211results about "Thiol preparation" patented technology

The invention discloses a method for preparing 12-mercaptan through solid organic acid catalysis, belongs to the technical field of 12-mercaptan preparation, and aims to solve the problems of low catalyst activity, harsh reaction conditions, serious pollution, high cost and dependence on import in the prior art. N-dodecanol and hydrogen sulfide are used as raw materials and are mixed according to the molar ratio of 1: 1.2-1: 1.3; the method comprises the following steps: gasifying n-dodecanol, mixing with purified hydrogen sulfide, preheating to 210-240 DEG C, introducing into a fixed bed reactor filled with a solid organic acid catalyst, and reacting at-0.08-3.0 MPa for 3.5-4 hours; and cooling and condensing the reaction product, carrying out gas-liquid separation, rectifying and purifying the liquid product to obtain 12-mercaptan with the purity of more than or equal to 99.5%, and recycling unreacted hydrogen sulfide. The solid organic acid can be a catalyst of p-toluenesulfonic acid and the like or mesoporous silica loaded nickel, cobalt and molybdenum metal oxides. The method has the advantages of high catalytic activity, mild reaction conditions, high product yield (the conversion rate of n-dodecanol is greater than or equal to 94.5%), environmental protection and low cost, can realize the domestic mass production of 12-mercaptan, and meets the market demand.

The invention discloses a bimetallic asymmetric reduction Schiff base catalyst for synthesizing ethylene carbonate and a preparation method of the bimetallic asymmetric reduction Schiff base catalyst. According to the catalyst, a diamine compound is subjected to selective single-side protection, the imine reduction position is controlled, and a bimetallic active center is introduced; the controllable synthesis of a product for reducing the outer side imine and a product for reducing the inner side imine is realized; the obtained product is recrystallized to obtain a monoimine-monoamine type ligand with a clear asymmetric structure, the monoimine-monoamine type ligand and metal salt form a bimetallic catalyst, and the catalyst generates a synergistic effect through double active sites and shows high catalytic activity and excellent product selectivity.

The present invention relates to a method for producing methyl mercaptan, comprising the following steps: A) methanol is reacted with hydrogen sulfide to form a stream (M), preferably in the gas state, comprising methyl mercaptan, unreacted H2S and possibly sulfur-bearing by-products; B) optionally, said stream (M) is condensed; C) at least one step of purifying said stream (M) is carried out in order to obtain a methyl mercaptan-enriched stream; D) the gaseous effluents resulting from said at least one purification step are recovered, said gaseous effluents comprising at least one sulfur-bearing compound, preferably H2S; E) a gas-liquid extraction of said at least one sulfur-bearing compound, preferably H2S, is carried out using liquid methanol so as to obtain a liquid methanol enriched in sulfur-bearing compound(s), preferably in H2S; and F) optionally, said enriched methanol is used as a reactant for the reaction of step A).

The invention provides a preparation method of a magnetic recoverable catalyst and a method for synthesizing 3-mercaptopropionic acid, and mainly solves the problem that a large amount of acid and alkali solutions are needed in the existing acrylonitrile-sodium hydrosulfide and acrylic acid-thiourea process routes. The thiohydracrylic acid synthesis catalyst is prepared. The use conditions of the catalyst are as follows: the temperature is 30-80 DEG C, the reaction pressure is 0.5-3 MPa, the mass ratio of the acrylic acid to the solvent is 0.1-5, and the mass ratio of the acrylic acid to the catalyst is 0.2-20. Compared with the prior art, the catalyst disclosed by the invention is used as a synthetic catalyst for preparing thiohydracrylic acid through reaction of acrylic acid and hydrogen sulfide, a solid catalyst and a liquid reaction system can be completely separated by adopting simple methods such as filtration, centrifugation or magnetic separation, and a complicated pickling step is not needed; and the problem that a homogeneous catalyst is difficult to rectify after salification in the use process is avoided.

The present invention relates to a process for the production of methyl mercaptan comprising the following steps: A) methanol is reacted with hydrogen sulfide to form a stream (M), preferably in the gaseous state, comprising methyl mercaptan, unreacted H2S and optionally sulfur by-products; B) optionally, said stream (M) is condensed; C) at least one purification step of said stream (M) is carried out to obtain a stream enriched in methyl mercaptan; D) the gas vents from said at least one purification step are recovered, said gas vents comprising at least one sulfur compound, preferably H2S; E) a gas-liquid extraction of said at least one sulfur compound, preferably H2S, is carried out with liquid methanol to obtain a liquid methanol enriched in sulfur compound(s), preferably H2S; and F) possibly, said enriched methanol is used as a reagent for the reaction in step A).

The present application belongs to the technical field of condensate, and particularly relates to a non-peptide small molecule condensate and preparation and application thereof. The present application provides a non-peptide small molecule condensate which is prepared by taking a small molecule shown in formula I as a precursor, wherein Y and Z are each independently NH, O or S, R = or X = O or S; R1 and R2 are each independently selected from H, C 3‑20 alkyl, -C 1‑8 alkylene-phenyl, -C 1‑8 alkylene-5-10-membered heteroaryl, -C 1‑8 alkylene-S-C 1‑8 alkyl, -C 1‑8 alkylene-SH, -C 1‑8 alkylene-O-C 1‑8 alkyl or -C 1‑8 alkylene-NH-C 1‑8 alkyl; and R1 and R2 are not H at the same time. The obtained condensate not only has good spontaneous non-classical fluorescence characteristics, but also has the abilities of drug loading and controllable release, and shows excellent resistance to enzymatic hydrolysis and good biocompatibility. Formula I

The polythiol composition according to an exemplary embodiment includes a tetrafunctional polythiol compound and a parapolythiol compound, the parapolythiol compound comprising C 13 H 28 S9 represents compounds and compounds derived from C 15 H 32 S 10 The compounds are indicated. The proportion of parapolythiol compounds, as measured by high-performance liquid chromatography (HPLC), ranges from 1% to 5%. By adjusting the content of parapolythiol compounds, optical products with excellent transmittance and optical properties can be manufactured.

A method for producing a high purity product sulfide from an olefin is provided. 【Solution means】Hydrogen sulfide or R 1 SH, and a method for producing a high purity product sulfide from an olefin of the formula C x H (2x) comprising the steps of: feeding hydrogen sulfide or R 1 SH, and an olefin of the formula C x H (2x) to a reactor system; separating the reactor effluent stream into a first portion and a second portion; recycling the first portion of the reactor effluent stream to the reactor system; and feeding the second portion of the reactor effluent stream to a sulfide separation system, the sulfide separation system comprising: at least one recycle stream comprising at least a portion of unreacted hydrogen sulfide, unreacted olefin of the formula C x H (2x) unreacted R 1 SH, and other components, and a product stream comprising the high purity product sulfide.

This invention provides a tert-nonylthiol and its synthesis method. The synthesis steps are as follows: nonene and hydrogen sulfide are preheated separately, then the preheated nonene and hydrogen sulfide are mixed, and the mixture is reacted under the action of a catalyst to obtain tert-nonylthiol. The preheating temperature of nonene is 40-50℃, and the preheating temperature of hydrogen sulfide is 50-60℃. This invention provides mild reaction conditions and precise preheating of nonene and hydrogen chloride separately. The product prepared by this method has a purity of over 99.0%, meeting the requirements of high-end industrial applications for high-purity tert-nonylthiol.

The present invention disclosed 3-substituted phenylamidine compounds of general formula (I), wherein R1, R2, R3, R4, R4a, R4b, A and E have the same meanings as defined in description. The present invention further discloses methods for their preparation and use of the compounds of general formula (I) as a crop protection agent.

The invention relates to the technical field of chemical material preparation, and particularly discloses a safe preparation method of a short fluorocarbon alkyl sulphobetaine surfactant, a product and application, and the safe preparation method comprises the following steps: (1) in a solvent system I, reacting epoxy chloropropane with secondary amine to obtain an intermediate 1; (2) in a solvent system II, reacting the intermediate 1 with sodium hydrosulfide or a hydrate thereof to obtain an intermediate 2; (3) reacting the intermediate 2 with short fluorocarbon alkyl iodide to obtain perfluoroalkyl thioether propyl tertiary amine; and (4) carrying out sulfonation treatment on perfluoroalkyl thioether propyl tertiary amine to obtain the short-fluorocarbon alkyl sulphobetaine surfactant. According to the invention, by designing a synthetic route without using a high-risk reagent, the safety and operability of the process are remarkably improved, and the sulphobetaine surfactant with excellent acid, alkali and salt chemical stability and excellent surface activity is successfully prepared; and a key material and a safe and reliable preparation process are provided for development of a new-generation efficient environment-friendly fire extinguishing agent.

The present invention relates to the field of organic synthesis, and discloses an ester compound synthesis method, which comprises: mixing an organic acid raw material and an organic alcohol raw material, and carrying out a reaction under the action of a homogeneous catalyst to obtain an ester compound, the mixing index of the organic acid raw material and the organic alcohol raw material being greater than or equal to 0.9 after the organic acid raw material and the organic alcohol raw material are mixed. According to the method, the conversion efficiency of the ester production process is improved by accurately controlling the mixing index of the esterification reaction system.

The present invention relates to a process for the production of specialty mercaptans from C4 oligomerization product. The oligomer product from the commercial C4 oligomerization process is separated in desired fractions of C8 and C12 olefins and these streams are further used as feed stock for the production of the specialty mercaptans such as tert octyl mercaptan (TOM) & tert dodecyl mercaptan (TDM). These fractionated oligomer stream (C8 and C12) from the C4 oligomerization process reacts with hydrogen sulfide in presence of pretreated cation exchange resin catalyst using appropriate inhibitors such as amine precursors, nitriles and metals to produce respective sulfur compounds tert-octyl mercaptan (TOM) and tert dodecyl mercaptan (TDM).

The divisional application provides a method for breaking and forming a tetravalent uranium photocatalytic carbon-carbon bond, which comprises the following steps: dissolving a tetravalent uranium catalyst with a molecular formula of L-U (NO3) 3 (OMe) in an organic solvent in an environment of-40 DEG C to 80 DEG C under the conditions of inert gas and blue light with a light source of 440-450 nm; and then adding olefin with a chemical structural formula shown in the specification and cyclic alcohol with a chemical structural formula shown in the specification for reaction to obtain a product. According to the forming method, tetravalent uranium serves as a photocatalyst, olefin which is almost not reacted originally reacts with cyclic alcohol with ring tension, the conversion rate of the reaction is increased, the conversion rate can reach 99% at most, and the excellent yield and the high atom economy are achieved.

The application discloses a kind of rice mycotic acid hapten and antigen preparation application, it is related to antigen preparation technical field, introduce sulfydryl in the 2 of rice mycotic acid, and obtain rice mycotic acid antigen by coupling with protein through connecting arm, rice mycotic acid hapten and antigen preparation application include the following specific flow: S1, the synthesis of rice mycotic acid hapten;S2, the preparation of rice mycotic acid immunogen;S3, the preparation of rice mycotic acid coating original;S4, the preparation of rice mycotic acid monoclonal antibody;S5, the preparation of rice mycotic acid immunofluorescence detection card;S6, rice mycotic acid detection in food;S7, detection limit experiment;S8, false positive rate, false negative rate experiment.The rice mycotic acid hapten retains the structural characteristics of rice mycotic acid, better exposes rice mycotic acid structural characteristics, improves the immunity and immune recognition ability of antigen, lays foundation for preparing specific, high sensitivity antibody, and improves its rapid detection ability.

The invention belongs to the technical field of chemicals, and discloses a synthesis method of dithioerythritol, which comprises the following steps: S1, mixing cis-1, 4-dichloro-2-butene, acetone and water, cooling to below zero, adding potassium permanganate, keeping the temperature to react for a certain time after the potassium permanganate is added, filtering and collecting filtrate, then extracting, collecting extract liquor, evaporating, cooling and crystallizing to obtain dithioerythritol; filtering and collecting solids, and drying to obtain 1, 4-dichloro-2, 3-butanediol; and S2, mixing 1, 4-dichloro-2, 3-butanediol, sodium hydrosulfide and methanol, carrying out a reflux reaction, filtering, evaporating methanol, adding dichloromethane, adding magnesium sulfate, dehydrating, freezing, crystallizing, filtering, collecting a solid, and drying to obtain the dithioerythritol. The method has the beneficial effects that substances such as cis-1, 4-dichloro-2-butene, sodium hydrosulfide and potassium permanganate are adopted as raw materials, the price is low, the raw materials are easy to obtain, the process is simple, the yield is high, and compared with an existing method, the scheme has the advantages that the raw material cost is greatly reduced, the product yield is increased, and the method is suitable for enterprise production.

The invention discloses a cysteine impurity as well as a quality control method and application thereof, and belongs to the technical field of drug detection. The technical problem to be solved is to provide a cysteine quality control method for impurities generated after terminal sterilization of cysteine. The key point of the technical scheme is that the structural formula of the cysteine impurity 1 is shown in the specification.

The invention relates to a method for the co-production of alkyl mercaptan and dialkyl disulfide, comprising the following successive steps:a) reacting a C1-C4 alcohol in the presence of hydrogen sulfide (H2S) to form a stream (M) comprising an alkyl mercaptan, water, and possibly unreacted hydrogen sulfide, b) purifying the stream (M) to obtain a stream (N) enriched in alkyl mercaptan, c) recovering a first portion of the stream (N) comprising alkyl mercaptan purified in step b), d) sulfur oxidation of the second portion of the stream (N) of alkyl mercaptan in order to form a stream (O) comprising a dialkyl disulfide, hydrogen sulfide, and possibly unreacted alkyl mercaptan, e) purifying the stream (O) to separate, on the one hand, the enriched dialkyl disulfide and on the other hand the hydrogen sulfide and the alkyl mercaptan possibly having not reacted in step d), f) recycling the hydrogen sulfide and possibly the alkyl mercaptan isolated in step e) to the stream (M) obtained in step a), g) recovering the dialkyl disulfide isolated in step e).

A method for producing a thiol compound including a light emission process in which light is emitted to a colored thiol compound or a composition containing the thiol compound. In the light emission process, it is preferable to emit light including light with a wavelength of 250 nm to 600 nm to the composition.

The invention discloses a preparation method of a probucol USP impurity C. The preparation method comprises the following steps: taking 2, 6-di-tert-butylphenol as an initial raw material, and synthesizing an intermediate TM1 through thiocyanation; reducing the intermediate TM1 through lithium aluminum hydride to synthesize an intermediate TM2; the preparation method comprises the following steps: taking 2, 4-di-tert-butylphenol as an initial raw material, and synthesizing an intermediate TM3 through thiocyanation; reducing the intermediate TM3 through lithium aluminum hydride to synthesize an intermediate TM4; and condensing the intermediate TM2, the intermediate TM4 and acetone to obtain the probucol USP impurity C. The probucol USP impurity C preparation method has the advantages that 2, 6-di-tert-butylphenol and 2, 4-di-tert-butylphenol are used as raw materials, the probucol USP impurity C can be prepared through the five-step reaction of thiocyanation, reduction and acetone condensation, the raw materials are easy to obtain, the total yield is high, the cost is low, the technical blank of probucol USP impurity C preparation is filled, and the probucol USP impurity C preparation method is suitable for industrial production. A low-cost and high-quality impurity reference substance can be provided for quality research of probucol, and the probucol impurity detection method is of great significance in guaranteeing safe medication of probucol.

The present invention relates to a process for the preparation of polythiols comprising preparing a mercaptanization reaction medium, simultaneously carrying out a radical mercaptanization reaction of said at least one polyene and an acid-catalyzed mercaptanization reaction of said at least one polyene, and recovering a mixture comprising at least two polythiols. The present invention also relates to a mixture of polythiols obtained according to said process and to the use of said mixture of polythiols.

The present disclosure relates to a method for producing L-cysteine hydrochloride hydrate crystals having a controlled particle size, and L-cysteine hydrochloride hydrate crystals having a controlled particle size produced by the production method.

The present application pertains to a method of making carbon disulfide. The method comprises reacting methane and sulfur under conditions sufficient to produce carbon disulfide, hydrogen disulfide, and heat. At least a portion of the produced hydrogen disulfide is reacted with methane under conditions sufficient to produce a mixture comprising carbon disulfide and hydrogen. Advantageously, at least a portion of the heat from reacting methane and sulfur is employed in the reacting of at least a portion of the produced hydrogen disulfide with methane.

The application provides a hydrophobic chain transfer agent, a preparation method thereof and application of the hydrophobic chain transfer agent in air entraining and viscosity reducing polycarboxylic acid water reducing agent, the hydrophobic chain transfer agent is prepared by esterification reaction of acid with sulfydryl and aliphatic alcohol; the air entraining and viscosity reducing polycarboxylic acid water reducing agent is prepared by using the prepared hydrophobic chain transfer agent, the main chain is capped, so that the HLB value of the main chain is reduced, the hydrophobic performance of the hydrophobic chain transfer agent is adjusted, the HLB value of the main chain can be controlled and adjusted, and the air entraining and viscosity reducing polycarboxylic acid water reducing agent with excellent air entraining performance and without affecting the strength of concrete is prepared. Moreover, the conversion rate of the polycarboxylic acid water reducing agent is more than 90%, the polydispersity coefficient is less than or equal to 1,75, the polydispersity coefficient is relatively small, and the molecular weight distribution is relatively narrow.

Nitric oxide precursors for providing nitric oxide are provided. The nitric oxide precursors comprise a reaction product of a thiolactone, a primary amine, and a nitrosating compound. The nitric oxide precursors are capable of decomposing to form nitric oxide.

The application relates to the field of organic synthesis, in particular to a method for synthesizing beta-trifluoromethylsulfinyl ketone derivatives by ring-opening of cyclopropanol. 3 C intermediates, and then adding a trifluoromethylating agent S-trifluoromethyl-4-methylthiobenzenesulfonate to obtain beta-trifluoromethylsulfinyl ketone derivatives. The application uses the simple, easy-to-prepare and stable S-trifluoromethyl-4-methylthiobenzenesulfonate as a trifluoromethylating agent, and the reaction condition is mild, and the synthesis method is simple and easy to operate.

A method for producing a polythiol composition including a reaction step of reacting a thiourethane resin and a nitrogen-containing compound that is at least one selected from the group consisting of a quaternary ammonium salt and an amine compound in the presence of water to generate a polythiol composition.

The application discloses a co-crystal medicine and a preparation method and application thereof, relates to the technical field of organic chemical synthesis, and forms a co-crystal medicine through intermolecular hydrogen bond action of two medicines. The prepared co-crystal medicine has the advantages of good solubility, strong stability and enhanced curative effect, solves the defects of poor solubility, poor stability and poor curative effect of original medicines, and thus improves clinical application.