125 results about "Methyl propionate" patented technology

The invention discloses a glue solution for a copper-clad plate and a preparation method of the glue solution, and relates to the technical field of copper-clad plates. According to the prepared glue solution for the copper-clad plate, the composite epoxy resin, the curing agent, the accelerant, the solvent, the flexibilizer and the inorganic filler, the composite epoxy resin comprises bisphenol A epoxy resin, epoxy phenyl polysiloxane, itaconic acid polyaryletherketone and hydroxyl-terminated fluorine-containing vinyl polysiloxane, so that the interface bonding force with the copper plate is enhanced; the dielectric constant and the dielectric loss are effectively reduced, the peel strength and the toughness of the material are also remarkably improved, and the toughening agent is modified polyether sulfone microspheres; the modified polyethersulfone microspheres are prepared by coating polyethersulfone microspheres with hexamethylenediamine tetrapropionamide diamine, the hexamethylenediamine tetrapropionamide diamine is prepared by carrying out acylation condensation reaction on hexamethylenediamine tetramethyl propionate and ethylenediamine, and the polyethersulfone microspheres are prepared by carrying out electrostatic spinning on a spinning solution of polyethersulfone and vinylpyridine, so that the peel strength of the glue solution is remarkably improved.

The present invention discloses a catalyst for aldol condensation reaction, its preparation and application, specifically relating to a method for preparing a catalyst for aldol condensation reaction using biomass-based SiO2 and using the catalyst to catalyze the preparation of methyl methacrylate from a mixed solution (or mixed aqueous solution) of formaldehyde and methyl propionate; the loading amount of the active metal on the catalyst is 1-10 wt%, and the total loading amount of the promoter is 0.5-5 wt%. The catalyst provided by the present invention has excellent water resistance and stability. The catalytic reaction is carried out in a fixed-bed reactor, and the carrier gas is an oxygen-containing inert atmosphere. The raw material formaldehyde in the reaction system can be obtained from methanol, and both methanol and the carrier SiO2 can be derived from biomass. Thus, under the background of aiming at "dual carbon" and popularizing green consumption, the high-value utilization of biomass resources is realized, and further the innovation of green and low-carbon technologies is achieved.

The invention relates to a synthetic method of a refined dimethenamid intermediate, which comprises the following steps: adding methanol and L-alanine into a reaction flask, starting to heat, dropwise adding an esterification reagent at a certain temperature while keeping the temperature, reacting at the same temperature while keeping the temperature after dropwise adding is finished, and after the reaction is finished, carrying out post-treatment to obtain a crude product of (S)-2-amino methyl propionate; adding a solvent and a first reducing agent into the reaction flask, dropwise adding the (S)-2-methyl aminopropionate crude product and a second reducing agent at low temperature, and after dropwise adding, carrying out heat preservation reaction for a period of time at the same temperature; and raising the reaction temperature, carrying out high-temperature heat-preservation reaction for a period of time, and carrying out post-treatment to obtain the refined dimethenamid intermediate (S)-(+)-1-methoxy-2-propylamine. When the method is used for preparation, the product can be obtained only by esterifying and reducing the raw materials, the steps are simple, the raw materials are cheap and easy to obtain, and the yield is greater than 90%.

The invention discloses an alkyl phenolic resin for improving the bonding performance of a GLR rubber adhesive and a preparation method thereof, and relates to the technical field of phenolic resin preparation, the alkyl phenolic resin comprises the following raw materials by weight: 60-70 parts of modified resin, 15-20 parts of modified EPDM, 2-4 parts of carbon fiber, 5-7 parts of naphthenic oil, and 0.8-1.0 part of an anti-aging agent. The modified resin is obtained by carrying out reaction grafting on methyl 3-dodecylthio-propionate, 5-amino-2-hydroxycycloheptyl-2, 4, 6-triene-1-ketone, punicic acid and the like, and then blending with alkyl phenolic resin. The modified EPDM is obtained by grafting a functional monomer and EPDM, wherein the functional monomer contains imidazole, amino, piperazine, phosphamide, hydroxyl and terminal carbon-carbon double bonds. The prepared alkyl phenolic resin has good corrosion resistance, toughness, antibacterial property, adhesion, oil resistance and flame retardance, and is worthy of popularization and application.

The invention provides a mesoporous nanosphere acid-base bifunctional catalyst for synthesizing methyl methacrylate and a preparation method of the mesoporous nanosphere acid-base bifunctional catalyst. The acidic metal ions are introduced into the skeleton of the mesoporous MCM-41 carrier as a modifier, the alkaline active site Cs species are loaded, and the good acid-base balance degree is achieved by regulating and controlling the proportion of the CS species and the acidic metal ions. The composition of the catalyst is Csa / Xb-MCM-41, X is selected from one or two of Zr, Ti, Al, La, Ce and Fe, and a is the mass fraction of Cs species calculated on the basis of a carrier and is 0.08-0.30 in terms of Cs2O; and b is the mass fraction of the oxide corresponding to the element X in the MCM-41 carrier, and is 0.04-0.20. When the catalyst provided by the invention is used for synthesizing methyl methacrylate through reaction of methyl propionate and formaldehyde, excellent catalytic activity and carbon deposition resistance are shown.

The invention relates to a method for controlling wheat septospora which is resistant to a C14-demethylase inhibitor fungicide. The present invention relates to a method for controlling wheat septospora on a cereal plant, which wheat septospora comprises at least one mutation in the CYP51 gene and is resistant to a C14-demethylase (in sterol biosynthesis) inhibitor fungicide (DMI fungicide), the method comprises applying to these plants, seeds or soil of the plants a fungicidally effective amount of (I) methyl 2-[2-chloro-4-(4-chlorophenoxy) phenyl]-2-hydroxy-3-(1, 2, 4-triazol-1-yl) propionate or (II) 2-[2-chloro-4-(4-chlorophenoxy) phenyl]-2-hydroxy-3-(1, 2, 4-triazol-1-yl) propionic acid.

The present application relates to a system for preparing high-purity MMA, comprising a diethyl ketone separation unit for separating diethyl ketone from ethylene carbonylation products; a condensation reaction unit arranged downstream of the diethyl ketone separation unit, for performing condensation reaction on the product separated by the diethyl ketone separation unit to generate MMA; and a rectification separation unit arranged downstream of the condensation reaction unit, for separating the product of the condensation reaction unit to obtain high-purity MMA. After the synthesis of methyl propionate by ethylene carbonylation, the byproduct DEK is first separated and removed by the diethyl ketone separation unit, and the methyl propionate and methanol material containing the diethyl ketone after removal are subjected to condensation reaction with formaldehyde to generate MMA, effectively avoiding the problem of difficult separation of diethyl ketone DEK and MMA with very similar boiling points, and then high-purity MMA is easily obtained by separation.

The invention belongs to the technical field of lithium batteries, and relates to a lithium ion battery, in particular to a phosphate battery with both battery rate capability and safety performance. The lithium ion battery comprises a positive plate, a negative plate, a diaphragm and a non-aqueous electrolyte, the positive plate comprises a positive electrode material layer containing a phosphate material; the organic solvent comprises a first solvent, and the first solvent is selected from at least one of methyl acetate, ethyl acetate and methyl propionate; the lithium salt comprises LiPF6 and LiFSI; the first additive comprises a compound as shown in a structural formula 1; the lithium ion battery satisfies 0.02 < = 10c / a + e < = 1.8, 40 < = a < = 60, 1.1 < = b < = 1.5, 0 < e < = 1.5, and 0.05 < = c < = 2. According to the lithium ion battery provided by the invention, high-concentration LiPF6, low-content LiFSI and high-content carboxylic ester are matched with one another, so that the compatibility of rate capability and safety performance of a phosphate battery is realized.

This invention discloses a method for preparing 1,3-propanediol by hydrogenation of methyl 3-hydroxypropionate. Using manganese-doped layered copper silicate prepared by deposition precipitation as a precursor, a highly dispersed and stable copper-based catalyst is obtained through reduction. The manganese doping and layered copper silicate species enhance the interaction between copper and the support, improving the dispersion of active copper species. Simultaneously, the layered copper silicate increases the difficulty of copper species reduction, thereby improving the Cu content of the catalyst. + / Cu 0 The strong metal-support interaction and the dispersing effect of manganese can effectively inhibit the migration and aggregation of active copper species during the reaction, thus improving the stability of the catalyst. The copper-based catalyst prepared in this invention exhibits high conversion and 1,3-propanediol selectivity in the hydrogenation reaction of methyl 3-hydroxypropionate, with high catalytic activity and stability, and few byproducts, showing good prospects for industrial application.

The present invention relates to a preparation method of galaxolide, comprising: preparing herb alcohol into herb alcoholate; reacting the herb alcoholate with a compound having a structural formula as shown in formula (1) to generate an intermediate having a structural formula as shown in formula (2), wherein in formula (1), R is a halogen element; and subjecting the intermediate to a transesterification reaction with methyl propionate under the action of a transesterification catalyst to obtain galaxolide. In the preparation method of galaxolide of the present invention, the raw materials and reactants are widely sourced, low in price, low in production cost, and the yield of galaxolide is high.

The application designs a method for preparing optically active methyl fluoropropionate by using diethylamine sulfur trifluoride, comprising the following steps: fluorination reaction: under the protection of nitrogen, methyl S-lactate is added to a dry reaction kettle as raw material, the kettle temperature is cooled to a first reaction temperature, diethylamine sulfur trifluoride is added dropwise into the reaction kettle, after dropping, the reaction kettle is heated to a second reaction temperature, after the reaction is completed, the reaction mixture is added dropwise into saturated sodium / potassium bicarbonate aqueous solution to obtain R-2-fluoropropionic acid methyl ester; the molar ratio of diethylamine sulfur trifluoride to methyl S-lactate is 1-1.5:1, the method is high in efficiency, low in three-waste amount, short in reaction path, suitable for industrial production, and has economic value.

The application discloses a mineral tackifier special for shotcrete and a preparation method thereof, and relates to the technical field of tackifiers. The mineral tackifier is obtained through graft copolymerization reaction of 1-vinyl-2-pyrrolidone, acrylic acid, xanthan gum and hyperbranched borate under the action of an initiator; the hyperbranched borate is generated through reaction of a hyperbranched product and 1,4-benzenediboronic acid under the catalysis of anhydrous magnesium sulfate; and the hyperbranched product is prepared through esterification reaction of 3-(bis(2-hydroxyethyl)amino)propionic acid methyl ester and 2-methyl-2-propenoic acid-2,3-dihydroxypropyl ester. The mineral tackifier prepared by the application has good compressive strength and short setting time.

The application discloses a bubble column reactor for preparing methyl propionate, a reaction system and a method. The reactor comprises a bubble column body, a gas distributor and a sieve plate. The application divides the inner cavity of the reactor into multiple spaces through multiple sieve plates, and performs CO segmented feeding on the reaction of synthesizing methyl propionate from a carbonyl group through multiple gas distributors, so that the partial pressure ratio of CO and ethylene in the reactor is reduced, the gas-liquid ratio is obviously reduced, and the reaction conversion rate is obviously improved.

Fungicidal compositions comprising carboxamides The present invention relates to fungicidal compositions comprising at least one compound selected from the group consisting (I-1) N-[1,3-dimethyl-1-(phenylmethyl)butyl]-8-fluoro-3- quinolinecarboxamide, (I-2) N-[(1R)-1-benzyl-1,3-dimethyl-butyl]-8-fluoro-quinoline-3- carboxamide, (I-3) N-[(1S)-1-benzyl-1,3-dimethyl-butyl]-8-fluoro-quinoline-3-carboxamide, as active component 2) at least one compound, or an N-oxide, or an agriculturally useful salt thereof, selected from the group consisting of (II-1) methyl 2-[2-chloro-4-(4- chlorophenoxy)phenyl]-2-hydroxy-3-(1,2,4-triazol-1-yl)propanoate, (II-2) fluoxytioconazole, (II-3) flumetylsulfurim, (II-4) pyrapropoyne, wherein the weight ratio of compound I to compound II is from 10:1 to 1:10. The invention also relates to an agrochemical composition comprising the composition and a solvent of solid carrier. Further, the invention relates to a non-therapeutic use of the inventive compositions controlling phytopathogenic harmful fungi.

The application discloses a preparation method of 3-methyl mercaptopropionate, and belongs to the technical field of pesticide intermediate preparation. The application takes di-tert-butyl disulfide and methyl acrylate as raw materials, generates 3-tert-butyl mercaptopropionate under the action of lithium borohydride, then generates 3-methyl mercaptopropionate and 5-tert-butyl-1,3-dimethoxybenzene under the action of tri (pentafluorophenyl) boron while isobutene is removed and isobutene reacts with m-dimethoxybenzene, and 3-methyl mercaptopropionate is obtained after rectification. In the method, the route is good in operability, low in three wastes and cost, and provides a reference for the preparation of the compound.

The present disclosure relates to a method for preparing methyl propionate from ethylene or C2 mixed gas, comprising the following steps: mixing a heterogeneous catalyst with a liquid acid to obtain a mixed catalyst; the heterogeneous catalyst comprises a Pd precursor, a phosphine ligand and an acidic molecular sieve; the pH of the liquid acid is greater than or equal to 4; the content of the liquid acid in the mixed catalyst is 500-3000 ppm; pure ethylene or C2 mixed gas, CO and methanol are contacted with the mixed catalyst to carry out the reaction of ethylene alkoxycarbonylation to prepare methyl propionate, to obtain a liquid phase mixed product containing methyl propionate and an optional gas phase product containing ethane; wherein the C2 mixed gas comprises ethylene and ethane. The present disclosure replaces the homogeneous catalyst with the heterogeneous catalyst, develops a process for preparing high-value-added methyl propionate from widely available ethylene and low-cost C2 mixed gas, and can realize large-scale industrial production.

The present invention relates to a method for efficiently producing a compound derived from the commercially available and readily available 3-((3S)-7-bromo-2-((2-hydroxypropyl)amino)-5-(pyridin-2-yl)-3H-benzo[e][1,4]diazepine-3-yl)propionate methyl ester, namely, the compound 3-[(4S)-8-bromo-1-methyl-6-(2-pyridinyl)-4H-imidazo[1,2-a][1,4]benzodiazepine-4-yl]propionate methyl ester benzenesulfonate (remimazolam besylate).

The invention discloses a formaldehyde probe as well as a preparation method and application thereof, and belongs to the technical field of fluorescent probe preparation. Dissolving benzylamine and potassium carbonate in anhydrous acetonitrile, adding 2-bromo-2-methyl propionate, and reacting to obtain a compound 3; dissolving the compound 3 and lithium hydroxide in a mixed solution of tetrahydrofuran and water, reacting for a period of time, and quenching the reaction with hydrochloric acid to obtain a carboxylic acid intermediate 4; and dissolving the carboxylic acid intermediate 4 in dichloromethane, then adding CDM, EDCI and DMAP, and carrying out a reaction to obtain the target product DPM. The DPM is a formaldehyde regeneration type fluorescent probe and can realize formaldehyde detection in a mode of disturbing an endogenous steady state to the minimum extent. The DPM is a steady-state maintenance type formaldehyde probe successfully applied to a spinal cord injury (SCI) model for the first time, and can realize visual monitoring on formaldehyde rise of a diseased region based on a non-invasive living imaging system (IVIS).

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 invention discloses a temperature difference MMA fixed bed anti-blocking method and a temperature difference MMA fixed bed anti-blocking device. In the method and the device, at least one section of heating belt and a pressure gauge are arranged on a pipeline at the front end of a feed port of an MMA fixed bed reactor. In a liquid raw material for preparing MMA through condensation of methyl propionate and formaldehyde, methanol and formaldehyde form hemiacetal, and methanol is excessive. Hemiacetal is decomposed when the temperature reaches a certain temperature, released formaldehyde is self-polymerized to form a plugging block, and the plugging block is gradually dissolved by newly entering methanol gas to form hemiacetal to enter. According to the method and the device provided by the invention, the temperature of the heating belt is dynamically adjusted, and the precipitation position of the polyformaldehyde is changed by dynamically adjusting the precipitation-redissolution process, so that the pipeline is prevented from being blocked. According to the method and the device, the anti-blocking effect is remarkable, the operation time of the reactor is prolonged to 650-1770 hours, and high reaction performance can be maintained; the problem of pressure rise can be solved on line without stopping by adjusting the heating belt or the cold tracing device in a segmented mode, and production energy consumption and cost are reduced.

The application discloses a heptadecyl imidazole type efficient corrosion inhibitor, a preparation method and application thereof, and belongs to the technical field of corrosion inhibitors for steel in an acidic environment. The efficient corrosion inhibitor is methyl 3-(2-heptadecyl imidazole)-2-methyl propionate, and a chemical structural formula is as follows: the efficient corrosion inhibitor is prepared through an addition reaction of 2-heptadecyl imidazole and methyl methacrylate; the application has the advantages of low drug dosage, simple synthesis method, high efficiency, safety and environmental protection; the application is used in an acidic environment such as industrial pickling and oil and gas well acidification, and compared with a conventional imidazole type corrosion inhibitor, a lower drug dosage can achieve high corrosion inhibition efficiency; in particular, in a 1 M HCl solution, when the drug dosage is 300 mg / L, the corrosion inhibition efficiency on Q235 steel reaches 98.11%.

The invention provides a method for preparing methyl propionate in one step by taking ethylene, carbon monoxide and methanol as raw materials. According to the method, cobalt salt or a cobalt compound and a pyridyl-containing organic compound form a catalytic system, and ethylene can be effectively catalyzed to be converted into methyl propionate at the temperature of 80-180 DEG C and the pressure of 0.5-8 Mpa. The mechanism for realizing the method is that divalent cobalt is promoted to be converted into key active species Co2 (CO) 8 and HCo (CO) 4 by utilizing the alkalinity and coordination capability of a pyridyl organic matter in a CO atmosphere with enough pressure, and a characteristic peak of a key intermediate HCo (CO) 4 is captured through electrospray ionization mass spectrometry (figure 4). Compared with the prior art, the methyl propionate synthesis method has the advantages that carbonyl esterification of ethylene can be realized under relatively mild conditions without using noble metals and acidic auxiliaries, unreacted gas can be recycled, the catalyst can be recycled through rectification, and the methyl propionate synthesis method is green and economical.

The invention provides a method for preparing methyl propionate through hydrogenation of methyl acrylate, belongs to the technical field of catalytic synthesis of organic matters, and aims to solve the technical problem of low catalytic activity of a catalyst in a hydrogenation reaction of methyl acrylate. Methyl acrylate is used as a raw material, and a nickel monatomic catalyst is used as a catalyst; the method comprises the following steps: activating a nickel monatomic catalyst through hydrogen, and then carrying out hydrogenation reaction in a hydrogen atmosphere to prepare methyl propionate; the nickel monatomic catalyst comprises a ZIF carrier and a nickel monatomic loaded on the ZIF carrier. A metal organic framework material ZIF-8 is used as a catalyst carrier precursor, metal atoms in the precursor are fixed to the surface of a carrier in a coordination binding mode, and the monatomic catalyst with transition metal nickel as an active component is obtained through high-temperature cracking and is applied to a reaction for preparing methyl propionate through methyl acrylate hydrogenation. The catalyst has the characteristics of high activity, high selectivity and high stability.

The utility model discloses a raw material classification weighing device for veratrone processing, which belongs to the technical field of veratrone processing and comprises an electronic scale body, a weighing square cylinder for accommodating methyl 2-chloropropionate, a blocking assembly and a rotating assembly. The weighing square cylinder is arranged on the electronic scale body. The blocking assembly is arranged on the weighing square cylinder. Wherein the blocking assembly comprises a movable square sleeve and a blocking block for blocking methyl 2-chloropropionate; the movable square sleeve is arranged on the weighing square cylinder in a sliding and sleeving manner; the four stop blocks are arranged on one side of the movable square sleeve in a square array through a rotating assembly. Wherein the four stopping blocks form a complete 2-chloropropionic acid methyl ester stopping plate; wherein each stop block is of an isosceles triangle structure, the opposite sides of every two adjacent stop blocks are arc-shaped faces, and the raw material classifying and weighing equipment for veratrone processing is simple, reasonable and ingenious in structural design, capable of preventing methyl 2-chloropropionate from being volatilized in the weighing process and high in practicability.

This invention relates to a method for preparing methyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, a raw material for synthesizing antioxidants 1010 and 1076. Specifically, this invention uses 2,6-di-tert-butylphenol and methyl 3-bromopropionate as reactants, adds an organic solvent, and reacts them in a reaction system under light and in the presence of a palladium catalyst to obtain methyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate; furthermore, the reaction system also includes an alkaline additive. This invention provides a novel method for preparing methyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate. By activating the C-H bond at the 4-position of the benzene ring of 2,6-di-tert-butylphenol, a methyl propionate group is directly attached to the 4-position of the benzene ring. Compared to existing technologies, this method does not require strong bases or highly toxic reagents and has a lower reaction temperature. This method has the potential to be an alternative to existing methyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate preparation processes and a new route for obtaining synthetic raw materials for antioxidants 1010 and 1076.

A method for preparing 1,3-propanediol with a high space-time yield, in which A methyl 3-hydroxypropionate solution is pumped into a tubular fixed-bed reactor loaded with a surface modifier-coated nano-Cu-based catalyst for continuous hydrogenation to obtain a reaction mixture, where the catalyst includes Cu as active component, a metal oxide XOn / 2 as additive and a SiO2—SnO2 composite carrier. The reaction mixture is subjected to rectification to separate light components from heavy components, where the light components include methanol, n-propanol, methyl propionate, methyl 3-hydroxypropionate and 1,3-propanediol, and the heavy components include 1,3-propanediol mono-propionate and 1,3-propanediol mono-3-hydroxypropionate. The heavy components are fed back to the tubular fixed-bed reactor for secondary hydrogenation, and the light components are separated to obtain 1,3-propanediol.

The utility model discloses a storage device for methyl 3-hydroxypropionate production, and relates to the technical field of methyl 3-hydroxypropionate storage, the storage device comprises a heat preservation box, a storage box is installed in the heat preservation box, and a plurality of partition plates are fixedly connected to the inner side wall of the heat preservation box from top to bottom at equal intervals. During use, the space between the outer side face of the storage box and the inner side wall of the heat preservation box is divided into the multiple cavities through the multiple partition plates, temperature sensors are installed in the multiple cavities, and then the multiple first temperature adjusting assemblies located in the multiple cavities are matched, so that when the local temperature is abnormal, the first temperature adjusting assemblies can adjust the temperature of the heat preservation box. According to the storage device, the temperature of the chamber where the temperature is abnormal can be independently adjusted, so that local temperature adjustment work can be rapidly and accurately completed, the reliability of temperature adjustment of the storage device is improved, energy consumption generated by temperature adjustment can be reduced, and the economical efficiency and practicability of the storage device are improved.

The invention discloses a synthetic method of (S)-2-(N-t-butyloxycarboryl)-3-(4-bromine-2-thiazolyl) methyl propionate, which is characterized in that (R)-N-t-butyloxycarbonyl-3-iodo-alanine methyl ester and 2, 4-dibromothiazole are used as reactants, a reducing agent, a catalyst and a cocatalyst are added into a reaction solvent, and the (S)-2-(N-t-butyloxycarboryl)-3-(4-bromine-2-thiazolyl) methyl propionate is synthesized through one-step reaction. According to the invention, cheap reagents are adopted, the reaction can be completed in one step, the defects of use of an expensive noble metal catalyst, harsh reaction conditions and complex operation in the existing synthesis method are overcome, the yield is higher, and the method can be suitable for industrial production and has good economic value.

The present disclosure relates to a monomer composition including methyl methacrylate, an α-olefin, and at least one compound selected from the group consisting of methyl propionate, methyl pyruvate, and methyl 2-methylbutyrate.

The invention discloses a method for preparing a chiral indazole intermediate (R)-2-amino-3-(7-methyl-1H-indazole-5-yl) methyl propionate of zavazepam, which comprises the following steps of: taking zavazepam as a raw material; the preparation method comprises the following steps: by taking methyl pyruvate as a raw material, generating an enol silyl ether compound of formula IV in situ under the action of a hydrogen pulling reagent and a silicon etherification reagent; coupling the alpha-keto ester compound with a halogenated indazole compound V under the action of a palladium catalyst to obtain an alpha-keto ester compound VI; and finally, carrying out stereoselective transaminase reaction on the compound shown in the formula VI by utilizing specific modified transaminase, so as to efficiently prepare the target chiral intermediate. According to the method, chemical synthesis and biological catalysis are creatively combined, the route only needs three steps, the process is remarkably simplified, the total yield is high, the reaction condition is mild, an expensive chiral catalyst does not need to be used, the yield is remarkably improved by introducing a reaction aid into key steps, and the whole process is easy to amplify and suitable for industrial production.