34 results about "Monoethyl malonate" patented technology

The invention discloses a method for preparing an Eprosartan impurity EP12A. The method comprises the step of condensing 4-[[(2-butyl-5-formyl)imidazol-1-yl]methyl]benzoic acid with monoethyl malonate in the presence of a catalyst, so as to obtain the Eprosartan impurity EP12A. The method has the beneficial effects that the reaction conditions are mild, the process is simple, the reaction time is short, side products are few, the yield is good, and the high-purity Eprosartan impurity EP12A can be obtained.

The invention relates to a process for the synthesis of moguisteine that is ethyl ester of (R,S)-3-[2-[(2-methoxyphenoxy)methyl]-1,3-thiazolidin-3-yl]-3-oxypropanoic acid which comprises the steps of forming a new cyclic intermediate of formula 2-[(2-methoxyphenoxy)methyl]-1,3-dioxolane (4), forming (R,S)-2-[(2-methoxyphenoxy)methyl]-1,3-thiazolidine (6) and reacting this latter with monoethylmalonic acid (7) or a salt thereof. The moguisteine of the invention is obtained in high yield and purity.

The invention relates to a furoxan ring, and provides a synthesis method of 3, 4-dicarboxylic acid diethyl ester furoxan. The method adopts a monoethyl malonate potassium salt as a raw material and takes sodium nitrate / nitrite as an oxidizing agent. The substances are subjected to oxidation nitration and a ring formation reaction in a carbon tetrachloride solution, thus obtaining the target compound 3, 4-dicarboxylic acid diethyl ester furoxan with purity up to 98.7% and yield up to 94.2%. The synthesis method provided in the invention has the advantages of high purity and high yield.

The invention discloses a synthesis process of an ezetimibe intermediate, the intermediate being (2S,3S)-2-(4-(benzyloxy)phenyl)-1-(4-fluorophenyl) ‑4‑Oxazetidine‑3‑carbaldehyde (intermediate E6) starting from (s)‑4‑phenyl‑2‑oxazolone and ethyl malonyl chloride by condensation of TMSCl and TBAF Catalyzed condensation to obtain intermediate E3, intermediate E3 and N-(4-fluorophenyl)-4-benzyloxybenzylidene condensed under the catalysis of titanium tetrachloride to obtain intermediate E4, intermediate E4 in BSA and FBAF Catalytic ring closure produces β-lactam intermediate E5, which is then reduced to aldehyde intermediate E6 by DIBALH. The raw materials used in the process are cheap and easy to obtain, the solvent is single, the reaction time is short, the production cost is low, the yield is high, the production unit operation is simple, and it is suitable for industrial production.

The invention provides a preparation method of clobazam. The preparation method comprises the following steps: (1), using 2-nitro-5-chlorodiphenylamine and ethyl malonyl chloride as raw materials, performing a reflow reaction in an organic solvent, after the reaction, decompressing the organic solvent in the reaction system, then performing evaporation to dryness, and adding a refining solvent for refining treatment so as to obtain a compound as shown in a formula II; (2), performing zinc powder reduction on the compound as shown in the formula II, and performing ammonolysis cyclization so as to obtain a compound as shown in a formula III; (3) enabling the compound as shown in the formula III to react with methyl iodide in an alkaline alcohol solution so as to obtain the clobazam, wherein alkali is one or more of sodium hydroxide, lithium hydroxide and potassium hydroxide. The clobazam prepared by the method is few in impurities and high in purity.

The invention relates to the technical field of organic synthesis and bulk drug intermediates, and concretely relates to a preparation method of a key intermediate 4-hydroxyquinoline-3-carboxylic acid of a new medicine ivacaftor for treating cystic fibrosis. The preparation method comprises the following steps: 1, carrying out a condensation reaction: reacting o-nitrobenzoic acid, potassium monoethyl malonate and N,N-carbonyldiimidazole to prepare ethyl 3-(2-nitrophenyl)-3-oxopropanoate; 2, carrying out a reduction reaction: carrying out catalytic hydrogenation reduction on ethyl 3-(2-nitrophenyl)-3-oxopropanoate to prepare ethyl 3-(2-aminophenyl)-3-oxopropanoate; 3, carrying out a cyclization reaction: carrying out nucleophilic addition and cyclization reaction on ethyl 3-(2-aminophenyl)-3-oxopropanoate and N,N-dimethyl formamide dimethyl acctel to obtain ethyl 4-hydroxyquinoline-3-carboxylate; and 4, carrying out a hydrolysis reaction: carrying out the hydrolysis reaction on ethyl 4-hydroxyquinoline-3-carboxylate to obtain 4-hydroxyquinoline-3-carboxylic acid. The preparation method has the advantages of easily available raw materials, mild reaction conditions, simplicity and convenience in post-treatment, suitableness for amplified preparation, and high yield.

The invention discloses a method for synthesizing a key intermediate of trametinib, which uses monoformamide monoethyl malonate and methylmalonic acid to complete the cyclization reaction to obtain a crude pyridinetrione compound; the obtained pyridinetrione The crude compound is directly cyclized with N-(2-fluoro-4-iodophenyl)-N'-cyclopropylurea to obtain the key intermediate of trametinib. The present invention adopts monoethyl malonate and methylmalonic acid to complete the cyclization reaction to obtain a pyridinetrione compound, which is directly cyclized with a urea compound without purification to obtain a key intermediate for synthesizing trametinib. The method steps are short, the total yield is 47.3%, and it has the potential of scale-up in pilot scale, which provides a new scheme for the synthesis of trametinib.