Abstract:
The present invention relates to a chemocatalytic liquid-phase process for the direct one-stage amination of alcohols to primary amines by means of ammonia in high yields using a catalyst system containing at least one transition metal compound and a xantphos ligand.
Abstract:
The present invention relates to a process for preparing primary amines comprising the process steps A) provision of a solution of a primary alcohol in a fluid, nongaseous phase, B) contacting of the phase with free ammonia and/or at least one ammonia-releasing compound and a homogeneous catalyst and optionally C) isolation of the primary amine formed in process step B), characterized in that the volume ratio of the volume of the liquid phase to the volume of the gas phase in process step B is greater than 0.05 and/or in that process step B is carried out at pressures greater than 10 bar.
Abstract:
The invention relates to a process for preparing primary amines which comprises the process steps A) provision of a solution of a secondary alcohol in a fluid, nongaseous phase, B) contacting of the phase with free ammonia and/or at least one ammonia-releasing compound and a homogeneous catalyst and optionally C) isolation of the primary amine formed in process step B), characterized in that the volume ratio of the volume of the liquid phase to the volume of the gas phase in process step B is greater than or equal to 0.25, and/or in that the ammonia is used in process step B) in a molar ratio based on the hydroxyl groups in the secondary alcohol of at least 5:1.
Abstract:
A process for the preparation of free carboxylic acids including: A) preparation of carboxylic acid by a biological cell located in an aqueous medium with addition of an amine of formula (I) where R1, R2 and R3, independently of one another, are identical or different, branched or unbranched, optionally substituted hydrocarbon radicals or H; B) for cases where the added amine A) is water-soluble, addition of a water-insoluble amine of formula (I), where, in A) or B), a multiphase system is obtained and the corresponding ammonium carboxylate is formed from the water-insoluble amine and the carboxylic acid; C) removal of the water-insoluble phase; and D) heating of the water-insoluble phase with release of free carboxylic acid.
Abstract:
A searchable library of catalysts, wherein each catalyst is defined by a specific performance profile, is created by a series of steps. The first involves the selection of a catalyst, a substrate and at least two different chemical reactions for catalyst characterization. The next involves contacting the catalyst and substrate under conditions suitable for the selected reaction and measuring for each of the selected reactions a reaction parameter, which is associated with catalyst performance. The catalyst performance is then determined and a value assigned. The performance profile is a table including the performance values. The catalyst is then placed into a library, which is searchable based on the performance profile.
Abstract:
Moldings based on pyrogenic silicon dioxide with a pore volume of 0.5 to 1.8 ml/g are prepared by homogenizing pyrogenic silicon dioxide with methylhydroxyethyl cellulose, wax and polyethylene glycol with the addition of water, subjecting this mixture to a compounding and shaping process, extruding, optionally cutting the extrudate to the desired length using a cutting device, drying at a temperature of 70° to 150° C. and conditioning for a period of 30 minutes to 10 hours at a temperature of 400° to 1200° C. The moldings may be used as catalysts or catalyst supports for the preparation of vinyl acetate monomer, the hydration of ethylene and the hydration of propylene.
Abstract:
A process for the continuous catalytic conversion of organic compounds, that, together with unwanted attendant materials, form a starting substance: first the organic compounds of the starting material are purposely extracted by means of condensed fluids. Then the extract, containing the condensed fluids and organic compounds as the reaction mixture is contacted with a catalyst for the catalytic conversion of the organic compounds to form a product mixture, which contains the individual products of the catalytic conversion. The product mixture is separated from the reaction mixture and the fluids employed are, optionally, conducted back for extraction.
Abstract:
The use of modified silicon dioxide as a catalyst support in catalytic reactions under hydrothermal conditions is described. The pore structure of the supports may be stabilized against hydrothermal reaction conditions by impregnating the catalyst supports with elements of Group IVB of the Periodic Tube of Elements.
Abstract:
A process is disclosed for continuously hydrogenating unsaturated fats, fatty acids or fatty acid esters on a shaped catalyst in a solid bed. The reactants flow over the catalyst in the presence of a medium or solvent mixture in supercritical conditions. This leads to considerably improved activity and selectivity of the hydrogenation reaction compared with conventional trickle bed hydrogenation processes.