46results about How to "Strong reaction selectivity" patented technology

The invention relates to a method for analyzing (1R, 2R)-2-amino-1-(4-(methylsulfonyl)-phenyl)-1,3-propylene glycol as an important intermediate of florfenicol, which is chloramphenicol spectrum antibiotic special for animals. The method comprises the following steps of: performing a reaction of methylsulfonyl benzaldehyde and nitro alcohol at 0-40 DEG C in the presence of a chiral catalyst to obtain (1R, 2R)-2-nitro-1-(4-(methylsulfonyl)-phenyl)-1,3-propylene glycol; and reducing the (1R, 2R)-2-nitro-1-(4-(methylsulfonyl)-phenyl)-1,3-propylene glycol through hydrogen to obtain the intermediate. In the invention, the compound (1R, 2R)-2-amino-1-(4-(methylsulfonyl)-phenyl)-1,3-propylene glycol with a high e.e. value is obtained by adopting the chiral catalyst, and the compound has the advantages of strong reaction selectivity, high productivity, simple process, low cost, easy preparation of raw materials and low price, is suitable for industrial production, avoids chiral separation frequently used in industry at present and saves the raw materials and the cost. The compound (1R, 2R)-2-amino-1-(4-(methylsulfonyl)-phenyl)-1,3-propylene glycol is used for preparing florfenicol and can reduce the preparation cost.

The invention belongs to the technical field of chemical engineering and particularly relates to a method for synthesizing an o-benzenedicarbinol derivative. Phthalide as a raw material is subjected to a reduction ring-opening reaction under the action of alkali and silane compounds, and o-benzenedicarbinol is prepared. According to the method, raw materials are easy to obtain, the method is simple and convenient to operate, the reaction selectivity is high, the product yield is high, and the reaction condition is mild; the synthesized monosubstituted or polysubstituted o-benzenedicarbinol derivative has high quality and good functional group compatibility.

The invention discloses a radio frequency plasma-catalyst synergic effect reaction device, which comprises components such as a non-balance plasma reaction chamber, a hollow tubular metal spiral coil with a cooling passage, a catalysis body with a catalyst, an air inlet sealing end part and air inlet end sealing flange, an exhaust sealing end part and exhaust end sealing flange, an electromagnetic shielding cover and the like. The radio frequency plasma-catalyst synergic effect reaction device belongs to a reaction device arranged by aiming at the inductance coupling radio-frequency plasma and catalyst synergic effect; the non-balance plasma reaction chamber made of quartz is used as a gas reaction passage; the metal spiral coil is used, so that corresponding other plasma generating imbalance can complete a chemical reaction through the synergic effect driving with the catalyst in the passage, so that the subsequent ingredient analysis of gas after a reaction is convenient; further, the application in aspects of the chemical engineering synthesis, greenhouse effect gas recovery utilization and renewable energy sources effective storage is realized; the advantages of high reaction selectivity, high energy utilization efficiency and the like are realized.

The invention discloses a method for extracting magnolol and honokiol from magnolia officinalis; the method includes that: magnolia officinalis powder and solid phase weak base reagent are mixed according to the weight ratio of 1:0.01-1, the mixture is grinded to obtain powder with granularity analysis result D90 of 10-200 um, and then water is added to the powder, the mixture is stirred sufficiently and is centrifuged to obtain sediment A and supernate A, acid X with pH value of 1.0-6.0 is added to the supernate A, then the supernate is centrifuged after standing to obtain sediment B as magnolol extractive. The invention firstly adopts mechanical chemical reaction technique to extract magnolol, and then adopts alkaline process to extract honokiol, has the advantages of high extraction rate, good separation effect of magnolol and honokiol, and short production cycle, and is the extraction and separation process with good popularization and application prospect.

The invention discloses a carbonyl starch oxidized by a Fenton similar system, and a preparation method of the carbonyl starch. The Fenton similar system is composed of a cerous nitrate salt-a catalyst-H2O2; the catalyst is ferrous sulfate or cuprous sulfateb; starch is oxidized in aqueous phase at a temperature of 20 to 60 DEG C. The preparation method comprises following steps: (1) 30 to 50 weight portions of starch and 60 to 170 weight portions of water are mixed so as to obtain a turbid liquid, and the turbid liquid is subjected to gelatinization in water bath for 0.5 to 2h at a temperature of 50 to 70 DEG C; (2) 0.3 to 2.0 weight portions of ceric ammonium nitrate and 0.0015 to 0.0075 weight portion of the catalyst are added and mixed fully, pH value of the reaction solution is adjusted to 2.5 to 4.0, and the reaction solution is reacted for 10 to 24h at a temperature of 20 to 45 DEG C in enclosed conditions; (3) 1.5 to 10 weight portions of H2O2 is added, the temperature is adjusted to 45 to 60 DEG C, and the mixture is reacted for 3 to 7h; and (4) after that, the mixture is subjected to suction filtration, is washed for 3 times with acetone, and is dried in a vacuum oven for 12 to 24h at a temperature of 40 to 60 DEG C so as to obtain the carbonyl starch containing 10 to 20% of carbonyl and 2 to 6% of carboxyl. According to the preparation method, both carbonyl and carboxyl are introduced into starch at the same time, so that functional groups of starch molecules are increased, and application area of oxidized starch is widened.

The invention discloses a synthesis method and device of 2,3,5-trimethylhydroquinone. According to the synthesis method for 2,3,5-trimethylhydroquinone, 2,3,5-trimethylbenzoquinone (TMBQ) and an alcohol-aromatic hydrocarbon or alcohol-alkane mixed solvent system are mixed, then a reaction solution is fully mixed with hydrogen through a hydrogen absorber, then the mixture enters a fixed bed filledwith a noble metal catalyst to complete a hydrogenation reaction, and 2,3,5-trimethylhydroquinone (TMHQ) is obtained. According to the technical scheme provided by the invention, the reaction selectivity is improved, the side reaction is effectively inhibited, the impurity content of the product is reduced, the purity of 2,3,5-trimethylhydroquinone (TMHQ) is improved, the production process is simplified, the emission of three wastes is reduced, and the method has good environmental protection benefits.

The invention relates to an electrode used in the electrolytic industry and a preparation method thereof. The electrode comprises a conductive rod and a substrate, wherein the substrate is composed of a three-dimensional network metal skeleton and a conductive material. The three-dimensional network metal skeleton is made of metallic mesh plates in a welded mode, the conductive rod is embedded in the substrate, and electro-catalytic active layers cover the surface of the substrate. According to the electrode, the electric conductivity is high, the service life is long, the reaction selectivity of the electrode is good, the electrode is not prone to passivity, the production cost is low and the application value is good.

The invention discloses a method for synthesizing a tertiary amine derivative by catalyzing a hydroboration reaction of tertiary amide by rare earth. Under the protection of nitrogen, in a rare earthcatalysis system, the tertiary amine derivative is prepared through a hydrogen transfer reduction reaction catalyzed by rare earth with tertiary amide and pinacol borane as raw materials. The method has the advantages and effects that a novel synthesis process is utilized, and the tertiary amine derivative prepared by using the method disclosed by the invention is high in quality and stable in process; the raw materials are widely sourced or easy to prepare and store, and the reaction yield is high; and in addition, a catalyst can be directly commercially purchased or is easily, directly and simply synthesized, and can be used in actual production.

The invention provides a preparation method of low molecular siloxane as well as a used catalyst and a preparation method thereof. The catalyst is a solid acid catalyst formed by a supporter loaded active component, wherein the active component at least contains platinum and zirconium oxide in a ratio of 1:(1-5). The preparation method of the low molecular siloxane comprises the following steps: by taking high hydrogen-containing silicone oil as a raw material, carrying out telomerization at the temperature of 50-110 DEG C in presence of a blocking agent and the catalyst, so that the low molecular siloxane is obtained. A novel catalyst is provided for preparation of the low molecular siloxane by adopting a telomerization process, and the catalyst has the advantages of high catalysis efficiency, specific product and high reutilization frequency.

The invention provides a preparation method of citral. The method comprises the following steps: carrying out a Grignard reaction or substitution reaction on halogenated acetaldehyde acetal or halogenated paraldehyde and a reagent 1 (magnesium powder, triphenylphosphine or triphosphite) to obtain a corresponding Grignard reagent or Wittig reagent, reacting the obtained Grignard reagent or Wittig reagent with 6-methyl-5-hepten-2-one, and successively conducting acidifying and deprotection to obtain citral. The preparation method has the advantages of usage of cheap and accessible raw materials,simple operation steps, high reaction atom economy, high selectivity, high yield, high purity, low product cost, and suitability for green industrial production.

The invention discloses a synthetic process method of high-density hydrocarbon. The synthetic process method comprises the following steps of the first step, hydrogenation of a raw material, industrial grade dicyclopentadiene raw material of which the mass percent is 85 percent is adopted for a hydrogenation reaction, meanwhile a separate-out distillation method is adopted to refine endo-tetrahydrodicyclopentadiene; the hydrogenation reaction is performed on the raw material on a bed layer filled with a metal catalyst; the hydrogen-oil ratio is (300 to 1000):1; the space velocity is 5-25h<-1>; the inlet pressure of a hydrogen reactor is 1.2 to 2.2 MPa; the inlet temperature of the reactor is 100 to 140 DEG C; the second step, a space isomerization reaction is adopted to generate an exo-tetrahydrodicyclopentadiene product; a molecule space isomerization reaction of an intermediate product is catalyzed by chloro metal; an inert solvent is adopted as an isomerization solvent; the reaction temperature is 70 to 150 DEG C; the reaction time is 1 to 3h; distillation separation is performed on the inert solvent under the condition of 80 to 85 DEG C to refine the high-density hydrocarbon. Compared with other processes, the liquid yield of the exo-tetrahydrodicyclopentadiene prepared by the synthetic process method is about 99 percent, the space velocity is higher, i.e. the charging rate is higher, and the production efficiency is higher.

The invention discloses a preparation method of 2-methylthio-5-benzothiazole, successively comprising the following steps: 1) mixing ethanol, a sodium hydroxide solution, 2-mercaptobenzothiazole and bromoethane to react until the 2-mercaptobenzothiazole is completely reacted; 2) cooling the product obtained by step 1) to room temperature, splitting phases, washing, and carrying out reduced pressure distillation and the like to obtain 2-methylthio benzothiazole; 3) dissolving the 2-methylthio benzothiazole into low-grade halohydrocarbon, and adding N-bromosuccinimide to react; and 4) after the reactive fluid obtained in step 3) is cooled to room temperature, successively filtering, washing, drying and carrying out reduced pressure distillation to obtain the wax-state solid product of the salmon 2-methylthio-5-benzothiazole. The 2-methylthio-5-benzothiazole prepared according to the method disclosed in the invention has the characteristics of simple technology, high yield, low cost, small three-waste discharge and the like.

The invention discloses a denitration agent, a preparation method thereof and a flue gas purification method, and belongs to the technical field of flue gas denitration. The denitration agent comprises an inorganic metal amide and an additive, or comprises a metal hydride and an additive, the inorganic metal amide comprises at least one of lithium amide, magnesium amide and a lithium amide magnesium alloy, and the metal hydride comprises at least one of lithium hydride, magnesium hydride and lithium magnesium hydride. Compared with an organic nitrogen-containing compound adopted in the prior art, the inorganic metal amide has high activity and strong selectivity, and the gas product is only ammonia gas NH3 and is directly used for reducing nitrogen oxide NOx in flue gas; the metal hydride gas product is only hydrogen H2 and also has a reduction effect on nitrogen oxides NOx. According to the application, the denitration efficiency can be improved, and the problem of ammonia escape in the flue gas denitration process can be relieved.

The invention relates to a water treatment method for reducing and degrading halogenated organic matters by copper-activated thiourea dioxide, and belongs to the technical field of wastewater treatment. The method comprises the following steps: adjusting the pH value of the halogenated organic matter wastewater to 6-9, and adding copper ions until the concentration is 0.05-1 mg/L or adding copper-containing solid metal until the concentration is 1-100 mg/L; adding thiourea dioxide of which the concentration is 5-1000 times of the molar concentration of the pollutants, adding buffer salt or alkali liquor to maintain the pH value at 6-9, stirring and uniformly mixing, and reacting at room temperature for 2-10 hours. The added copper ions can be recycled, and no metal mud waste is generated;the reducing agent thiourea dioxide is low in price, and decomposition products are non-toxic and pollution-free; no energy input or complex reaction equipment is needed in the reaction process, the operation is simple and convenient, the reaction is efficient, the effect is stable, the reaction condition requirement is low, the interference of other coexisting inorganic ions and organic matters in the water on the action effect of the method is weak, the reaction selectivity is high, and the halogenated organic pollutants in the water can be removed in a targeted manner.

The invention belongs to the field of synthesis of western medicines, and particularly discloses a preparation method of a medicine nefiracetam for treating Alzheimer's disease. According to the preparation method, carboxyl in 2-oxopyrrolidine acetic acid is activated through N',N-carbonyldiimidazole (CDI), the reaction activity is improved, the reaction rate is increased, side reactions are reduced, the obtained product is high in yield and purity, the production cost is reduced, and industrial production is facilitated.