Abstract: The invention relates to a process for preparing chloroacetaldehyde acetals of monohydric, dihydric or higher-functionality aliphatic alcohols, in which the chloroacetaldehyde acetal is obtained from an aqueous chloroacetaldehyde solution in the presence of the alcohol to be acetalized and an acid catalyst by azeotropic removal of water with the aid of a solvent, wherein the solvent is a halogenated solvent.

Abstract: The invention relates to a process for preparing chloroacetaldehyde acetals of monohydric, dihydric or higher-functionality aliphatic alcohols, in which the chloroacetaldehyde acetal is obtained from an aqueous chloroacetaldehyde solution in the presence of the alcohol to be acetalized and an acid catalyst by azeotropic removal of water with the aid of a solvent, wherein the solvent is a halogenated solvent.

Abstract: A process for preparing hydroxytyrosol, wherein a compound where X is CH2OH or CH2OM (M=Li, Na, K, Mg, Ca), R1 and R2 are identical or different and are C1-C8 alkyl radical, benzyl radical, alkyl- or halogen-substituted benzyl radical or arylalkyl radical, where R1 and R2 can also be linked via to give a ring, R2, R4, R5 and R6 are identical or different and are hydrogen or C1-C6 alkyl radical, aryl radical, alkyl-substituted aryl radical, where R5 and R6 can also be linked via —(CH2)4—, —(CH2)5— or —(CH2)6— to give a ring, is reacted with an aluminum compound AlR7R8R9 (2), where R7, R8 and R9 are identical or different and are H or C1-C8 alkyl radical, and then an aqueous solution of a hydroxycarboxylic acid is added to form a clear homogeneous acidic solution with a pH<3, and hydroxytyrosol is extracted therefrom.

Abstract: A process for preparing hydroxytyrosol, wherein a compound where X is CH2OH or CH2OM (M=Li, Na, K, Mg, Ca), R1 and R2 are identical or different and are C1-C8 alkyl radical, benzyl radical, alkyl- or halogen-substituted benzyl radical or arylalkyl radical, where R1 and R2 can also be linked via to give a ring, R3, R4, R5 and R6 are identical or different and are hydrogen or C1-C6 alkyl radical, aryl radical, alkyl-substituted aryl radical, where R5 and R6 can also be linked via —(CH2)4—, —(CH2)5— or —(CH2)6— to give a ring, is reacted with an aluminum compound AlR7R8R9 (2), where R7, R8 and R9 are identical or different and are H or C1-C8 alkyl radical, and then an aqueous solution of a hydroxycarboxylic acid is added to form a clear homogeneous acidic solution with a pH<3, and hydroxytyrosol is extracted therefrom.

Abstract: A catalyst on an oxidic support and processes for selectively hydrogenating unsaturated compounds in hydrocarbon streams comprising them using these catalysts are described.

Abstract: A process for introducing annular coated catalysts K into a reaction tube of a tube bundle reactor, in which adhering pairs of annular coated catalysts K formed in the preparation of the annular coated catalysts K, before the introduction thereof into the reaction tube, are removed at least partly from the annular coated catalysts K.

Abstract: The invention relates to a process for acetylating celluloses, lignocelluloses and hemicelluloses such as wood, straw and cotton, and regenerated celluloses produced from natural products, by means of ketene.

Abstract: Glycosylation of 2,6-diaminopurines or silyl derivatives thereof with a compound of the structure is facilitated by the presence of an optionally silylated 1,3-dicarbonyl compound during glycosylation. Byproducts are minimized, while stereoselectivity may be altered by choice of Lewis acid and other reaction condictions.

Abstract: A catalyst on an oxidic support and processes for selectively hydrogenating unsaturated compounds in hydrocarbon streams comprising them using these catalysts are described.

Abstract: A process for introducing annular coated catalysts K into a reaction tube of a tube bundle reactor, in which adhering pairs of annular coated catalysts K formed in the preparation of the annular coated catalysts K, before the introduction thereof into the reaction tube, are removed at least partly from the annular coated catalysts K.

Abstract: The invention relates to a novel process for hydroxymethylating noncyclic ?,?-dialkylcarboxylic acid derivatives with formaldehyde using amide bases at temperatures of from ?40° C. up to the boiling point of the solvent or solvent mixture used.

Abstract: The invention is directed to a method and a device for detecting fault current arcing in electric circuits for consumers with relatively constant power consumption, particularly in onboard aircraft power supplies. The object of the invention is to find a novel possibility for detecting arc faults in electric lines of consumers with a relatively constant power consumption which appreciably reduces erroneous triggering of safeguards without compromising the reliability of switching off in the event that arcing actually occurs. This object is met, according to the invention, in that a voltage value is measured simultaneous with the current measurement, a ratio is formed of the current measurement values and voltage measurement values that are detected in parallel, and an indicator signal is generated for detected arcing when changes in the ratio of current measurement values and voltage measurement values exceed a predetermined threshold value.

Abstract: Glycosylation of 2.6-diaminopurines or silyl derivatives thereof with a compound of the structure is facilitated by the presence of an optionally silylated 1,3-dicarbonyl compound during glycosylation. Byproducts are minimized, while stereoselectivity may be altered by choice of Lewis acid and other reaction condictions.

Abstract: In a process for concentrating an at least partially crystalline solid containing at least one zeolite in a mixture comprising at least one auxiliary, for example a template compound, and said solid, the mixture is ultrafiltrated in a step (II) to divide the mixture into a retentate and a permeate, the solids content in the retentate being higher than that in the mixture and the solids content in the permeate being lower than that in the mixture. This procedure allows auxiliaries, in particular template compounds, present in the permeate to be recycled into a crystallizing step (I) upstream of step (II).

Abstract: In a process for preparing 3-aminomethyl-3,5,5-trimethylcyclohexylamine (isophoronediamine, IPDA) having a cis/trans isomer ratio of at least 70/30 from 3-cyano-3,5,5-trimethylcyclohexanone (isophoronenitrile, IPN), NH3 and H2, the hydrogenation is carried out at from 50 to 200° C. and a pressure of from 50 to 300 bar in the presence of a hydrogenation catalyst having an alkali metal content of ?0.03% by weight, calculated as alkali metal oxide referring to the total weight of the catalyst. The alkali metal content is made up of the contents of Li, Na, K, Rb and Cs; in particular, the alkali metal content is the Na content. A process for producing hydrogenation catalysts having an alkali metal content (in particular a sodium content) of ?0.03% by weight, calculated as alkali metal oxide/sodium oxide referring to the total weight of the catalyst, and the hydrogenation catalysts themselves are also provided by the invention.

Abstract: The invention relates to a novel process for hydroxymethylating noncyclic ?,?-dialkylcarboxylic acid derivatives with formaldehyde using amide bases at temperatures of from ?40° C. up to the boiling point of the solvent or solvent mixture used.

Abstract: The invention is directed to a method and a device for detecting fault current arcing in electric circuits for consumers with relatively constant power consumption, particularly in onboard aircraft power supplies. The object of the invention is to find a novel possibility for detecting arc faults in electric lines of consumers with a relatively constant power consumption which appreciably reduces erroneous triggering of safeguards without compromising the reliability of switching off in the event that arcing actually occurs. This object is met, according to the invention, in that a voltage value is measured simultaneous with the current measurement, a ratio is formed of the current measurement values and voltage measurement values that are detected in parallel, and an indicator signal is generated for detected arcing when changes in the ratio of current measurement values and voltage measurement values exceed a predetermined threshold value.

Abstract: The invention relates to a method for cleaning crude terephthalic acid by means of catalytic, hydrogenating aftertreatment using a catalyst material containing at least one hydrogenation metal applied to a carbon carrier consisting of carbon fibres. The invention also relates to a catalyst consisting of the at least one catalyst material containing the at least one hydrogenation metal applied to the carbon fibres, the BET surface of the carbon carrier being <500 m2/g, and a monolithic catalyst consisting of said at least one catalyst material containing the at least one hydrogenation material applied to the carbon fibres, and at least one support element or skeleton element which differs from the catalyst material and is connected to the same, said element mechanically supporting the catalyst material and maintaining the same in a monolithic form.

Abstract: In a process for concentrating an at least partially crystalline solid containing at least one zeolite in a mixture comprising at least one auxiliary, for example a template compound, and said solid, the mixture is ultrafiltrated in a step (II) to divide the mixture into a retentate and a permeate, the solids content in the retentate being higher than that in the mixture and the solids content in the permeate being lower than that in the mixture. This procedure allows auxiliaries, in particular template compounds, present in the permeate to be recycled into a crystallizing step (I) upstream of step (II).

Abstract: A process is provided for preparing optically active alcohols, amines and derivatives thereof by reacting aldehydes or imines at a temperature of less than 15° C. in the presence of a chiral, enantiomerically pure auxiliary with an organozinc halide which is obtained from zinc and a reactive halogen compound, and water, acid or base, or an alkylating, arylating, acylating or silylating reagent is subsequently added.