47results about How to "Yield unchanged" patented technology

The invention relates to a microwave-assisted aqueous two-phase extraction method for separating kudzu root total flavone, which comprises the following steps: 1) preparation of an aqueous two-phase system: taking an inorganic salt, adding water to dissolve the inorganic salt, and adding an organic solvent to obtain a aqueous two-phase extractant; and 2) microwave-assisted aqueous two-phase extraction: adding kudzu root powder into the aqueous two-phase extractant obtained in the step 1), carrying out microwave-assisted extraction, and carrying out vacuum filtration to obtain an obvious phase-separated kudzu root flavone extracting solution. Compared with the prior art, the method provided by the invention has the following advantages: (1) the method is simple to operate and does not need to wait for phase separation; 2) the process is integrated; 3) the extraction process is quick and efficient; 4) the extraction solvent is low in toxicity; 5) the interfacial tension is small, thereby being beneficial to mass transfer between the two phases; 6) abundant impurities can be removed along with solid matters, thereby being beneficial to purifying the sample; and 7) the extraction method does not have obvious scale-up effect, can easily implement technique amplification and continuous operation, and can be directly connected with the subsequent purification procedure without special treatment.

The invention provides a method for preparing a D-(+)-biotin intermediate. The method comprises the steps of: taking L-cysteine monohydrochloride as a starting material; using benzaldehyde and sodium cyanate as a ring closure reagent to synthesize (7aR)-3-phenyl-6-benzyl-1H, 3H-imidazo[1, 5-C]thiazole-(6H, 7aH)-5, 7-dione through the cyclization; then utilizing benzyl bromide to perform benzyl protection on N atoms; then taking zinc as a reducing agent to perform ring-opening synthesis on N, N-dibenzyl-L-sulfhydryl hydantoin; introducing a side chain through an esterification reaction with monomethyl adipate acyl chloride; and taking titanium as the reducing agent to perform reductive ring closure to generate the intermediate. According to the method, the cheap and readily available sodium cyanate is used as the ring closure reagent to replace sodium isocyanate which is toxic and difficult to purchase in an original method, reaction conditions are optimized and reaction order is adjusted, so the disadvantages of harsh reaction conditions and low yield in the original method of ring opening first and then benzyl protection are overcome by the method of performing benzyl protection on the N atoms of an imidazole part first and then performing ring opening; and the total yield reaches 34.0-38.0 percent.

The invention discloses a carboxyl functionalized porous heteropoly acid polyionic liquid and a use thereof. A carboxyl functionalized polyquaternary ammonium salt with a long chain linear structure and a heteropoly acid as building units are self-assembled into a three-dimensional network porous structure under electrostatic interaction so that the polyionic liquid is obtained, or a carboxyl functionalized polyquaternary ammonium with a long chain cross-linked structure and a Dawson-type vanadium-doped heteropoly acid as building units are self-assembled into a three-dimensional network porous structure under electrostatic interaction. The carboxyl functionalized porous heteropoly acid polyionic liquid can be used as a heterogeneous catalyst. Industrial grade hydrogen peroxide is used asan oxidant. A cyclic ketone compound undergoes Baeyer-Villiger oxidation to produce a corresponding cyclic lactone under the solventless condition. The catalytic system has a novel structure, is usedfor a Baeyer-Villiger oxidation reaction, and has the characteristics of good selectivity, mild reaction condition, large operation flexibility and convenient recycling of the catalytic system.

The invention discloses a process for preparing 2,6-dimethylpyridine comprising the following steps, using Pd/C as catalyst, C1-C4 alcohols as solvent, subjecting 2,6-dimethyl-4-chloropyridine to hydrogenization dechlorination reaction under the conditions of hydrogen pressure 0.1-0.2MPa, 20-55 deg. C, finally carrying out post-treatment to obtain the 2,6-dimethylpyridine.

The invention discloses a clean preparation method for 2,4-dichloro-alpha-chloromethyl benzyl alcohol and belongs to the field of catalytic synthesis process of 2,4-dichloro-alpha-chloromethyl benzyl alcohol. 2,2',4'-trichloroacetophenone is taken as an initial raw material, aluminium isopropoxide serves as a catalyst, isopropyl alcohol serves as not only a solvent but also a reactant, and reduction reaction, reduced pressure distillation, acidation, water washing and curing are conducted to obtain the 2,4-dichloro-alpha-chloromethyl benzyl alcohol. An isopropyl alcohol and acetone mixed solution obtained through reduced pressure distillation is rectified, 80-84 DEG C fraction is collected for recycling, and the yield is basically kept unchanged. Acidized acid water is neutralized by ammonia water, then filtered to obtain aluminium hydroxide, and finally roasted to acquire aluminium oxide after being dried. The method is mild in reaction conditions, short in reaction time and convenient in after-treatment, and avoids environmental pollution. The conversion rate and the product yield of 2,2',4'-trichloroacetophenone are more than 99%, and the manufacturing cost is low. The method is an efficient and environmental-friendly method for synthesizing 2,4-dichloro-alpha-chloromethyl benzyl alcohol and facilitates large-scale industrial production.

The invention discloses a preparation method of high-purity topiramate. Under the condition of dissolving the topiramate into an organic solvent, a proper concentration of alkali is added, so that the topiramate slat forms solid to be separated out in the solvent; the solid is dissolved into water, and is acidified into a weak acidic state; the solid is a topiramate coarse product; the topiramate coarse product is recrystallized to obtain the high-purity topiramate. The preparation method of the high-purity topiramate has the advantages that the purity reaches 99.90 percent or higher; under the condition that the product purity reaches 99.9 percent or higher, the yield of the product keeps unchanged; no additional excessive cost is added. The operation is convenient; the process is safe; the industrial production is easy.

The invention relates to a preparation method of bosutinib. According to the preparation method, 4-chloro-6-methoxyl-7-hydroxyl-3-quinoline formonitrile and 2,4-dichloro-5-methoxyl aniline are taken as the initial raw materials, 1-methyl-2-pyrrolidone is taken as the solvent, and a crude product of bosutinib is obtained through three steps. The preparation method has the advantages of few steps and mild conditions. The reaction conditions of the prior art are improved, the yield is prominently increased, the cost is reduced, and the preparation method is suitable for industrial production.

The invention relates to a cocatalyst for reducing the FCC (fluid catalytic cracking) regeneration flue gas pollutant discharge and application thereof. The cocatalyst comprises microsphere particles A and microsphere particles B, wherein through being metered by 100 percent of the weight of the microsphere particles A, the microsphere particle A is prepared from 80 to 98 percent of aluminum oxide, 0.1 to 10 percent of silicon oxide, 1 to 15 percent of oxide of one or two kinds of metals selected from groups VIB and IB and 0.1 to 3 percent of oxide of rare earth elements; through being metered by 100 percent of the weight of the microsphere particles B, the microsphere particle B is prepared from 50 to 80 percent of aluminum oxide, 10 to 50 percent of oxide of one or several kinds of metals selected from groups IIA, IVB and VIII and 0.1 to 10 percent of oxide of rare earth elements. The cocatalyst is applied to the reduction of nitrogenous pollutant discharge; the discharge of atmospheric pollutants such as NOx, Sox and CO in regeneration flue gas can be obviously reduced.

The invention discloses a method for preparing 8-hydroxyl caprylaldehyde and belongs to the field of chemical synthesis. The method comprises the steps of introducing air to 1,8-octanediol, which serves as a starting raw material, in a solvent at room temperature in the presence of a composite catalyst prepared from cuprous halide, substituted ethylenediamine and Tempo, carrying out a reaction forcertain time, then, carrying out filtering to remove the catalyst, and subjecting filter liquor to reduced-pressure distillation to remove the solvent, so as to obtain the product, i.e., the 8-hydroxyl caprylaldehyde. According to the method for preparing the 8-hydroxyl caprylaldehyde, disclosed by the invention, the technical line has the characteristics of short route, simplicity and convenience in operation and easiness in industrial production, and thus, the method for synthesizing the 8-hydroxyl caprylaldehyde is very economical, simple and convenient.

The invention relates to a low-carbon olefin production method. The method comprises the following steps: 1, preheating a cracking substance A containing a cracking raw material and water vapor to a cross-over temperature; 2, allowing hydrogen having an amount being 0.5-1.5% of the weight of the cracking raw material and oxygen having an amount being 2-12% of the weight of the cracking raw material to contact with the preheated cracking substance A in the presence of a hydrogen selective-combustion catalyst under a hydrogen selective-combustion reaction condition to obtain a cracking substance B; and 3, carrying out steam cracking of the cracking substance B obtained in step 2 to obtain a substance C, and carrying out separating recovery of the substance C to obtain low-carbon olefins. The invention also discloses an another low-carbon olefin production method. The another low-carbon olefin production method is carried out in a cracking system comprising a cracking furnace and a cracking gas header tube, and a hydrogen selective-combustion device is arranged at the bottom of the convection zone of the cracking furnace. The low-carbon olefin production methods can prolong the running period of the cracking furnace.

The invention discloses a method for preparing 2, 5-dihydroxymethyl tetrahydrofuran (BHMTHF) through catalytic hydrogenation of 5-hydroxymethylfurfural (5-HMF) and application of the 2, 5-dihydroxymethyl tetrahydrofuran (BHMTHF). According to the invention, by using a supported catalyst, a first active component and a second component of the supported catalyst are respectively from corresponding non-noble metal salt solutions and are selected from Ni(NO3)2.6H2O and Co(NO3)2.6H2O; typical acidic oxide gas phase SiO2 is used as a carrier, the loading capacity of the two active components is (4/1)-(1/1), and the bimetallic catalyst is prepared by adopting a coprecipitation method; and the catalyst is simple and convenient in preparation method, low in price and cyclical, the catalytic reaction system is green, the reaction substrate is renewable, the reaction condition is mild, the input cost is low, and the catalyst has a wide industrial application prospect.

The invention relates to a preparation method of TAT, comprising the following steps of: slowly dripping acetic anhydride with 1.5-2.5 times of the mass of HA at 5-10 DEG C by using the HA, ammonium acetate and water as raw materials; reacting for 30-50 minutes to obtain DAPA under stirring; reacting for 2-3 hours by using DAPT and the acetic anhydride as the raw materials and increasing temperature to 100-110 DEG C; and reacting for 1-2 hours by reducing the temperature to 30-35 DEG C to obtain a product TAT, in the presence of water as a catalyst, wherein the water accounts for 5-35 percent of the mass of the acetic anhydride raw material. The invention replaces the catalyst in a Lukasavage process method with the inexpensive water, obviously enhances the yield of the TAT, enables the synthesizing process of the TAT to be easy and reduces the production cost.

The invention relates to a preparation method of diphenhydramine, which takes benzhydrol and dimethylaminoethanol as raw materials, under existence of dibutyltin oxide and ion liquid compound, benzhydrol and dimethylaminoethanol are subjected to an intermolecular dehydration reaction to obtain diphenhydramine. The method has the advantages of simple preparation technology, mild reaction condition, low cost, high product yield and high purity.