144 results about "Dimethylamine hydrochloride" patented technology

The invention discloses a preparation method of metformin hydrochloride. The preparation method is characterized by using dicyandiamide and dimethylamine hydrochloride as raw materials, feeding the materials in a mole ratio of (1:1)-(1:1.2), using N,N-dimethylacetamide or dimethyl sulfoxide 2-4 times dicyandiamide by weight as a solvent, and reacting for 4-8 hours at 140+ / -5 DEG C to prepare a crude metformin hydrochloride product; recrystallizing the crude product with ethanol, regulating the pH value to be 5-6, decoloring the crystal, cooling the crystal to minus 10-0 DEG C while stirring, precipitating the crystal, obtaining a refined metformin hydrochloride product through filtering and drying, and recovering the solvent from filtrate. The qualified product has yield of 80-85% and high purity. The preparation method has the advantages that as the selected reaction solvent has a relatively high boiling point, the recovery rate of the solvent is high; the phenomenon of material surging can be effectively avoided, so that the preparation method has the advantages of mild reaction conditions, simplicity in operation and high safety.

The invention belongs to the field of wet metallurgy and in particular discloses a compound leaching agent for preventing landslide in the process of leaching weathering crust deposit type rare earth ore in situ. The compound leaching agent consists of a mixed aqueous solution of an organic amine salt anti-swelling agent, a leaching agent and a pH regulator, wherein the concentration of the organic amine salt anti-swelling agent is 1-15g / L; the concentration of the leaching agent is 5-30g / L; the pH value of the mixed aqueous solution is regulated to be 4.0-6.0 by using the pH regulator. The compound leaching agent is preferably any one of dimethylamine hydrochloride, di-n-propylamine hydrochloride, diethylamine hydrochloride and triethylamine hydrochloride. Due to the addition of the anti-swelling agent, the compound leaching agent has the capacity of well preventing swelling of clay minerals, the rare earth leaching effect is not influenced, the leaching agent has the functions of leaching and preventing swelling, and landslide is effectively avoided in the process of leaching the weathering crust deposit type rare earth ore in situ.

The invention discloses a method for purifying metformin hydrochloride in the technical field of chemical synthesis. The invention adopts a technical proposal that: a crude product of metformin hydrochloride obtained through synthesis of dimethylammonium chloride and dicyandiamide is put into a purified water of which the weight is three times of that of the crude product of metformin hydrochloride, heated to 65 to 75 DEG C for circumfluence to be dissolved completely, and then is cooled to separate a mother liquid; and thus refined metformin hydrochloride is obtained. The obtained product avoids blocking the filter press pipes easily, and does not need heat preservation in the filter press pipes, filter press of 200kg of metformin hydrochloride takes about 0.5 hour, and the method has easy operation and decreased cost.

The invention relates to a preparation method of duloxetine, which takes 2-acetyl phenol, paraformaldehyde and dimethylamine hydrochloride as raw materials to obtain the target product by five steps of Mannich reaction, reduction, resolution, etherification and demethylation, and optimizes the reaction conditions of resolution and etherification, wherein, the resolution reaction comprises the steps of one-time resolution, racemization-resolution and secondary racemization-resolution. The invention can improve the yield of the duloxetine and reduce the production cost, and is easy for industrial production.

The present invention provides a method for preparing a relugolix intermediate compound 8. The method comprises: (a) carrying out a reaction on a compound 2 and N,N'-carbonyldiimidazole to obtain a compound 3; (b) carrying out a reaction on the compound 3 and 2,6-difluorobenzyl chloride to obtain a compound 4; (c) carrying out a reaction on the compound 4 and 3-amino-6-methoxypyridazine to obtaina compound 5; (d) carrying out a reaction on the compound 5 and N,N'-carbonyldiimidazole to obtain a compound 6; (e) carrying out a reaction on the compound 6, N-bromosuccinimide and azobisisobutyronitrile to obtain a compound 7; and (f) carrying out a reaction on the compound 7 and dimethylamine hydrochloride to obtain a compound 8. The invention further provides a relugolix preparation method, which comprises: (g) carrying out a reaction on the compound 8 obtained by the method and hydrogen under a catalyst to obtain a compound 9; and (h) carrying out a reaction on the compound 9, N,N'-carbonyldiimidazole and methoxy amine hydrochloride to obtain relugolix. According to the present invention, the method adopts the route sequentially comprising loop closing and coupling, such that the method has characteristics of simple operation, less side-reaction, mild reaction condition, high yield, high product purity and easy product purification, and is suitable for commercial scale production.

The invention relates to a method for preparing rivastigmine hydrogen and tartrate thereof, which comprises the following steps: taking metamethoxyacetophenone as an initial raw material, and obtaining 1-(3-methoxyphenyl)ethanol by the reduction; then performing the chlorination to obtain 1-(chloroethyl)-3-methoxyphenyl; then reacting the1-(chloroethyl)-3-methoxyphenyl with dimethylamine hydrochloride to obtain 1-(3-methoxyphenyl)-N, N-dimethylethanamine; demethylating the reaction product to obtain 3-[1-(dimethylamino)ethyl]phenol; then performing salt formation resolution with (s)-(+)-camphor-10-sulfonic acid, recrystallizing, and dissociating to obtain (s)-3-[1-(dimethylamino)ethyl]phenol; then taking ethylamine as a raw material to react with ethyl formate to obtain formylethylamine; then reacting the formylethylamine with phosphorus oxychloride to obtain an imine intermediate; reducing the imine intermediate by sodium borohydride to obtain ethyl methyl amine; then reacting the ethyl methyl amine with triphosgene to obtain N-methyl-N-ethylformyl chloride; and finally using (s)-3-[1-dimethylamino)ethyl]phenol to condensate with the N-methyl-N-ethylformyl chloride, and then performing salt formation with levotartaric acid to obtain the rivastigmine hydrogen tartrate. The method has the advantages of easily-obtained raw materials, simple and convenient operation, low cost, high yield and small pollution, and is a brandnew synthesis route at present.

The invention discloses a method for preparing an enamine ketone compound, wherein the enamine ketone compound with two substituents on a nitrogen atom is prepared through an enolate intermediate. A formylation reaction is carried out by using a ketone compound with alpha-methyl or alpha-methylene as a substrate to obtain enolate; and a dehydration-condensation reaction of the enolate and dimethylamine hydrochloride is further carried out to obtain the enamine ketone compound. A reaction formula is as shown in the figure. The raw materials adopted by the method are all ordinary and easily obtained materials, and the method has simple preparation process and mild reaction condition, does not need large expensive equipment and is adaptable to industrialized large-scale production; moreover, the reaction selectivity is high, and the prepared enamine ketone has high yield, is easy to separate and purify and has broad application prospect.

The invention discloses a production method of high-purity metformin hydrochloride. The method comprises the following steps: heating a solvent to a temperature of 75 to 90 DEG C, adding solid dicyandiamide under stirring, maintaining the solvent temperature in a range of 75 to 90 DEG C, dropwise adding a dimethylamine hydrochloride solution to carry out reactions at the temperature of 75 to 90 DEG C, wherein during the reaction process, crystals are gradually generated; stopping stirring after the reactions have been carried out for a while, cooling until the temperature reaches 25 to 30 DEG C, filtering, and drying the crystals so as to obtain the metformin hydrochloride product, wherein the mother liquor can be recycled. The technology has the advantages of high purity and low cost.

The invention relates to the synthesis of organic compounds, in particular to a method for synthesizing 6-fluoroindole-3-acetonitrile, which comprises the following steps: step one, synthesis of 6-fluorogramine: blending raw materials of 6-fluoroindole, dimethylamine hydrochloride and paraformaldehyde according to the mol ratio of 1:1-1.5:1-2, mixing the raw materials evenly and then adding the mixture to an organic solvent, stirring continuously the mixture during the reaction, and heating and refluxing the mixture to prepare the 6-fluorogramine for stand by services; and step two, synthesis of the 6-fluoroindole-3-acetonitrile: blending the raw materials of the 6-fluorogramine prepared in the step one and sodium cyanide according to the mol ratio of 1:1-2, mixing the raw materials into the organic solvent, refluxing the mixture and evaporating out the solvent, and extracting an organic layer to obtain the 6-fluoroindole-3-acetonitrile. The method has the advantages that the short synthetic route is short and can be completed in just two steps, the raw materials are readily available, the substitution of the third position of indole is accurate, the control is convenient with low cost, the reaction yield is high, and a prepared high-purity medicament intermediate product is applicable to industrial production.

The invention aims at providing a treatment scheme of ammonia nitrogen in sucralose production wastewater, and discloses a method for recovering dimethylamine from sucralose production wastewater. The method comprises the following steps: a highly alkaline material is added into wastewater containing 10-30% of dimethylamine hydrochloride and 1-5% of N,N-dimethylformamide, such that an intermediate product with a dimethylamine concentration of 10-30% is obtained; the intermediate product is subjected to rectification purification, such that a dimethylamine solution with a concentration higher than 35% is obtained. The technical scheme provided by the invention has the advantages of low energy consumption, low investment, and reasonable economic benefit. While ammonia nitrogen wastewater is treated, dimethylamine is recovered. The method has high practicality and good economic applicability for enterprises.

The invention discloses a preparation method of metformin hydrochloride. The method is characterized by including the following steps of firstly, adding dicyandiamide and dimethylamine hydrochloride in a reaction still, and adding cyclohexanol, wherein the mole ratio of dicyandiamide to dimethylamine hydrochloride is 1:1.2, and the mole ratio of cyclohexanol to dicyandiamide is 3:1; secondly, starting a stirring device, controlling the rotating speed at 45-50 r / min, regulating the vacuum degree in the reaction still to 0.08-0.09 MPa, heating the mixture to 135-145 DEG C, and preparing crude metformin hydrochloride after the reaction is conducted for 2.5 hours; thirdly, conducting recrystallization on the crude product through ethyl alcohol, and conducting filtering and drying to obtain the metformin hydrochloride. By means of the method, the reaction time is greatly shortened, the production cost is reduced, side reactions can be effectively restrained, the impurity content is reduced, and therefore the yield of the product is greatly improved.

The invention discloses a method for recovering dimethylamine from dimethylamine hydrochloride, which comprises the following steps: the dimethylamine hydrochloride and sodium hydroxide aqueous solution are reacted through taking toluene as solvent; and dimethylamine is recovered and obtained through heating, rectification, and arefaction with solid sodium hydroxide. The recovering method provided by the invention has high efficiency, is convenient for operation, solves the problem of recovering and reusing the dimethylamine from the dimethylamine hydrochloride, can be used for effectively recovering high purity dimethylamine from the dimethylamine hydrochloride, solves the problem of environment protection in waste treatment as obtained waste sodium chloride can be easily treated, and is suitable for large scale industrial production.

The invention provides a method for producing large-grained crystals of metformin hydrochloride in the technical field of chemical synthesis. The invention adopts a technical proposal that: a crude product of metformin hydrochloride obtained through synthesis of dimethylammonium chloride and dicyandiamide is firstly washed with absolute ethanol; after a parent liquid washed by ethanol is separated, the obtained crude product of metformin hydrochloride is put into a purified water of which the weight is three times of the weight of the crude product of metformin hydrochloride, heated to 65 to 75 DEG C for circumfluence, stirred to be cooled to 40 to 50 DEG C, and stood to be cooled to 20 DEG C, then the parent liquid is separated, and thus large-grained crystals of metformin hydrochloride is obtained. The granularity of 95 percent of the large-grained crystals of metformin hydrochloride exceeds 40 meshes, the large-grained crystals of metformin hydrochloride has a taste of edible monosodium glutamate, can meet the requirements of customers, and contributes to the reduction of production cost.

The invention discloses a method for treating artificial leather enterprise dimethylamine wastewater and equipment thereof. The complete equipment mainly includes a stripping tower, an absorption tower, a distilling kettle, a crystallizing kettle, a centrifuge and a drying device. In the method, the dimethylamine wastewater from a deaminization rectifying tower is collected and enters the stripping tower, the stripping tower is heated by steam and adopts air for blowing, and gas phase dimethylamine is generated, the gas phase dimethylamine is sent to a first-stage absorption tower, hydrochloric acid and dimethylamine are reacted to obtain a dimethylamine hydrochloride solution, uncompletely-absorbed dimethylamine tail gas is absorbed and treated by waste gas equipment and a second-stage absorption tower so as to high-altitude up-to-standard emission, the dimethylamine hydrochloride solution enters a distillation kettle for evaporation and concentration, then enters a freezing crystallization kettle for crystallization, crystals are separated by the centrifuge, the crystals are filtered and dried by drying equipment to produce a dimethylamine hydrochloride solid treated as hazardous waste. Dimethylamine can be recycled by the method, and the method has the advantages of simple process, high removal efficiency and no secondary pollution.

The invention discloses a high-purity metformin hydrochloride preparation method. N-methyl pyrrolidone is used as a solvent, dicyandiamide and dimethylamine hydrochloride are taken as a solute, the solvent and the solute are added into a synthesis kettle for reaction, and metformin hydrochloride is prepared through steps of stirring, cooling, spin-drying, washing, crystallizing and drying. The metformin hydrochloride prepared through the preparation method provided by the invention has the advantages that the yield is higher than 96.4 percent, and the product purity is higher than 99.93 percent.

The invention provides a method for treating extraction wastewater in sucralose production. The method comprises the following steps: neutralizing materials obtained in a chlorination step in sucralose production to be neutral; then before evaporation concentration and dehydration, carrying out ammonia nitrogen removal treatment on extraction wastewater obtained by extracting an intermediate product sucralose-6-ethyl ester by using an organic solvent, wherein the ammonia nitrogen removal treatment comprises the following steps: adding strong alkali into the extraction wastewater to decompose ammonium chloride to generate ammonia and a corresponding chloride salt, decomposing dimethylamine hydrochloride to generate dimethylamine and a corresponding chloride salt, and then carrying out rectifying by using a rectifying tower, wherein a mixed water solution of ammonia and dimethylamine is obtained at the tower top, and a water solution of a chloride salt and a small amount of impurities isobtained at the tower bottom; then inputting the tower bottom mixture subjected to the ammonia nitrogen removal treatment into an evaporation concentration system; evaporating out water to obtain a concentrated chloride salt solid-liquid mixture; and optionally carrying out crystallizing to obtain a chloride salt crystal.

The invention provides a dimethylamine borane preparation method. Sodium borohydride or potassium borohydride is reacted with dimethylamine hydrochloride in tetrahydrofuran solvent at the temperature ranging from 25 DEG C to 30 DEG C, the yield can reach 90%, and the purity is 99.5%. The unfavorable conditions that the reaction is difficult to control and reaction solvent is prone to volatilize when two solid reactants are added into one reaction bottle simultaneously are avoided by means of respective burdening and dripping reaction. Consumption of tetrahydrofuran serving as the reaction solvent is lowered by 50%, and using alkaline solution for separative purification after reaction is completed can reduce loss of inorganic salt adsorption feed liquid in a direct filtration method, improve yield and increase solvent recovery rate. Crystallization is directly performed under a solvent-free condition after treatment by the alkaline solution is completed. The dimethylamine borane preparation method is simple, convenient to operate, high in yield and product quality and suitable for industrial production and has high application value.

The invention provides a new synthesis method for crizotinib. An atomic economic reaction is adopted to reduce environmental pollution. A high-optical purity raw material is obtained by chiral prolinol induced chiral reduction; a chiral centre is constructed through an SN2 substitution reaction; post-processing and purification difficulties caused by Mitsunobu reaction are overcome. Malononitrile derivative is constructed by adopting a coupling reaction of malononitrile and bromo-pyridinium derivative; N,N-dicarboamide derivatives are obtained by performing aminolysis on N,N-dimethylamine hydrochloride; in the N,N-dicarboamide derivatives, N,N-dimethylamine serving as an easy-to-leave group and hydrazine perform a ring closing reaction to construct a pyrazolone ring, so that an expected final product, namely crizotinib, is obtained. According to the method, though continuous steps are used, the reaction of each step is high, the optical purity is high, and the total yield is also high. In addition, raw materials used in the synthesis method are low in cost and easily obtained; the using amount of a catalyst is small; total cost is easy to control. An operating process is simple and convenient and easy to control, and is suitable for industrial production.

The invention discloses a method for recovering dimethylamine from nicosulfuron waste water. The method comprises the following steps: mixing the nicosulfuron waste water containing dimethylamine hydrochloride with a sodium hydroxide aqueous solution, after sufficient reaction, heating for distilling so as to obain dimethylamine, after washing with water and adsorbing for multiple times, obtaining a recovered dimethylamine agueous solution. The concentration of the recovered dimethylamine agueous solution can reach 30%-50%, and the dimethylamine agueous solution can be used for producing nicosulfuron. The method for recovering the dimethylamine, disclosed by the invention, is simple, and convenient to operate, so that the technical problem of recovering the dimethylamine from the nicosulfuron waste water containing the dimethylamine hydrochloride is solved, and obvious economic benefits and social benefits are achieved. The method is suitable for industrial production.

The invention discloses a synthesis process of dimethylamine borane. The process includes the steps of making hydroboron MBH4 and dimethylamine hydrochloride (CH3)2NH HCl mixed and sufficiently reacting in a solvent at the controlled temperature of 5-15 DEG C under the protection of inert gas to generate dimethylamine borane, and conducting after-treatment to remove the organic solvent and salt toobtain a water solution or solid of dimethylamine borane. The synthesis process is conducted under the reaction conditions of injecting inert gas for protection, hydrogen generated in reaction is brought away in time, safety risks are effectively reduced, the feeding speed and reaction severity can be tolerated to a large extent in the reaction, and the process has the advantages of being efficient, safe, capable of saving energy and the like on the premise of basically realizing the yield and purity in the prior art.

The invention relates to the technical field of production of tinned copper wires, and aims to provide a flux for producing continuous annealed tinned copper wires and a preparation method for the flux. The flux for the tinned copper wires is prepared from the following components: 0.3 to 0.6 percent of ethylene glycol, 0.3 to 0.6 percent of triethanolamine, 0.3 to 0.6 percent of glycerol, 0.05 to 0.12 percent of dimethylamine hydrochloride, 0 to 0.6 percent of zinc chloride, 0.3 to 0.6 percent of ammonium chloride, 1.6 to 2.6 percent of hydrochloric acid, and the balance of water. The flux is strong in welding aid property and good in welding aid effect, eliminates a cooper leakage phenomenon in continuous production, and is good in wetting effect, strong in welding capability, bright and smooth after being welded and easy to decompose at a high temperature; when the flux is matched with an exhaust fan, smog and peculiar smell are eliminated at a tin furnace; coatings of the produced tinned copper wires are bright and smooth; and the flux has good effects of protecting the coatings and preventing oxidation.

The invention discloses a method for preparing 3-N,N-dimethylamino ethyl acrylate from a transition metal carbonyl complex.The method comprises the steps that a specified amount of alkali metal alkoxide and alcohol-containing organic solvent or alkali metal and / or alkali metal hydride and the alcohol-containing organic solvent are taken as raw materials to react to generate an intermediate; a condensation reaction is performed for 4-10 h in a high-pressure reaction kettle by taking the intermediate, ethyl acetate and carbon monoxide gas or ethyl formate as raw material and taking a specified substance containing a transition metal element as a catalyst under the pressure of 2-5 MPa at the temperature of 50 DEG C-100 DEG C to generate a solution containing a specified alkali metal salt; the solution is added into an aqueous dimethylamine hydrochloride solution in batches to obtain 3-N,N-dimethylamino ethyl acrylate.According to the method, by adding the transition metal element, the raw material conversion rate and the product yield are increased, the product purity is improved, the economic benefit is increased, the raw materials are easy to obtain, the atom economy is good, and the raw material utilization rate is high; part of the original auxiliary materials are recycled and reused, and therefore discharge of three wastes is greatly reduced.

The invention discloses a method for preparation of high purity and high yield metformin hydrochloride by a two-component solvent. The method includes: preparation of dimethylamine hydrochloride and preparation of metformin hydrochloride. During preparation of dimethylamine hydrochloride, dimethylamine gas and 31% hydrochloric acid are adopted as the raw materials to carry out reaction, through co-cooling of a cooler and a reaction kettle jacket, pumping circulating, spraying absorption of dimethylamine tail gas and absorption of dimethylamine tail gas by hydrochloric acid, the utilization rate of the raw materials is maximumly ensured, the loss of raw materials is reduced, and the product yield is improved. During preparation of metformin hydrochloride, dimethylformamide and ethylene glycol monopropyl ether two components are used as the solvent, the synergistic effect of the two solvents with different natures are utilized, and the prepared metformin hydrochloride product has yield of over 95% and purity of more than 99.90%.

The invention relates to a dimethyltin dichloride functionalized erbium-embedded tellurium tungstate material containing a polyacid mixture construction block. The material has the chemical formula as[H2N(CH3)2]8H6[Er2(OH)(B-alpha-TeW7O28)Sn2(CH3)4(W5O18)]2.18H2O, belongs to a monoclinic system, a space group is P2 / c, and the cell parameters comprise: a is equal to 17.923 (3) angstrom, b is equalto 17.882 (3) angstrom, c is equal to 29.463 (4) angstrom, alpha is equal to 90.00 degrees, beta is equal to 122.22 degrees, gamma is equal to 90.00 degrees, V is equal to 7989 (2) angstrom <3>, Z isequal to 2, R1 is equal to 0.0812, and wR2 is equal to 0.1635. The dimethyltin dichloride functionalized erbium-embedded tellurium tungstate material containing {B-alpha-TeW7028} and {W5018} mixtureconstruction block is synthesized by adopting a one-step assembling strategy, and is obtained by reacting simple raw materials such as Na2WO4.2H2O, Sn(CH3)2Cl2, Er(NO3)3.6H2O, dimethylamine hydrochloride and K2TeO3 under the condition of a water solution. The photoluminescence properties of the material in a visible region and a near-infrared region are researched, the tellurium tungstate materials 1-Er / Yb co-doped Er / Yb with different proportions are prepared, the photoluminescence properties of the materials in the visible region and the near-infrared region are researched, and an up-conversion luminescence phenomenon of the ellurium tungstate material co-doped Er / Yb being equal to 0.06:0.94 is firstly observed.

The invention provides a preparation method of 2-[[[5-(dimethylamino)methyl-2-furanyl]methyl]thio]ethylamine. The preparation method comprises mixing a dimethylamine hydrochloride solution, polyformaldehyde and a quaternary ammonium salt, heating the mixture to 50 to 70 DEG C, adding furfuryl alcohol into the reaction system, carrying out a first condensation reaction process to obtain an intermediate, mixing the intermediate, cysteamine hydrochloride, concentrated hydrochloric acid and perchloric acid, carrying out a second condensation reaction process at the system temperature of 15 to 25 DEG C to obtain a mixed solution of 2-[[[5-(dimethylamino)methyl-2-furanyl]methyl]thio]ethylamine hydrochloride, alkalifying the mixed solution, extracting the solution through dichloromethane and distilling the extract to obtain 2-[[[5-(dimethylamino)methyl-2-furanyl]methyl]thio]ethylamine. The preparation method has the advantages of high yield, high product purity, simple processes and industrialization easiness.

The invention provides a treating method of high-ammonia-nitrogen mother liquor wastewater in MCP (methyl cyclopentenolone) production. A water phase and an organic phase are separated from high-ammonia-nitrogen mother liquor through an extraction agent; the extraction agent can be recycled and MCP can be recovered through distillation and condensation of the organic phase; dimethylamine hydrochloride can be recovered and continuously put into production for use through decolorization and distillation crystallization treatment of the water phase, and steam used for distillation is waste heat tail gas. With the adoption of the method, MCP crude products can be effectively recovered, meanwhile, the waste heat tail gas is used for evaporating the wastewater, and the dimethylamine hydrochloride is recovered, so that multiple effects of cleanness, environmental pollution and recycling of resources are realized.

The invention provides a betaine type chloramine antibacterial agent and a synthetic method thereof and belongs to the technical field of chemical synthesis and application of chloramine antibacterialagents. The antibacterial agent takes bromoalkyl 5,5-dimethylhydantoin II and dimethylamine hydrochloride as raw materials, and a chloramine precursor compound IV1 / IV2 is prepared through different chemical synthesis routes and then reacts with excessive tertiary butyl hypochlorite under normal temperature conditions to prepare an antibacterial agent compound I1 / I2. The antibacterial agent provided by the invention integrates a chloramine group with a salt group in betaine in a molecule, so that while the hydrophilicity of the chloramine compound is improved, a synergistic bactericidal effectof betaine structure units with different structures and the chloramine group is realized. Escherichia coli and staphylococcus aureus are taken as model strains; antibacterial test results show thatthe bactericidal activity of the carboxylic acid inner salt type chloramine antibacterial agent is significantly better than that of a previously-reported quaternary ammonium salt type chloramine antibacterial agent, and the antibacterial activity is slightly inferior to that of a quaternary ammonium chloride antibacterial agent.

The invention discloses an exemestane intermediate 17-oximino-6-methyleneandrost-1,4-diene-3-one, and a preparation method and an application thereof. Most of existing methods have the defect of low total yield, and are not suitable for industrial production. The invention discloses the exemestane intermediate 17-oximino-6-methyleneandrost-1,4-diene-3-one with a novel structural formula. The preparation method comprises the following steps: dimethylamine hydrochloride and paraformaldehyde are refluxed with water in isoamyl alcohol; 17-oximino-androstadienone is added for carrying out a Mannich reaction, such that 17-oximino-6-methyleneandrost-1,4-diene-3-one is obtained; and exemestane can be prepared through the hydrolysis of 17-oximino-6-methyleneandrost-1,4-diene-3-one. The method is simple, and has high industrialization value.

The invention discloses an unsymmetrical synthesis method of (S)-rivastigmine. The method comprises the following steps of: reacting hydroxyacetophenone with methylethylcarbamoyl chloride to generate N-ethyl-N-methyl-carbamate 3-acetylphenyl formate, carrying out chiral reduction on the N-ethyl-N-methyl-carbamate 3-acetylphenyl formate under the catalysis effect of a complex of (S)-(-)-alpha, alpha-diphenyl prolinol and trimethyl borate, carrying out methanol dissociation to generate N-ethyl-N-methyl- carbamate 3-[(R)-1-hydroxyethyl]phenyl formate, and reacting the N-ethyl-N-methyl- carbamate 3-[(R)-1-hydroxyethyl]phenyl formate with methylsufonyl chloride and dimethylamine hydrochloride to obtain the (S)-rivastigmine. According to the method disclosed by the invention, a target product can be prepared from conventional reagents only through a three-step reaction, the reaction yield reaches 40% and is far higher than that by a racemic resolution method and that by other chiral synthesis methods, the application of virulent reagents and highly corrosive reagents are avoided in the process, and the unsymmetrical synthesis method is easy to operate, environment-friendly, low in production cost, and suitable for industrialized production.