44 results about "Dihydroxylation" patented technology

The invention discloses a method for preparing high-purity estra-1, 3, 5 (10)-triene-3, 15 alpha, 16 alpha, 17 beta-tetrol (abbreviated as estratrol), which is characterized in that 3-hydroxy-17 beta-hydroxyestra-1, 3, 5 (10), 15-tetraene is used as a raw material, and the estratrol is prepared by three steps of phenolic hydroxyl group protection, asymmetric dihydroxylation and hydrolysis. According to the preparation method, 3-hydroxy-17beta-hydroxyestra-1, 3, 5 (10), 15-tetraene is taken as a raw material, 3-hydroxyl is protected by alkoxy-substituted benzoyl, asymmetric dihydroxyl reaction is carried out through catalytic oxidation of potassium osmate, double alpha-hydroxyl is introduced to 15, 16-positions, chemical reagents and catalysts with high cost are not needed in the preparation method, and the preparation method is simple and easy to implement. The dihydroxylation has the advantages of high stereoselectivity, easiness in purification and separation, mild reaction conditions and simplicity and convenience in operation, and high-efficiency preparation of high-purity estetrol (more than or equal to 99.5%) can be realized.

The present invention relates to a method for preparing an isohexide-based polycarbonate copolymer. The isohexide-based polycarbonate copolymer is obtained by sequentially carrying out a transesterification reaction, a pre-polycondensation reaction, and a final polycondensation reaction on diol and dialkyl carbonate under the action of a catalyst, wherein the diol includes diol A1 and diol A2, or further includes diol A3; the diol A1 is isohexide; the molecular structural formula of the diol A2 contains a cyclic ether structure and two primary hydroxyl groups, and the primary hydroxyl groups are linked to the cyclic ether structure via a methylene group; the diol A3 is a dihydroxy compound; and during the pre-polycondensation reaction, the temperature is first gradually increased to 180-200ºC within 5-15 min, the pressure is gradually reduced to 45-55 kPa within 5 min, and finally, gradient heating and gradient pressure reduction are carried out. The copolymer prepared by the present invention has high molecular weight, high heat resistance, high strength, high toughness, and transparency, and thus has a wide range of applications.

The invention discloses a preparation method of heat-resistant bisphenol A type copolycarbonate, and belongs to the technical field of polycarbonate synthesis. Comprising the following steps: by taking bisphenol A and diester carbonate as monomers, aromatic dibasic acid, aromatic dibasic acid ester or aromatic dihydroxy compound as a copolymerization unit and imidazole ionic liquid as a catalyst, carrying out transesterification under a protective atmosphere, and then carrying out condensation polymerization under a vacuum condition to obtain the heat-resistant bisphenol A type copolycarbonate. A metal-free catalyst is used for carrying out melt polycondensation on bisphenol A type copolycarbonate, so that efficient polymerization and heat-resistant modification of polycarbonate are realized. The performance of the copolycarbonate is regulated and controlled by controlling the type and proportion of the added copolymerization units, so that the glass-transition temperature is increased while the mechanical properties and optical properties of the bisphenol A polycarbonate are retained.

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.

Disclosed is a process for asymmetric cis-dihydroxylation ("AD") of styrene and conjugated dienes to produce cis-glycols of styrene and conjugated dienes or tetrols of conjugated dienes in high yields (i.e. Yields > = 30%) and high enantioselectivity (i.e. Enantiomeric excess > = 60%). The process uses an iron-based catalyst, such as one or more Fe (II) complexes, etc., as a catalyst. The process generally includes: (i) maintaining the reaction mixture at a temperature sufficient to form a product for a period of time, where the reaction mixture contains styrene or conjugated diene, one or more iron-based catalysts, an oxidizing agent, and a solvent, and where the product contains a cis-diol or tetraol.

The efficient synthesis of cis-diol compounds by cis-dihydroxylation of olefins using osmate(VI) as a catalyst is disclosed, which has important applications especially in the efficient large-scale preparation of α,α-cedrane diol from α-cedrene.

The polycarbonate copolymer of the present invention is a polycarbonate copolymer containing units derived from at least one or more primary dihydroxyl compounds and units derived from at least two or more secondary dihydroxyl compounds, and the polycarbonate copolymer has a pencil hardness of H or more as measured by a pencil hardness test (ISO 15184) and a glass transition temperature (Tg) of about 90° C. to about 160° C. as measured by ISO 11357. The polycarbonate copolymer is excellent in heat resistance, scratch resistance, moldability, light resistance, weather resistance, transparency, mechanical strength, etc.

The present disclosure relates to a method for olefin oxygen oxidation, comprising the following steps: contacting an olefin compound with a catalyst under oxygen condition to perform an oxidation reaction; the catalyst is a composite catalytic material, the composite catalytic material comprises a framework heteroatom molecular sieve and a metal element M dispersed in the intracrystalline of the molecular sieve; the framework heteroatom molecular sieve is a molecular sieve in which at least part of silicon in a full-silicon molecular sieve framework is replaced by a heteroatom element Q, and the heteroatom element Q is selected from one of titanium, boron, zirconium, aluminum, tin, phosphorus and germanium. The method uses a metal-containing multi-level porous heteroatom molecular sieve for olefin oxygen oxidation reaction, and high conversion rate of olefin and high selectivity of ketone and dihydroxyl compound can be obtained under relatively mild conditions.

Methods for asymmetric cis-dihydroxylation ("AD") of quinones to produce cis-diols of quinones with high yield (i.e. a yield ≥ 30%) and high enantioselectivity (i.e. an enantiometric excess ≥ 30%) are disclosed. The method uses an iron-based catalyst, such as one or more Fe(II) complexes, as the catalyst, and can be performed under mild reaction conditions (e.g. a temperature ≤ 50°C at 1 atom in open air). The method generally includes: (i) maintaining a reaction mixture at a temperature for a period of time sufficient to form a product, where the reaction mixture contains a quinone, one or more iron-based catalyst (s), and a solvent, and where the product contains a chiral cis-diol. Optionally, the method also includes adding an oxidant into the reaction mixture prior to and / or during step (i), such as a hydrogen peroxide solution.

The invention relates to the field of carbonate polymerization, and discloses isosorbide polycarbonate and a preparation method thereof. The preparation method of the isosorbide polycarbonate comprises the following steps: under the action of a ketonic acid metal salt catalyst, taking a dihydroxy compound, diester carbonate and aliphatic dihydric alcohol as raw materials, and carrying out transesterification and polycondensation reaction to obtain the isosorbide polycarbonate. The keto acid metal salt is used as the catalyst for synthesizing the isosorbide polycarbonate, the catalyst is low in price and not prone to inactivation, and the isosorbide polycarbonate with high molecular weight and ideal transparency is catalytically synthesized.

The present invention proposes a process for preparing high-purity estetrol, which uses (17β)-3-(phenylmethoxy)-estra-1,3,5(10),15-tetraen-17-ol acetate as a raw material, introduces hydroxyl groups at positions 15 and 16 through a dihydroxylation reaction, protects the hydroxyl groups at positions 15 and 16 through a ketal reaction, separates isomers, and then sequentially removes the benzyl protecting group, the acyl group, and the ketal protecting group. Finally, the process is purified to obtain a compound of formula (I) #imgabs0#. The present invention uses a ketal method to protect the hydroxyl groups at positions 15 and 16, and then separates the isomers, thereby achieving a satisfactory isomer removal effect and refining yield. Moreover, the process is convenient, and the ketal reaction only requires the use of an organic ketone reagent and a catalytic amount of acid. The organic ketone reagent can be completely recovered and reused, and almost no waste is generated.

A method for producing a polycarbonate, said method comprising: a polymerization step in which a dihydroxy compound and a diaryl carbonate, or a prepolymer thereof, are polymerized in a polymerization reactor; a cleaning step in which a purge vapor containing a hydroxyaryl compound, a diaryl carbonate, and a dihydroxy compound discharged from the polymerization reactor in the polymerization step is brought into contact with a cleaning liquid in a scrubber; and a condensation step for condensing the exhaust vapor after cleaning in the cleaning step. At least a portion of the bottom liquid of the scrubber in the cleaning step is supplied to the polymerization reactor.

Methods for asymmetric cis-dihydroxylation ("AD") of styrenes and conjugated dienes to produce cis-diols of styrene and conjugated diene or tetraols of conjugated diene with high yield (i.e., a yield ≥ 30%) and high enantioselectivity (i.e., an enantiometric excess ≥ 60%) are disclosed. The method uses an iron-based catalyst, such as one or more Fe(II) complexes, as the catalyst. The method generally includes: (i) maintaining a reaction mixture at a temperature for a period of time sufficient to form a product, where the reaction mixture contains a styrene or conjugated diene, one or more iron-based catalyst(s), an oxidant, and a solvent, and where the product contains a cis-diol or tetraol.

The invention relates to a double-acid catalytic system for catalytic synthesis of a dihydroxy compound and a method for catalytic synthesis of the dihydroxy compound. The double-acid catalytic system comprises a Lewis acid catalyst and a sulfydryl-containing protonic acid catalyst and is used for catalytically synthesizing the dihydroxy compound. Compared with a traditional catalytic method, the dihydroxy compound is synthesized by one-step reaction of a carbonyl compound and an aromatic hydroxy compound through a synergistic catalysis effect of a double-acid catalytic system selected in the invention. According to the method, a good catalytic effect can be obtained at a relatively low reaction temperature within a relatively short reaction time, the conversion rate of the carbonyl compound is greater than 40%, the selectivity of the product dihydroxy compound is greater than 40%, the use of strong inorganic acid is completely abandoned, the defects of high pollution, strong corrosivity and low selectivity of a traditional method are greatly avoided, and the method is suitable for industrial production. Good industrialization prospects are realized.

The invention provides a method for preparing ethylene glycol by catalyzing one-step oxidation dihydroxylation of ethylene, and relates to the technical field of ethylene glycol preparation. Ethylene is used as a raw material, a halogen-containing compound is used as a catalyst, water is used as a reaction medium, a reaction is performed in a high-pressure reaction kettle, and ethylene glycol is prepared through one-step oxidation dihydroxylation. The invention can solve the problems of flammable and explosive ethylene oxide in the traditional ethylene oxide hydration process, high water ratio, high energy consumption, environmental pollution and the like in the hydration process. The method has the advantages of simple and easily available catalyst, simple process and high conversion rate and selectivity, and can be used in industrial production of ethylene glycol from ethylene.

The present invention relates to a method for the manufacture of polycarbonate comprising the steps of i) melt reacting a dihydroxy compound and a carbonate, optionally in the presence of one or more of a transesterification catalyst, thereby forming a stream of molten polycarbonate, i') combining said stream of molten polycarbonate obtained in step i) and from 0 5000 ppm of water based on the weight of the polycarbonate, ii) feeding the stream of molten polycarbonate obtained in step i) or step to a melt mixing device, iii) combining, in said melt mixing device, said stream of molten polycarbonate and from 0 5000 ppm of water based on the weight of the polycarbonate, ii) feeding the stream of molten polycarbonate obtained in step i) to a melt mixing device, iii) combining, in said melt mixing device, said stream of molten polycarbonate and from 0 5000 ppm of water based on the weight of the polycarbonate, wherein the total amount of water to be combined with the stream of molten from 5 5000 ppm based on the weight of the polycarbonate, iv) subjecting the stream obtained in step iii) at least partially to a vacuum in the range from 1 - 800 mbar in order to remove the water from the stream of molten polycarbonate at least in part, and v) passing the stream obtained in step iv) through a melt filter.

Preparation of a crosslinked and plasticized polymer electrolyte The invention relates to a method for preparing a so-called quasi-solid electrolyte comprising at least the following steps: (i) providing a composition comprising at least one plasticizing agent; at least one polyalkylene carbonate having two free terminal hydroxyl functions and having an average molar mass Mw, less than or equal to 200,000 g.mol-1; at least one triisocyanate compound in a dihydroxylated polycarbonate(s) / triisocyanate(s) mass ratio of between 0.5 and 5; at least one alkali or alkaline-earth metal salt; at least one catalyst for the coupling reaction between a hydroxyl function and an isocyanate function; and optionally at least one inorganic filler; and (ii) crosslinking said composition, to form said quasi-solid electrolyte.It also concerns the quasi-solid electrolyte thus obtained, and its use in an electrochemical system, in particular in a lithium battery. Figure for the abstract: None.

The present invention provides an estetrol synthesis process, and relates to the technical field of steroid compound synthesis processes, and the method comprises the following steps: taking estrone as an initial raw material, firstly carrying out 3-site hydroxyl protection, and then carrying out an oxidative dehydrogenation reaction in the presence of a metal catalyst and in an oxygen atmosphere to prepare a key intermediate ketene, then 17-site carbonyl reduction, 17-site hydroxyl protection, 15, 16-site double bond dihydroxylation, 3-site protecting group removal and hydrolysis reaction are sequentially carried out, and finally the target product estetrol is obtained. The method adopts metal catalysis to directly oxidize to construct cycloenone, effectively avoids the problem of poor stability of partial intermediates in the prior art, has the advantages of simple process, short reaction steps, greenness, environmental protection and the like, and is suitable for industrial production.

To provide a method of producing polycarbonate which reduces raw material loss.SOLUTION: A method of producing polycarbonate includes: a preliminary polymerization process of subjecting a polymerization raw material including a dihydroxy compound, diaryl carbonate, and at least one catalyst selected from the group consisting of alkali metal and alkali earth metal compounds to ester exchange reaction under a reduced pressure condition in a polymerization reactor to obtain a molten prepolymer; and a condensation polymerization process of further subjecting the molten prepolymer to ester exchange reaction under a reduced pressure condition in the polymerization reactor to obtain polycarbonate, where the ester exchange reaction in the preliminary polymerization process is performed under a condition satisfying the following formula (1). (1) 1,100≤(-0.043×A+0.028×B+0.79)×C×D≤22,000.SELECTED DRAWING: None

The present invention addresses the problem of providing a composition containing a dihydroxy compound having a biphenanthrene skeleton, the composition making it possible to diminish troubles caused by metals remaining in large amounts in conventional dihydroxy compounds having a biphenanthrene skeleton. This composition contains a dihydroxy compound having a biphenanthrene skeleton, the dihydroxy compound being represented by general formula (1a) and having a total content of sodium, potassium, iron, and copper metals of 40 ppm or less. (In the formula, the R1 moieties each independently represent a C2-C4 alkylene group, the R2 moieties each independently represent a C1-C6 alkyl group, a C6-C18 aryl group, or a halogen atom, and each n independently indicates 0 or an integer of 1-4.)

The present invention provides a method for preparing polycarbonate by low-temperature positive pressure synthesis, the method comprising the following steps: (1) mixing the ester exchange material obtained by the ester exchange reaction of diphenyl carbonate and dihydroxy compound with non-alcoholic polar organic matter, carrying out polycondensation reaction, and obtaining light phase material and heavy phase material through liquid-liquid separation process; (2) flashing and extruding the heavy phase material in step (1) to obtain the polycarbonate. The present invention adds non-alcoholic polar organic matter to extract phenol generated by the polycondensation reaction in the polycondensation reaction of polycarbonate preparation, so that the polycondensation reaction is carried out under low temperature and positive pressure conditions, and the obtained polycarbonate has the characteristics of high number average molecular weight, low yellowness index and high quality.

This polycarbonate diol contains a structural unit (1) represented by general formula (I) and a structural unit (2) represented by general formula (II). The percentage content of the structural unit (2) in the polycarbonate diol is 4.3 mol% or less relative to the total structural units of the polycarbonate diol which is 100 mol%.　The present invention can provide: a method for producing a polycarbonate diol, in which a diol such as 1,4-butanediol is used as a raw material and a polycarbonate diol with a molecular weight close to the theoretical molecular weight in high yield can be obtained; and a polycarbonate diol that makes it possible to obtain a polyurethane having excellent mechanical properties and chemical resistance and configured to suppress variation in the mechanical properties.　In general formula (I), n is an integer of 4-6. Also, in general formula (II), m is an integer of 2-4.

The polycarbonate copolymer of the present invention comprises: a unit derived from at least one type of primary dihydroxyl compound; and a unit derived from at least two types of secondary dihydroxyl compounds, wherein the polycarbonate copolymer has a pencil hardness of H or greater, when a specimen is measured according to the pencil hardness test (ISO 15184), and a glass transition temperature (Tg) of about 90° C. to about 160° C., measured according to ISO 11357. The polycarbonate copolymer has excellent heat resistance, scratch resistance, moldability, light resistance, weather resistance, transparency, mechanical strength, and the like.

A polycarbonate diol composition contains: a polycarbonate diol containing a structural unit (1) derived from a compound (1) represented by the following general formula (1); HO—(CH2)n—OH (1) (n is an integer of 3 to 6) and an aldehyde having 3 or more and 8 or less carbon atoms. A method for producing a polycarbonate diol composition, includes: polycondensing a carbonate compound and a dihydroxy compound composition containing a compound (1) represented by the following general formula (1) and an aldehyde having 3 or more and 8 or less carbon atoms by a transesterification reaction in the presence of a catalyst, to obtain a polycarbonate diol composition containing a polycarbonate diol. A polyurethane is obtained by using this polycarbonate diol composition.

The polycarbonate copolymer of the present invention comprises: a unit derived from at least one type of primary dihydroxyl compound; and a unit derived from at least two types of secondary dihydroxyl compounds, wherein the polycarbonate copolymer has a pencil hardness of H or greater, when a specimen is measured according to the pencil hardness test (ISO 15184), and a glass transition temperature (Tg) of about 90° C. to about 160° C., measured according to ISO 11357. The polycarbonate copolymer has excellent heat resistance, scratch resistance, moldability, light resistance, weather resistance, transparency, mechanical strength, and the like.

A highly efficient synthesis of cis-diol compounds through cis-dihydroxylation of olefins using osmate (VI) salt as catalysts is disclosed, which has found important application in efficient large-scale preparation of, among others, α,α-cedranediol from α-cedrene.

Provided are a method for producing a modified aluminosilicate capable of highly selectively producing hydroquinones by a reaction of phenols and hydrogen peroxide under industrially advantageous conditions, a method for producing a catalyst for producing an aromatic dihydroxide compound, a catalyst containing a modified aluminosilicate, a method for producing an aromatic dihydroxide compound using the catalyst, and a modified aluminosilicate. The method for producing an aluminosilicate may include preparing a liquid in which sol-like silica containing water is contacted with a metal compound (AL) containing aluminum and oxygen to obtain an aluminosilicate having a specific range of a molar ratio of water to silica (HMR); treating the aluminosilicate with an acid; subjecting the treated product to primary calcination; and contacting the calcined product with a liquid containing one or more elements in Group 4 and Group 5 of the Periodic Table, followed by carrying out drying and secondary calcination.

The present invention relates to a process for manufacturing a polycarbonate comprising the steps of: i) melt reacting a dihydroxy compound and a carbonate, optionally in the presence of one or more transesterification catalysts, thereby forming a stream of molten polycarbonate, i ') combining the stream of molten polycarbonate obtained in step i) with 0 to 5000 ppm of water, based on the weight of polycarbonate, ii) feeding the stream of molten polycarbonate obtained in step i) or step i') to a melt mixing device, iii) combining the stream of molten polycarbonate with 0 to 5000 ppm of water, based on the weight of polycarbonate, in the melt mixing device, ii) feeding the stream of molten polycarbonate obtained in step i) to the melt mixing device, iii) combining the stream of molten polycarbonate and 0 to 5000 ppm, based on the weight of polycarbonate, of water in the melt mixing device, the total amount of water to be combined with the stream of molten being 5 to 5000 ppm, based on the weight of polycarbonate, iv) subjecting the stream obtained in step iii) at least partially to a vacuum in the range of 1 to 800 mbar, and v) passing the stream obtained in step iv) through a melt filter in order to at least partially remove water from the stream of molten polycarbonate, and v) passing the stream obtained in step iv) through the melt filter.

The invention relates to a synthesis process of brassinolide, which is characterized in that a compound A is used as an initial raw material, and is subjected to esterification reaction, ring-closing reaction, oxidation reaction, oxidation ring-opening reaction, dihydroxylation reaction and oxidation rearrangement reaction to prepare the brassinolide. And the technological process is simpler and more convenient, and the yield is higher. # imgabs0 #

The invention relates to a method for producing a polycarbonate, comprising the steps of:-subjecting a dihydroxy compound and a carbonate to a melt reaction, optionally in the presence of a transesterification catalyst, thereby forming a molten polycarbonate stream, and-combining the molten polycarbonate stream with 5 to 5000 ppm of water and 50 to 10000 ppm of a siloxane compound, based on the weight of the polycarbonate.