14results about How to "Short route" patented technology

The invention relates to a preparation method of a nerofloxacin intermediate 2, 4-difluoro-3-methoxy-1-benzoic acid. The invention further relates to a preparation method of the nerofloxacin intermediate 2, 4-difluoro-3-methoxy-1-benzoic acid. Specifically, the invention discloses a preparation method for preparing 2, 4-difluoro-3-methoxy-1-benzoic acid in the presence of a non-nucleophilic strong alkali reagent, the 2, 4-difluoro-3-methoxy-1-benzoic acid reacts with methyl peroxide in the presence of a non-nucleophilic strong alkali reagent, a methoxy substitution reaction is directly carried out, and then the 2, 4-difluoro-3-methoxy-1-benzoic acid is prepared in the presence of magnesium metal and carbon dioxide. Reaction conditions are mild, and industrial production is very easy.

The invention relates to a synthesis method of (4-chlorphenyl) (4-hydroxy-3, 5-dimethoxyphenyl) ketone, belongs to the field of organic chemical synthesis, and provides a method for solving the problems of high cost, low yield and more byproducts in the existing preparation method, and the method comprises the following steps: 1) reacting a compound shown as a formula I with an acyl chloride substance under the protection of nitrogen to obtain a compound II; 2) mixing the compound shown in the formula II with alkali, dropwise adding a Grignard reagent, and carrying out Grignard reaction to obtain a compound shown in a formula III; and 3) demethylating the compound in the formula III under the action of Lewis acid to obtain a compound in a formula IV. The technical scheme provided by the invention has the beneficial effects that the method for synthesizing (4-chlorphenyl) (4-hydroxy-3, 5-dimethoxyphenyl) ketone is novel in process route, the total yield is greater than 50%, and the method has the characteristics of short route, high chemical purity, easiness in production and the like.

This invention discloses a chemical-biological fusion method for cholesterol synthesis. Using plant-derived 21-hydroxy-20-methylpregn-4-en-3-one, also known as bis(2-hydroxy-2-yl)-3-one (BA), as a raw material, cholesterol is synthesized through a four-step reaction involving sulfonation, acetylation, enzymatic hydrolysis and reduction, and Grignard coupling. Addressing the drawbacks of traditional animal-derived cholesterol, which carries unpredictable risks of pathogenic bacteria and viruses, this invention uses plant-derived steroidal raw material BA to synthesize cholesterol. This method not only offers high safety, avoiding the risk of pathogenic bacteria and viral infections, but also utilizes the tandem catalysis of esterase and carbonyl reductase during synthesis, along with coenzyme regeneration, to obtain key intermediates with high stereoselectivity and in a safe and clean manner. This significantly shortens the cholesterol synthesis route, increases efficiency, simplifies operation, minimizes solvent recycling losses, reduces waste, and allows for mild reaction conditions. This method is safe, economical, and suitable for industrial production.

An amide-containing aromatic diamine has the following structural formula: where Ar is a group with an aromatic ring structure. The preparation method includes the following steps: (1) mixing and reacting components including aromatic diamine, p-nitrobenzoic acid, alkyl phosphoric anhydride and polar aprotic organic solvent; (2) adding carboxylic acid and halogen-free quaternary ammonium salt to the product obtained in step (1) to obtain a mixed solution, which is placed in the cathode cell of an H-type electrolytic cell; the anode cell and the cathode cell are separated by a Nafion membrane; adding the same polar aprotic organic solvent and halogen-free organic electrolyte as the cathode cell to the anode cell of the H-type electrolytic cell, and adding a metal ion-free reducing agent; and conducting the reaction by electrolysis; (3) purifying the cathode reaction solution obtained in step (2) by post-treatment to obtain the amide-containing aromatic diamine. The yield, purity and whiteness of the amide-containing aromatic diamine are higher.

The invention belongs to the technical field of friction material processing, and discloses forming equipment for friction material processing. The forming equipment for friction material processing comprises a placing table and is characterized in that a driving mechanism is arranged in the placing table, the driving mechanism comprises a moving plate, the moving plate is arranged in the placing table, a clamping mechanism and a processing mechanism are arranged in the moving plate, the driving mechanism comprises a linear rail, and the linear rail is arranged on the clamping mechanism. The linear rails are fixedly installed on the inner walls of the front side and the rear side of the containing table. According to the forming equipment for friction material machining, through the design of the driving mechanism, the time spent on production and machining on multiple pieces of equipment in the past is shortened, the machining and production route is shortened, certain working efficiency is improved, the stability in the hot pressing process and the moving process is improved in cooperation with the clamping mechanism, and the machining efficiency is improved. And the situation that shaking occurs or firm clamping cannot be achieved is avoided, and the production and machining quality is improved.

The application discloses givinostat and a synthesis method thereof, wherein compound 1 is used for synthesizing compound 2 in step 01; compound 3 is used for synthesizing compound 4 in step 02; compound 4 is used for synthesizing compound 5 in step 03; compound 5 is used for synthesizing compound 6 in step 04; and compound 6 and compound 2 are used for synthesizing givinostat in step 05. After optimization, the yield of compound 1 to compound 2 reaches more than 80 %, raw materials and reagents used in the reaction are cheap and easy to obtain, and the preparation cost is very low; only four steps are needed from compound 3 to the target product, the route is short, and the operation is simple; and after optimization, the total yield of compound 3 to the target product reaches more than 40 %, the yield is high, and the preparation cost is significantly reduced.

The present application relates to a kind of devices and refining methods for removing acetal in ethanol, device includes the light tower (2) of removal, acetal removal tower (3) and refining tower (4) connected in sequence by pipeline, the light tower (2) of removal is used to separate out light component in the system to be separated, the acetal removal tower (3) is used to separate out acetal, ethyl ester in the system to be separated, the refining tower (4) is used to separate out ethanol rectification and purify in the system to be separated.Compared with prior art, the present application is developed by special acetal removal tower, acetal is removed by using the method of negative pressure rectification, so that its content is reduced to 150ppm below, meet the quality requirements of high-purity ethanol.

The invention provides a synthesis method of (3R, 4S)-3-methyl-2-oxa-8-azaspiro [4.5] decane-4-amine hydrochloride (compound I), and the synthesis route is as follows: # imgabs0 #, and X is halogen. The preparation method has the advantages of short synthesis steps, single reaction product configuration, avoidance of chiral resolution in post-treatment and high yield, and an efficient synthesis method is provided for synthesis of the compound.

The application belongs to the field of pharmaceutical chemical synthesis, and particularly relates to a preparation method of a varenicline intermediate. The method comprises the following steps: 1) in the presence of an organic solvent A, a compound of formula 4 is used as raw material, ammonium acetate and a reducing agent are added, and a compound of formula 3 or a salt thereof is obtained through reaction; 2) in an organic solvent B, the compound of formula 3 or the salt thereof is reacted with trifluoroacetic anhydride or trifluoroacetic ethyl ester under the action of a base to obtain a compound of formula 2; and 3) in the presence of a solvent C and a catalyst, the compound of formula 2 is subjected to nitration reaction with a nitrating agent to obtain a compound of formula 1. The application solves the problems of the prior art, such as complicated steps, low atom utilization rate, high cost and the like, provides a novel route, directly introduces an amino group, does not need to be deprotected, has good atom economy, has mild reaction conditions, is simple in post-treatment, and is suitable for industrial production.

The present application provides an intermediate compound and a preparation method therefor and an application thereof. The intermediate compound has the following structural formula (I). By using the intermediate compound of the present application, dedrogesterone can be conveniently synthesized only by performing AB ring double bond construction and side chain modification, the total yield is high, and the route is short.

The invention provides an efficient preparation method of tetrahydrofuran type lignan Sumatranin A. The efficient preparation method specifically comprises the following steps: removing methyl protection from asaraldehyde to obtain a compound 1; performing benzyl protection to obtain a compound 2; carrying out continuous Wittig reaction to obtain a compound 3; reacting SN2 among molecules to obtain a cyclization precursor 4; an intermediate 5 is obtained through Ni catalysis series cyclization; removing benzyl protection to obtain a compound 6; and finally, carrying out ring closing under an acidic condition to obtain the tetrahydrofuran type lignan Sumatranin A. The preparation method has the three characteristics of high yield, low cost and short route; the total synthesis of the tetrahydrofuran type lignan Sumatranin A racemate serving as a natural active medicine is realized; good popularization and application prospects are realized.

The invention belongs to the technical field of drug synthesis, and particularly relates to a preparation method of a ticagrelor intermediate, which comprises the following five steps: S1, preparing an intermediate II; s2, preparing an intermediate III; s3, preparing an intermediate IV; s4, preparing an intermediate V; and S5, preparing an intermediate VI. Compared with a multi-step and complex synthesis process in the prior art, the method has the advantages that the route of the ticagrelor key intermediate V is greatly shortened, the synthesis process of the intermediate V is simplified, the production efficiency and the yield are remarkably improved, the production period is shortened, the raw material consumption and the generation of byproducts are reduced, and the requirements of industrial production are met.

The invention discloses a bicyclo [2.2. 1] heptanone derivative as well as a synthesis method and application thereof. The invention relates to a bicyclo [2.2. 1] heptanone derivative, which has a structure shown as a formula IV, and in the formula IV, R1 is aryl or heteroaryl; r2 can be alkyl, ester group, CN or amide; and R3 is methyl, OTBS or phenyl. The invention provides a novel method for preparing the electroluminescent material monomer I. The preparation method of the electroluminescent material monomer I provided by the invention only needs four steps. Compared with the prior art, the method provided by the invention has the advantages of short route, simple and easily available raw materials, easy reaction control, avoiding of the use of a noble metal catalyst, reduction of the reaction cost, and high economic value. # imgabs0 #

The invention provides a preparation method of bepedioic acid and an intermediate thereof, the preparation method of the bepedioic acid comprises the following steps: reacting a compound 4 with a compound 5 in the presence of alkali to obtain a compound 6, and hydrolyzing the compound 6 and removing a hydroxyl protecting group to obtain the bepedioic acid, and the reaction formula is shown in the specification. The preparation method of the bepedioic acid is short in route, low in cost, high in yield of each step of reaction, few in by-products and suitable for industrial large-scale production.