131results about How to "High molar yield" patented technology

The invention discloses an improved method for preparing cyclohexanol and cyclohexanone. The invention is characterized in that the decomposition reaction of cyclohexyl peroxide is accomplished with two steps; during the first decomposition reaction, the flow of circulated alkaline is equal to or larger than that of cyclohexane oxydic liquid, thereby ensuring the alkaline water phase to become a continuous phase of the material in the first decomposition reaction; the cyclohexane phase is dispersed; the decomposition reaction is accomplished under an emulsification state, or is called even phase decomposition; the compound from the decomposition reaction is rough separated through a hydrocyclone separator; a large amount of alkaline liquid is separated from the lower outlet of the hydrocyclone separator to be recycled; the material of cyclohexane from the upper outlet of the hydrocyclone separator is changed to the continuous phase, while little alkaline liquid is changed into the dispersing phase; the waste alkaline liquid is separated by lifting a separation groove through gravity; the second decomposition reaction is then accomplished to ensure a full decomposition reaction. With the technical improvement, the total mol yield of the oxidation of cyclohexane prepared cyclohexanol and the cyclohexanone device is increased by 5 percent.

The invention relates to a medicine synthesis method, in particular to a process method for screening of immobilized cefprozil synthetase and enzymatic synthesis of cefprozil. In order to solve the problems that a conventional cefprozil enzymatic synthesis process has difficulties in screening and evaluating immobilized anzyme, tedious in production process step, poor in control point, long in reaction time, low in conversion ratio and the like, the invention provides an immobilized cefprozil synthetase and a novel process for cefprozil synthesis.

The invention belongs to the technical field of chemical drug synthesis, and particularly relates to a preparation method of an isoxazoline insectifuge. The preparation method is characterized in thatthe isoxazoline insectifuge is fluralaner; an intermediate I is sequentially subjected to an amidation condensation reaction, a substitution reaction and a ring closing reaction in the same reactioncontainer; and after the reactions are finished, a reaction product is poured into water, stirring and filtering are conducted to obtain a solid, and the obtained solid is recrystallized to obtain theisoxazoline insectifuge. The method has the beneficial effects that the method uses a solvent and one-pot method to synthesize fluralaner, technological operation of a synthesis process is reduced, treatment time and reaction time are shortened, product yield is improved, and the method is suitable for large-scale production.

A preparation method of methyl glucoside relates to preparation of methyl glucoside, in particular to a new way for directly preparing the methyl glucoside by taking cellulose as raw material, then combing the cellulose in a methanol medium, and then conducting catalyzed reaction between the cellulose and the methanol under the existence of an acid catalyst, and a related acid catalyst. The invention provides the preparation method of methyl glucoside, which has rich resource of adopted reactants, does not compete with grain such as starch, and has simple technological process and the highestmolar yield of the methyl glucoside of 65 percent. The cellulose, the methanol and the acid catalyst are mixed and added in a high pressure autoclave, then nitrogen is led in for evacuation, and afterreaction, cooling is conducted to obtain the methyl glucoside. The molar yield of the methyl glucoside is higher, which is 40 percent generally, and can reach 65 percent maximally.

The invention relates to a preparation method of a cefotaxime sodium crystal. The preparation method comprises the following steps of: dissolving sodium acetate in a mixed solvent of organic solvent and water below 10-40 DEG C, wherein the volume fraction of organic solvent in the mixed solvent is 30-70%; adding cefotaxime acid, and stirring until the cefotaxime acid reacts in the solution; adding a cefotaxime sodium crystal in the solution, then adding elution agents with a feeding time of 2-8 hours, cooling to 5 DEG C below zero to 5 DEG C; and filtering, washing and drying a crystal slurry to obtain the cefotaxime sodium crystal. By the preparation method, the phenomenon of gelatinization frequently seen in the crystallization process of the cefotaxime sodium crystal is avoided, the size distribution of the products is centralized and the major particle size is adjustable from 5mu m to 60my m, the liquidity of the product is good, the process yield is higher than 87%, and the product purity is higher than 95.5%.

The present invention is technological process of preparing bisphenol monoacrylate compound as oxidant with bisphenol compound, acrylic acid and phosphorus oxychloride as materials, triethylamine as acid absorbent and aliphatic hydrocarbon as solvent, and through acyl chlorination and esterification in a reactor. The technological conditions include the molar ratio between bisphenol compound and acrylic acid of 1 to 1.05, the molar ratio between acrylic acid and phosphorus oxychloride of 3 to 1.05, the molar ratio between phosphorus oxychloride and triethylamine of 1 to 3.5; reaction temperature of 63-66 deg.c and reaction time of 150-155 min. After reaction, the resultant is filtered to eliminate solid triethylamine hydrochloride, the filtrate is cooled to re-crystallize to produce white crystal product of smelting point 117.5-18.6 deg.c. The present invention is simple, and has high bisphenol monoacrylate compound yield and low material consumption.

The invention mainly discloses a silanization reaction catalyst. Etherate is obtained by erythromycin oxime through etherification, (2', 4'')-O-bis(trimethylsilyl)erythromycin A-9-O-(1-ethoxy-1-methylethyl) oxime of intermediate for synthesizing clarithromycin is prepared by the silanization reaction, the catalyst is added into the silanization reaction and is hydrobromide with a general formula being RHBr, wherein R is organic alkali, or the catalyst is strong acid and weak base salt with a general formula being XBr, wherein X is weak base cations. The consumption of the catalyst is 0.01-0.4 of the erythromycin oxime according to the mol, the temperature of the silanization catalysis reaction is 0-40 DEG C and the time of the silanization catalysis reaction is 1-10h. The invention enables the process for preparing the (2', 4'')-O-bis(trimethylsilyl)erythromycin A-9-O-(1-ethoxy-1-methylethyl) oxime to be stable, the yield to be high, the cost to be low and the three wastes to be less.

The invention provides a method for preparing methyl heptenone by using 3-methylcrotonaldehyde, which comprises the steps of condensation and selective reduction, wherein the step of condensation comprises the sub-steps of adding acetone and a catalyst, and dropwise adding 3-methylcrotonaldehyde; and the step of selective reduction comprises the sub-steps of adding materials and carrying out hydrogenation reaction; and the sub-step of adding materials, namely adding 1 part of methyl diheptenone, 0-10 parts of a solvent, and 0.001-0.05 part of transition metal Pd/Rh catalyst precursor compounds and diphosphine ligand compounds into a reaction kettle. According to the invention, through two-step reaction, the mole yield of the methyl diheptenone to 3-methylcrotonaldehyde is high, and the methyl heptenone product content reaches 98.0-98.7%; in the step of selective reduction, the conversion rate of methyl diheptenone is greater than or equal to 99.0%, and the selectivity reaches 90.8-94%; and in the step of condensation, the conversion rate of 3-methylcrotonaldehyde is 99.0%, and the mole yield of the methyl diheptenone to 3-methylcrotonaldehyde reaches 89.8-92.7%.

The invention discloses a Cefuroxime sodium lyophilized powder and a method for preparing the same. The method is characterized in that a Cefuroxime sodium solution is added with active carbon, decolored, subjected to decarbonization and aseptic filtration and washed by purified water; a mixture of a filtrate and an eluant is pressed into a feed tray or a penicillin bottle of a freezedryer; a product with the moisture of Cefuroxime sodium of less than 2 percent is prepared by a lyophilization method; and the method simplifies a process, reduces labor intensity, aseptic risk, production cost and pollution and has rapid dissolution speed, good stability and high yield.

The invention discloses a preparation method of 2, 4-diamino-6-hydroxy-5-carboxamido pyrimidine. The preparation method comprises the following step: carrying out an acylation reaction on 2, 4-diamino-5-nitroso-6-hydroxypyrimidine in formamide and water under the catalytic action of a catalyst A to obtain the 2, 4-diamino-6-hydroxy-5-carboxamido pyrimidine. The invention also discloses a preparation method of guanine formate or guanine. The preparation method of guanine formate or guanine comprises the following step: reacting the 2, 4-diamino-6-hydroxy-5-formamidopyrimidine in formic acid toobtain guanine. According to the synthesis methods of the 2, 4-diamino-6-hydroxy-5-formamidopyrimidine and guanine, the production process is greatly shortened, the generation amount of three wastes is greatly reduced, the product quality of the guanine product meets related quality requirements, and the molar yield is higher than that of the guanine product prepared by the prior art. Therefore, the preparation methods disclosed by the invention are efficient, economic, green and environment-friendly preparation methods.

The invention discloses a method for preparing gamma-butyrobetaine ester, which uses gamma-chloro butyric ester and trimethylamine as raw materials and alcohol as a solvent. The raw materials and the solvent are heated to react in a high-pressure autoclave, and products of the gamma-butyrobetaine ester are obtained by concentrating processing and fine purification. The gamma-butyrobetaine ester is methyl ester or ethyl ester. The feeding mol ratio of the gamma- chloro butyric ester to the trimethylamine is 1:1.2-3.0, wherein the degree of purity of the gamma-chloro butyric ester is not less than 97 percent, and the degree of purity of the trimethylamine is more than 98 percent. The alcohol as the solvent is one of methanol, absolute ethyl alcohol, propanol, or isopropanol, and the use level of the alcohol is 1-5 times higher than that of the gamma-chloro butyric ester. The reaction is carried out at the temperature of 50-120 DEG C and the high pressure for 5-24h in an airtight mode. Because the technical scheme is adopted, the preparing cost is decreased, the domestic blank for preparing the gamma-butyrobetaine ester is replenished, and the mol yield of the products is enhanced and can reach more than 90 percent.

The invention provides a method for preparing aromatic hydrocarbon by hydrocracking an aromatic ring-containing polymer. The method comprises the following steps: reacting crushed polymer with hydrogen at the temperature of 350 DEG C or below under the action of a catalyst; separating reaction products to obtain aromatic hydrocarbons. The catalyst comprises a carrier and an active component loadedon the carrier, wherein the active component is selected from at least one of Ru, Rh, Pt, Pd, Fe, Ni, Cu and Co; wherein the carrier is selected from at least one of a metal oxide, a phosphate, a molecular sieve, SiO2 and sulfonated carbon, and the metal oxide is selected from at least one of Al2O3, Nb2O5, Nb2O5-Al2O3, Nb2O5-SiO2, TiO2, ZrO2, CeO2 and MoO3; the phosphate is selected from at leastone of NbOPO4 and ZrOPO4; wherein the molecular sieve is selected from at least one of Nb-SBA-15, Nafion, H-ZSM-5, H-Beta and H-Y in a molecular screening manner.

The invention relates to the chemical field and in particular to a preparation process for cyanomethyl ester. The cyanomethyl ester is prepared with a high yield by taking acetonitrile, methanol, anhydrous hydrogen chloride and a 28% cyanamide aqueous solution as main reaction raw materials and taking toluene as a solvent. The preparation process has the advantage that according to the preparation method for the cyanomethyl ester, the molar yield of the cyanomethyl ester is increased to 85%; content of product cyanomethyl ester is greater than or equal to 99.5%; and the reaction process is gentle and safe.

The invention relates to amycolatopsis sp. and application thereof. The amycolatopsis sp. HM-141 (the preservation number is CGMCC (China General Microbiological Culture Collection Center) No.22871) disclosed by the invention is applied to production of vanillin by taking ferulic acid as a substrate. Experiments confirm that the amycolatopsis sp. HM-141 uses ferulic acid as a substrate to produce vanillin, the molar conversion rate can reach up to 87%, impurities (or byproducts) in the product are obviously lower than that in the prior art, the detection amount of vanillin alcohol is 0, the detection amount of vanillic acid is as low as 0.25 g/L, and the amycolatopsis sp. HM-141 has obvious advantages.

The invention discloses a method for preparing propionate by means of a microreactor. Production equipment comprises a first metering pump, a second metering pump and a third metering pump, wherein the first metering pump and the second metering pump are communicated with a first blender, the third metering pump is communicated with a second blender, the blenders are communicated with the microreactor, a material output pipe with a sampling stop valve is arranged at a discharging end of the microreactor, the material output pipe is connected with a filter, a drainage pipe and a discharging pipe are connected with an output end of the filter in parallel, the discharging pipe is connected with a rectifying tower, and an output pipe of the rectifying tower is connected with a dehydration tank; a preparation process comprises the steps that propionic acid and monohydric alcohol are pumped by the first metering pump and the second metering pump respectively, an acidic ion liquid catalyst ispumped by the third metering pump, a reaction temperature is controlled to be 50 to 100 DEG C, and reaction time is controlled to be 5 to 60 min. The method for preparing the propionate by means of the microreactor has the advantages that the material diffusion speed can be further improved, the evenness of material mixing is further improved, the reaction time and a production cycle are greatlyshortened, energy consumption is low, and the conversion rate is high.

The invention relates to methods for preparing semi-synthetic paclitaxel and an intermediate thereof. The method for preparing the semi-synthetic paclitaxel comprises the following steps: dissolving 10-DABIII (10-deacetylbaccatinIII) into pyridine, protecting hydroxyl on position-7 carbon on the 10-DABIII with triethyl silicyl to obtain an intermediate I, acetylating hydroxyl on position-10 carbon of the intermediate I to obtain an intermediate II, reacting the intermediate II, a side-chain radical compound and 4-dimethylaminopyridine in an organic solvent to prepare an intermediate III, and reacting the intermediate III with trifluoroacetic acid under an acidic condition to obtain a crude paclitaxel product. The preparation methods are simple and easy for industrialization; the active hydroxyl of the raw material 10-DABIII is effectively protected, so that fewer byproducts are finally generated, and a prepared paclitaxel product has high molar yield of 70 to 81 percent and high paclitaxel purity of 99.5 to 99.9 percent; the residual rate of the raw material in the steps of synthesizing the intermediate II and synthesizing the paclitaxel is low, side reactions are reduced, and the raw material is high in reaction selectivity and utilization rate; the product can be directly used as a raw material for the medical field of treatment of ovarian cancer, breast cancer and the like.