Abstract: Method for preparing a ?-hydroxyketone having 4 to 8 carbon atoms by reacting formaldehyde with a branched or unbranched dialkyl ketone having 3 to 7 carbon atoms in the liquid phase in a reactor in the presence of a basic component at a temperature of 50 to 150° C. and a pressure of 0.2 to 10 MPa abs, in which (a) a trialkylamine having 1 to 4 carbon atoms per alkyl group is used as basic component and the reaction (b) is carried out in the presence of 1 to 25% by weight water, based on the liquid phase, and (c) at a molar ratio of trialkylamine to formaldehyde in the liquid phase of from 1 to 5.

Abstract: Method for preparing 1-hydroxy-2-methyl-3-pentanone (I) by reacting formaldehyde with diethyl ketone in a reactor in the presence of water and a basic component at a temperature of 50 to 150° C. and a pressure of 0.2 to 10 MPa abs, in which the basic component used is a trialkylamine from the group comprising trimethylamine, N,N-dimethylethylamine, N,N-diethylmethylamine, triethylamine, N,N-dimethyl-n-propylamine, N-ethyl-N-methyl-n-propylamine, N,N-dimethylisopropylamine, N-ethyl-N-methylisopropylamine, N,N-dimethyl-n-butylamine, N,N-dimethylisobutylamine and N,N-dimethyl-sec-butylamine, and from the reaction mixture obtained, trialkylamine as low boiler and a bottom product comprising 1-hydroxy-2-methyl-3-pentanone (I) as high boiler are separated in a distillation apparatus, wherein the distillation apparatus is operated at a top pressure of 0.2 to 1 MPa abs.

Abstract: Many optically active amines are valuable pharmaceuticals and intermediates for the preparation of active compounds. It is frequently the case that only one of the two enantiomers is active or not harmful, so that isolation of this enantiomer from the racemic mixture is necessary. Processes for racemate resolution make it possible to separate racemic mixtures into their enantiomers. Here, it is useful to once again racemize the enantiomer which is not required and recirculate it to racemate resolution and thus improve the yield of the desired enantiomer. The present invention relates to processes for the racemization of optically active amines, in particular arylalkylamines, in the presence of hydrogen and a hydrogenation/dehydrogenation catalyst comprising nickel, cobalt and copper as active components at elevated temperature.

Abstract: A process for preparing aluminum oxide with a low calcium content, in which (1) crude alpha- and/or gamma-aluminum oxide with a total calcium content in the range from 50 to 2000 ppm, based on the crude alpha- and/or gamma-aluminum oxide, is mixed with an aqueous solution or suspension comprising the compounds selected from the group of inorganic acid, organic acid and complexing agent, (2) the mixture from step (1) is admixed with a flocculating aid, (3) in the mixture of step (2), the solids are separated from the liquid, (4) the solids separated are mixed with water in the presence or in the absence of a flocculating aid, (5) in the mixture of step (4), the solids are separated from the liquid, (6) optionally, steps (4) and (5) are repeated once or more than once, (7) optionally, the solids separated optionally after addition of further compounds, are dried.

Abstract: A process for preparing aluminum oxide with a low calcium content, in which (1) crude alpha- and/or gamma-aluminum oxide with a total calcium content in the range from 50 to 2000 ppm, based on the crude alpha- and/or gamma-aluminum oxide, is mixed with an aqueous solution or suspension comprising the compounds selected from the group of inorganic acid, organic acid and complexing agent, (2) the mixture from step (1) is admixed with a flocculating aid, (3) in the mixture of step (2), the solids are separated from the liquid, (4) the solids separated are mixed with water in the presence or in the absence of a flocculating aid, (5) in the mixture of step (4), the solids are separated from the liquid, (6) optionally, steps (4) and (5) are repeated once or more than once, (7) optionally, the solids separated optionally after addition of further compounds, are dried.

Abstract: A process for preparing magnesium compounds by precipitation, in which an aqueous solution or suspension of a magnesium compound is mixed with a precipitant and the corresponding magnesium compound is precipitated wherein the aqueous solution or suspension of a magnesium compound is obtained by reaction of an organomagnesium compound with an aldehyde or a ketone or another electrophile and subsequent aqueous workup of the reaction mixture at a pH of at most 10 or from a magnesium salt with a maximum calcium content and/or potassium content of 200 ppm, based on the magnesium salt used.

Abstract: Process for the preparation of cyclopentane derivatives of the formula I in which R is a C1- to C10-alkyl group, which comprises reacting cyclohexanol or cyclohexene or mixtures of both compounds to give 1-methyl-1-cyclopentene (1st stage) and subsequently adding a C1- to C10-alkanol onto the double bond of the 1-methyl-1-cyclopentene (2nd stage).

Abstract: Process for the preparation of 1-methylcyclopentene by thermal reaction of cyclohexanol or cyclohexene or mixtures of both compounds to give 1-methylcyclopentene, wherein the resulting by-products 3-methylcyclopentene and 4-methylcyclopentene (double-bond isomers of 1-methylcyclopentene) are returned to the reaction.

Abstract: Chiral compounds of the formula (1), which are optically pure or highly optically enriched in which R0 is C1-C12-alkyl which is unsubstituted or substituted by 1 to 2 C1-C4-alkoxy; cyclo-pentyl or cyclohexyl, which is unsubstituted or substituted by 1 to 3 C1-C4-alkyl or C1-C4-alkoxy; or benzyl, phenyl or naphtyl which is unsubstituted or substituted by 1 to 3 C1-C4-alkyl, C1-C4-alkoxy, C1-C4-fluoroalkyl or C1-C4-fluoroalkoxy, F or Cl, or R0 is —CR5R6OH or —CR5R6OSi(C1-C8-alkyl)3 wherein R5 and R6 are independently selected from the group consisting of H, unsubstituted C1-C12 alkyl, substituted C1-C12 alkyl, unsubstituted C4-C8 cyclo alkyl, substituted C4-C8 cyclo alkyl, unsubstituted aryl, substituted aryl or wherein R5 and R6 can form an unsubstituted 5-6 membered aliphatic carbocycle or a substituted 5-6 membered aliphatic carbocycle, each of R1 and R?1 independently is hydrogen or has the meaning of R0 whereby R1, R?1 and R0 can be same or different, R2 and R3 are independently a C-bonded hydrocarbon radi