39 results about "Ester hydrochloride" patented technology

The invention provides a method for synthesizing N-methylated polypeptide, which comprises the following steps: dissolving a carboxylic acid compound, N-methyl amino-acid ester hydrochloride or N-methyl amino-acid ester, an alkaline substance and pivaloic anhydride in an organic solvent, reacting at 15-80 DEG C for 3-10 hours, and post-treating the obtained reaction liquid to obtain an N-methyl dipeptide compound, the method comprises the following steps: removing a protecting group in an N-methyl dipeptide compound to obtain a free-state N-methyl dipeptide compound, and condensing the free-state N-methyl dipeptide compound and amino acid or N-methyl amino-acid ester protected by amino to obtain the N-methylated polypeptide, the mixed anhydride intermediate is formed in situ, and the reaction is completed in one step; according to the method, trimethylacetic anhydride is used as a condensing agent, the structure is simple, the reaction is safe, cheap and non-toxic, a large amount of nitrogen-containing byproducts are not generated in the reaction, and purification is convenient; the method is high in stereoselectivity, and racemization is avoided; according to the method, environment-friendly solvents such as ethyl acetate can be used, the reaction condition is mild, and the reaction time is short.

The invention discloses an antifouling elastic sofa fabric and a preparation method thereof, and relates to the technical field of fabrics. Diphenylmethane diisocyanate, polypropylene oxide glycol and modified silicon dioxide are subjected to surface reaction to prepare a nano waterproof finishing agent, and the modified silicon dioxide is prepared by modifying sodium hydroxide, so that the antistatic effect of the fabric can be improved; dL-3-fluorophenylalanine methyl ester hydrochloride is grafted to cotton fibers, fluorine-containing groups of the DL-3-fluorophenylalanine methyl ester hydrochloride are greatly enriched on the surface of the fabric, the low surface energy of the fabric is reduced, stains are prevented from being attached to the surface of the fabric, the antifouling effect is achieved, meanwhile, DL-3-fluorophenylalanine methyl ester hydrochloride can be bonded with the nano waterproof finishing agent, a net-shaped cross-linked structure is formed, and the anti-fouling effect is achieved. The nano waterproof finishing agent is adsorbed into fibers of the fabric, so that the waterproof and antifouling effects of the fabric are further improved. The fabric prepared by the invention has waterproof and antifouling effects.

The invention discloses a preparation method of (2R, 3S)-2-Boc amino-3-hydroxy-3-(pyridine-4-yl) alanine, and belongs to the technical field of medical intermediates. The preparation method comprises the following steps: by taking glycine ester hydrochloride as a raw material, carrying out benzophenone dimethyl ketal reaction to generate a glycine ester imine intermediate; then, the 2-amino-3-hydroxyl-3-(pyridine-4-yl) alanine and pyridine-4-formaldehyde are subjected to acidolysis, and 2-amino-3-hydroxyl-3-(pyridine-4-yl) alanine is generated; then, the 2-Boc amino-3-hydroxyl-3-(pyridine-4-yl) alanine is subjected to a reaction with Boc2O, and a 2-Boc amino-3-hydroxyl-3-(pyridine-4-yl) alanine racemate is generated; and finally, salifying and resolving by adopting a cyclohexanedibenzylamine resolving agent, and then dissociating to obtain a target product. The raw materials are available in the market, direct condensation reaction is performed between pyridine-4-formaldehyde and amino acid imine, effective resolution can be performed by adopting 0.5 eq of a resolution reagent, and the whole route is simple and convenient to operate and suitable for large-scale production.

The application belongs to the technical field of chemical industry, and discloses a synthesis method and application of (2R,4S)-4-hydroxypyrrolidine-2-carboxylic acid methyl ester hydrochloride, wherein trichloroisocyanuric acid is used as an oxidant, and silica gel loaded 2,2,6,6-tetramethylpiperidine oxide is added as a novel supported catalyst; the supported catalyst is removed and recovered through filtration to obtain an oxidation product IM1; then, sodium triacetoxyborohydride is used as a reducing agent to reduce a trans chiral ketone carbonyl to obtain a trans amino acid product IM2 which cannot be obtained through a fermentation method; finally, the target product (2R,4S)-4-hydroxypyrrolidine-2-carboxylic acid methyl ester hydrochloride is synthesized through a one-step synthesis method under a heating reaction condition in a methanol system. The product prepared through the method has high purity, low raw material cost, simple operation, and is suitable for industrial production and can meet the needs of the future medical and other fields.

The invention provides a synthesis method of celacarburine and a key intermediate thereof, which comprises the following steps: taking methyl 4-aminobutyrate hydrochloride as an initial raw material, and sequentially carrying out o-nitrobenzenesulfonyl protection, alkylation, amide condensation, hydrolysis and deprotection, intramolecular cyclization, removal of o-nitrobenzenesulfonyl protecting group and optional acylation reaction to obtain a target product. A synthetic route is designed through an innovative strategy, the technical bottlenecks that raw materials and reagents are difficult to obtain, steps are tedious, conditions are harsh, the yield is low and the like which commonly exist in an existing macrocyclic synthesis method are overcome, and the target product is simply and safely prepared in a high-yield mode under the mild condition. The method has the advantages of cheap and easily available raw materials and reagents, simple operation, mild conditions and no need of special equipment, has significant industrial application potential, and provides a stable and reliable material basis for subsequent pharmacological research and new drug development of celacarflurine.

The application provides a synthesis method of celacarfurine and key intermediates thereof, comprising the following steps: taking 4-amino butyric acid methyl ester hydrochloride as a starting material, sequentially performing ortho-nitrobenzenesulfonyl protection, alkylation, amide condensation, hydrolysis and deprotection, intramolecular cyclization, deprotection of ortho-nitrobenzenesulfonyl, and optional acylation to obtain a target product. The synthesis route is designed by an innovative strategy, and overcomes technical bottlenecks such as difficulty in obtaining raw materials and reagents, long steps, harsh conditions and low yield which exist in the existing macrocycle synthesis method, and the target product is prepared under mild conditions with high yield, simplicity and safety. The method is simple in operation, mild in conditions, and does not need special equipment, has significant industrial application potential, and provides a stable and reliable material basis for subsequent pharmacological research and new drug development of celacarfurine.

The invention belongs to the field of chemical synthesis, and particularly relates to a synthetic method of azetidine-2-yl (methyl) benzyl carbamate hydrochloride. According to the invention, 1-benzyl azetidine-3-alcohol is used as a basic raw material, and a series of reactions such as substitution reaction and the like are carried out to obtain the high-yield and high-purity azetidine-2-yl (methyl) benzyl carbamate hydrochloride, and the method is suitable for industrial production.

This invention provides a method for preparing (S)-2-amino-4-chlorobutyric acid alkyl ester and its salt, comprising the following steps: (1) reacting a compound of formula I with a base to generate a compound of formula II; (2) reacting a compound of formula II with a chlorinating agent to generate a dichloride; and (3) reacting the dichloride with an alcohol to generate a compound of formula III. The preparation method of this invention improves the physicochemical properties of the reaction by constructing a dimer intermediate from the intramolecular bifunctional group of the compound of formula I, then achieving hydroxyl chlorination with a chlorinating agent, and finally, under the action of an alcohol, achieving the one-pot preparation of (S)-2-amino-4-chlorobutyric acid alkyl ester hydrochloride. This method effectively reduces the amount of chlorinating agent and alcohol used, significantly improves the atom economy and effective conversion rate of the reaction, has mild reaction conditions, produces products without significant racemization, has controllable impurities, and simplifies post-processing and purification. The by-product waste salt can be recycled, making it suitable for large-scale industrial production.

The application discloses a trifluoromethyl benzyl ether substituted amino acid derivative, a preparation method and application thereof, and belongs to the technical field of organic compound synthesis and medicine. The synthesis method of the trifluoromethyl benzyl ether substituted amino acid derivative is obtained through two-step reaction, that is, first, a photo extension reaction is carried out between a benzyl alcohol compound and hydroxynaphthaldehyde (or hydroxybenzaldehyde), then a Schiff base is formed after an amino acid ester hydrochloride, and then the Schiff base is reduced by sodium cyanoborohydride, and then simple hydrolysis is carried out to obtain the trifluoromethyl benzyl ether substituted amino acid derivative. The preparation method has the characteristics of simple steps, mild reaction conditions and fast reaction, and meets the requirements of green chemistry. The compound prepared according to the method can selectively adjust S1P1 receptors without exciting S1P3 receptors, and is expected to be developed into a new preparation for treating idiopathic pulmonary fibrosis.

The invention provides a high performance liquid chromatography detection method of L-homoserine lactone hydrochloride, which comprises the following steps: diluting a test sample containing L-homoserine lactone hydrochloride with a diluent to obtain an L-homoserine lactone hydrochloride solution, filtering the L-homoserine lactone hydrochloride solution, and detecting the filtered L-homoserine lactone hydrochloride solution in a high performance liquid chromatograph, a CAD detector is adopted as a detector; the chromatographic column is formed by chemically bonding hydrophilic groups on organic mixed silica gel particles; the mobile phase comprises a mobile phase A and a mobile phase B, wherein the mobile phase A is acetonitrile or methanol; and the mobile phase B is an ammonium formate or ammonium acetate aqueous solution. Under the chromatographic conditions, after a base line is stable, samples are sequentially injected according to the sequence of standard sample solutions and test sample solutions with multiple gradient concentrations, standard sample solution map data and test sample map data with multiple gradient concentrations are obtained, then a standard curve of the concentration and the peak area is made, and the content of the L-homoserine test sample is calculated by combining the weighing amount of the L-homoserine test sample.

The invention belongs to the technical field of biological medicines, and particularly relates to a preparation method of a high-purity litexitinib tosylate intermediate. The intermediate is N-((3R, 6S)-6-methylpiperidine-3-yl)-7H-pyrrole [2, 3-d] pyrimidine 4-amine, and the preparation method comprises the following steps: reacting (2S, 5R)-5-amino-2-methylpiperidine-1-benzyl formate hydrochloride with 4-chloro-7-Ts-pyrrole [2, 3-D] pyrimidine in the presence of an acid-binding agent under a reflux condition, extracting and concentrating to obtain a primary substitution product, and purifying to obtain the intermediate. And removing benzyl ester (Cbz) protecting groups by using hydrochloric acid, concentrating after extraction, removing Ts by using sodium hydroxide, and carrying out solid-liquid separation, water washing and drying to obtain the target intermediate. The synthesis method provided by the invention has the advantages of less side reaction, high yield, less organic solvent dosage and less three wastes. And the obtained litexitinib tosylate intermediate is high in purity, good in character, small in batch-to-batch difference and stable in quality.

The invention relates to a compound MDMB-BUTINACA-D3 as well as preparation and application thereof, and the structural formula of the compound MDMB-BUTINACA-D3 is as follows: 2-(1H-indazole-3-formamido)-3, 3, 4-triazole-3-carboxylic acid is obtained through condensation reaction of indazole-3-carboxylic acid and tert-leucine methyl ester hydrochloride; the preparation method comprises the following steps: adding 2-(1H-indazole-3-formamido)-3, 3-dimethyl butyric acid methyl ester into 2-(1H-indazole-3-formamido)-3, 3-dimethyl butyric acid methyl ester, adding 3-phenoxybromopropane into a Grignard reagent, carrying out a substitution reaction to obtain butoxybenzene-D4, further adding a brominating agent boron tribromide, carrying out a bromination reaction to obtain bromobutane-D3, and finally carrying out a substitution reaction on 2-(1H-indazole-3-formamido)-3, 3-dimethyl butyric acid methyl ester and bromobutane-D3 again to obtain MDMB-BUTINACA-D3. According to the method, the matrix effect can be well avoided, meanwhile, mass spectrum cross signal overlapping caused by natural isotopes can be avoided, and the mass spectrum quantitative analysis precision can be remarkably improved when the method is used as an internal standard substance for MS quantitative determination.

The utility model provides a nitrogen supplementing device for diazaspiro-nonane-tert-butyl formate hydrochloride production, which comprises a base, the upper end of the base is fixedly connected with a supporting block, the middle part of the upper end of the supporting block is an arc-shaped concave surface, a gas cylinder is placed in the arc-shaped concave surface, the lower end of the base is provided with a fixed table, and the fixed table is provided with a gas cylinder. The fixing table comprises a fixing plate, a fixing hole is formed in the fixing plate in a penetrating mode, a guide rod is vertically and fixedly connected to the center of the interior of the base, a locking block of a cylindrical step structure is arranged on the guide rod in a sliding mode, the lower portion of the locking block is matched with the fixing hole, and a spring is arranged on the upper portion of the locking block. And the spring upwards abuts against the inner wall of the base, and the side wall of the upper portion of the locking block is fixedly connected with a shifting rod. According to the gas cylinder supporting device, the gas cylinder supporting stability can be improved, and meanwhile the placement occupied area is reduced.

The application provides a medical light guide gel with high light guide performance and a preparation method thereof. The medical light guide gel with high light guide performance comprises pure water, glycerol and carbomer, and further comprises aminolevulinic acid propyl ester hydrochloride. The aminolevulinic acid propyl ester hydrochloride is recrystallized, mixed with other components, stirred for 10-15 min, and then the product is prepared by standing. The technical scheme has the technical characteristics of high light penetration, and improves the treatment efficiency and the phototherapy effect.

The invention provides comeflufen hydrochloride as well as a crystal form, a preparation method and application thereof. The comeflufen hydrochloride disclosed by the invention is 3-(3-ethyl-1-methyl-1H-hexahydroazepine-3-yl) and 2-(2-fluoro-4-biphenyl)-phenyl propionate hydrochloride, has good solubility and stability, is quick in drug effect, and can avoid the first-pass effect of the liver, improve the bioavailability and achieve the effects of reducing toxicity and enhancing efficiency; the preparation method of the comeflufen hydrochloride is simple, and the product yield is high.

The application provides a refining method of a sacubitril valsartan sodium intermediate, and relates to the field of drug intermediate synthesis. The sacubitril valsartan sodium intermediate compound is (2R, 4S)-4-amino-5-(diphenyl-4-yl)-2-methylvalerate ethyl ester hydrochloride. The application also relates to a control method of specific impurities in the refining process of the compound, which comprises the following steps: mixing the sacubitril valsartan sodium intermediate crude product with ethyl acetate or isopropyl acetate, then heating to a reflux state, keeping the reflux state for 1-2 hours, and then performing slow cooling, pressure filtration, vacuum drying and other process procedures to obtain the sacubitril valsartan sodium intermediate (2R, 4S)-4-amino-5-(diphenyl-4-yl)-2-methylvalerate ethyl ester hydrochloride. The sacubitril valsartan sodium intermediate obtained by the refining method has high purity, no solvent residue, mild reaction conditions and is easy to be industrialized.

The invention belongs to the technical field of chemical engineering, and discloses a synthesis method and application of (2R, 4S)-4-hydroxypyrrolidine-2-carboxylic acid methyl ester hydrochloride, according to the method, trichloroisocyanuric acid is used as an oxidizing agent, silica gel supported 2, 2, 6, 6-tetramethylpiperidine oxide is added as a novel supported catalyst, the supported catalyst is removed and recycled through filtration, and the (2R, 4S)-4-hydroxypyrrolidine-2-carboxylic acid methyl ester hydrochloride is obtained. An oxidation product IM1 is obtained; carrying out trans-chiral reduction on ketone carbonyl by using sodium triacetoxyborohydride as a reducing agent to obtain a trans-amino acid product IM2 which cannot be obtained by a fermentation method; finally, the target product-(2R, 4S)-4-hydroxypyrrolidine-2-carboxylic acid methyl ester hydrochloride is synthesized in one step through thionyl chloride under the heating reaction condition in a methanol system. The product prepared by the method is relatively high in purity, low in raw material cost, simple to operate and suitable for industrial production, and can meet the requirements in the fields of medicines and the like in the future.

The invention relates to the technical field of polypeptide drugs, and particularly discloses a synthetic method of pseudo-proline dipeptide. The method comprises the following steps: by taking amino-protected Fmoc-Xaa-OH and serine methyl ester hydrochloride or threonine methyl ester hydrochloride as raw materials, firstly carrying out amino acid condensation, then carrying out acid catalysis with 2, 2-dimethoxypropane to obtain a cyclized intermediate, and finally hydrolyzing in the presence of an organic tin alkali reagent to generate the target compound pseudo-proline dipeptide. The method has the advantages of mild conditions, high selectivity, high conversion rate, few by-products, almost complete avoidance of racemization, perfect reservation of the acid-sensitive oxazolidine ring, no influence on other common protecting groups such as Fmoc, Boc and Trt, high selectivity, no influence on other more stable esters such as tert-butyl ester and benzyl ester, and good substrate adaptability.

The invention belongs to the technical field of organic chemical synthesis, relates to synthesis of gizzerosine, and particularly discloses a preparation method and application of gizzerosine. According to the developed gizzerosine active compound preparation method, a compound a and a compound b are subjected to substitution and hydrolysis two-step reaction in the presence of a catalyst and alkali, and a target product can be synthesized. The compound a is (1H-imidazole-4-yl)-acetaldehyde or 4-(2-chloroethyl) imidazole hydrochloride, and the compound b is (1H-imidazole-4-yl)-acetaldehyde or 4-(2-chloroethyl) imidazole hydrochloride; and the compound b is any one of N-(t-butyloxycarbonyl) lysine methyl ester hydrochloride, (S)-6-amino-2-((t-butyloxycarbonyl) amino) tert-butyl hexanoate hydrochloride or N2-(t-butyloxycarbonyl)-L-lysine tert-butyl ester. The method has the advantages of simple and rapid specific operation steps, high reaction yield and easy satisfaction of required raw materials and reaction conditions, and can be widely applied to related scientific research fields such as toxicology and immunological detection.

A process of manufacturing of (2S,5R)-5-(2-chlorophenyl)-1-(2′-methoxy-[1,1′-biphenyl]-4-carbonyl)pyrrolidine-2-carboxylic acid (1), including the preparation of (2S,5R)-methyl 5-(2-chlorophenyl)pyrrolidine-2-carboxylate hydrochloride (6·HCl) as an intermediate of synthesis:Also, the sodium salt of the (2S,5R)-5-(2-chlorophenyl)-1-(2′-methoxy-[1,1′-biphenyl]-4-carbonyl)pyrrolidine-2-carboxylic acid (1), and its use in a pharmaceutical composition including sodium the (2S,5R)-5-(2-chlorophenyl)-1-(2′-methoxy-[1,1′-biphenyl]-4-carbonyl)pyrrolidine-2-carboxylate and a method for treating and / or preventing inflammation in a patient.

The invention belongs to the technical field of biological pharmacy, and relates to a method for directly preparing amoxicillin from D-p-hydroxyphenylglycine, which comprises the following steps: esterifying D-p-hydroxyphenylglycine to prepare a D-p-hydroxyphenylglycine methyl ester hydrochloride aqueous solution, then mixing the D-p-hydroxyphenylglycine methyl ester hydrochloride aqueous solution with a 6-APA aqueous solution, adjusting the pH value, and carrying out solid-liquid separation to obtain the amoxicillin. The mixed solution passes through an immobilized enzyme column bed filled with immobilized penicillin acylase for synthesis from top to bottom, and under the action of enzyme, 6-APA and D-p-hydroxyphenylglycine methyl ester are subjected to a condensation reaction to generate amoxicillin. In the method, compared with the traditional stirring type enzyme reaction, the reaction mode of using the immobilized enzyme column bed reduces the contact time of the 6-APA, the D-p-hydroxyphenylglycine methyl ester and the amoxicillin with the immobilized enzyme column bed, further reduces the degradation of the D-p-hydroxyphenylglycine methyl ester and the amoxicillin, and improves the reaction efficiency. According to the present invention, the feeding amount of the D-p-hydroxyphenylglycine methyl ester is reduced, the yield of the amoxicillin is improved, the impurities are correspondingly reduced, and the amoxicillin meeting the CP quality standard can be prepared without the recrystallization process.

This invention relates to a method for preparing ennasstat in the field of pharmaceutical synthesis technology. The method involves first hydrolyzing compound 2 with a strong base to generate 7-hydroxy-5-(2-phenylethyl)-[1,2,4]triazolo[1,5-a]pyridine-8-carboxylic acid, which is then reacted in situ with pentanoyl chloride to form a mixed anhydride. This anhydride is then condensed with glycine ester hydrochloride, followed by direct hydrolysis without separation to finally obtain high-quality ennasstat. This invention offers advantages such as safer process, higher product purity and yield, significantly reducing the raw material cost of ennasstat and demonstrating substantial economic and social benefits.

The application discloses a kind of (2-carboxyethyl) dimethyl sulfonium chloride and L-homoserine lactone hydrochloride coproduction method, it is related to organic chemistry technical field;Step is: acrylic acid, L-methionine is dissolved in deionized water, and solution A is obtained;Solution A is reacted with hydrochloric acid, distillation to no distillate under reduced pressure, cooling crystallization, filtration, and L-homoserine lactone hydrochloride is obtained;The filtrate of filtration is dissolved into organic solvent after distillation under reduced pressure, catalyst is added, and is reacted with methylating agent, then distillation to no distillate, add hydrochloric acid, cooling crystallization, filtration, and (2-carboxyethyl) dimethyl sulfonium chloride is obtained;The application uses L-methionine, acrylic acid and hydrochloric acid as raw materials, while preparing L-homoserine lactone hydrochloride, its byproduct beta-methylthiopropionic acid can further prepare (2-carboxyethyl) dimethyl sulfonium chloride, waste is treasure, improves raw material utilization, and three wastes are less, and production cost is low.

This invention relates to the field of feed additive preparation technology, and proposes a method for preparing ethyl guanidine hydrochloride, comprising the following steps: S1, dissolving glycine ethyl ester hydrochloride in a solvent, adjusting the pH to 10-11 at 0-5°C using an alkaline adjuster to obtain a reaction solution containing free glycine ethyl ester; S2, adding a cyanamide aqueous solution to the reaction solution containing free glycine ethyl ester at 0-5°C, and reacting at 55-80°C to obtain a reaction solution; S3, after cooling the reaction solution, adjusting the pH to 6-7 using an acidic adjuster, precipitating a solid, which is then filtered and washed to obtain crude ethyl guanidine hydrochloride; S4, recrystallizing the crude ethyl guanidine hydrochloride to obtain ethyl guanidine hydrochloride. This technical solution solves the problems of low yield and low purity of ethyl guanidine hydrochloride in related technologies.

The invention relates to the technical field of medicine analysis and detection, in particular to a method for detecting related substances of (S)-2-amino-3-[2-(tert-butoxy)-2-oxoacetamido] tert-butyl propionate hydrochloride. The detection method comprises the following steps: detecting by adopting a high performance liquid chromatography; wherein the chromatographic conditions are as follows: a chromatographic column is an octadecyl silane bonded silica gel chromatographic column; an aqueous solution of alkali is used as a mobile phase A, acetonitrile and / or methanol is used as a mobile phase B, and gradient elution is carried out. The detection method disclosed by the invention can be used for accurately, stably, reliably and sensitively analyzing and detecting impurities existing in a process route based on (S)-2-amino-3-[2-(tert-butoxy)-2-oxoacetamido] tert-butyl propionate hydrochloride, and has very important significance on quality research and control of the INR101 injection.

The invention discloses a guanidyl-containing polysubstituted benzoate hydrochloride impurity and application thereof. The guanidyl-containing polysubstituted benzoate hydrochloride impurity comprises an impurity 1 and an impurity 2, the structural formula of the impurity 1 is shown in the specification; the structural formula of the impurity 2 is shown in the specification. The structures of the impurity 1 and the impurity 2 in the synthesis process of the guanidyl-containing polysubstituted benzoate hydrochloride are confirmed, the impurity generation process in the synthesis process is speculated, potential side reactions are analyzed, contributions are made for further promoting medicine preparation, and the method has a wide application prospect. The method is applied to preparation of guanidyl-containing polysubstituted benzoate hydrochloride raw materials and / or pharmaceutical preparations.

The invention provides a preparation method of D-dihydrophenylglycine methyl ester hydrochloride, and belongs to the technical field of pharmaceutical chemicals. Deoxidizing the reactor, adding methanol and D-dihydrophenylglycine, and stirring and dispersing; adding triphosgene in batches under the conditions of nitrogen protection and-5 to 10 DEG C, and heating to 50 to 60 DEG C to carry out esterification reaction after the triphosgene is completely added; when it is detected that the conversion rate of D-dihydrophenylglycine reaches 96% or above, the esterification reaction is finished, and methanol is subjected to reduced pressure distillation until a dry solid is obtained; controlling the decompression temperature to be below 60 DEG C, adding a solvent sleeve to distill residual methanol, adding the solvent again to disperse and cool the solid, and cooling; and filtering and drying in vacuum to obtain the finished product D-dihydrophenylglycine methyl ester hydrochloride. The one-time yield of the method is greater than 90%, and the method can be used for the cefradine enzymatic side chain and has a great industrialization prospect.

The invention relates to the technical field of chemical pharmaceutical synthesis, and particularly discloses a synthetic method of omipag isopropyl ester, and the synthetic method provided by the invention comprises three experimental steps of preparing a pyridine sulfonamide intermediate, preparing a bromo omipag isopropyl ester precursor and preparing omipag isopropyl ester. According to the present invention, the bromo-omipag isopropyl ester precursor is creatively constructed, and the bromo-omipag isopropyl ester precursor and the 2-amino acetic acid isopropyl ester hydrochloride are subjected to the Buchwald coupling reaction to synthesize the omipag isopropyl ester through the carbon-nitrogen coupling method; the synthesis of an unstable precursor is successfully avoided, so that the raw materials are easier to obtain, and the method has a good commercial application prospect.

This invention discloses ((S)-2-amino-3-(4-(benzyloxy)phenyl)propionyl)-L-leucine benzyl ester hydrochloride, its preparation method, and its applications, relating to the field of chemical synthesis technology. By providing a dipeptide hydrochloride with tyrosine and leucine as key structural units, the synthesis method of this dipeptide hydrochloride is simple, the reaction conditions are mild, and the product has high purity, high yield, and low impurity content. When the above-mentioned dipeptide hydrochloride provided by this invention is used as a partial active fragment of polypeptide products, it can also significantly improve the purity and yield of polypeptide products.