15 results about "Sodium methanethiolate" patented technology

The invention discloses a preparation process of 2-chloro-4-(methylsulfonyl)-3-methyl benzoic acid, and relates to the technical field of preparation of inorganic compounds. The invention relates to a preparation process of 2-chloro-4-(methylsulfonyl)-3-methyl benzoic acid, which comprises the following steps: reacting 3-chloro-2-methylaniline with hydrochloric acid and sodium methyl mercaptide to form an intermediate C1, reacting with acetyl chloride, catalyzing with anhydrous aluminum trichloride to form an intermediate C2, reacting with hydrogen peroxide and sodium hypochlorite to form an intermediate C4, and reacting with sodium chloride to form the 2-chloro-4-(methylsulfonyl)-3-methyl benzoic acid. The 2-chloro-4-(methylsulfonyl)-3-methyl benzoic acid is obtained after the reaction is completed.

The invention discloses a recombinant O-acetyl-L-homoserine mercaptotransferase mutant, a recombinant genetically engineered bacterium and application of the recombinant O-acetyl-L-homoserine mercaptotransferase mutant and the recombinant genetically engineered bacterium. The mutant is obtained by performing single mutation or multiple mutation on the 33rd site, the 55th site, the 237th site and the 238th site of an amino acid sequence shown in SEQ ID NO.2. The method has the beneficial effects that the method has more efficient catalytic activity and stronger substrate tolerance, has the advantages of mild conditions, less discharge of three wastes, high selectivity and high product yield when being used for catalyzing OAH and sodium methyl mercaptide to synthesize L-methionine, and has a wide development space in the aspect of industrial production of L-methionine.

The application belongs to the technical field of adsorbents, and relates to a kind of for adsorbing silver amidoxime polyacrylonitrile-based modified microspheres and its preparation method and application, including the following steps: S1 obtains amidoxime polyacrylonitrile;S2, the preparation of amidoxime polyacrylonitrile-polydopamine microspheres: using hydrochloric acid dopamine and amidoxime polyacrylonitrile reaction obtains amidoxime polyacrylonitrile-polydopamine microspheres;S3, the preparation of thiol-modified amidoxime polyacrylonitrile-polydopamine microspheres: using sodium thiomethoxide and amidoxime polyacrylonitrile-polydopamine microspheres in sealed environment reaction obtains thiol-modified amidoxime polyacrylonitrile-polydopamine microspheres.The modified microspheres can adsorb nearly 80% of silver in solution within 2min at room temperature, and reach adsorption equilibrium after 30min, and the adsorption capacity can reach 483.5mg / g when the adsorption rate is nearly 100% (i.e., the adsorption rate reaches saturation).

The present application relates to the technical field of mesotrione, and particularly relates to a preparation method of mesotrione intermediate, which comprises the following steps: (1) a first reaction of a compound shown in formula (II) and sodium thiomethoxide in the presence of a first solvent to obtain a compound shown in formula (III); (2) a second reaction of the compound shown in formula (III) and hydrogen peroxide in the presence of a second solvent under the action of a catalyst to obtain a compound shown in formula (IV); (3) a third reaction of the compound shown in formula (IV) and acid liquor to obtain mesotrione intermediate shown in formula (I); wherein R1 is selected from F, Cl, Br or I; and R2 is selected from C1-C4 alkyl or aromatic group. The method can effectively improve the purity and yield of mesotrione intermediate.

The invention belongs to the technical field of synthesis, and particularly relates to a synthetic method of ethyl methylthioacetate, which comprises the following steps: taking ethyl chloroacetate and sodium methyl mercaptide as raw materials, taking water and ethyl acetate as solvents, and carrying out catalytic reaction, phase splitting, desolvation and rectification of a phase transfer catalyst to obtain the ethyl methylthioacetate. According to the method, the esterification decomposition influence of the raw materials in an alkaline water phase environment is solved, and meanwhile, the process cost and the process difficulty are greatly reduced.

The application relates to the technical field of pesticide intermediate preparation, and discloses a synthesis method of a sulfonyl pyrazole intermediate.(1) A compound shown as formula (1) is reacted with carbon monoxide, 1,3-dimethyl-5-hydroxypyrazole in the presence of a palladium catalyst, a base and an optional ligand to obtain a compound shown as formula (2); (2) the compound shown as formula (2) is reacted with sodium thiomethoxide, and then subjected to an oxidation reaction to obtain a compound shown as formula (3). The intermediate (1,3-dimethyl-1H-pyrazole-5-(4-trifluoromethyl-2-nitrobenzoyloxy)) provided by the application is further used to prepare a sulfonyl pyrazole intermediate 1,3-dimethyl-1H-pyrazole-5-(4-trifluoromethyl-2-methylsulfonylbenzoyloxy), and the method has the advantages of simple process, moderate reaction condition, simple post-treatment and strong industrial practicability.

This invention relates to the field of herbicide technology, specifically to a method for preparing a sulfadiazine intermediate, comprising: (1) reacting 3,4-dichloronitrobenzene, methyl cyanoacetate, and a first base in the presence of a first solvent to obtain a compound of formula (II); (2) reacting the compound of formula (II) with sodium methanethiol in the presence of a second solvent to obtain a compound of formula (III); and (3) reacting the compound of formula (III) with a second base and hydrogen peroxide in the presence of a third solvent to obtain the sulfadiazine intermediate of formula (I). This method has the advantages of mild reaction conditions, high reaction yield and purity, and low cost, making it suitable for industrial production.

The invention discloses a method for preparing 2, 2-dimethylthiopropane, which comprises the following steps: respectively conveying feed liquids containing sodium methyl mercaptide, acetone and inorganic acid into a microchannel reactor at the same time, quickly mixing to form a multiphase Taylor flow reaction system, and then reacting in a microchannel under high temperature and high pressure conditions; and after the reaction is finished, rapidly cooling the material, enabling the material to enter a continuous gas-liquid-liquid separation system, and washing, drying and rectifying an organic phase obtained by separation to obtain high-purity 2, 2-dimethylthio propane. The method effectively solves the problem that the foul smell of methyl mercaptan escapes in the prior art, remarkably improves the operation environment, and realizes the effects of high raw material conversion rate and short reaction time through high-temperature and high-pressure continuous reaction in the microchannel. In addition, the micro-reaction process has the characteristics of simplicity and convenience in operation, high reaction efficiency and intrinsic safety.

3-chloro-2-methyl phenyl dimethyl sulfide is a key intermediate for synthesizing tembotrions, and the target product 3-chloro-2-methyl phenyl dimethyl sulfide is finally synthesized by taking 3-chloro-2-methylaniline and sodium methyl mercaptide as raw materials through diazotization and methyl mercaptan. In order to solve the danger problem existing in the diazotization production process, the invention provides a production process for continuous production of 3-chloro-2-methylphenyldimethyl sulfide in the micro-channel reactor, and the production process has the advantages that compared with a traditional reaction kettle, the micro-channel reactor is provided with a reaction channel with a small diameter, so that the yield of 3-chloro-2-methylphenyldimethyl sulfide is increased; and the catalyst has the advantages of large specific surface area, large volume ratio, high mass transfer and heat transfer efficiency, good operability, no obvious amplification effect and the like. Particularly, the risk of over-temperature explosion in the diazotization reaction process is greatly reduced due to the efficient heat transfer efficiency and the tiny material holding amount of the microreactor.

The invention relates to a synthesis method of 2-nitro-4-methylsulfonyl toluene, which comprises the following steps: reacting 2-nitro-4-chlorotoluene with sodium methyl mercaptide and other raw materials to synthesize 2-nitro-4-methylthio toluene, and oxidizing to obtain 2-nitro-4-methylsulfonyl toluene, the synthesis route is simple, the problem of large amount of waste acid and waste water is solved, and the synthesis method is green and environment-friendly.

The invention discloses a method for synthesizing ametryn, which comprises the following steps: reacting cyanuric chloride, an isopropylamine aqueous solution, a monoethylamine aqueous solution and a sodium hydroxide aqueous solution in an organic solvent, washing after the reaction, and reacting the obtained atrazine slurry with a sodium methyl mercaptide aqueous solution under the action of a catalyst to obtain ametryn. According to the invention, the synthesis of the atrazine and the synthesis of the ametryn are operated in series, the reaction liquid of the atrazine is used for synthesizing the ametryn, and the reaction of the atrazine and the ametryn adopts the same solvent, so that the types of solvents and the use of one solvent are reduced, the operation process is simplified, the production and storage pressure is reduced, and the production cost is reduced; according to the method, the reaction liquid of the atrazine is directly used for synthesizing the ametryn, so that distillation desolvation, centrifugation and drying operations of the reaction liquid of the atrazine are omitted, the process is simplified, and the production cost is reduced; the ametryn is slowly crystallized by adopting crystallization equipment, a powdery product is directly obtained, the crushing treatment process of a block material is omitted, and the operation is simplified.

The utility model relates to the technical field of metering tank, concretely is a kind of product metering tank for sodium methanethiol solution production, including bottom plate, the upper surface of bottom plate is fixedly connected with nitrogen storage tank and control switch, the inner wall of bottom plate is fixedly connected with metering tank main body, the top of metering tank main body is fixedly connected with metering pump, the top of metering tank main body is fixedly connected with driving motor, the inner wall of metering tank main body is fixedly connected with bearing and annular pipe.The product metering tank for sodium methanethiol solution production, driving motor output power is rotated by being set to drive stirring rod, the structure can break the solid particle precipitate in sodium methanethiol solution in real time, avoid solution layering, significantly improve solution overall uniformity, solve the problem " because of solution unevenness leads to measurement error " from source, provide basic guarantee for subsequent metering pump accurate measurement, substantially improve the measurement accuracy of sodium methanethiol solution.

The application discloses an O-succinyl-L-homoserine thiotransferase mutant and application thereof, wherein the mutant is obtained by single mutation or multiple mutation of positions 59 and 119 of an O-succinyl-L-homoserine thiotransferase amino acid sequence shown in SEQ ID NO. 1. The application improves MetZ by semi-rational design and site-directed mutagenesis technology, and finally obtains a mutant with improved tolerance to high-concentration sodium methanethiol under the condition of not losing enzyme activity. The mutant of the application has greatly improved tolerance to sodium methanethiol, is increased from 5% before mutation to 15%, and has great industrial value. The mutant of the application has significantly improved conversion rate of a substrate, and is beneficial to production and application.

The application relates to the field of chemical pharmacy, and discloses a synthesis method of a metformin intermediate 3-[3-bromo-2-methyl-6-(methylsulfonyl)phenyl]-4,5-dihydroisoxazole. 2,3-dimethylchlorobenzene is used as raw material to perform a sulfonylation reaction first to generate 2,3-dimethylbenzenesulfonyl; then a bromination reaction is performed to obtain 2,3-dimethyl-4-bromobenzenesulfonyl. Then, through an oximation, chlorination and cyclization, 3-[3-bromo-2-methyl-6-(methylsulfonyl)phenyl]-4,5-dihydroisoxazole is obtained. In the application, sodium methylsulfinic acid is directly used for sulfonylation, avoiding the use of foul-smelling reagents such as sodium methyl mercaptide and dimethyl disulfide, and also reducing the oxidation process of dimethyl sulfide, so that the overall reaction yield is high, the environmental pressure is small, the cost is low, the wastewater treatment difficulty is small, and the application is suitable for industrial production.

The invention relates to the technical field of chemical pharmacy, and discloses a synthesis method of a topramezone intermediate 3-[3-bromo-2-methyl-6-(methylsulfonyl) phenyl]-4, 5-dihydroisoxazole, which comprises the following steps: carrying out sulfonylation reaction by using 2, 3-dimethylchlorobenzene as a raw material to generate 2, 3-dimethylphenylsulfone; and then carrying out a bromination reaction to obtain the 2, 3-dimethyl-4-bromophenylsulfone. And then carrying out oximation, chlorination and cyclization to obtain the 3-[3-bromo-2-methyl-6-(methylsulfonyl) phenyl]-4, 5-dihydroisoxazole. According to the method, sodium methanesulfinate is adopted for direct sulfonylation, use of foul reagents such as sodium methyl mercaptide and dimethyl disulfide is avoided, the oxidation procedure of dimethyl sulfide is reduced, and the method is high in overall reaction yield, small in environmental pressure, low in cost, small in wastewater treatment difficulty and suitable for industrial production.