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485 results about "Diethyl malonate" patented technology

Diethyl malonate, also known as DEM, is the diethyl ester of malonic acid. It occurs naturally in grapes and strawberries as a colourless liquid with an apple-like odour, and is used in perfumes. It is also used to synthesize other compounds such as barbiturates, artificial flavourings, vitamin B₁, and vitamin B₆.

Method for preparing 2-para octylphenyl ehtyl-2-amino propanediol

The invention provides a method to prepare a compound method, including the steps: ethylbenzene and capryl chloride make Friedel-Crafts reaction to generate p-capryl chloroethylbenzene; convert capryl chloroethylbenzene under the action of sodium iodide into p-capryl iodoethylbenzene; p-capryl iodoethylbenzene and acetylamino diethyl malonate condense under the action of alkali to generate 2-(p-capryl phenethyl)-2-acetylamino diethyl malonate; or p-capryl iodoethylbenzene makes elimination reaction under the action of alkali to generate p-capryl styrene, which together with acetylamino diethyl malonate condenses under the action of alkali into 2-(p-capryl phenethyl)-2- acetylamino diethyl malonate; a compound is reduced into 2-[4-(1-hydroxyoctyl) phenethyl-]2- acetylamino propylene alcohol; the other coumpound makes hydrogenolysis to obtain 2-(p-octyl phenethyl)-acetylamino propylene alcohol; make alkali hydrolyzation and then acidifies them into salt, so as to obtain it. It also provides a method to prepare intermediate in the above preparing course.
Owner:马启明

Magnetic water-soluble fullerene, and preparation method and application thereof

The invention relates to a magnetic water-soluble fullerene, and a preparation method and application thereof. The invention effectively solves the problems of low water solubility, low compatibility and poor targeting property of the fullerene. The method comprises the following steps: dissolving fullerene in toluene, adding sodium hydride and diethyl bromomalonate, stirring in a nitrogen protective atmosphere to remove sodium hydride and toluene, adding the dried diethyl-bromomalonate-substituted fullerene into the toluene, hydrolyzing until the toluene phase becomes colorless, adding concentrated hydrochloric acid, filtering to obtain a filter cake, removing insoluble substances and methanol, drying to obtain malonic-acid-substituted fullerene, dissolving in an ethylene glycol and di-acetal mixed solvent, adding sodium acetate and ferric iron salt to react, washing, drying to obtain ferroferric-oxide-carried fullerene, carrying out ultrasonic dispersion on the ferroferric-oxide-carried fullerene, amino water-soluble substance and EDC.HCl in phosphate, reacting in a dark place, carrying out vacuum filtration, and drying to obtain the magnetic water-soluble fullerene. The magnetic water-soluble fullerene has the advantages of favorable magnetic targeting propertt, strong water dispersity, low toxicity for organisms, high physical and chemical stability, good quality and low cost.
Owner:ZHENGZHOU UNIV

Preparation technology of water-solubility fluorescent carbon quantum dot

The invention discloses a preparation technology of a water-solubility fluorescent carbon quantum dot. The preparation technology comprises the following steps of: adding glucose to a dried florence flask containing diethyl malonate according to a proportion of 5g/20 milliliter, cooling to a room temperature after refluxing at 140-160 DEG C, collecting brown precipitates, and carrying out vacuum drying for 2 hours at 100-120 DEG C; and dissolving the dried precipitates in a 10ml of distilled water, carrying out high-speed centrifugal seperation (1200r/m) to remove a trace amount of precipitates, and cooling and drying the centrifuged solvent, thus obtaining a target fluorescent carbon point. The preparation technology is simple in the entire flow operation, low in cost and high in feasibility, can be used for macro-production of the water-solubility fluorescent carbon quantum dot and meets industrialization application; the particle size of the product is uniform and is mainly in the range of 2-4 nanometers; the fluorescence quantum efficiency is high and can reach 24%; added ions do not need to be removed by dialysis during after treatment as no positive ions are added in the preparation process; and the water-solubility fluorescent carbon quantum dot has good water-solubility and can be widely applied in practical application.
Owner:MINNAN NORMAL UNIV

Preparation method of 2-methyl-3-bromopyridine

The invention belongs to the field of organic synthesis and particularly relates to a preparation method of 2-methyl-3-bromopyridine. The preparation method includes the following steps that 1, diethyl malonate reacts with alkali metal to generate salt, then a methylbenzene solution of 2-chlorine-3-nitropyridine is added dropwise to be conducted a condensation reaction, and the 2-methyl-3-nitropyridine is obtained through decarboxylation under an acidic condition; 2, under the catalysis of Pd/C, methanol serves as a solvent, a hydrogenation reduction and suction filtration are conducted on the 2-methyl-3-nitropyridine, filtered liquid is condensed, and 2-methyl-3-aminopyridine is obtained; 3, the 2-methyl-3-aminopyridine reacts with acid to generate salt, the cooling is conducted to enable the temperature to be in -10 DEG C-0 DEG C, bromine is added dropwise, after the addition, then a sodium nitrite solution is added dropwise, after addition, pH of the solution is adjusted to be alkaline, then extracting, drying and concentration are conducted, and the 2-methyl-3-bromopyridine is obtained. The preparation method of the 2-methyl-3-bromopyridine has the advantages that the reaction condition is moderate, the operation is easy, the post-processing is simple, enlarged production is easy, and the preparation method is very suitable for industrial production; the catalysis effect is good, and the reaction yield ratio is high; the price of the raw material is low, and the production cost is low.
Owner:洪帅金

Synthesizing technology of donepezil hydrochloride

The invention relates to the synthesis of donepezil hydrochloride. According to a published patent CN100436416 which relates to a synthesizing technology of donepezil hydrochloride, diethyl malonate is adopted as an initial material, and 5 steps of condensation, reduction, substitution, ring-closing, and decarboxylation are adopted, such that donepezil hydrochloride is obtained. The steps are complicated, and the total yield is not high. The invention aims at providing a donepezil hydrochloride synthesizing technology employing 5,6-dimethoxy-2-(4-pyridyl)methylene-indan-1-one as an initial material. The technical scheme of the invention comprises steps that: the raw material is processed through hydrogenation, cooling, and filtration; a solvent glacial acetic acid is removed by reduced-pressure distillation; the obtained solution is processed through neutralization and extraction; a filtrate is condensed, and is dissolved in dichloromethane; the mixture is stirred, and triethylamine and benzyl chloride are dropped into the solution; the solution is cooled, the filtrate is condensed, and the obtained material is dissolved in methanol; a methanol solution of hydrogen chloride is dropped into the solution, such that a salt is formed; and the solution is cooled, crystallized, filtered, and dried, such that donepezil hydrochloride is obtained. The synthesizing technology provided by the invention is advantaged in short synthetic route and improved total yield. With the technology, the donepezil hydrochloride content is higher than 99%. The technology is suitable for industrialized productions.
Owner:陕西方舟制药有限公司
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