59results about How to "Reduce hydrolysis reaction" patented technology

The invention provides a preparation method of anhydrous cesium chloride. The preparation method is characterized in that cerium oxide is taken as a raw material, reaction is conducted by using ammonium chloride solid, then dried hydrogen chloride gas enters, heating is conducted until the reaction is completed, and products are dried to obtain anhydrous cesium chloride. By the combined use of theammonium chloride and the hydrogen chloride gas, and by the combination and the proportioning of the using amount of reactants, the synergistic effect of the ammonium chloride and the hydrogen chloride is achieved to adjust the position relationship of each reactant, to make the reaction more complete, the yield of the reaction product is high, drying is conducted under an inert atmosphere by reducing pressure to prevent the occurrence of redox side reaction, improve the product purity, and the preparation method is safe and effective, and the products are pure.

The invention relates to a preparation method of prednisolone. The preparation method comprises the steps of sequentially carrying out 3, 20-keto protective reaction, 11-keto reduction reaction, 21-hydroxyl esterification reaction, 3, 20-keto deprotection reaction and 21-acetic ester hydrolysis reaction by taking prednisone acetate as a raw material to obtain prednisolone. The invention provides a novel synthesis route sequentially comprising the steps of esterifying and deprotecting; nitrosification quenching reaction and resin hydrolysis reaction are omitted in the deprotection process; and ester hydrolysis reaction is finished under the protection of a mixed solvent and inert gases, so that the condition that byproducts are produced by hydrolysis reaction is avoided. The preparation method is novel in process route, simple and rapid in operation process, low in production cost and suitable for large-scale industrial production.

The invention relates to a decolorization method of a panax notoginsenoside extract. In the decolorization method, panax notoginsenoside is decolorized mainly by combining strongly polar polystyrene copolymer macroporous resin ADS-7 with neutral aluminium oxide. According to the method, the strongly polar polystyrene copolymer macroporous resin ADS-7 is used for decolorizing, the decolorization effect is good, the amount of residues of the panax notoginsenoside in the resin is reduced, and hydrolysis of the panax notoginsenoside is reduced.

The invention relates to a rocuronium bromide-containing injection. The injection is prepared from rocuronium bromide serving as an active ingredient and a pharmaceutically-acceptable carrier as accessories. The pH value of a system is maintained by adding a 1-5 percent acetate buffer solution, so that the stability of the solution is enhanced, the pH value of a system is maintained at the same time, degradation of main medicaments in a preparation process is suppressed, the stability of the main medicaments is enhanced, and the quantity of rocuronium bromide impurities C in an autoclave sterilizing process is reduced. Finally, a rocuronium bromide injection which has high stability and stable quality and is suitable for storing for a long time is obtained.

Disclosed is an alternate pulse formation charging process. The alternate pulse formation charging process comprises the steps of primary acid addition, battery connection, power supplying, and charging and forming, wherein in the procedure of charging and forming, the forming and charging process of a storage battery is divided into multi-mode and multi-stage alternate charging, such as trickle preprocessing, constant current charging, standing, positive and negative pulse charging, intermittent pulse charging and the like according to certain chemical and physical characteristics of a lead-acid storage battery. By virtue of the process of the invention, the polarization reaction and the electrolyte temperature in the middle and later periods of the traditional constant-current charging mode formation are reduced, the charging efficiency is improved, the formation time is shortened, the formation period is shortened by 30%, the charge electric quantity is reduced by 20%, energy conservation and consumption reduction are achieved, and the production efficiency is improved; meanwhile, the polar plate conversion efficiency is improved, the initial capacity of the battery is increased; and formation of acid mist in the middle and later periods of formation is reduced, electrochemical polarization in the middle and later periods of formation is eliminated, the hydrolysis reaction is reduced, the groove temperature and voltage are lowered, the gas evolution is reduced, and the environmental protection is facilitated.

The invention belongs to the technical field of pharmacy, and in particular relates to a preparation method of nimodipine, comprising urethane reaction and cyclization reaction, wherein in the urethane reaction, after ammonia introducing reaction, adding an inorganic salt for dewatering the urethane reaction liquid, then rectifying to obtain isopropyl-3-aminocrotonate; and performing cyclization reaction with 2-(3-nitrobenzylidene)-acetoacetic acid-2-methoxyethyl ester by taking fatty alcohol as a reaction solvent. The invention has the advantages of high product yield and good quality, the primary yield can reach 85-89%, the solvent can be recovered for use, the raw material cost can be greatly reduced, and the content of total impurities is decreased from 0.4-1.0% of the original process to 0.1-0.3% by HPLC (High Performance Liquid Chromatography) detection.

The invention discloses an insulating silicone grease with high heat conductivity coefficient special for electron industry. The insulating silicone grease is prepared from raw materials including long-chain alkyl silicone oil (viscosity of 600-900mm2/s), polyether silicone oil (viscosity of 200-400mm2/s, viscosity of 400-600mm2/s), zinc oxide (1mum), spherical aluminum oxide (20mum), aluminum nitride (10mum), boron nitride (3mum), silicon carbide (5mum) and sulfonated graphene. The invention also discloses a preparation method for the insulating silicone grease with high heat conductivity coefficient special for electron industry.

The invention discloses a freeze dried of mushroom polysaccharide, which comprises the following steps: adopting neutral amino acid as rack agent; blending evenly; reducing the density of sodium hydroxide; filtering; adjusting pH value.

The invention provides a metal-free sulfur-doped carbon material hydrogen peroxide reduction catalyst and a preparation method. The preparation method is characterized by comprising the following steps: putting benzyl disulfide and a carbon material into sufficient ethanol according to a mass ratio of (5-6): (95-94), ultrasonically treating the mixture for 0.5 to 1 hour, centrifuging the mixture to remove the upper substances, vacuum drying the mixture for 5 to 6 hours at the temperature of 50 to 60 DEG C to form solid powder, putting the solid powder into a high-temperature furnace to be reacted for 7 to 8 hours at the temperature of 800 to 900 DEG C under the protection of nitrogen, cooling the solid powder to room temperature under the protection of nitrogen to obtain the sulfur-doped carbon material hydrogen peroxide reduction catalyst. The sulfur is used for substituting carbon to form S-C bonds to form an activity center of the electroreduction of H2O2. The source of the raw material is wide, and the price is low. Not only is the electrochemical activity high, but also the stability is high, and the toxicity resistance is high. The hydrolysis reaction of the H2O2 can be prevented, and the oxygen can be reduced. The electric oxidation performance and utilization rate of the H2O2 can be greatly improved.

The invention provides a chlorination reaction device and a chlorination reaction technology for preparing cyanogen chloride. Chlorination reaction is carried out at a relatively low temperature in the divided three steps of pre-reaction, intermediate reaction and post-reaction. Cyanide is almost completely consumed, and the product residence time is shortened by the technology, so that unnecessary side reactions can be removed, and the raw material yield is maximized.

The invention discloses a processing method with water oil to prepare biological diesel, which comprises the following steps: 1 pretreating rough water oil with water; getting refined water oil; 2 esterifying the refined water oil; proceeding ester exchange; getting rough eater; 3 washing the rough eater; getting neutral rough ester; 4 distilling the neutral rough ester; getting the product. The each technical index of this biological diesel can reach request, which possesses very high practical value.

The invention discloses special silica gel with high coefficient of thermal conductivity for electronic industries. The special silica gel with the high coefficient of thermal conductivity is preparedfrom long-chain alkyl silicone oil (viscosity 600-900mm<2>/s), polyether silicone oil (viscosity 200-400mm<2>/s), trifluoropropyl silicone oil (viscosity 400-600mm<2>/s), 6-11 parts of zinc oxide (1micrometers), spherical aluminum oxide (20 micrometers), aluminum nitride (10 micrometers), boron nitride (3 micrometers), silicon carbide (5 micrometers), sodium hydrochloride, polydimethylsiloxane,sulfonated grapheme, 1-hydroxybenzotriazole, dicyclohexylcarbodiimide, and N-methylpyrrolidone. The invention also discloses a preparation method of the special silica gel with the high coefficient ofthermal conductivity for electronic industries.

The invention relates to a method for preparing titanium-based polyester through a DMT process. The preparation method comprises the following steps: mixing DMT, EG, a polyester titanium-series catalyst composite material system and an ester exchange catalyst, and then carrying out an esterification reaction and a condensation polymerization reaction to obtain the titanium-based polyester, whereinthe polyester titanium-series catalyst composite material system is mainly composed of a polyester prepolymer with a polymerization degree of 5-30, and a flaky titanium-series polyester catalyst anda phosphorus-series stabilizer which are dispersed in the polyester prepolymer. According to the method for preparing the titanium-based polyester through the DMT process in the invention, the polyester prepolymer with a polymerization degree of 5-30 is used to wrap the flaky titanium-series polyester catalyst with excellent hydrolysis resistance, and the polyester titanium-series catalyst composite material only melts at a high temperature to release the titanium polyester-series catalyst, so the hydrolysis reaction of the titanium-series polyester catalyst caused by water contained in the storage and transportation process can be reduced or even avoided, the high dispersity and high activity of the titanium-series polyester catalyst are ensured, and the yellowing of the titanium-based polyester is reduced.

The invention provides a meclofenoxate hydrochloride microcapsule for injection and a production method thereof. The meclofenoxate hydrochloride microcapsule for the injection is composed of the meclofenoxate hydrochloride and adjuvant, which is characterized in that the adjuvant contains gelatin, dextran and emulsifier. The invention also provides the production method of a meclofenoxate hydrochloride freeze-dry powder and injection. As the meclofenoxate hydrochloride microcapsule with high stability in water is used, the meclofenoxate hydrochloride is not hydrolyzed when redissolving; the clarity is good after redissolving; thereby a product in the invention has the advantages of good stability and good quality, which is good for storing the product for a long time.

A postprocessing method for synthetic borneol comprises the steps of preparing the raw materials of synthetic borneol to obtain raw ester according to a conventional production method, then washing the ester by water, postprocessing the washed ester through a light oil steaming method, mixing the waste water (including oxalic acid and boric acid) obtained by washing the raw ester and oil mud generated by postprocessing refined ester obtained by steaming the light oil, adding non-ionic surface active agent to be taken as a demulsifying agent, conducting oil-mud separation to obtain red oil, and postprocessing the waste water after the oil-mud separation so as to achieve the purposes of recycling and discharging after reaching the standard. If the boric acid content is too high, part of boric acid crystals can be separated out by cooling and crystallizing, so that mother liquor containing boric acid achieves the demanded index and then returns to be taken as a water source for washing the raw ester; and the boric acid crystals can return to be taken as the water source for washing the raw ester through a prepared buffer solution.

The invention provides a preparation method of an amino acid surfactant, and relates to the field of fine chemical engineering. The preparation method of the amino acid surfactant provided by the invention comprises the following steps: mixing water, amino acid and polyethylene glycol, adding alkali liquor to adjust the pH value of a mixed system to 8-13, adjusting the temperature of the mixed system to 10-60 DEG C, adding acyl chloride and alkali liquor into the mixed system, maintaining the pH value of the mixed system in a range of 8-13, and reacting for 2-4 hours to obtain the amino acid surfactant. And reacting to obtain the N-acylamino acid surfactant. According to the invention, polyethylene glycol is introduced into a reaction system on the basis of preparing the N-acylamino acid surfactant through a Shore-Baumann condensation reaction at present, so that the contact surface between acyl chloride and amino acid can be increased, the conversion rate of acyl chloride can be increased, the reaction time can be shortened, and the hydrolysis reaction of materials can be reduced; generation of fatty acid and fatty acid salt is effectively reduced, and the problems of unstable product indexes, turbidity and the like are solved.

The invention provides a preparation method of clindamycin phosphate freeze-dried powder injection for injection, and belongs to the technical field of medicine preparation. The preparation method comprises the steps that water for injection with the temperature smaller than or equal to 25 DEG C is taken, clindamycin phosphate is added in batches, meanwhile, an alkali solution is slowly dropwise added, the system temperature is maintained to be smaller than or equal to 25 DEG C, and the aqueous alkali is dropwise added until the clindamycin phosphate is dissolved and the pH value of the system is 6.0-6.4, and decoloration, degerming filtration and freeze drying is carried out to obtain the clindamycin phosphate freeze-dried powder injection for injection. By adjusting the feeding mode and the dissolving temperature of the clindamycin phosphate and finally adjusting the pH value, the hydrolysis reaction of the clindamycin phosphate is effectively reduced, the stability of the clindamycin phosphate is improved, the impurity content of the finished product is reduced, and the problem that the impurity content of the finished product is relatively high is solved.

The invention discloses a neostigmine methylsulfate composition and a preparation method thereof. The neostigmine methylsulfate composition comprises an effective amount of neostigmine methylsulfate; a chelating agent; a pH adjusting agent; and water. The composition is simple and small in dosage, the production cost is reduced, the production risk of microorganism and bacterial endotoxin pollution is reduced, the high-temperature resistance of the neostigmine methylsulfate composition is remarkably improved, and the amount of impurity A can be reduced by half after the composition is subjected to high-temperature sterilization.

The invention provides a friction modifier for drilling fluids. The friction modifier includes a mercaptoalkyl silane coupling agent represented by formula I or formula II, and a composition of a lubricant for drilling fluids; and in the formula I and the formula II, n is an integer between 1 and 3, A is a methyl group or an ethyl group, and X is selected from chlorine, methoxy groups, ethoxy groups, methoxyethoxy groups and acetoxy groups. The mercaptoalkyl silane coupling agent can be used in the friction modifier for drilling fluids as an additive, so the friction resistance reduction effect of traditional lubricants is enhanced, and the drilling rate is improved.