82results about How to "Lower reaction yield" patented technology

According to the method of the present invention, a methyl tetrazole pyridine bromide (2) and pinacol diboron are subjected to a reaction under catalysis of a transition metal to obtain a boronic acid pinacol ester (3), the compound (3) is separated or is not separated, and the separated compound (3) or the un-separated compound (3) and Cbz-protected bromobenzene (4) are subjected to a reaction under catalysis of a transition metal to obtain a key intermediate (1) of tedizolid. According to the present invention, the compound (3) is not subjected to separation purification, and reacts with the compound (4) in a kettle to generate the compound (1).

The invention provides a novel route for cefathiamidine compounds. The new route comprises the following steps of: reacting N,N'-diisopropyl thiourea and sodium bicarbonate, adding 2-bromacetic acid in the mixture for reaction, adding triphosgene and triphenylphosphine oxide serving as catalysts, reacting the product of the previous reaction with N,N'-diisopropyl amidine sulfur radical acetic acid to obtain solution(A), and adding the solution(A) to aqueous solution of 7-ACA dropwise for reaction to obtain the target product. The cefathiamidine compounds prepared by the method have the advantages of higher purity and yield, low-priced raw materials, simple synthesis process, simple equipment and easy separation and purification of products.

The invention discloses a simulated moving bed reaction and regeneration device for solid acid alkylation and a raw material reaction and catalyst regeneration method. The device comprises a raw material and product zone, a regeneration material zone, a rotary valve and a counter-current simulated moving bed reactor. Under control of the rotary valve, a raw material in the raw material and product zone is introduced into the counter-current simulated moving bed reactor for an alkylation reaction, a product produced in the counter-current simulated moving bed reactor returns to the raw material and product zone, a catalyst regeneration medium in the regeneration material zone is introduced into the counter-current simulated moving bed reactor for catalyst regeneration, and a material produced after catalyst regeneration in the counter-current simulated moving bed reactor returns to the material regeneration zone. By means of the device and the method, the continuous and stable operation of the solid acid alkylation reaction, product extraction, moderate catalyst generation and deep catalyst generation is achieved, the operation cycle and the service life of the device are prolonged, and the operation economy of the device is greatly improved.

The invention discloses a technological method for synthesizing ketoxime. In a system of a carbonate water solution, a titanium silicalite molecular sieve is adopted as a catalyst, and ketone, ammonia and hydrogen peroxide react to generate ketoxime; the pH value of the reaction system is monitored in real time in the reaction process to judge the reaction process and determine the optimal reaction ratio. The pH value in the reaction system is monitored to judge the reaction process and determine the optimal reaction ratio, and then the pH value of the system is adjusted through a carbonate water solution in order to increase the reaction rate and the conversion rate of ammonia.

The invention relates to a process of preparing dicamba by 3, 6-dichlorosalicylic acid, and belongs to the technical field of herbicide dicamba preparation processes. The process includes the steps of methylation reaction, saponification, methanol recovery, acidizing reaction and the like. By means of saponification with specific process parameters, efficiency can be greatly improved, saponification time is shortened, wastewater quantity is remarkably reduced, and equipment utilization rate is increased.

The invention provides a novel route for cefathiamidine compounds. The new route comprises the following steps of: reacting N,N'-diisopropyl thiourea and sodium bicarbonate, adding 2-bromacetic acid in the mixture for reaction, adding triphosgene and triphenylphosphine oxide serving as catalysts, reacting the product of the previous reaction with N,N'-diisopropyl amidine sulfur radical acetic acid to obtain solution(A), and adding the solution(A) to aqueous solution of 7-ACA dropwise for reaction to obtain the target product. The cefathiamidine compounds prepared by the method have the advantages of higher purity and yield, low-priced raw materials, simple synthesis process, simple equipment and easy separation and purification of products.

The invention relates to a preparation method of important intermediate 2-[3-cyan-(2-isobutoxy) phenyl]-4-methyl-5-thiazolecarboxylate of febuxostat which is a new generation of xanthine oxidase inhibitor. The method takes 2-(4-nitrobenzophenone)-4-methyl-5-thiazolecarboxylate as material to have cyanation reaction and isobutylation reaction under the existence of dimethyl sulfoxide to produce 2-[3-cyan-(2-methylpropoxy) phenyl]-4-methyl-5-thiazolecarboxylate. The material source is wide, the intermediate is easy to prepare, the reaction condition is mild, the operation is easy and the production cost is low, therefore, the preparation method is suitable for industrial production.

The invention provides an N-protection-3, 5-disubstituted indole derivative, its preparation method and application. The N-protection-3, 5-disubstituted indole derivative can be used for preparing the anti-migraine drug Almotriptan. Compared with reported literature, the preparation method provided in the invention has the advantages of: cheap and easily available raw materials, mild reaction conditions, simple operation, greatly shortened reaction steps, quality controllable and high purity product, less pollution of ''three wastes'', and easy industrial production. The N-protection-3, 5-disubstituted indole derivative is a free alkali or salt of the compound having a structural general formula (I).

The invention discloses a method for preparing 2-cyclohexenone compound, which comprises the following steps: under the action of a metallic catalyst MYn.L, 1, 6-heptadiyne compound showed in formula (I) taken as a raw material is reacted in an ionic liquid at a temperature of between 0 and 150 DEG C; after the reaction liquid is treated, the 2-cyclohexenone compound showed in formula (II) is prepared; and at the same time, the ionic liquid fixed with the metallic catalyst can be recycled. The method has the advantages of simple and reliable operation, high yield and selectivity, repeated recycling and use of the noble metal catalyst, environmental protection, and the like. Because the cyclohexenone compound is a good raw material for synthesizing medicines, pesticides and chemical products, the method has wide industrial application prospect.

The invention discloses a biodiesel hydrodeoxygenation technique. The technique is characterized by adopting a fixed-bed reactor, wherein the fixed-bed reactor is filled with a hydrodeoxygenation catalyst, and the catalyst comprises a support and an active component. The support is MCM-41 doped with heteroatom Cu<2+> in a synthetic skeleton structure. The active component is a mixture of dimolybdenum nitride Mo2N, tungsten nitride W2N, molybdenum carbide Mo2C and tungsten carbide WC. The catalyst also contains a catalytic aid, and the catalytic aid is a mixture of TiO2, CeO2, V2O5 and NbOPO4. The reaction conditions of the fixed-bed reactor are as follows: the reaction temperature is 300-450 DEG C, the hydrogen pressure is 2.5-3.5 MPa, the hydrogen / oil volume ratio is 500-800, and the volumetric space velocity is 1.0-2.5 h<-1>. When the technique is used for biodiesel hydrodeoxygenation, the deoxygenation rate can be up to 99.8% or above, and the catalytic activity after 500-hour continuous operation does not obviously decrease.

The invention provides a preparation method of an anti-migraine drug Almotriptan. The method includes the following steps of: taking an N-protection-3, 5-disubstituted indole derivative as a starting material, removing the N-protection group in a solvent and in the presence of a catalyst, and then collecting Almotriptan from the reaction system. The method provided in the invention for preparing Almotriptan has the advantages of safety, mild reaction condition, easy operation, high yield, cheap and easily available raw materials, easy ''three wastes'' treatment, and convenient industrial implementation. The N-protection-3, 5-disubstituted indole derivative has a chemical structural formula as shown in formula (I).

The invention provides an N-protection-3, 5-disubstituted indole derivative, its preparation method and application. The N-protection-3, 5-disubstituted indole derivative can be used for preparing the anti-migraine drug Almotriptan. Compared with reported literature, the preparation method provided in the invention has the advantages of: cheap and easily available raw materials, mild reaction conditions, simple operation, greatly shortened reaction steps, quality controllable and high purity product, less pollution of ''three wastes'', and easy industrial production. The N-protection-3, 5-disubstituted indole derivative is a free alkali or salt of the compound having a structural general formula (I).