32results about How to "Avoid purification steps" patented technology

The invention discloses a method for synthesizing azoxystrobin (a compound I) and a key intermediate thereof, namely 2-{2-[6-(2-cyanophenoxy)pyridine-4-yl-oxo]phenyl}-3,3-dimethoxymethyl propionate (a compound V). The method comprises two steps of: performing a coupling reaction of 2-(2-hydroxyphenyl)-3,3-dimethoxymethyl propionate (II), 2-cyanophenol (III) and 4,6-dichloropyrimidine (IV) to form the 2-{2-[6-(2-cyanophenoxy)pyridine-4-yl-oxo]phenyl}-3,3-dimethoxymethyl propionate (the compound V); and transforming the compound V into the azoxystrobin (the compound I) under the action of a catalyst B. In the method, two coupling reactions are performed in the same reactor (one-pot method), so that the using amount of alkali and a solvent is greatly reduced, the reaction time sequence is short, the total yield is high, the aftertreatment is simple and convenient, and the method is suitable for industrialized production.

The invention provides a preparation method of a water-soluble nitrogen-phosphorus co-doped carbon quantum dot capable of exciting emission wavelength dependence concentration. The preparation method comprises the following steps: preparing a cane sugar precursor solution; mixing the cane sugar precursor solution and strong phosphoric acid according to the volume ratio of 1 to (5 to 3) to obtain a first mixed solution; heating the prepared first mixed solution to obtain a brown solution; placing the brown solution in ice-water bath, and mixing the brown solution with ethylenediamine according to the volume ratio of 5 to (1 to 5) to obtain a second mixed solution, filtering the second mixed solution to obtain a filtrate; dialyzing the filtrate to obtain dialysate; evaporating the dialysate to obtain the water-soluble nitrogen-phosphorus co-doped carbon quantum dot. The preparation method of the water-soluble nitrogen-phosphorus co-doped carbon quantum dot has the advantages of abundant and low-cost carbon sources, simple preparation process, freeness from pollution and toxicity in a whole preparation process, environmental-friendliness, capability of performing large-scale preparation.

The invention discloses a method for compounding a trans-hydroxyl active metabolite of loxoprofen. The method comprises the following steps: taking 2-[p(bromomethyl)phenyl]propionic acid as a raw material and carrying out resolution and methyl esterification, thus obtaining an intermediate, namely, a compound as shown in a formula 3; preparing a chiral assistant, namely, a compound as shown in a formula 7, by starting from L-phenylalaninol; firstly forming Schiff base as shown in a formula 9 by cyclopentanone and the chiral assistant, namely, the compound as shown in the formula 7, and then condensing the Schiff base as shown in the formula 9 and the intermediate, namely, the compound as shown in the formula 3, into an intermediate, namely, a compound as shown in a formula 11; carrying out acidic hydrolysis on the intermediate, namely, the compound as shown in the formula 11, and perfroming stereoselective reduction on cyclopentanone carbonyl groups, thus obtaining the trans-hydroxyl active metabolite, namely, a compound as shown in a formula TM. In a compounding path, raw materials can be easily obtained, the operation is convenient, environmental friendliness is realized, a separation means of column chromatography is prevented from being used, and the technical requirements of industrial large-scale production can be completely met.

The invention belongs to the field of organic synthesis, and concretely relates to a preparation method of a pyrazolyl acrylonitrile compound. A pyrazole carboxylic ester compound and p-tert-butylphenylacetonitrile are shown in a general formula (II), in the existence of an organic solvent and alkali, a reaction is carried out at 60-160 DEG C, 2-(4-(tert-butyl)phenyl)-1-(1-ethyl-3-methyl-1hydrogen-5-pyrazolyl)-2-cyan vinyl alcohol sodium salt or kali salt is obtained as shown in a general formula (III), a reaction is directly carried out between the obtained compound (III) and pivaloyl chloride at 60-160 DEG C, and the pyrazolyl acrylonitrile compound as shown in a general formula (I) is obtained. The method has the advantages of high yield of the target compound, low 'three wastes (waste gas, waste water and industrial residue)' discharge, and simple operation; and the method is suitable for large scale industrial production.

The invention belongs to the field enzyme catalysis, and particularly relates to a preparing method for L-2-aminobutyric acid. An enzyme catalyst and an enzyme activating agent are added into substrates, wherein the substrates are threonine and ammonium formate, the enzyme catalyst is threonine dehydratase, leucine dehydrogenase and formate dehydrogenase, and the enzyme activating agent is phosphate. According to the method for preparing the L-2-aminobutyric acid, the phosphate is used as the enzyme activating agent and used in cooperation with the leucine dehydrogenase, reaction intermediateproducts are rapidly converted, the catalytic rates of the threonine dehydratase, the leucine dehydrogenase and the formate dehydrogenase are mutually matched, the conversion efficiency of enzyme catalysis are improved, a stacking phenomenon of by-products is avoided, the yield of products is increased, and separation and purification of the products are more facilitated.

The invention provides novel 4H-1,2,4-triazole quaternary ammonium salt derivatives (shown as formula I), a preparing method thereof and applications of the derivatives especially as bromination catalysts, and belongs to the technical field of chemical medicine synthesis. Through adding the catalysts to reactions, the reaction activity is increased, reaction temperatures are reduced, the using amounts of bromination agents are greatly reduced, a column chromatography purification step is avoided, and the production cost is reduced. The derivatives are stable and controllable in quality, are suitable for commercial production of medicine intermediates, and make catalysis bromination more environmentally friendly.

The invention discloses a preparation method of three-dimensional porous carbon. The preparation method comprises the following steps: uniformly mixing a sugar source, dopamine and ammonium chloride,heating the obtained mixture from room temperature to 250-300 DEG C under the protection of an inert atmosphere, accelerating temperature rise to 800-1200 DEG C, and sintering at constant temperaturefor 2h-6h, and cooling to room temperature to obtain the self-supported three-dimensional porous carbon. By the preparation method, only one step of pyrolysis is performed without any additional stepsto obtain the self-supported three-dimensional porous carbon having a specific surface area of up to 2700 m<2>/g.

The present invention discloses recyclable polymeric catalyst of Formula I, for chlorination of organic acids and alcohols using chlorinating agents such as carbonyl chloride, oxalyl chloride or thionyl chloride,

wherein, ‘m’ on the pendent groups on polystyrene backbone can have values from 1 to 5 and R is the alkyl group ranging from C1 to C5.

The invention relates to a process for the preparation of organo-iodinated compounds as well as the preparation intermediates thereof. More specifically, the invention relates to a process for the preparation of organo-iodinated compounds useful as preparation intermediates in the synthesis of the contrast product ioversol.

The invention relates to the technical field of organic chemistry, in particularly to a method for synthesizing N-(carbobenzoxy) succinimide by one-pot two-phase method. The method comprises the following steps: adding purified water and hydroxylamine sulfate into a reaction container, dropwise adding liquid caustic soda while stirring, adding butanedioic anhydride in batches after dropwise addingis finished, and carrying out high-temperature vacuum dehydration under acid catalysis until no water is extracted so as to prepare an N-hydroxysuccinimide solution; adding an alkali into the N-hydroxysuccinimide solution to adjust the pH value of the reaction solution, controlling the temperature at 0-60 DEG C, and dropwise adding benzyl chloroformate; after dropwise adding, separating out an organic layer, concentrating to be dry, and recrystallizing to obtain an N-(carbobenzoxy) succinimide finished product. According to the method provided by the invention, separation and purifying stepsafter synthesis of the N-hydroxysuccinimide are avoided, and the N-(carbobenzoxy) succinimide is synthesized by directly adopting a two-phase method in a one-pot manner, so that the process cost is effectively reduced, the operation steps are reduced, and large-scale industrial production is facilitated.

A pharmaceutical formulation including a chelator-somatostatin receptor ligand and a transchelator is provided. The chelator-somatostatin receptor ligand is conjugated with a metal source or a radionuclide source, whereas the transchelator is capable of capturing free metal source or radionuclide source that is not conjugated to the chelator-somatostatin receptor ligand. By using such pharmaceutical formulation, the preparation of radiolabeled somatostatin analogues could be made more efficient, and is feasible for imaging of SSTR pathway-activated systems in cancers and neurological diseases.

The application relates to a process for the synthesis of a Near Infra-Red (NIR) fluorescent probe which is a cRGD-Cy5.5 conjugate of formula (I) known as DA364 comprising an aza-bicycloalkane based cyclic peptide labelled with a Cy5.5 dye moiety and used in the guided surgery of tumors and pathologic regions.

The invention belongs to the field of medicine synthesis, relates to a preparation method of a pyridine derivative, and in particular, relates to a preparation method of a formula III, wherein the preparation method comprises the steps: in the presence of alkali and a solvent, taking an N-heterocyclic carbene palladium (II) (Pd (II)-NHC) complex as a catalyst, and reacting a compound represented by a formula I with a compound represented by a formula II to obtain the compound represented by the formula III. The compound represented by the formula III generates a mixture containing a compound represented by the formula IV in the presence of a solvent and NBS, and then the compound represented by the formula IV is obtained through recrystallization. In addition, the invention also provides a preparation method of the compound represented by the formula I. In the presence of inorganic alkali and methanol, 2,4-dichloropyridine reacts to generate 2-chloro-4-methoxypyridine, then the 2-chloro-4-methoxypyridine and acid form salt, and then the salt is converted into high-purity 2-chloro-4-methoxypyridine. The N-heterocyclic carbene palladium (II) complex is used as the catalyst, so that the yield is remarkably improved, and the dosage of the catalyst is remarkably reduced; and the method overcomes the problems of large dosage (2%) of palladium catalysts and ligands, low atom utilization rate, high cost, high reaction temperature, long reaction time, low yield and the like in the prior art, and is more suitable for industrial production.