摘要:
A process is described for preparing N-substituted 3-hydroxypyrazoles of the formula I ##STR1## where R.sup.1 is unsubstituted or substituted alkyl, alkenyl, alkynyl, cycloalkyl, aryl or heteroaryl andR.sup.2, R.sup.3 are hydrogen, cyano, halogen and unsubstituted or substituted alkyl, alkenyl, alkynyl, cycloalkyl, aryl or heteroaryl,by oxidizing a corresponding pyrazolidin-3-one.
摘要:
The present invention relates to a process for carrying out a chemical reaction in the presence of a ruthenium-carbene complex supported on silicon dioxide in a continuously operated reactor and also the use of corresponding supported catalysts in continuously operated reactors.
摘要:
Ketones of the formula II where A is optionally alkyl-substituted C2-C12-alkanediyl, R1 and R2 are each, independently of one another, C1-C6-alkyl, or R1 and R2 together form optionally alkyl-substituted C3-C10-alkanediyl, and R3 is hydrogen or C1-C6-alkyl, are prepared by reacting a cyclic olefin of the formula I with dinitrogen monoxide to form the ketone of the formula II. The ketone of the formula II can be further hydrogenated to form the saturated ketone of the formula III. Macrocyclic ketones of the formula III, e.g. muscone, are sought after as fragrances.
摘要:
Process for obtaining formic acid by thermal separation of a stream comprising formic acid and a tertiary amine (I), in which a liquid stream comprising formic acid, tertiary amine (I) and water is produced by combining tertiary amine (I) and a formic acid source in the presence of water, water and organic decomposition products of the tertiary amine (I) are removed and formic acid is removed by distillation from the resulting liquid stream in a distillation apparatus, wherein the stream comprising water and organic decomposition products of the tertiary amine (I) which have been separated off is separated into two liquid phases, the upper liquid phase is removed and the lower, water-comprising liquid phase is recirculated to the formic acid source.
摘要:
The invention relates to a tube bundle reactor with a flat feed hood. Alternatively, the release hood may also have a flat design. The flat design reduces the heat of reaction which arises in the hood in the case of reaction types which take place not only in the tube bundle (uncatalyzed reactions and reactions with homogeneously distributed catalyst). This greatly suppresses undesired reactions which already take place in the hood owing to accumulated heat, which achieves a higher selectivity in the case of thermally sensitive reactions. In addition, the thermal distribution within the hoods can be controlled precisely.The tube bundle reactor comprises a tube bundle which has a feed end which is connected to a feed hood of the tube bundle reactor, wherein the feed hood is configured in a flat design with a cross-sectional area at the feed end and an internal volume, and the ratio of internal volume to cross-sectional area is less than 0.35 m. The invention is further implemented by means of a process for operating a tube bundle reactor, comprising: introducing a reactant mixture into a tube bundle and converting at least a proportion of the reactant mixture within the tube bundle to a product. The introducing comprises: feeding the reactant mixture into an interior of a feed hood of the tube bundle reactor and passing the reactant mixture on into a feed end of the tube bundle in the form of a fluid stream. The fluid stream has a cross-sectional area on entry into the feed end, and the interior of the feed hood through which the fluid stream flows has an internal volume; where the ratio of internal volume to cross-sectional area is less than 0.35 m.
摘要:
The invention provides a method for producing polyols, comprising the steps of a) reacting unsaturated natural fats, unsaturated natural fatty acids and/or fatty acid esters with dinitrogen monoxide, b) reacting the product obtained in step a) with hydrogen using a heterogeneous catalyst.
摘要:
A method for separating acetonitrile from water, comprising (i) providing a stream S1 containing at least 95 wt.-%, based on the total weight of S1, acetonitrile and water, wherein the weight ratio of acetonitrile:water is greater than 1; (ii) adding a stream P, comprising at least 95 wt.-% C3, based on the total weight of stream P, to S1 to obtain a mixed stream S2, C3 being propene optionally admixed with propane with a minimum weight ratio of propene:propane of 7:3; (iii) subjecting S2 to a temperature of 92° C. at most and a pressure of at least 10 bar, obtaining a first liquid phase L1 essentially consisting of C3, acetonitrile, and water, and a second liquid phase L2 essentially consisting of water and acetonitrile wherein the weight ratio of acetonitrile:water in L2 is less than 1; (iv) separating L1 from L2.
摘要:
Process for preparing glycidyl esters, wherein carbonate esters of the formula I are reacted in the presence of a homogeneous catalyst with elimination of carbon dioxide to form glycidyl esters of the formula II where R in the above formulae is an organic radical having from 1 to 20 carbon atoms.
摘要:
The present invention provides a process for the epoxidation of propene which comprises reacting propene with hydrogen peroxide in the presence of methanol as solvent and a titanium zeolite catalyst, the process further comprising separating propylene oxide from the reaction mixture to obtain a mixture comprising methanol, water, at least one carboxylic acid and at least one carbonyl compound, wherein the at least one carboxylic acid is at least partially neutralized, said process optionally comprising a hydrogenation stage.
摘要:
The invention relates to a method for producing cyclopentanone. Said method comprises the step of reacting a mixture (G1), which contains at least cyclopentene, with a mixture (G2), which contains at least dinitrogen monoxide. The reaction is carried out in at least one reactor (R1) having channels with a diameter in the range of 0.1 mm to 50 mm, the reactor comprising at least two zones (Z1) and (Z2) having channels with different diameters and the diameters of the channels of zone (Z1) being smaller than the diameter of the channels of zone (Z2).