76results about How to "High chemical yield" patented technology

The invention discloses a composite solid acid catalyst for antioxidant RD preparation. The composite solid acid catalyst is characterized in that D002-type strong acid cation exchange resin is compounded with arylsulfonate substances to prepare the solid acid catalyst; in the presence of the composite solid acid catalyst, aniline reacts with acetone to generate an antioxidant RD monomer with high aniline conversion rate and high chemical yield; and then the antioxidant RD monomer is polymerized, distilled and granulated to prepare the antioxidant RD finished product. The composite solid acidcatalyst has the advantages that the continuous environment-friendly process with simple process, high product chemical yield, high content of dimer of the product antioxidant RD, excellent antioxidant effect of the finished product, no three-waste emission and low production cost is suitable for industrial production.

The present invention provides a convenient and efficient process for the synthesis of d₂-benzo[d][1,3]dioxoles.

The present invention relates to a process for asymmetric synthesis in the presence of a chiral catalyst comprising at least one complex of a metal of transition group VIII with ligands capable of dimerization via noncovalent bonds, such catalysts and their use.

The present invention relates to enzymic processes for preparing S-butan-2-ol; and to enzymes for carrying out said processes; to nucleic acid sequences coding for said enzymes, to expression cassettes, vectors and recombinant hosts containing said nucleic acid sequences.

The invention discloses a making method and application of chiral sulfonamide amide-alcohol ligand based on proamide-alcohol, which is characterized by the following: adopting L-proamide-alcohol as raw material; making each ligand framework possess 1-3 chiral center; proceeding selectivity loop-opening reaction for cycloethyliminum; improving receiving rate obviously; adopting chiral sulfonamide amide-alcohol ligand and similarity as catalyst ligand in the asymmetrical synthetic reaction; fitting for applying in the asymmetrical diethyl zinc additioning reaction, alkynyl zinc additioning reaction for carbonyl compound, reducing reaction and aldehyde alcohol condensing reaction.

The invention discloses a process for the preparation of compounds having structures typical for proton pump inhibitors in enantiomerically enriched form by using particular metal catalysts in an enantioselective oxidation step. Also disclosed are useful further processes and pure intermediate and subsequently final products.

The invention relates to a synthetic method of a sulfonamide compound, The process of the invention comprises: taking a sulfochloride compound as a raw material, firstly dissolving the sulfochloride compound into an organic solvent, beginning to input an ammonia gas at a temperature of between -10 and 0 DEG C, and raising the decomposition temperature to the room temperature when the internal pressure in a reaction kettle reaches 0.01 to 0.04Mpa, by now the internal pressure in the reaction kettle increases to 0.1 to 0.6Mpa. After the reaction for 1 to 20h, the target product is acquired through filtration and recrystallization in an alcohols solvent. The synthetic method changes the feeding sequence of materials, and saves mass ammonia gas and overcomes the defects of complex operation, large consumption of ammonia gas and environmental pollution of the existing method, and the synthetic method of the sulfonamide compound has advantages of simple operation, mild reaction conditions, rather high chemical yield and low cost, and is suitable for the industrialized production.

A novel process for the synthesis of fenofibrate, includes reacting a metal salt of fenofibric acid with an isopropyl halide, in a solvent system composed of a mixture of dimethyl sulfoxide and a C₂-C₄ alkyl acetate. The process can be used on an industrial scale and makes it possible to obtain a fenofibrate of a quality in accordance with the Pharmacopoeia without the need for purification by recrystallization.

The invention relates to a method for preparing optically pure enantiomers of racemic cis apovincaminic acid ester from the racemic cis apovincaminic acid ester. Chiral resolving agent R*-COOH reacts with the racemic cis apovincaminic acid ester to generate a corresponding salt; the salt is resolved according to the difference of the salt solubility of two enantiomers; the salt is neutralized, released and finally recrystallized, purified and enriched in the optical purity to prepare one signal enantiomer with high optical purity; in addition, because appropriate resolving agent and resolving solvent are used, a mother solution can be concentrated and resolved to obtain a salt of another enantiomer, wherein the salt has high chemical purity and high optical purity; and the salt is neutralized, released and refined to obtain another enantiomer with high-purity. The example of directly obtaining two optically pure enantiomers of a raceme to be resolved by using the same resolving agent is rare, and particularly it is the first time that the racemic cis apovincaminic acid ester including vinpocetine is resolved. The resolving operation is simple and efficient. The racemic cis apovincaminic acid ester is resolved by using the method to obtain the vinpocetine, thus another method of preparing the racemic cis apovincaminic acid ester including the vinpocetine is invented.

A novel process for the preparation of omeprazole and its enantiomers, such as esomeprazole, as well as the preparation of related 2-(2-pyridinylmethyl-sulphinyl)-1H-benzimidazoles, including pantoprazole, lansoprazole and rabeprazole, as recemates or single enantiomers, and their alkali or alkaline salts has been developed. The novel process involves the surprising discovery that protection of the free-base benzimidazole sulfoxide (e.g. omeprazole or esomeprazole), by reaction with an alkyl, aryl or aralkyl chloroformate following oxidation of the corresponding sulfide, eliminates the need for its direct isolation. Subsequent removal of the protecting group with a solution of alkali or alkaline earth alkoxide in a C1-C4 alcohol directly provides the corresponding salt. By eliminating the need to handle the free-base benzimidazole sulfoxide, this advantageous procedure provides increased chemical yields over processes described in the art.

The invention provides a synthetic method of 5,5,5-trichloro-2-methyl-2-pentene. The synthetic method comprises the following steps: taking 2-methyl-3-butene-2-ol as an initial compound of a reaction;adding a haloid acid into the reaction system, and conducting distilling to obtain an intermediate product 1-halo-3-methyl-2-butene; adding the intermediate product and chloroform into a reaction kettle, conducting stirring at a low temperature, and adding an inorganic base into the system in batches; wherein the reaction temperature is 0-40 DEG C, the reaction time is 2-10 hours, the mass ratioof the 2-methyl-3-butene-2-ol to the haloid acid in the reaction is (0.3-1):1, the weight ratio of the chloroform to the 1-halo-3-methyl-2-butene is (1-10):1, and the weight ratio of the inorganic base to the 1-halo-3-methyl-2-butene is (0.1-2.0):1. The method is high in reaction yield and low in environmental pollution degree, and the corrosion degree of equipment is reduced.

The invention discloses a copper salt catalyzing system. The copper salt catalyzing system is used for catalyzing esterification reaction to prepare a methyl benzoate compound. The copper salt catalyzing system is composed of a copper salt, an oxidant and an alkali, wherein the mol ratio of the copper salt to the oxidant is 1: 15 to 40; the copper salt is selected from one or a mixture of more than one of 8-hydroxyquinoline copper, cupric acetate monohydrate, copper acetylacetonate, cuprous bromide, anhydrous cupric sulfate, copper fluoride dihydrate and pure copper; and the oxidant is one of tert-butyl hydroperoxide, di-tert-butyl oxide or dicumyl peroxide. The newly developed copper salt catalyzing system for benzyl alcohol esterification reaction greatly reduces the reaction cost, the raw materials are simple and easy to gain, the system is in a wide applicable scope of substrates, the yield is up to 99%, the reaction is carried out in the air atmosphere, the operation is simple, and the chemoselectivity is high; and the copper salt catalyzing system is environmentally friendly, has no three-waste discharge, meets green chemistry requirements, and is also beneficial for industrial application.

The invention provides a preparation method of 2-azyl-5-bromopyrimidine. The 2-azyl-5-bromopyrimidine is prepared by serving 2-aminopyrimidine and N-bromo-succinimide as raw materials, brominating the raw materials and reacting in the presence of a catalyst N-dimethylformamide. The synthesis method provided by the invention is moderate in reaction conditions, simple and convenient to operate, convenient to purify, high in chemical yield and low in cost, thereby being suitable for synthesis methods of pyrimidine compounds in industrial production.

Process for preparation of (S)-1-phenyl-1,2,3,4-tetrahydroisoquinoline wherein 1-phenyl-1,2,3,4-tetrahydroisoquinoline is reacted with D-(−)-tartaric acid in a solvent system comprising of methanol and water, preferably at 3.3:1 to 1:1 volume ratio, the crystallization mixture is left for crystallization and (S)-1-phenyl-1,2,3,4-tetrahydroisoquinoline is released from obtained crystalline diastereoisomeric salt according to standard procedures. (S)-1-Phenyl-1,2,3,4-tetrahydroisoquinoline is the intermediate in enantiomeric synthesis of solifenacin.

The invention concerns a novel method for synthesis of 4-benzofuran-carboxylic acid or alkyl ester thereof.

This method is characterized in that a reaction for aromatization of a compound of formula (II) is performed for the synthesis of the compound of formula (I), according to the scheme A2 below:

wherein R independently represents hydrogen or a linear or branched C₁-₁₅ alkyl group.

With the invention, it is possible to industrially synthesize 4-benzofuran-carboxylic acid or alkyl ester thereof with good yield and very good purity.