124results about How to "High reaction safety" patented technology

The invention discloses a making method of beta-carotene through coupling reaction, which is characterized by the following: adopting 30% hydrogen dioxide solution to couple two molecular organic phosphors; saving cost effectively; reacting vitamin A derivant and triphenylphosphine to produce organic phosphine salt; coupling under hypochlorite to obtain the product with water and water dissolution as organic solvent; avoiding explosive accident; improving reacting safety effectively.

The invention discloses a catalyst with ruthenium-loaded titanium dioxide hollow spheres embedded with silicon dioxide nanoparticles and a preparation method and application of the catalyst. The preparation method includes: using tetraethyl silicate as the raw material to prepare silicon dioxide microspheres; using titanium tetraisopropanolate to wrap the silicon dioxide microspheres with a layerof titanium dioxide and surfactant hexadecylamine, processing the product in an ammonia water solution through a hydrothermal method to partially etch the silicon dioxide microspheres inside so as toform cavities between the shell titanium dioxide and the inside silicon dioxide, and calcining under certain temperature and removing the surfactant to form crystal-form titanium dioxide; using a deposition-precipitation method to load precious metal ruthenium of different content. The catalyst has a special mesoporous spherical structure and large specific surface area and has high conversion rate and selectivity to guaiacol and other biomass phenol hydrogenation. The preparation method is easy to operate, simple in production process, low in equipment requirement and promising in industrialapplication prospect.

The invention relates to a novel green synthesis method for preparing o-amidated aryl heterocyclic derivatives from an N1,N3-disubstituted imidazole ionic liquid as a solvent and dioxazolone compoundsas an amide source by transition metal catalyzed C-H coupling reaction. Compared with the traditional technology, the method is safer, simpler, more efficient and more environmentally friendly; a functional group has good tolerance and high yield; the solvent and a catalyst can be recycled, and the cost is greatly reduced; the by-product is merely carbon dioxide, a large amount of waste is avoided, and the atomic utilization rate is increased; pre-activation of a substrate is not needed, the reaction conditions are mild, and the operation difficulty is reduced. An o-amidated aryl heterocyclicderivative molecular library can be obtained efficiently and quickly, natural compounds can be modified later, and accordingly, new drug candidate molecules are synthesized.

The invention discloses a device for synthesizing bi(trichloromethyl) carbonic ester. The device comprises a liquid chlorine gasifier, a dimethyl carbonate gasifier, a heat exchanger, a tubular reactor, a gas storage tank, a stirring kettle, a flaker and the like. The invention further discloses a method for synthesizing the bi(trichloromethyl) carbonic ester. The method comprises the following steps: mixing chlorine with gasified dimethyl carbonate in a mole ratio of (5-7):1, performing heat exchange so as to obtain mixed gas phase, feeding the mixed gas phase into the tubular reactor filled with a solid catalyst, keeping reaction temperature to be 90-100 DEG C and the pressure to be 0.1-0.15Mpa, and performing reaction for 5-10 minutes; recycling unreacted chlorine for circulation use; performing flash evaporation, and performing flaking molding, so as to obtain the bi(trichloromethyl) carbonic ester. By adopting the method for synthesizing the bi(trichloromethyl) carbonic ester, the use amount of the chlorine can be reduced, the reaction time can be shortened, the equipment security can be improved, the reaction efficiency is high, continuous reaction can be achieved, the product yield can be greatly increased, and the dimethyl carbonate conversion rate can be greatly increased.

The invention discloses a preparation method of high-purity benzoyl peroxide. The high-purity benzoyl peroxide is prepared through a synthesis process and a purification process. Alkali selected in the synthesis process is ammonium hydrogen carbonate, so that reaction safety is high, overall reaction is mild and control, and product purity can reach 99.5% and higher. A solvent selected in the purification process is safe and has lower toxicity than chloroform and methanol, operation is easy, and obtained crystal particles are large.

The invention provides a method for synthesizing gefitinib and an intermediate thereof. The method comprises the following steps: a compound 4 serving as a raw material is subjected to quinazoline annulations (iv) with carboxamidine or salt thereof in a polar aprotic solvent under catalysis of Cu(I) salt, L-proline and alkali to synthesize a compound 5; the compound 5 and 3-hydroxy-4-methoxybenzoic acid serving as initial raw materials are subjected to esterification, bromination, condensation, quinazoline annulation, substitution and other steps to prepare gefitinib.

The invention relates to the field of petrochemical industry, in particular to a method for continuous production of propylene oxide by direct oxidation of propylene with hydrogen peroxide through tubular reactors. The method comprises the steps: a catalyst, namely phosphotungstic acid quaternary ammonium salt is mixed with the hydrogen peroxide and an organic solvent, and the mixture is subjectedto azeotropic dehydration and then sequentially reacts through the multi-stage tubular reactors which are connected in series; and a raw material, namely the liquid propylene is divided into multiplestrands to be parallelly added into all the stages of tubular reactors, reacting mixed liquid flowing out from the tubular reactor of the last stage enters a tower reactor, and after reacting of thereacting mixed liquid in the tower reactor is completed, the reacting mixed liquid enters a separating system. The design is ingenious, through combination of the tubular reactors and the tower reactor and reasonable control over the reacting temperature and the reacting pressure, the atmosphere needing to be protected by N2 in the reactors in a laboratory process is omitted, and condensation filter tower devices which are additionally arranged in the reactors because of protection of the N2 and control over the oxygen content are omitted; the equipment investment and the tail gas treatment cost are saved greatly, tail gas emission of the reactors is less, and thus pollution to the environment is less; and the method has potential market value.

The invention discloses a synthesis method of 2-methyl-4-nitrobenzoic acid. The method is used for synthesizing the 2-methyl-4-nitrobenzoic acid by taking 4-dimethylnitrobenzene as a basic raw material and dilute nitric acid as an oxidant. A free radical initiator and a phase transfer catalyst which are added in the reaction process can be used for remarkably increasing the reaction yield and ensuring that the yield of the 2-methyl-4-nitrobenzoic acid as an oxidation product is up to 83.5%. The method disclosed by the invention is mild in reaction condition, capable of avoiding high temperature and high pressure, good in selectivity, high in yield and suitable for engineering application.

The invention relates to a method for preparing diisobutylphosphine from liquid phosphine, which comprises the following steps: adding low-temperature liquid phosphine and liquid isobutene into a reaction kettle in sequence, uniformly mixing, heating to a target reaction temperature, slowly dropwise adding an initiator solution into the reaction kettle through a diaphragm metering pump, and initiating free radical addition reaction; and after the reaction is finished, carrying out rectification separation on the obtained reaction product to obtain the target product diisobutylphosphine. The method not only improves the purity of the sodium hypophosphite byproduct phosphine as a raw material, but also creates conditions for low-pressure feeding of liquid phosphine and isobutene; purified liquid phosphine is used as a raw material, liquid-phase uniform mixing reaction of phosphine and isobutene is achieved, large-amount use of organic reaction solvents such as methylbenzene is avoided, and reaction efficiency is improved; meanwhile, compared with a hydrogen phosphide gas compression method, the reaction pressure of the system is reduced, and the reaction safety is improved. In addition, an addition reaction byproduct is selected as the initiator solvent, no new solvent substance is introduced into the system, and separation and recovery of the initiator solvent are avoided.

According to the method, 2-methyl-5-bromobenzoic acid is adopted as a raw material, and Suzuki coupling reaction, condensation reaction, dehydration cyclization reaction and amide condensation reaction are performed to finally obtain the fluralan. According to the synthesis method, the reaction cost is reduced, the yield is improved, and the reaction period is shortened.

The invention discloses a preparation method of O-benzylhydroxylamine hydrochloride, and relates to the technical field of organic synthesis. The method comprises the following steps: synchronously dropwise adding alcoholic solutions of benzyl halide and alkoxide into oxime to perform a reaction; when no benzyl halide exists in the reaction system, carrying out solid-liquid separation, dropwise adding dilute hydrochloric acid for carrying out hydrolytic rectification, and distilling while dropwise adding the dilute hydrochloric acid to separate out ketone; concentrating the reaction solution and separating out O-benzylhydroxylamine hydrochloride; and drying the benzylamine hydrochloride to obtain an O-benzylhydroxylamine hydrochloride pure product. Oxime is used as a raw material, and thefinally generated ketone or aldehyde can also be recycled to synthesize corresponding oxime. According to the method, the atom utilization rate is improved, the production cost of the product is reduced, the emission of three wastes is reduced, and the goal of green production is achieved.

The invention discloses a compound stabilizer for the epoxidation reaction of an unsaturated compound and an application method of the compound stabilizer. The compound stabilizer comprises carbamide, ethylene diamine tetraacetic acid, potassium sodium tartrate and sodium silicate. Peroxide and a peroxoic acid stabilizer including the ethylene diamine tetraacetic acid, the potassium sodium tartrate, concentrated sulfuric acid and 732 resin are uniformly mixed; the addition of the peroxoic acid stabilizer is 0.1 to 5 wt% of that of the peroxide; organic acid is dropwise added to the peroxide and the peroxoic acid stabilizer at 25 to 35 DEG C, so that peroxoic acid mixed solution is obtained after reaction; an epoxidation stabilizer including the carbamide, the ethylene diamine tetraacetic acid, and the potassium sodium tartrate and the sodium silicate is added into the unsaturated compound, and then the peroxoic acid mixed solution is added into the epoxidation stabilizer at 65 to 95 DEG C, so that an epoxidation compound is obtained after epoxidation reaction. The compound stabilizer has the advantages that the coordination of various stabilizers improves the stability of hydrogen peroxide and peroxoic acid in reaction solution, the frequency of the occurrence of secondary reaction is reduced, the reaction time is shortened, and the production cost is reduced.

The invention discloses a method for continuously synthesizing 4-oxoisophorone in a microchannel reactor. The method comprises the following steps: feeding a metered catalyst solution, oxygen and beta-isophorone into the microchannel reactor in proportion, fully mixing and then reacting to obtain the 4-oxoisophorone. According to the process method disclosed by the invention, the microchannel reactor is utilized, so that the reaction mass-transfer efficiency is high, the reaction temperature is stable, and the experimental operability is greatly improved; the metered oxygen is used as an oxidant, the reactor volume is small, no waste gas is generated, the flash-explosion risk of a traditional kettle type gas-liquid two-phase reaction is effectively avoided, and the safety performance of the reaction is improved; a special system is adopted, so that a homogeneous catalyst is prevented from slagging during the reaction so as to plug the reactor, and the efficient continuous production of the 4-oxoisophorone becomes possible.

The invention relates to a method for preparing a repaglinide intermediate shown in a formula (I). The method comprises steps of: adding a Grignard reagent into ethanol, and hydrolyzing to obtain the repaglinide intermediate shown in the formula (I).

The invention provides a preparation method of 2-amino-6-propylamino-4,5,6,7-tetrahydrobenzothiazole. According to the preparation method, 2-amino-6- propionamido-4,5,6,7-tetrahydrobenzothiazole is adopted as a raw material and is reduced through I2 and sodium borohydride to prepare the 2-amino-6-propylamino-4,5,6,7-tetrahydrobenzothiazole. The preparation method has the advantages that the raw material is easy to obtain, the reaction condition is mild, the control is easy and the reaction safety is high; and the preparation method is suitable for industrial production.