509results about How to "Short reaction path" patented technology

The invention relates to a method for preparing 2-bromine-4, 5-dimethoxy benzene propane nitrile, which consists of steps: 3-4-dimethoxy benzaldehyde and bromine are dissolved in acetic acid to be reacted; when solid is precipitated, 2-bromine-4, 5-dimethoxy benzaldehyde crystal is obtained through suction filtration; the crystal and acetonitrile are dissolved in organic solvent; after a catalytic reaction, yellow solid is precipitated, cooled, extracted and dried to get 2-bromine-4, 5-dimethoxy cinnamonitrile solid which is then dissolved in methanol with reducing agent and is reduced to obtain 2-bromine-4, 5-dimethoxy benzene propane nitrile after a reflux reaction; or the obtained 2-bromine-4, 5-dimethoxy cinnamonitrile is reduced with hydrogen under the catalysis of palladium-charcoal to get 2-bromine-4, 5-dimethoxy benzene propane nitrile. The 2-bromine-4, 5-dimethoxy benzene propane nitrile prepared by the invention has high yield coefficient; original raw materials of the preparation method are easy to get; the price is low; the reaction operation is simple; the reaction route is short; and the method is easy for industrialization production.

The invention discloses a preparation method of p-methylsulfonyl benzaldehyde, which takes p-chlorobenzaldehyde as starting material, and comprises the steps of: enabling the starting material to have reaction with sodium methyl mercaptide water solution under the action of phase transfer catalyst to obtain p-methylthio benzaldehyde; and oxidizing the p-methylthio benzaldehyde by hydrogen peroxide under the action of sulfuric acid and oxidation catalyst to obtain the p-methylsulfonyl benzaldehyde. The preparation method is easy in obtaining of raw material of the p-methylsulfonyl benzaldehyde, simple and convenient in operation, low in cost, high in yield and suitable for industrial production.

The invention discloses a synthetic method of 4-(2,2-difluoro-1,3-benzodioxole-4-yl)pyrrole-3-nitrile. The method comprises the following steps of: preparing an intermediate 2,2-difluorobenz-1,3-dioxole through reacting catechol with dibromodifluoromethane, and preparing an intermediate 2-cyano-3-(2,2-difluorobenz-1,3-dioxole-4-yl)-2-acrylate. The fludioxonil prepared by the synthetic method provided by the invention has the purity of more than 99.0% and the total yield of more than 45.0%; the synthetic method has the advantages of cheap and easily available raw materials, simple process, high product yield in each step, good purity, low production cost, applicability to batch industrial production and the like.

The invention provides a novel method for preparing lapatinib. Specifically, the method for preparing a compound shown in a formula I or medicinal salt thereof comprises the following steps of: (1) reacting a compound shown in a formula II or salt thereof and a compound shown in a formula III at the first temperature; (2) reacting a reaction product obtained in the step (1) and a compound shown in a formula IV in reaction liquid in the step (1) at the second temperature; (3) adding a reducing agent into reaction liquid in the step (2) to reduce the reaction product obtained in the step (2) to obtain the compound shown in the formula I; and optionally (4) reacting the compound shown in the formula I and obtained in the step (3) and acid to obtain medicinal salt of the compound shown in the formula I. The method is high in yield, and can overcome one or more disadvantages of the conventional method and the purity of a product is high.

The invention relates to a method for selective preparation of p-xylene and toluene from p-methylcyclohexene carboxaldehyde. The method comprises that p-methylcyclohexene carboxaldehyde undergoes dehydroaromatization and in-situ hydrodeoxygenation reactions at a temperature of 200-500 DEG C in the presence of a loaded metal catalyst to produce p-xylene and toluene. The raw material undergoes a reaction in a fixed bed reactor. The raw material goes through a catalyst bed layer through inert gas purging so that p-xylene and toluene are obtained. The method has simple processes and high desired product selectivity. Isoprene and acraldehyde as raw materials from biomass resources undergo a one-step reaction to produce a substrate. The method provides a novel method for preparing a fragrant chemical product directly from biomass.

The present invention discloses a method for synthesis of 2'-fluoro terphenyl liquid crystal. With the present invention, problems of more reaction steps, low yield, heavy environmental hazard, expensive catalysts, or hazard on the human body in the prior art are solved. The technical scheme of the present invention is that: a catalyst is added to an organic solvent of the raw material to carry out a suzuki coupling reaction to realize the synthesis of the 2'-fluoro terphenyl liquid crystal. According to the present invention, 4-bromo-3-fluoro iodobenzene, a phenyl boronic acid derivative and a base are adopted as raw materials, and are subjected to two suzuki coupling reactions in the solvent under the effect of the catalyst at the reaction temperature of 70-100 DEG C to obtain the 2'-fluoro terphenyl liquid crystal, wherein the times of the two suzuki coupling reactions are respectively 4-10 hours and 10-20 hours. The method of the present invention has advantages of simple process, mild conditions, low preparation cost, high yield, environmental protection, and strong practicability.

The invention relates to the field of drug synthesis and discloses a method for preparing 5,6,4'-trihydroxy flavone-7-0-D-glucuronic acid. The method is characterized by taking 5,6,7,4'-tetrahydroxy flavone as a raw material, adopting a brand-new synthetic route and carrying out acylation reaction, glycosylation reaction and two-step hydrolysis reactions, thus preparing high-purity 5,6,4'-trihydroxy flavone-7-0-D-glucuronic acid. The preparation method has the advantages of short synthetic route, low cost, high reaction yield and easiness in product purification, and is suitable for industrial production of 5,6,4'-trihydroxy flavone-7-0-D-glucuronic acid.

The invention discloses a preparation method of a sitagliptin intermediate represented by formula 1. The preparation method comprises the following steps: step A, carrying out a reaction of beta-ketonic ester 2 with a chiral amine to obtain a chiral enamine 3, wherein the chiral amine is R(+)-alpha-phenylethylamine or D-(-)-phenylglycinol; step B, reducing the chiral enamine 3 to obtain a compound 4; step C, carrying out catalytic hydrogenation of the compound 4 to remove a chiral auxiliary group, and thus obtaining a compound 5; step D, protecting amino of the compound 5 by Boc to obtain a compound 6; and step E, hydrolyzing the compound 6 to obtain beta-amino acid 1. The method has the advantages of cheap and easily obtained chiral raw materials, short reaction route, simple operation, mild reaction conditions, no special requirements on equipment, high yield, low cost and small environment protection pressure, and has relatively good industrial application and economic value.

The invention discloses a method for preparing DL-threonine chelated copper serving as a feed additive. The invention adopts a technical scheme of taking aminoacetic acid as raw material, allowing aminoacetic acid to react with basic copper carbonate to form glycine chelated copper and allowing glycine chelated copper to react with acetaldehyde to form DL-threonine chelated copper. Compared with the conventional method for preparing threonine chelated copper, the method of the invention has the following outstanding advantages that: 1) as threonine and threonine chelated copper are prepared from aminoacetic acid, the method is readily available in raw material, needs no threonine and is low in cost; 2) as the feed additive amino-acid chelated copper does not need separation, and DL-threonine copper is directly utilized, so over 50 percent of cost is reduced; and 3) the preparation of the DL-threonine chelated copper is performed at normal temperature under normal pressure and is short in reaction route, little in equipment investment and convenient for industrial production.

The invention provides a preparation method of a high-purity DOPO (9,10-dihydro-9-oxa-10- phosphaphenanthrene-10-oxide) derivative, and relates to a flame retardant in the field of chemical materials. According to the preparation method, CDOP (10-chloro-9,10-dihydro-9-oxa-10-phosphaphenanthrene) is used as a raw material and reacts with ethylene glycol under the action of a catalyst, wherein the reaction temperature is 10-200 DEG C, and the reaction time is 5 to 30 hours, so that a product with high optical purity can be directly obtained. The preparation method has the advantages that reaction routes are short, the product does not contain another two isomers, and the melting point of the product reaches up to about 300 DEG C. The high-purity DOPO derivative can be used as the flame retardant.

The invention discloses a preparation method of glufosinate-ammonium and derivatives thereof. The method comprises the following steps: (1) by using a substituted hydantoin and methylphosphonate compounds as a raw material, adding alkali, carrying out nucleophilic substitution reaction at the reaction temperature of 20-100 DEG C in a reaction solvent to obtain a hydantoin derivative, and tracing product generation condition by high performance liquid chromatography in the reaction process to judge the reaction endpoint, wherein the molar ratio of the methylphosphonate compounds, substituted hydantoin and alkali is 1:(1.0-5.0):(1.0-4.0); (2) carrying out reflux reaction for prepared hydantoin derivative prepared and an inorganic acid in water for 30-60 hours; after reaction, adding ammonia water to adjust the pH of the liquor to 12; spirally distilling to remove the solvent; adding absolute methanol for reflux for 30-60 minutes; filtering; spirally drying the mother liquor; adding methanol for recrystallization to obtain pure glufosinate-ammonium shown in formula (I) or derivatives thereof, wherein the molar ratio of the hydantoin derivative and inorganic acid is 1.0:(4.0-9.0).

The invention provides a preparation method for trenbolone acetic ester. In the preparation method, 17beta-hydroxy-estra-4,9-diene-3-keton as an initiative material (compound 2). The method sequentially comprises the following steps of: 1) esterifying 17-position hydroxyl and 3-position enol of the compound 2 to obtain 3,5(10),9(11)-estratriene-3,17beta-glycol diacetic ester (compound 3); 2) hydrolyzing 3-position enol ester of the compound 3 to obtain 17beta-hydroxy-estra-5(10),9(11)-diene-3-ketone acetic ester (compound 4); and 3) dehydrogenizing 5(10),9(11) conjugated double bond of the compound 4 by using dichloro dicyan quinone (DDQ) to obtain the trenbolone acetic ester (compound 1). The method plays an important role in preparation of medicines (such as finaplix, Revalor, Parabol 25 mg, Forplix, Toreter and the like) by using trenbolone acetic ester as the raw material medicine and has wide application prospect.

The invention relates to a method for preparing 4-methylbenzaldehyde from isoprene and acrolein. The method specifically comprises the following steps: enabling acrolein and analogues thereof to react with isoprene to carry out a Diels-Alder reaction at a proper temperature under the action of Lewis acidic ionic liquid to generate 4-methyl cyclohexene-3-formaldehyde and analogues thereof; by taking an organic solvent as a reaction medium and graphite oxide as a catalyst, carrying out a dehydrogenation reaction on 4-methyl cyclohexene-3-formaldehyde under proper temperature and pressure, and preparing 4-methylbenzaldehyde (4-methylbenzaldehyde, MBAD for short). According to the method disclosed by the invention, the isoprene and acrolein are taken as raw materials and are subjected to a simple two-step reaction to generate an aromatic target product with high additional value; the raw materials can be prepared from biomass resources, the product is cheap, regenerative, convenient to operate and high in yield, and a novel method for directly preparing chemicals from biomasses is provided.

The invention discloses a new method for preparing solid lignin quaternary ammonium salt. Epichlorohydrin is added into tertiary amine, and a glycidyl quaternary ammonium salt intermediate is obtained after a reaction; on the condition that an initiating agent exists, the intermediate reacts with alkali lignin; then a reactant is added into a polarity organic solvent, and a precipitate is the solid lignin quaternary ammonium salt. According to the new method for preparing the solid lignin quaternary ammonium salt, the raw materials and reagents are easy to obtain, the reaction path is short, the reaction condition is moderate, and postprocessing is simple. The invention further discloses the application of the solid lignin quaternary ammonium salt obtained through the method.

The invention discloses a preparation method of baricitinib and belongs to the technical field of drug preparation. The method comprises that 4-chloropyrrolopyrimidine as a starting raw material is subjected to amino protection, the product, hydrazine hydrate and acrolein undergo a one-pot displacement reaction and a cyclization reaction to produce an intermediate 4, a starting raw material 1, 3-dibromoacetone and ethylene glycol undergo a condensation reaction to produce an intermediate 5, the intermediate 5 and ethyl sulfonamide undergo a condensation reaction to produce an intermediate 6, the intermediate 6 and diethyl cyanomethylphosphonate undergo a reaction under action of a strong base to produce an intermediate 7, the intermediate 4 and the intermediate 7 undergo an addition reaction under the action of a catalyst, and the product undergoes a deprotection reaction to produce a desired product 1. The preparation method needs mild reaction conditions. The intermediate purification method is simple and easy, has a total yield of 40-55% and is suitable for industrial production.

The invention relates to a method for selective preparation of p-xylene from 4-methyl-3-cyclohexene-1-carbaldehyde. Specifically speaking, the method comprises the following steps: dehydrogenation and aromatization as well as in-situ hydrogenation and deoxidation reactions of 4-methyl-3-cyclohexene-1-carbaldehyde are carried out in the effects of a tungsten-based catalyst at 250-450 DEG C, and p-xylene is prepared. The method can be carried out in a fixed bed reactor, a fluidized bed reactor or a moving-bed reactor separately, and reaction raw materials are directly injected into a reactor by an injection pump, or the reaction raw materials pass a catalyst bed layer with purging of carrier gas in order to obtain p-xylene. The process has the advantages of simple reaction process, and high selectivity of target product; the substrates can be obtained by Diels-Alder reaction from isoprene and acrolein which are derived from biomass resources and are used as raw materials, and mole yield of p-xylene reaches 90%. Compared with the prior art, the method has the advantages of cheap raw materials and wide sources, economy of reaction carbon atoms, and the like; the tungsten-based catalyst is cheap, and a new route for preparing p-xylene from biomass is provided.

The invention relates to a method to compound 2, 5-dichlorophenol by catalytic oxidation. The feature is that 1, 4-dichlorobenzene adopts heteropolyacid, heteropolyacid salt or the load of heteropolyacid as catalyst, uses H₂O₂ as oxidant to take catalytic oxidation reaction solution. After reacting, decreasing pressure and distilling, the 2, 5-dichlorophenol would be gained. The method has short reaction way, simple technology, and is benefit to environment protection.

The invention discloses a synthetic method of cefoxitin acid. Cephalotin acid used as a raw material reacts with prepared tert-butyl hypochlorite in the presence of sodium methylate to obtain a methoxy substance; the methoxy substance is subjected to a hydrolysis reaction and salt formation is carried out in the presence of benzathine to obtain methoxy cefalotin benzathine; methoxy cefalotin benzathine reacts with CSI, and hydrolysis is carried out to obtain a cefoxitin acid crude product; and the cefoxitin acid crude product undergoes the step of recrystallization to finally prepare cefoxitin acid. The synthetic method is simple to operate and is low-cost. By the synthetic method, quality and total yield reach 95.8%. The produced cefoxitin acid is a white solid powder, and purity of the product reaches more than 99.0%. The product has good quality and is suitable for industrial production.

The invention discloses a synthesis method of tapentadol. The method includes taking 1-dimethylamino-2-methyl-3-pentanone as a starting material, obtaining 3-bromine-N,N-2-trimethylpentyl-1-amine after reduction and halogenation reactions, then performing a coupling reaction with a metal reagent under the catalysis of transition metal to obtain 3-(3-methoxyphenyl)-N,N-2-trimethylpentyl-1-amine, and obtaining the tapentadol after demethylation and resolution. The synthesis method has the advantages that the raw materials are low in cost and easy to obtain, the steps are few, the operation is simple, and the cost can be effectively reduced; highly purified tapentadol can be obtained through the method, and the liquid phase purity and ee value of hydrochloric acid tapentadol obtained after salification can reach above 99%; and the method can be applied to the medical field.

The invention discloses a novel method for synthesizing 3-oxetanone. 1,3-dichloroacetone is taken as an initial raw material, a key intermediate is obtained through hydrolysis and ring-closing one-pot reaction, the yield is over 80 percent, the 3-oxetanone is obtained through deprotection, the total yield is over 50 percent, and the route is shown in the specification. The method has the advantages that: the use of a dangerous chemical reagent is avoided, the reaction route is shortened, the reaction cost is reduced, the reaction yield is improved, the method is easy to operate, and the industrialized production can be realized.