33 results about "Ethylmalonic acid" patented technology

The invention relates to a method for purifying phenyl ethyl malonate, comprising the following steps: dissolving coarse phenyl ethyl malonate into a nonpolar solvent; decoloring by active carbon; filtering; mixing and crystallizing at the temperature of -10 DEG C to -5 DEG C; filtering to obtain a first filter cake; decompressing and recovering the solvent by the first filter cake to obtain colorless oil liquid as a fine product; dissolving the fine product into the nonpolar solvent; stirring and crystallizing at the temperature of -10 DEG C to -5 DEG C; filtering to obtain a second filter cake; decompressing the second cake to recover the solvent; and obtaining colorless transparent liquid as a phenyl ethyl malonate pure product. The purity of the phenyl ethyl malonate is greater than or equal to 99.5 percent, 2-phenyl-2-ethyl malonate impurities are less than 0.1 percent, and the total yield is greater than 90.0 percent.

A process for preparation of diethyl 2-aetamido-2-(4-octyl phenyl)ethyl malonate (III), a key intermediate of fingolimod hydrochloride comprising reaction of 2-(4-octylphenyl)ethyl iodide (IV) with diethyl acetamido malonate in presence of a base and an iodinating agent and in an organic solvent. The compound of formula (III) thus obtained provided fingolimod hydrochloride (Ia) having associated impurities below the regulatory limits.

The invention discloses a method for preparing vinpocetine intermediate gamma-hydroxypropyl-ethylmalonic acid, and belongs to the chemical industry synthesis field. The preparation method comprises the following steps: 1, adding sodium hydride into an organic solvent, adding 2-ethyl diethylmalonate and 1-bromo-3-chloropropane, extracting by using ethyl acetate, and carrying out reduced pressure concentration of a solvent to obtain gamma-chloropropyl-ethyl diethylmalonate; and 2, adding gamma-chloropropyl-ethyl diethylmalonate to an ethanol-water solvent of sodium hydroxide, refluxing, adding a proper amount of water, adjusting the pH value to 1 by using concentrated hydrochloric acid, crystallizing, and carrying out pumping filtration to obtain a white solid gamma-hydroxypropyl-ethylmalonic acid, wherein a molar ratio of 2-ethyl diethylmalonate to 1-bromo-3-chloropropane to sodium hydride in step 1 is 1:1-1.2:1-1.3; and a reaction temperature in the step 1 is 10-40DEG C, and a reaction time of 1-bromo-3-chloropropane, 2-ethyl diethylmalonate and 1-bromo-3-chloropropane is 8-15h. The intermediate is gamma-hydroxypropyl-ethylmalonic acid, and the preparation method has the advantages of cheap and easily available raw materials, low cost, short reaction steps, simple operation, good product quality, and benefit for protecting the green resource.

Provided is a process for producing 3,5-dimethyldodecanoic acid, which is an active ingredient of the pheromone of California prionus. More specifically provided is a method for producing 3,5-dimethyldodecanoic acid (5) comprising the steps of converting 2-methylnonyl halide (1) to a 2-methylnonyl metal reagent (2), and reacting the 2-methylnonyl metal reagent (2) with 2-ethylidene malonic acid ester (3) to form 2-(1,3-dimethyldecyl)malonic acid ester (4) as a result of 1,4-addition of the 2-methylnonyl metal reagent (2) to the 2-ethylidene malonic acid ester (3), as shown in the following scheme:

The invention discloses a method for preparing high-quality mercaptoacetic acid from a tail solution from O-alkyl-N-alkyl thinocarbamate production. The method comprises the following steps: (1) performing acidizing treatment on the tail solution by using an inorganic acid, and controlling the pH value to be 0.5-1.5; (2) leaving to stand for 6-48 hours, separating suspended organic matters, extracting by using an organic solvent, and extracting by using an extraction agent, thereby obtaining an extraction liquid, wherein the volume ratio of the total amount of the organic solvent to an acidifying liquid is (2.5:0.01)-(2.5:0.1), the organic solvent consists of 40-60wt% of glutaric acid diethyl ester and 40-060wt% of ethyl malonic acid diethyl ester, the volume ratio of the total amount of the extracting agent to a new acidifying liquid is (2:0.1)-(2:2), and the extracting agent is prepared by mixing n-amyl ether, isoamyl ether and sec-butyl methyl ether in a mass ratio of (1-3):(1-3):(1-3); (3) removing the solvent and water from the extraction liquid, thereby obtaining crude acid; (4) performing flash evaporation on the crude acid. The method is high in recycling rate, high in product purity, good in quality and simple in process.

A highly active supported chromium catalyst composition for ethylene and other olefins polymerization and also for ethylene copolymerization with efficient incorporation of comonomer, produces polymers with superior spherical morphology, improved bulk density and almost 0% fines. The catalyst composition component includes at least one chromium compound, mainly chromium acetylacetonate, or chromium hexaflouroacetonylacetonate, or chromium diethylmalonate. One magnesium compound, or aluminum compound, metal alkoxy compound and defined polymer particles mainly chloromethylated cross linked styrene-DVB copolymer or polyvinylchloride. The catalyst composition, when used in conjunction with an organoaluminum compound or a mixture of organoaluminum compounds, can be used for olefin polymerization to produce medium or high density polyethylene and copolymers of ethylene with alpha-olefins having about 3 to 18 carbon atoms.