16 results about "Methyl malonate" patented technology

The invention belongs to the technical field of medicine detection, and particularly relates to dipropyl malonic acid prepared by a dimethyl malonate method and a detection method of impurities of the dipropyl malonic acid. According to the detection method provided by the invention, the dipropyl malonic acid prepared by a dimethyl malonate method and impurities thereof are detected through high performance liquid chromatography (HPLC) for the first time; the impurities comprise propyl malonic acid, 2-methyl-2-propyl malonic acid, 2-propyl-2-butyl malonic acid, propyl malonic acid monomethyl ester, 2-methyl-2-propyl malonic acid monomethyl ester, dipropyl malonic acid monomethyl ester, 2-propyl-2-butyl malonic acid monomethyl ester, propyl malonic acid dimethyl ester, dipropyl malonic acid monopropyl ester and propyl malonic acid dimethyl ester; the invention relates to a method for preparing dipropyl malonic acid, which is selected from one or more of dipropyl malonic acid dimethyl ester, dipropyl malonic acid methyl ester propyl ester and 2-propyl-2-butyl malonic acid dimethyl ester, and solves the problems of quality control and process evaluation of dipropyl malonic acid serving as an intermediate of sodium valproate prepared by a dimethyl malonate method.

This invention discloses a method for preparing a key intermediate of iodopyridine, using dimethyl malonate as a raw material, and sequentially undergoing dihydroxylation S1 → acetalization S2 → hydrolysis and acidification S3 → decarboxylation S4 to obtain iodopyridine. The raw materials of this invention are inexpensive and readily available in the market, and the reaction efficiency is high, improving the purity and yield of the product. Intermediates 1 and 2 obtained from the process do not require separation and purification operations and can be directly used in the next step of the reaction. The purification effect is significant, yielding intermediate products with a purity ≥99%, and the total yield of the five steps is as high as 65-70%, which is beneficial for large-scale production.

The present application relates to the preparation method of magnesium valproate shown in chemical structural formula I: under the action of potassium carbonate and PTC, dimethyl malonate is subjected to dipropylization with 1-chloropropane in DMF solvent to prepare dimethyl dipropyl malonate shown in formula III; III is subjected to hydrolysis reaction to prepare dipropyl malonic acid shown in formula II; II is uniformly mixed with magnesium oxide, and heated to prepare magnesium valproate shown in formula I by decarboxylation, and the total yield of magnesium valproate is not less than 90.0%; the preparation reaction is as follows: wherein, the PTC for dipropylization is selected from quaternary ammonium salt, the reaction temperature is 50-140 DEG C, the reaction time is 4.0-14.0 h; the hydrolysis temperature is 70-95 DEG C, the time is 2.0-4.0 h; the decarboxylation temperature is 140-158 DEG C, and the time is 3.0-5.0 h.

The invention relates to the field of biopesticides, in particular to a method for synthesizing sex pheromone of pinus tabulaeformis, which comprises the following steps: reacting 1-bromo-n-heptane (3) serving as an initial raw material with magnesium, and then reacting with (R)-epoxypropane (4) to obtain chiral alcohol 5; then reacting with paratoluensulfonyl chloride, and then reacting with dimethyl malonate to obtain malonate 7; carrying out sodium hydroxide catalytic hydrolysis and high-temperature decarboxylation to obtain an acid 8, and carrying out lithium aluminum hydride reduction and NBS bromination to obtain a chiral bromide 10; reacting with magnesium, and reacting with sulfonate 12 to obtain silyl ether 11; then carrying out TBAF deprotection to obtain chiral alcohol 13; and finally, reacting the chiral alcohol 13 with acetic acid to obtain acetic acid (2S, 3S, 7S)-3, 7-dimethyl-2-pentadecanol ester (1), and reacting the chiral alcohol 13 with propionic acid to obtain propionic acid (2S, 3S, 7S)-3, 7-dimethyl-2-pentadecanol ester (2). The method has the advantages of high total yield, low synthesis cost and the like.

The present application belongs to the field of gasoline additive, and particularly relates to an environment-friendly gasoline antiknock agent and a preparation method thereof. The antiknock agent comprises two newly designed modified compounds: 3,5-di-tert-butyl phenyl carborane carboxylate and 2-(dicyclohexyl phosphino)-1,2-oxaborinin-4-carboxylic acid iso-octyl ester. In the preparation, a cosolvent is first added into a reactor, and then the two modified compounds, polyisobutylene amine, isobutyl acetate and dimethyl malonate are sequentially added under an inert atmosphere. After mixing by continuous stirring, the temperature is raised, an antioxidant is added, and then stirring is continued. Finally, the product is obtained by cooling and filtering. The two modified compounds are prepared by condensation reaction of carborane carboxylic acid and steric phenol, esterification of oxaborinin carboxylic acid and iso-octanol, and then phosphination reaction. The antiknock agent does not contain metal elements, has biodegradable characteristics, can significantly improve the octane number of gasoline and reduce engine deposits and harmful gas emissions, and meets the green environmental protection requirements.

The invention belongs to the technical field of spice raw material synthesis, and particularly relates to a synthesis method of methyl cis-dihydrojasmonate, which comprises the following steps: dissolving 1-heptyne in toluene, discharging into a first reaction tank, adding a cobalt catalyst, and discharging 1-bromine-ethylene and carbon monoxide gas into the first reaction tank; adding triphenylphosphine into a first catalyst recovery tank, discharging catalyst precipitates, and carrying out sectional distillation to distill, cool and recover 1-heptyne; absolute methanol is discharged into the layering tank; dimethyl malonate is discharged into a second reaction tank, sodium methoxide is slowly added, an addition reaction is carried out at the temperature of-5 DEG C to 0 DEG C, and then heating is carried out for a decarboxylation reaction; 4-bromo-dihydrojasmonic acid methyl ester obtained by distillation is discharged into a third reaction tank; and discharging methyl jasmonate with alpha, beta-double bonds into a fourth reaction tank for reaction. By simplifying the steps, improving the recovery rate of the catalyst and realizing continuous production, the problems of high cost, low yield, low recovery rate of the catalyst and the like in preparation of the methyl cis-dihydrojasmonate in the prior art are solved.

This invention discloses a highly efficient method for synthesizing proxalutamide intermediates, belonging to the field of pharmaceutical synthesis technology. First, dimethyl malonate and 2-chloro-5-nitropyridine are used as raw materials, condensed in the presence of potassium carbonate to generate dimethyl 2-(5-nitropyridine-2-yl)malonate. This is then reacted with tert-butyl acrylate and acid-hydrolyzed to obtain 4-(5-nitropyridine-2-yl)butyric acid. After activation with N,N'-carbonyl diimidazole, it is coupled with aminoacetaldehyde dimethyl acetal to form N-(2,2-dimethoxyethyl)-4-(5-nitropyridine-2-yl)butyramide. Then, a cyclization reaction mediated by phosphorus pentoxide and methanesulfonic acid is used to generate crude 2-(3-(5-nitropyridine-2-yl)propyl)oxazole. After purification, the nitro group is reduced by catalytic hydrogenation, and finally, it reacts with 1,5-naphthalenedisulfonic acid to form a salt, yielding the proxalutamide intermediate. This method achieves highly efficient synthesis of proxalutamide intermediates.

The application discloses a preparation method of fluopyram, which comprises the following steps: step 1: in the presence of solvent 1 and a base, dimethyl malonate and 2,3-dichloro-5-trifluoromethyl pyridine are added to react, a salt reaction is carried out by adjusting pH, and 2-[3-chloro-5-(trifluoromethyl) pyridyl] dimethyl malonate potassium salt, namely intermediate 1, is obtained; step 2: o-trifluoromethyl benzoyl chloride, an organic base and chloromethylamine are added to react, and intermediate 2 is obtained; step 3: solvent 3, intermediate 1 and intermediate 2 are added to react, and intermediate 3 is obtained; step 4: water, a base, solvent 4 and intermediate 3 are added, pH is adjusted after reaction, and continuous reaction is carried out, and fluopyram is obtained. By adopting the preparation method, the yield of fluopyram is high, the purity is high, the reaction time is short, the reaction condition is mild, and the method is suitable for mass production.

This invention discloses a near-infrared photocatalytic coupling method for 2-benzene-1,2,3,4-tetrahydroisoquinoline compounds with nucleophiles. The method uses (MV)Bi₂I₈ type perovskite as a catalyst, wherein the organic portion of the catalyst, MV… 2+ The product is a methyl viologen cation. 2-Benzene-1,2,3,4-tetrahydroisoquinoline compounds are reacted with nucleophiles (dimethyl malonate, nitromethane, ethyl nitrosyl acetate) under light irradiation at room temperature or in air to undergo cross-dehydrogenation coupling reactions to obtain the corresponding product. This invention is simple to operate, operates under mild conditions, and uses readily available catalysts. It successfully achieves cross-dehydrogenation coupling between substrates using only near-infrared light, and yields high product yields.

The invention belongs to the technical field of separation of drug intermediates, and particularly relates to recovery and application of 2-methyl-2-propylmalonic acid. The method comprises the following steps: adding a polar solvent into a dipropylmalonic acid crude product prepared by a dimethyl malonate method, heating, pulping for a certain time, cooling, filtering and drying to obtain high-purity dipropylmalonic acid; and distilling the filtrate to recover the polar solvent to obtain the 2-methyl-2-propylmalonic acid as shown in the formula I. The HPLC (High Performance Liquid Chromatography) of the 2-methyl-2-propylmalonic acid is greater than 99.0% (Figure 1). The 2-methyl-2-propylmalonic acid is an intermediate for preparing the spices, namely the 2-methylpentanoic acid; and carrying out decarboxylation on the 2-methyl-2-propyl malonic acid to obtain the 2-methylvaleric acid.

The present application relates to the technical field of delta-lactone synthesis, in particular to a high-purity delta-lactone synthesis method, comprising the following steps: using potassium carbonate to catalyze Michael addition reaction of the active methylene functional group of dimethyl malonate and the alpha, beta-alkenyl functional group of 1-octene-3-ketone to generate intermediate product I; intermediate product I generates decarboxylation reaction under the catalysis of boric acid to generate intermediate product II; chiral ligand supported nickel catalyst catalyzes asymmetric hydrogenation reaction of the delta-carbonyl functional group of intermediate product II to generate chiral delta-hydroxyl functional group, and ester exchange reaction of the chiral delta-hydroxyl functional group and the ester functional group of intermediate product II to generate chiral delta-decalactone. The present application designs and synthesizes four chiral ligand supported nickel catalysts on one hand, and designs a new route capable of synthesizing chiral delta-decalactone with high optical purity on the other hand.

The invention discloses a preparation method of malononitrile, and belongs to the technical field of fine chemical engineering. The method comprises the following steps: mixing dimethyl malonate with ammonia water, carrying out a stirring reaction at normal temperature and normal pressure, and after the stirring reaction is finished, carrying out post-treatment to obtain a malonamide solid; dissolving the obtained malonamide in an organic solvent, adding a dehydrating agent, stirring and reacting under normal pressure, and distilling and recovering the organic solvent after the reaction is finished to obtain a malononitrile crude product; the obtained malononitrile crude product is rectified, fractions are collected, and high-purity malononitrile with the gas chromatographic purity being 99.5% or above is obtained. The method has the advantages of eliminating potential safety hazards and environmental protection pressure and remarkably reducing raw material cost; the method has the advantages of low requirement on equipment, low energy consumption, simplicity and safety in operation, simple process, short process route and environmental friendliness; a large amount of solid waste is not generated, post-treatment is simple and convenient, and industrial large-scale production requirements are easily met; the requirements of high-end application fields such as medicines and pesticides on high-purity raw materials can be met.

The invention belongs to the field of gasoline additives, and particularly relates to an environment-friendly gasoline antiknock and a preparation method thereof, the antiknock comprises two newly designed modified compounds: 3, 5-di-tert-butyl phenyl carborane carboxylic ester and 2-(dicyclohexylphosphino)-1, 2-oxaborin-4-carboxylic acid isooctyl ester. The preparation method comprises the following steps: adding the cosolvent into a reactor, sequentially adding the two modified compounds, the polyisobutene amine, the isobutyl acetate and the dimethyl malonate in an inert atmosphere, continuously stirring and mixing, heating, adding the antioxidant, continuously stirring, and finally cooling and filtering to obtain a finished product. The two modified compounds are prepared through condensation reaction of carborane carboxylic acid and sterically hindered phenol, esterification of borane carboxylic acid and isooctanol and phosphination reaction respectively. The antiknock agent disclosed by the invention does not contain metal elements, has the characteristic of biodegradability, can remarkably improve the octane number of gasoline and reduce engine sediments and harmful gas emission, and meets the green and environment-friendly requirements.

This invention belongs to the field of fine chemical intermediate synthesis technology, and discloses a method for preparing 3,5-dihydroxytoluene. The steps are as follows: Preparation of 3-ethoxycarbonyl-3-penten-2-one: Using ethyl acetoacetate and acetaldehyde as raw materials, 3-ethoxycarbonyl-3-penten-2-one is generated by Knoevenagel condensation reaction; 3-ethoxycarbonyl-3-penten-2-one is reacted with dimethyl malonate under alkaline conditions by Michael addition and intramolecular Claisen condensation reaction, followed by hydrolysis and decarboxylation to obtain 5-methylcyclohexane-1,3-dione; 5-methylcyclohexane-1,3-dione is subjected to catalytic dehydrogenation reaction to obtain 3,5-dihydroxytoluene. The method of this invention has advantages in raw materials, mild reaction conditions, simple operation, high yield, and environmental friendliness.

The invention discloses a synthesis method of dimethyl malonate. The synthesis method comprises the following steps: methanol and methyl glycolate are subjected to a contact reaction with an etherification catalyst, an obtained product methyl methoxyacetate is subjected to a reaction with CO under the action of a carbonylation catalyst, and dimethyl malonate is obtained. According to the method disclosed by the invention, the dimethyl malonate is prepared through etherification-carbonylation two-step reaction, so that the utilization rate of the methyl glycolate and the yield of the dimethyl malonate are greatly improved.

The application discloses a preparation method of 5-cyanoindole, S1) o-chloroaniline and dimethyl malonate are dissolved and subjected to catalytic reaction to prepare dimethyl 2-(2-aminophenyl)malonate; S2) dimethyl 2-(2-aminophenyl)malonate is dissolved, hydrolysis reaction is carried out by adding alkali, and then high-temperature decarboxylation reaction is carried out by adding acid to prepare o-aminophenylacetic acid; S3) o-aminophenylacetic acid is dissolved and subjected to amino para-bromination to prepare 2-(2-amino-5-bromophenyl)acetic acid; S4) 2-(2-amino-5-bromophenyl)acetic acid is dissolved, and intramolecular condensation is carried out by adding a condensing agent to prepare 5-bromo-oxindole; S5) 5-bromo-oxindole is subjected to reduction reaction to prepare 5-bromoindoline; S6) 5-bromoindoline is subjected to oxidation reaction to prepare 5-bromoindole; and S7) substitution reaction is carried out on the bromine of 5-bromoindole by using cyano to prepare 5-cyanoindole. The application has the advantages of simple process, environmental protection, no pollution, low cost, safe operation, easy scale production, mild reaction condition, high conversion rate and good product quality.