38results about "Preparation by isomerisation" patented technology

The invention belongs to the technical field of organic synthesis, and particularly discloses a method for synthesizing carveol hydrate by using 2, 3-epoxy pinane, which comprises the following steps: by using 2, 3-epoxy pinane as a raw material, adding deionized water in a solvent in the presence of organic phosphoric acid as a catalyst and a micro-channel reactor as reaction equipment, carrying out ring-opening rearrangement reaction on the 2, 3-epoxy pinane to obtain carveol hydrate. Under the combined action of the catalyst and the microchannel reactor, high-yield and high-purity carveol hydrate is obtained; the method is mild in reaction condition, simple and convenient to operate, capable of effectively avoiding violent heat release of epoxy ring opening and generated by-products, high in reaction efficiency and good in industrial application prospect, the product yield can reach 98%, and the content can reach 99%.

The invention provides a method for preparing allyl alcohol through epoxypropane isomerization, and relates to the technical field of chemical synthesis. According to the method, propylene oxide is subjected to an isomerization reaction in the presence of a polymerization inhibitor to prepare allyl alcohol; wherein the polymerization inhibitor is a phenol polymerization inhibitor and / or a quinone polymerization inhibitor. The technical scheme of the invention can effectively reduce the deactivation rate of the catalyst and prolong the service life of the catalyst. The method for preparing allyl alcohol through epoxypropane isomerization is high in production efficiency and low in production cost, and has important industrial application value.

The present invention relates to a method for the preparation of 3-methyl-3-butene-1-ol (isoprenol), comprising the steps of preparing isobutylene (also: isobutene, 2-methylpropene) by contacting 3-methylbutan-1-ol (isoamyl alcohol) to a catalyst comprising at least one catalytically active metal and reacting at least one formaldehyde source and the isobutylene obtained in step a-i) to obtain isoprenol. Furthermore, the present invention refers to processes for the preparation of 3-methyl-2-butene-1-ol (prenol), of 3-methyl-3-butenal (isoprenal), of 3-methyl-2-butenal (prenal), and of 3,7-dimethy l-octa-2, 6-dienal (citral) and further downstream products comprising the use of isoprenol of the present invention and the resulting products and product streams.

The present invention relates to a method for preparing 3-methyl-2-butenal (prenal), 3-methyl-2-buten-1-ol (prenol), diprenyl acetate of prenal, and 3,7-dimethyl-octa-2,6-dienal (citral), wherein the aldehyde content in one or more reaction flows is maintained below a threshold. Furthermore, the present invention relates to available product flows of prenal, prenol, diprenyl acetate of prenal, and citral.

The application provides a method for synthesizing 3-methyl-2-buten-1-ol, and belongs to the technical field of isopentenol synthesis. The method comprises the following steps: introducing 3-methyl-3-buten-1-ol and an atmosphere containing hydrogen into a fixed bed reactor, and performing a hydrogenation isomerization reaction under the action of a Pd / Al2O3 catalyst to generate 3-methyl-2-buten-1-ol; wherein the content of formaldehyde in the 3-methyl-3-buten-1-ol is 0.03-0.15%. The application adopts a fixed bed reactor to perform continuous production, adopts a Pd / Al2O3 catalyst with low palladium content as the catalyst, the preparation method is simple, the price is relatively low, and the content of formaldehyde in the 3-methyl-3-buten-1-ol is controlled to inhibit a side reaction, so that the reaction conversion rate and the product selectivity are high.

The present invention relates to a process for the preparation of self-supported chiral catalyst polymers via non-radical polymerization and the catalyst polymers thus obtained. A novel at least heterogeneous chiral catalyst readily obtainable via self-supported non-radical polymerization using a homogeneous chiral catalyst and optionally a homogeneous linker is disclosed. These heterogeneous chiral materials can be used as catalysts for different chemical conversions.

A method is disclosed for isomerizing a feed containing an olefinically unsaturated alcohol by shifting a double bond to obtain an isomerized olefinically unsaturated alcohol. The method includes providing a cascade of n reactors, where n is an integer of at least 2. The method further includes merging an i-th supplementary stream with an i-th recycle stream to obtain an i-th reactor inlet stream; feeding the i-th reactor inlet stream into the i-th reactor and isomerizing the i-th reactor inlet stream on a heterogeneous isomerization catalyst to produce an i-th effluent stream; and splitting the i-th effluent stream into the i-th recycle stream and an i-th forward stream. In this method, i ranges from 1 to n; where for i=1, the feed constitutes the first supplementary stream, and for i=2 to n, the (i-1)-th forward stream constitutes the (i)-th supplementary stream; and the n-th forward stream is the product stream. This method allows for the isomerization of olefinically unsaturated alcohols with high conversion and improved selectivity.

This invention provides a method for isomerizing 3-butenol compounds in a hydrogen-medium environment to prepare 2-butenol compounds, comprising the following steps: In a hydrogen atmosphere, a mixture of an inorganic base and a 3-butenol compound is passed through a catalyst bed to undergo an isomerization reaction, yielding the 2-butenol compound; the amount of inorganic base added is 0.01–1.5% of the mass of the 3-butenol compound; the catalyst is porous silica supported on palladium, cerium, and selenium. This invention, by adding an additional base to the 3-butenol feedstock, effectively prevents the unsaturated alcohol from converting to a saturated alcohol during the hydrogen-containing isomerization process. Simultaneously, the addition of the electron promoter selenium to the catalyst in this application inhibits the adsorption capacity of the palladium catalyst for hydrogen, thereby reducing the hydrogenation activity of the palladium catalyst while maintaining the stability of the palladium compound cation. Furthermore, the structure promoter cerium improves the diffusivity of palladium, increases the active centers and coordination of palladium, and structurally improves the performance of the palladium catalyst.

The present invention relates to a process for the preparation of unsaturated alcohols of the formula (I), which comprises subjecting unsaturated aldehydes of the formula (II) to a hydrogenation in the presence of a catalyst and a tertiary amine; characterized in that the hydrogenation takes place in a reactor cascade. Conducting the hydrogenation in a reactor cascade, in particular a cascade of stirred vessel reactors, a cascade of bubble column reactors, or a cascade of jet loop reactors, reduces the amount of formed side products and enhances yield and selectivity of the products.

The application discloses a method for preparing borneol by continuously dehydrogenating and hydrogenating isoborneol, which comprises the following steps: dissolving isoborneol in an organic solvent, mixing the isoborneol with hydrogen, and carrying out dehydrogenation and hydrogenation reaction in a catalytic reactor by a two-stage temperature method, so as to realize the preparation of borneol products; and the reactor is loaded with a catalyst which takes one or more of Ru, Rh, Pd, Pt, Cu, Co, Ni and Fe as an active component and takes alumina, titania or silicon oxide as a carrier. The method can improve the conversion rate of isoborneol and the yield of borneol, and the content of borneol in the obtained product meets the requirements of pharmacopoeia.

A process for isomerizing a first olefinically unsaturated alcohol by shifting a double bond to obtain a second olefinically unsaturated alcohol, the process comprising contacting a stream of the first olefinically unsaturated alcohol with at least one heterogeneous isomerization catalyst, characterized in that the stream of the first olefinically unsaturated alcohol contacted with the heterogeneous isomerization catalyst comprises less than 25 ppmw of organically bound nitrogen relative to the weight of the first olefinically unsaturated alcohol. The process allows isomerizing olefinically unsaturated alcohols with high selectivity.

In accordance with the purpose(s) of the present disclosure, as embodied and broadly described herein is versatile polyene cyclization strategy that exploits conjugated b-ionyl derivatives. Photomediated disruption of the extended p-system within these chromophores unveils a contra-thermodynamic polyene that engages in a Heck-type cyclization to afford [4.4.1]-propellanes. The connectivity of overbred polycycles generated from this process is controlled by the position of the requisite C–Halide bond. Thus, compared to conventional biomimetic polyene cyclization, this approach allows for complete control of regiochemistry and facilitates incorporation of both electron-rich and electron-deficient (hetero)aryl groups. This strategy was successfully applied to the total synthesis of abietanes such as, for example, taxodione and salviasperanol, two isomeric abietane-type diterpenes that previously could not be prepared along the same synthetic pathway.

The invention relates to a process for the preparation of 3-methyl-2-butenal (isopentenal), for the preparation of 3-methyl-2-buten-1-ol (isopentenol), for the preparation of diisopentenyl acetic acid esters for the preparation of isopentenal, and for the preparation of 3, 7-dimethyl-oct-2, 6-dienal (citral), in particular to a process for the preparation of 3, 7-dimethyl-oct-2, 6-dienal. Wherein the aldehyde content in the one or more reactant streams is maintained below a threshold. Furthermore, the present invention relates to product streams of isopentenal, isopentenol, diisopentenyl acetate of isopentenal, and citral, which can be obtained.

The invention provides a method for preparing n-hexanol through a continuous reaction, which comprises the following steps: (1) carrying out an isomerization reaction on a raw material butyl ethylene oxide under the action of an isomerization catalyst to obtain an isomerization reaction solution; (2) carrying out hydrogenation reaction on the isomerization reaction liquid under the action of a hydrogenation catalyst to obtain hydrogenation reaction liquid; and (3) carrying out post-treatment on the hydrogenation reaction liquid to obtain the n-hexanol, wherein the isomerization catalyst is a supported catalyst and comprises a carrier, an active metal component and a metal additive, the carrier is one of aluminum oxide, silicon oxide, silicon nitride, silicon carbide, SBA-15 and a molecular sieve, the active metal component is one or more of chromium, niobium, zirconium, molybdenum and tungsten, and the metal additive is one or more of potassium, calcium, zinc, copper, gallium and indium. According to the invention, the hydrogenation catalyst is directly added into the isomerization reaction liquid obtained by the isomerization reaction to carry out the hydrogenation reaction, and the obtained hydrogenation reaction liquid is separated and purified to obtain the high-purity n-hexanol product. In the isomerization reaction, the active components and auxiliary components in the isomerization catalyst cooperate to catalyze and inhibit side reactions such as dehydration and polymerization in the isomerization reaction, and high target product selectivity and high stability are obtained.

The present invention relates to a method, comprising the isomerization of neral of formula (II) to geranial of formula (I), or the isomerization of geranial to neral, characterized in that (a) the isomerization is accomplished by irradiation with light. The method according to the present invention makes it possible to convert an undesired isomer, which is an unavoidable by-product generated during the production of neral and / or geranial, into a desired isomer highly efficiently, thus greatly improving the economic performance of the method for producing the desired isomer (in high yield by avoiding cost intensive distillation and with avoiding possible side products).

This invention discloses a method for resolving racemic mixtures based on dynamic kinetics, belonging to the field of catalysis technology. The method includes the following steps: taking a proton-selective permeable membrane and pretreating it; using the pretreated proton-selective permeable membrane to separate the aqueous phase and organic phase for reaction, thereby resolving the racemic mixture; wherein the aqueous phase is an acid solution, and the organic phase contains at least the racemic mixture, an acyl donor, an enzyme, and an organic solvent, and the racemic mixture is a racemic mixture of a chiral secondary alcohol or its derivative. This invention utilizes a proton-selective permeable membrane as a racemic catalyst applied to the dynamic kinetic resolution process, solving the problem of incompatibility between racemic catalysts and enzyme catalysts in conventional dynamic kinetic resolution techniques. This method has advantages such as a simple reaction system, easy process control, environmental friendliness, simple post-processing, and low cost.

The present invention relates to processes for preparing 3-methyl-2-butenal (prenal), for preparing 3-methyl-2-buten-1-ol (prenol), for preparing diprenyl acetate of prenal as well as for preparing 3,7-dimethyl-octa-2,6-dienal (citral), wherein the aldehyde contents in one or more reactant streams are maintained to be below thresholds. Furthermore, the present invention relates to obtainable product streams of prenal, prenol, diprenyl acetate of prenal as well as citral.

The application belongs to the technical field of medicine and spice synthesis, and particularly relates to a synthesis method of trans-2-octenal. The synthesis method comprises the following steps: 1-octene-3-ol is subjected to isomerization reaction under the catalysis of 3,4-dinitrobenzoic acid to obtain a trans-2-octene-1-ol intermediate; and the trans-2-octene-1-ol is subjected to oxidation by interchloroiodobenzene, 4-hydroxy-TEMPO (4-hydroxy-2,2,6,6-tetramethylpiperidinooxy) and peroxoacetic acid to obtain the trans-2-octenal. The preparation method has mild reaction conditions, simple operation and does not need to use expensive reagents or catalysts.

The invention belongs to the technical field of pharmaceutical chemicals, and particularly discloses a bicyclo [2.1. 1] hexane derivative as well as a preparation method and application thereof. The bicyclo [2.1. 1] hexane derivative is a compound as shown in a formula (I) or a formula (II), a pharmaceutically acceptable salt, a stereoisomer or an isotope label of the bicyclo [2.1. 1] hexane derivative, wherein R1 is optionally selected from C1-C6 alkyl groups, bromomethyl alkyl, benzyl alkyl, ester groups, acylamino and acyl groups; r2 is optionally selected from hydrogen, C1-C6 alkyl, benzyl alkyl, aryl, heteroaryl, alkenyl, halogen and silicon; r3 is optionally selected from hydrogen, C1-C6 alkyl, bromomethyl alkyl, benzyl alkyl, an ester group, an acylamino group, an acyl group, an amido group, a sulfenamide group, halogen and a carboxyl group; and R4 is optionally selected from C1-C6 alkyl, benzyl alkyl, aryl, heteroaryl and alkenyl. And the formula (II) can be obtained by carrying out half-pinacol intramolecular rearrangement on the formula (I). Tests prove that the compounds in the formula (I) and the formula (II) can be used for treating osteoarthritis diseases.

The invention discloses an olefinic unsaturated alcohol isomerization catalyst and a preparation method and application thereof. The catalyst comprises a carrier and an active component, the element composition of the active component is represented by a general formula of PdaXbYcZd, X is selected from one or more of Pt, Ru and Rh, Y is selected from one or more of Se and Te, and Z is selected from one or more of Cd and Sn. The catalyst is prepared by the steps of contacting an active component precursor solution with the carrier, washing, drying and reducing. The catalyst can be applied to an olefinic unsaturated alcohol isomerization reaction, and has the characteristics of long service life and high activity and selectivity.

The invention relates to a method for preparing a compound shown in a formula I. The method comprises the following steps: reducing a compound c to obtain a compound b; oxidizing the compound b to obtain the compound shown in the formula I. The method is mild in reaction condition, easy to control in operation, safe, reliable and low in cost, and can lay a foundation for later industrial enlarged production. Meanwhile, the preparation method disclosed by the invention is high in reaction yield, and the obtained product is high in purity.

The application discloses a method for preparing farnesol from nerolidol, wherein a composite catalytic system composed of a phosphate and a vanadate or molybdate is used to perform isomerization reaction on nerolidol to prepare farnesol. The synthetic route of the application is simple, the catalytic system is simple and easy to obtain, the reaction process is simple, the isomerization reaction has very high chemical selectivity and stereoselectivity, and the synthesis method of farnesol is greatly simplified.

The application provides a method for preparing isoamylene alcohol from 3-methyl-1-butene, which comprises: oxidizing 3-methyl-1-butene to obtain a 2-isopropyl oxirane intermediate, and then isomerizing the intermediate to obtain isoamylene alcohol. The synthetic route is novel, 3-methyl-1-butene, a cheap by-product of refining C5, is used as a starting material, and isoamylene alcohol is prepared through two-step reactions of epoxidation and isomerization, which is simple and efficient, and an economic and feasible route for preparing the product is provided. In the second step of isomerization, lithium phosphate treated by sodium alcohol or potassium alcohol is used as a catalyst to efficiently realize the isomerization of the epoxy intermediate, and isoamylene alcohol is conveniently and quickly prepared.

The invention relates to an improved process for isomerizing polyunsaturated non-aromatic compounds including acyclic conjugated polyenes and alicyclic conjugated polyenes. In particular it relates to an improved and safe process for forming a 11-E retinoid compounds in high yield by expending as few energy as possible and with avoiding at most possible side products or product mixtures. This is achieved by feeding at least one of retinoid compounds of formula 2 to 5, or at least one of retinoid compounds of formula 2 to 5 and retinoid compound of formula 1, an organic solvent and a photosensitizer into a reaction device and irradiating the thus obtained reaction mixture with visible monochromatic light, at least 90% of the power of said monochromatic light and at most 100% of said power being emitted in the range from 460 nm to 580 nm.

The invention discloses a preparation method and application of a catalyst and a composite catalyst. The catalyst disclosed by the invention comprises a titanium silicalite molecular sieve, V2O5 and a metal compound, and the titanium silicalite molecular sieve loads the V2O5 and the metal compound; wherein the metal compound is metal oxide and / or metal carbonate; the metal in the metal oxide is selected from one or more of metal elements in the II main group and lanthanide series; the metal in the metal carbonate is selected from one or more of metal elements in the II main group and lanthanide series; wherein the molar ratio of vanadium in V2O5 to metal in the metal compound is (20-50): 1; the ratio of the sum of the mole numbers of metals in the metal compound and vanadium in V2O5 to the mass of the titanium silicalite molecular sieve is (0.05-2) mol: (0.5-20) kg. The catalyst provided by the invention has a brand new structure, and when the composite catalyst provided by the invention is used for a reaction for preparing isopentenol from methyl butenol, the reaction conversion rate and selectivity are better.

The present invention refers to new air-stable molybdenum alkylidyne catalysts, a process for the preparation thereof and their use for high performance alkyne metathesis.

The present invention relates to a process comprising isomerizing nerolaldehyde of formula (II) to geranial of formula (I), or isomerizing geranial to nerolaldehyde, characterized in that (a) isomerization is accomplished by irradiation with light. The method according to the invention makes it possible to very efficiently convert undesired isomers, which are unavoidable by-products generated during the production of nerolaldehyde and / or geranial, into desired isomers, the economic benefits of the process for producing desired isomers (in high yields by avoiding cost-intensive distillation and avoiding possible by-products) are thus greatly improved.

This invention provides a method for isomerizing propylene oxide to prepare allyl alcohol. The method includes contacting preheated propylene oxide with a catalyst under an inactive carrier gas to carry out an isomerization reaction. The catalyst is a lithium phosphate catalyst supported on elemental Pt. The loading of elemental Pt in the catalyst is 0.5 wt% to 2 wt% based on the mass of lithium phosphate. The method of this invention has higher conversion rate, selectivity, and better catalytic stability (long catalyst life).

Organically bound nitrogen is removed from the ethylenically unsaturated alcohol stream by contacting the ethylenically unsaturated alcohol stream with a weakly acidic solid adsorbent. Trace amounts of organically bound nitrogen tend to impair the action of the oxidation catalyst in subsequent oxidation processes using the ethylenically unsaturated alcohol stream.