art, the probe can specifically detect Al 3+ and N2H4, and has the characteristics of low detection limit, short response time, wide pH application range and the like; the probe has the characteristics of good biocompatibility, small toxicity, good optical properties and the like, and can be applied to cell imaging experiments.

The invention relates to a method for synthesizing benzoate derivatives from dimethyl sulfoxide, belongs to the technical field of application of organic sulfides, and solves the technical problems that existing aryl formate synthesis generally needs strong acid or strong alkali, synthetic products and synthetic conditions are limited and the like. The solution is as follows: the method for synthesizing benzoate derivatives from dimethyl sulfoxide comprises the following steps: 1) preparing benzyl methyl sulfide: putting dimethyl sulfoxide and benzyl bromide or benzyl bromide derivatives into a reaction container, and fully reacting at a first temperature to prepare benzyl methyl sulfide; and 2) preparation of the benzoate derivative: putting a photosensitizer, an inorganic base, an organic solvent, the benzyl methyl sulfide prepared in the step 1) and an organic bromide into a reaction container, and fully reacting under the irradiation of a visible light range at a second temperature and a target atmosphere condition to prepare the benzoate derivative. Compared with the prior art, the method has the advantages of high efficiency, greenness, economy, mild conditions, high social and economic benefits and the like.

The invention relates to a large Stokes shift cholinesterase near-infrared fluorescent probe and a construction method thereof.Quinoline is used as a core skeleton, and a conjugated system is constructed through a D-pi-A electronic regulation strategy: aryl, alkenyl or amido is introduced to the 4th site / 6th site to regulate the emission wavelength; the construction method comprises the following steps: synthesizing a fluorophore main skeleton through a Wittig reaction / Heck reaction, connecting a recognition unit through a substitution reaction, and introducing the electron-withdrawing group through a Najing condensation reaction. Stokes shift breaks through 100 nm, and excitation light interference can be inhibited. According to the probe, a recognition unit simulating acetylcholine / butyrylcholine'dumbbell-shaped 'conformation is covalently connected to a quinoline nitrogen atom through a benzyl bromide group, the recognition unit comprises an aromatic cavity adaptive to AChE / BChE substrate pocket hydrophobicity and an active site for catalyzing ester bond hydrolysis, an enzymatic reaction triggers intramolecular electron rearrangement and C-N bond breakage, a fluorescence quenching state is relieved, and the quinoline nitrogen atom can be detected. And "off-on" type signal conversion is realized.

The invention provides a synthetic method of a gemfibrozil impurity A, and belongs to the technical field of chemical synthesis. According to the technical scheme, gemfibrozil is used as an initial raw material and firstly reacts with propionyl chloride in a 1, 2-dichloroethane environment under the catalysis of aluminum trichloride, a product reacts with benzyl bromide in a DMF environment by taking potassium carbonate as an acid-binding agent, an organic phase is collected and dissolved with methanol, and then reduction reaction is performed with sodium borohydride under the catalysis of cerium chloride heptahydrate to obtain gemfibrozil. Collecting to obtain an oily liquid compound, dissolving the oily liquid compound in toluene, carrying out a dehydration reaction under the catalysis of TsOH.H2O, carrying out a hydrolysis reaction on the reaction product in an isopropanol and sodium hydroxide system, carrying out reduced pressure distillation to remove isopropanol, carrying out acid adjustment, extracting with ethyl acetate, drying with sodium sulfate, filtering, concentrating to obtain a white solid, and finally refining and purifying to obtain the 2-(2, 4-dichlorophenyl)-1, 2, 3, 4, 5-tetramethyl-1, 3-pentanediol. A gemfibrozil impurity A finished product is obtained. The method is short in synthetic route, high in process efficiency, convenient to refine and purify and high in yield and purity, and has outstanding technical advantages.

The invention discloses a preparation method of phentolamine EP impurity acid salt, which comprises the following steps: (1) taking a compound I resorcinol and a compound II p-toluidine as raw materials, and performing dehydration reaction to obtain an intermediate product III; (2) carrying out nucleophilic substitution reaction on the intermediate product III and benzyl bromide to generate an intermediate product IV; (3) carrying out nucleophilic substitution reaction on the intermediate product IV and ethyl bromoacetate to obtain an intermediate product V; (4) carrying out ester amidation reaction on the intermediate product V and N-tert-butyloxycarbonyl-1, 2-ethylenediamine to obtain an intermediate product VI; and (5) taking the intermediate product VI, and carrying out deprotection reaction to obtain a final product VII, wherein X represents hydrochloric acid, sulfuric acid, acetic acid, formic acid or trifluoroacetic acid. The purity of the prepared phentolamine EP impurity acid salt reaches 99% or above, the reaction yield is high, a test sample is provided for phentolamine research, and the phentolamine EP impurity acid salt has important research value in clinical pharmacokinetic research.