72 results about "Sodium methanethiolate" patented technology

The invention discloses a preparation method of p-methylsulfonyl benzaldehyde, which takes p-chlorobenzaldehyde as starting material, and comprises the steps of: enabling the starting material to have reaction with sodium methyl mercaptide water solution under the action of phase transfer catalyst to obtain p-methylthio benzaldehyde; and oxidizing the p-methylthio benzaldehyde by hydrogen peroxide under the action of sulfuric acid and oxidation catalyst to obtain the p-methylsulfonyl benzaldehyde. The preparation method is easy in obtaining of raw material of the p-methylsulfonyl benzaldehyde, simple and convenient in operation, low in cost, high in yield and suitable for industrial production.

The invention provides a synthetic method for sulforaphane and belongs to the field of drug synthesis. The method comprises the following steps that: after amino in 4-amino-1-butanol is protected by Boc groups, hydroxy in 4-amino-1-butanol is changed into methanesulfonyl ester by methanesulfonyl chloride, and then the resultant reacts with sodium methyl mercaptide to produce 4-methylthio butyl-1-tert-butoxycarbonylamide; Boc protective groups are removed under acidic condition to obtain 4-methylthio-1-butylamine; 4-methylthio-1-butylamine reacts with carbon disulfide for one hour in the presence of triethylamine and p-toluenesulfonyl chloride is added for treatment for half an hour to produce 4-methylthio butyl-1-isothiocyanate; and at last 4-methylthio butyl-1-isothiocyanate is oxidized by m-CPBA to produce sulforaphane. According to the invention, complex hydrazinolysis of phthalimide in aftertreatment is avoided and toxic thiophosgene is not needed in the preparation of isothiocyanate; overall yield of sulforaphane is 64%, substantially higher than the overall yield of 8% reported in literature; the whole preparation process is simple and time-saving and is suitable for large scale production.

The invention relates to a medicine producing field, specifically, to an improved producing method of antibacterial medicine nifuratel. The method makes use of thiourea as initial material to produce nifuratel. The improvement is that it is no longer to use methyl mercaptan or methomyl in the known method while producing the intermediate 2-(methylthiomethyl)hydropropane. Furthermore, the invention is no longer to use metal natrium in the known method when the 3-methylthio-2-hydroxy-propylhydrazine and diethyl carbonate are heated to produce N-amido-5-methylthiomethyl-2-oxazolidone in the existance of alkali. All of the improvements largely improve the preparation of the nifuratel, especially for the production condition in a large scale, reduce the environment pollution and benefit to ensure the production safety.

The invention discloses a synthetic method of nifuratel. The synthetic method comprises the steps of carrying out a substitution reaction between epoxy chloropropane and sodium methyl mercaptide in the presence of a phase transfer catalyst to obtain epoxy propyl dimethyl sulfide, and then performing hydrazinolysis, cyclization and condensation on the obtained epoxy propyl dimethyl sulfide to obtain the nifuratel. The synthetic method is high in nifuratel yield, high in purity and low in impurity content; besides the method has the advantages that a ring-closure reaction is carried out under the alkaline condition of sodium methoxide, the use of metal sodium is avoided, production safety is ensured, and simultaneously, the reaction is easy to arouse, easy to control in process, the used raw materials are easy to get, basically no waste liquid is generated in the reaction of each step, and therefore, industrial pollution is greatly reduced; and as a result, the synthetic method of nifuratel is applicable to industrial production.

A preparation method of 1, 2-benzisothiazole-3-ketone (BIT) is a BIT synthetic route realized by adopting a 2-chlorobenzonitrile method which selects water to replace chlorobenzene as a sulfurization and chlorination solvent. By adopting the method, the pollution of the chlorobenzene to atmosphere and water body is thoroughly eliminated and the total production cost of BIT is greatly reduced. The method comprises the following steps: chlorobenzonitrile is added with water accounting for 0-50% of the mass of the chlorobenzonitrile, and is added with a catalyst, then is added with sodium methyl mercaptide solution dropwise for a sulfuration reaction after heating, and the reactant is cooled for standing, a lower layer water phase is given out, water is added to rinse an upper layer organic phase, then the organic phase obtained in the sulfurization process is added with water accounting for 30%-200% of the volume of the organic phase; and chlorine is introduced into for reacting for 2-5h while stirring, then filtration is carried out to obtain a filter cake after the organic phase completely disappears and a white-pink suspended solid is produced, the filter cake is washed by clear water and is dried at low temperature to obtain the BIT product.

The invention discloses a waste gas treatment and methyl mercaptan recycling process in cimetidine and ranitidine production. The waste gas treatment and methyl mercaptan recycling process comprises the following steps: (1) introducing waste gas in the production process of cimetidine and ranitidine into a washing tank, controlling pressure to 0.2-0.3MPa, removing volatile substances which are low in boiling point and easily soluble in water in the waste gas; (2) introducing the waste gas subjected to washing treatment into an alkaline washing tank, controlling pressure to 0.2-0.3MPa, removing volatile substances which are insoluble in water and soluble in alkaline by alkaline liquor in the alkaline washing tank; (3) introducing the waste gas subjected to the alkaline washing into a three-stage absorbing device, removing methyl mercaptan in the waste gas to generate sodium thiomethoxide; and (4) introducing the waste gas subjected to the three stages of absorption into a hydrogen peroxide falling film absorbing tower for performing oxidation treatment, and then discharging. According to the waste gas treatment and methyl mercaptan recycling process, useful chemical raw materials in the waste gas are recycled on the basis of solving the problem of waste gas emission, and thus the waste gas is prevented from being discharged, the economic benefit is increased, a new value is created, and the recycling economy is realized. The waste gas treatment and methyl mercaptan recycling process is good in application prospect.

A production technology of high-purity sodium methyl mercaptide includes the steps that a reaction product of the raw materials of sodium hydrosulfide and dimethyl sulfate is subjected to washing and alkali liquor absorption for concentration adjustment and then subjected to cooling crystallization and drying, and then the high-purity sodium methyl mercaptide product is obtained. By means of the technology, the high-purity sodium methyl mercaptide liquid or solid product can be obtained, the transportation cost of the sodium methyl mercaptide product is greatly lowered, meanwhile, the equipment investment and operating cost of manufacturers using sodium methyl mercaptide are also lowered, and requirements of sodium methyl mercaptide using markets are met.

The invention discloses a synthesis method of an s-triazine clean-series weedicide. An s-triazine Jin-series weedicide and sodium methyl mercaptide used as raw materials are synthesized under closed conditions to obtain the s-triazine clean-series weedicide technical toxicant. The method solves the problems of uncontrollable smell, complex wastewater treatment and the like in the existing technique, enhances the reaction efficiency and yield, lowers the power and raw material consumption, lowers the production cost, and has the advantages of accessible reaction raw materials, closed reaction process, controllable smell, no use of catalyst, environment friendliness, high controllability, high efficiency and the like; and the obtained product has high quality and high yield, has wide application range, and can bring in considerable economic benefits and social benefits after implementing industrialization.

The invention discloses a method for removing iron ions from a sodium thiomethoxide solution. The method for removing iron ions from the sodium thiomethoxide solution comprises the following steps: adding appropriate complexing agent iron ions into an alkaline solution, heating to a certain temperature, stirring at constant temperature for an appropriate period of time, standing, settling for a certain period of time and filtrating. The iron ion content in the alkaline solution treated by the method is obviously reduced, namely the solution is changed from red to be colorless and transparent, does not become red any longer after exposure to air and has an basically unchanged content. The method for removing iron ions from the sodium thiomethoxide solution is easy to operate, readily available in raw materials, and is applicable to industrial treatment.

The invention relates to the technical field of preparation of dimethyl disulfide and provides a production method of dimethyl disulfide. The production method includes the steps of A, using sodium hydroxide solution containing catalyst to absorb a methyl mercaptan mixture so as to obtain mixed solution containing sodium thiomethoxide; B, mixing oxygen or oxygen-rich air with the alkaline solution obtained in the step A, allowing reaction to generate dimethyl disulfide, dimethyl sulfide and sodium hydroxide; and C, separating the oxygen or oxygen-rich air surplus in the reaction to generate dimethyl sulfide so as to obtain dimethyl disulfide liquid. The production method has low cost, high yield and low pollution. A production apparatus of dimethyl disulfide is further provided; the production apparatus comprises an absorption column, a heater, an oxidization column, a flash separator tank and a recovery system connected in order through a pipeline, wherein the heater is used for heating the alkaline solution to a set temperature, the oxidization column is used for generating dimethyl disulfide, the flash separator tank is used for separating materials, and the recovery system is used for recovering the alkaline solution. The production apparatus is automatically controllable, thus labor is saved, reutilization of the alkaline solution is achieved and production cost is lowered.

The invention discloses an industrial production method of o-nitrobenzenesulfonyl chloride. The method comprises the following steps that o-nitrochlorobenzene and sodium methyl mercaptide are subjected to an etherification reaction, filtering is conducted, an obtained filter cake is subjected to recrystallization, and through centrifugation separation and drying, a dry product of o-nitrobenzene dimethyl sulfide is obtained; the dry product of o-nitrobenzene dimethyl sulfide is subjected to a chlorination reaction in batches to obtain a wet crude product, an appropriate amount of hydrochloric acid is added in a chlorination reaction system, the chlorination reaction is carried out in a hydrophilic organic acid solvent, and the mole ratio of the o-nitrobenzene dimethyl sulfide to water during the chlorination reaction is 1:(5-15); a finished product of o-nitrobenzenesulfonyl chloride is obtained through refining and drying. Through HPLC detection, the content of the o-nitrobenzenesulfonyl chloride synthesized by means of the method is 98-98.5%; the yield is 0.72-0.75, the acquisition rate is 0.97 or above, the turbidity (ppm) is 1.5-2, and the melting point is 66-67 DEG C. By adopting the hydrophilic organic acid solvent, the problems about large-scale production discharging, yield and quality are solved, and meanwhile the purposes of mixed application and post-treatment separation of large-scale production water-soluble solvents are achieved.

The invention relates to a preparation device and a preparation method of 3-methylmercapto propionaldehyde. The preparation device is provided with a reaction kettle, washing tanks, a washing circulating pump, absorbing kettles, an absorbing circulating pump, a separating device and a vacuum pump, wherein a methanthiol outlet of the reaction kettle is connected with methanthiol inlets of the washing tanks, an acrolein solution inlet of the reaction is externally connected with an acrolein solution source, and discharging holes of the washing tanks are connected with the reaction kettle and the washing tanks; and methanthiol outlets of the washing tanks are connected with methanthiol inlets of the absorbing kettles, acrolein inlets of the absorbing kettles are connected with the acrolein source, discharging holes of the absorbing kettles are communicated with a feeding hole of the absorbing circulating pump, a discharging hole of the absorbing circulating pump is communicated with feeding holes of the absorbing kettles, and 3-methylmercapto propionaldehyde is conveyed to a finished product through discharging holes of the absorbing kettles. A first preparation method comprises the steps of adding dimethyl sulfate into a sodium hydrosulfide water solution to obtain methanthiol, washing with cooling water, and reacting methanthiol with acraldehyde liquid, so as to obtain 3-methylmercapto propionaldehyde. A second preparation method comprises the steps of adding sulfuric acid into a sodium methyl mercaptide solution to obtain methanthiol gas, washing, cooling, and reacting methanthiol gas with acrolein, so as to obtain 3-methylmercapto propionaldehyde.

The invention discloses a method and a device for producing sodium thiomethoxide from a by-product obtained through synthesis of dimethyl sulfide. Specifically, the by-product in a synthesis process of dimethyl sulfide is taken as a raw material, feed gas is pumped into a water extraction column, soft water is fed into the water extraction column from the upper part of the water extraction column, and methanol in the feed gas is extracted with the soft water; the material with methanol removed is subjected to distillation, and removed thioether returns to a dimethyl sulfide workshop for use; crude methyl mercaptan after thioether is removed is fed into a stripper, and most hydrogen sulfide in the raw material is removed through stripping; trace hydrogen sulfide is removed with an iron oxide desulfurizer, and refined methyl mercaptan gas is obtained; refined methyl mercaptan gas is fed into an absorption column and absorbed by liquid caustic soda, and a sodium thiomethoxide solution is obtained. The invention further provides the device corresponding to the method. The method can effectively produce a sodium thiomethoxide product from the by-product methyl mercaptan obtained through synthesis of dimethyl sulfide, waste is changed into wealth, and higher economic and environmental protection values are realized.

The invention provides a method for preparing ametryn through a green salt-free technology. The method comprises the following step: under the action of a catalyst, enabling atrazine and methanethiolto react in isopropyl alcohol to prepare the ametryn. According to the method provided by the invention, the production and utilization of sodium thiomethoxide with an offensive odor are avoided; meanwhile, a catalyst with the offensive odor, i.e., trimethylamine hydrochloride, is not used, and the environment-friendly catalyst is used, so that the odor can be avoided radically and the quality ofa product and the environment of a production site are extremely improved; meanwhile, industrial salt is not generated; the method is environmentally friendly and the environment protection cost is greatly reduced.

The invention discloses a preparation method for methomyl oxime. The preparation method comprises the following steps: (1) respectively dissolving acetaldehyde oxime and chlorine gas in an organic solvent to obtain an organic solution of acetaldehyde oxime and an organic solution of chlorine gas, and dissolving sodium methyl mercaptide and sodium hydroxide in an organic solvent to obtain a mixed organic solution; (2) with the organic solution of acetaldehyde oxime and the organic solution of chlorine gas as raw materials, carrying out continuous feeding for a chlorination reaction; and (3) immediately subjecting a chlorinated mixed solution obtained by a chlorination reaction to a methylthio substitution reaction with the mixed organic solution, removing the solvent from a crude methomyl oxime product obtained by the reaction, and adding a small amount of water to wash the crude methomyl oxime product so as to obtain high-quality methomyl oxime. The method is controllable in reaction heat, small in by-product influence, short in time, capable of avoiding decomposition of chloroacetaldoxime, low in the amount of generated wastewater and free of wasterwater odor, and the obtained finished methomyl oxime is high in yield and quality.

The invention relates to a continuous synthesis method of 2, 3-dimethyl phenyl dimethyl sulfide, and belongs to the technical field of fine chemical engineering. According to the method, a micro-channel reactor is used as reaction equipment, a channel A is a hydrochloric acid solution of 2, 3-dimethylaniline, a channel B is a sodium nitrite solution, and a channel C is a sodium methyl mercaptide solution; the method comprises the following steps: reacting substances in a channel A and a channel B in a first reaction zone, and then reacting an obtained reaction solution with substances in a channel C in a second reaction zone to obtain a reaction solution containing 2, 3-dimethylphenylmethyl sulfide. According to the method, the continuous production of synthesizing the 2, 3-dimethylphenylsulfide by taking the 2, 3-dimethylaniline as the raw material is realized, the operation process is simplified, the production cost is reduced, and the safety of subsequent production is improved.

The invention relates to a synthetic method of a novel pyruvate kinase M2 activator. The structural formula of the pyruvate kinase M2 activator is shown in the specification. The method comprises the following steps: 1, condensing 5-bromo-2-formylthiophene and ethyl triazoacetate to generate a compound A; 2, refluxing the compound A in toluene to carry out loop closing in order to generate a compound B; 3, reacting the compound B with DMF and POCl3 to introduce an aldehyde group in order to generate a compound C; 4, introducing a methyl group to the compound C by using iodomethane in order to generate a compound D; 5, carrying out ring formation on the compound D under the action of hydrazine hydrate to generate a compound E; 6, condensing the compound E and 3-nitrobenzyl bromide to generate a compound F; 7, carrying out a reaction on the compound F under the action of reduced iron powder to generate a compound G; 8, reacting the compound G with sodium methyl mercaptide to generate a compound H; and 9, oxidizing the compound H by m-chloroperbenzoic acid to generate the product I.

The invention discloses a sodium methyl mercaptide production environment-protecting processing device and technology. The device comprises a technology waste liquid processing mechanism and a technology waste gas processing mechanism which mainly comprises a burner, an air preheater, a front absorption tower and a back absorption tower. The technology waste liquid processing mechanism mainly comprises an acid pickling device, a sulfuric acid middle tank, a waste liquid filtering tank, a sodium sulfate solution circulating tank, a crystallization liquid circulating pool, a crystallization tower, a flash dryer, an anhydrous sodium sulphate storage tank, a washer group, an alkali liquid middle tank and a humidifying evaporator. Sodium methyl mercaptide production waste liquid and waste gas are creatively combined organically for processing, technology waste gas high in combustion value is used for incineration and absorbing, sodium sulfite by-products are obtained, a large amount of high-temperature gas is obtained, the high-temperature gas is used for obtaining anhydrous sodium sulphate by-products with higher value, the purposes of sodium methyl mercaptide production deodorization disinfecting and environment improving can be achieved, sodium bisulfide, sodium sulfite and anhydrous sodium sulphate can be obtained by recycling, and the production cost of sodium methyl mercaptide is lowered.