Abstract: A process for the preparation of carbonyl compounds by oxidation of alcohols in the gas phase with a gas containing oxygen in the presence of catalysts containing copper and silver.

Abstract: 4-Formyltetrahydropyrans of the general formula I ##STR1## where R.sup.1 is hydrogen, C.sub.1 -C.sub.12 -alkyl, C.sub.2 -C.sub.12 -alkenyl, C.sub.1 -C.sub.6 -alkoxy-substituted C.sub.1 -C.sub.12 -alkyl, C.sub.4 -C.sub.12 -cycloalkyl, unsubstituted or substituted aryl, hetaryl or aralkyl, or an unsubstituted or substituted, saturated or unsaturated 5-membered or 6-membered ring which may be interrupted by N, O or S, are prepared by a process in which a pyran derivative of the general formula II ##STR2## where R.sup.1 is as defined above, R.sup.2 and R.sup.3 are each OH or together are an oxygen atom and thus form an oxirane ring, and R.sup.4 is hydrogen where R.sup.2 and R.sup.3 are each OH, and is hydrogen or tert-butoxycarbonyl where R.sup.2 and R.sup.3 together are an oxygen atom, is treated at elevated temperatures with a catalyst selected from the group consisting of zeolites, phosphates, boric acid on a carrier and silica or mixtures of these. Novel 4-formyltetrahydropyrans are also proposed.

Abstract: A process for the preparation of carbonyl compounds by oxidation of alcohols in the gas phase with a gas containing oxygen in the presence of catalysts containing copper or silver and a phosphorus compound that is volatile under the conditions of the reaction, the ratio of the mass of phosphorus to the mass of the alcohol being less than 0.5 ppm.

Abstract: Bifunctional compounds of the formula ##STR1## where R.sup.1, R.sup.2 and R.sup.3 are each alkyl of 1 to 6 carbon atoms, R.sup.2 and R.sup.3 may furthermore be hydrogen, R.sup.2 is furthermore alkoxy and R.sup.4 is hydrogen, alkyl of 1 to 6 carbon atoms or alkoxy, and a double bond may be present between carbon atoms 2 and 3, are prepared by converting a tetraalkoxyalkane or a dialkoxyalkanoate of the formulae ##STR2## where R.sup.1, R.sup.2, R.sup.3 and R.sup.4 have the above meanings, in the presence of a catalyst, such as a zeolite, in particular one of the pentasil type, and/or a phosphate and/or phosphoric acid on a carrier.

Abstract: In order to compound organic materials which are crystalline under standard conditions, these materials, in the pulverulent and/or molten state, are processed in a self-purging, twin-screw extruder in which the screws rotate in the same direction, ejected through one or more narrow passages into a low pressure zone, cooled and comminuted to give particles. In order to improve the pourability and shelf life, the materials are completely crystallized by the time they reach the end of the screws, and are heated during discharge through the narrow passage, in order to form a melt film. Dust-free granules havig a smooth surface can be produced in this manner.

Abstract: An aqueous glyoxal solution is decolorized by a process in which the said solution is passed over granulated active carbon which is arranged in a fixed bed and whose differential pore radius distribution has a maximum of from 10 to 100 A, the Peclet number being from 500 to 5000, the decolorized glyoxal solution is discharged, the active carbon bed is then regenerated by treating it with an aqueous solution of an alkaline agent and then with an aqueous acid, and further glyoxal solution to be decolorized is passed over the active carbon regenerated in this manner.

Abstract: Imidazoles which carry a hydroxymethyl radical on a carbon atom of the imidazole ring are prepared by treating a 1-hydroxymethylimidazole, which is unsubstituted in one or more of the positions 2, 4 and 5 of the imidazole ring, with an anion exchanger.

Abstract: 2-Methyl-2-alkenals of the formula ##STR1## where R.sup.1 and R.sup.2 are each hydrogen, alkyl which may additionally carry aromatic radicals, or an aromatic radical, are prepared by isomerizing a 2-alkylacrolein of the formula ##STR2## in the presence of hydrogen and of a catalyst which contains palladium and an oxide or salt of a rare earth metal as active components, at from 20.degree. to 120.degree. C. and under from 1 to 100 bar.

Abstract: Trimethylolalkanes are prepared by reacting an n-alkanal with formaldehyde and a trialkylamine in aqueous solution and then hydrogenating the product, by a method in which from 2.2 to 4.5 moles of formaldehyde and from 0.6 to 3 moles of trialkylamine are used per mole of the alkanal, and the reaction mixture is worked up by distillation either before or after the hydrogenation.

Abstract: Substituted phenols of the general formula I ##STR1## where R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are each hydrogen or an aliphatic or aromatic hydrocarbon radical, are prepared by dehydrogenating a cyclic alcohol of the general formula II ##STR2## or a cyclic ketone of the general formula III ##STR3## where one of the broken lines can be an additional C-C bond, in the gas phase at from 150.degree. to 380.degree. C. over a supported noble metal catalyst, by a process in which the dehydrogenation catalyst used is palladium or platinum on an aluminum spinel carrier, in particular an aluminum spinel which has a BET specific surface area of from 5 to 150 m.sup.2 /g or, for the dehydrogenation of cyclohexenones, preferably from 10 to 50 m.sup.2 /g. Particularly suitable aluminum spinels are those which, in addition to aluminum, contain magnesium, zinc, cobalt or nickel.

Abstract: Aqueous solutions of glyoxal which contain acids are purified by treatment with a solution which contains from 20 to 60% by weight of a tertiary amine and from 80 to 40% by weight of an alcohol which is not infinitely miscible with water, the treatment being carried out by mixing the two solutions during a residence time of less than 5 minutes.

Abstract: A process for the preparation of 1-substituted imidazoles by reacting an .alpha.-dicarbonyl compound with ammonia, an aldehyde and a primary amine in an aqueous medium, in a single stage, at 20.degree.-150.degree. C.

Abstract: Aromatic amines (anilines) are obtained directly or via the corresponding cycloaliphatic amines by an aminating/hydrogenating reaction of phenols with ammonia and hydrogen over a supported palladium catalyst which also contains elements from group 1b, 2b or 7b of the periodic table as well as iron, cobalt or nickel, as such or in the form of their compounds, and, preferably, an inorganic base, said catalysts also having dehydrogenating properties.

Abstract: Hydrogenation catalysts which are prepared from mixed crystals of copper-zinc compounds, obtained by precipitation, of the formulaCu.sub.1.5-3 Zn.sub.1-2.5 (CO.sub.3).sub.1-2 (OH).sub.4-6.(H.sub.2 O).sub.0-1by decomposition at 200.degree.-500.degree. C., and are used for the catalytic preparation of propanediols of the formula ##STR1## where the R's may be identical or different and each is an aliphatic, araliphatic or aromatic radical, or the two R's together with the adjacent carbon atom are members of an alicyclic ring, by hydrogenating hydroxypropionaldehydes of the formula ##STR2## where R has the above meanings, and to processes for the preparation of propanediols, using such catalysts. The propane-1,3-diols obtainable by the novel process are valuable starting materials for the preparation of lubricants, plastics, surface coatings and synthetic resins, for example of polyesters derived from the propanediols.

Abstract: Hydrogenation catalysts, which have a specific surface area of from 50 to 150 square meters per gram, solely or partially contain crystals having a spinel structure and copper in the form of copper oxide, and have been obtained by precipitating copper and aluminum in a ratio of from 0.25 to 3 atoms of copper per atom of aluminum from their compounds in the presence of a carbonate at a pH of from 4.5 to 9 and calcining the resulting precipitate at from 300.degree. to 800.degree. C., for the catalytic preparation of propanediols by hydrogenating hydroxypropionaldehydes at not more than 300 bar pressure and from 50.degree. to 200.degree. C., and processes for the preparation of propanediols by the use of such catalysts.The propanediols obtainable by the process of the invention, in particular 2,2-dimethylpropane-1,3-diol, are valuable starting materials for the preparation of lubricants, plastics, surface coatings and synthetic resins, for example corresponding polyesters.

Abstract: Hydrogenation catalysts, which have a specific surface area of from 50 to 150 square meters per gram, solely or partially contain crystals having a spinel structure and copper in the form of copper oxide, and have been obtained by precipitating copper and aluminum in a ratio of from 0.25 to 3 atoms of copper per atom of aluminum from their compounds in the presence of a carbonate at a pH of from 4.5 to 9 and calcining the resulting precipitate at from 300.degree. to 800.degree. C., for the catalytic preparation of propanediols by hydrogenating hydroxypropionaldehydes at not more than 300 bar pressure and from 50.degree. to 200.degree. C., and processes for the preparation of propanediols by the use of such catalysts.The propanediols obtainable by the process of the invention, in particular 2,2-dimethylpropane-1,3-diol, are valuable starting materials for the preparation of lubricants, plastics, surface coatings and synthetic resins, for example corresponding polyesters.

Abstract: Aromatic amines, in particular substituted amines, are obtained from corresponding alicyclic alcohols or ketones, in one step, by amination and dehydrogenation with ammonia in the presence of hydrogen and of a palladium catalyst which also contains zinc or cadmium.

Abstract: 3,6-Dimethyl-3-hydroxy-oct-1-ynes and -oct-1-enes and their esters with lower alkanoic acids, of the general formula I ##STR1## where X and Y are H or the two X's and/or the two Y's together are a further bond between the carbon atoms on which they are present, and R is H, --CO--CH.sub.3, --CO--C.sub.2 H.sub.5 or --CO--C.sub.3 H.sub.7, their use as scents, and a process for the preparation of 3,6-dimethyl-3-hydroxy-octane. The novel compounds exhibit interesting, predominantly floral, woody, herbal and fruity notes. The alcohols of the formula I are of particular importance because they serve as intermediates for a novel and particularly advantageous method of obtaining 3,6-dimethyl-3-hydroxy-octane, a compound required in large amounts as a fragrance for soaps and detergents.

Abstract: A process for the preparation of cis-2,6-dimethylmorpholine by isomerizing trans-2,6-dimethylmorpholine, wherein trans-2,6-dimethylmorpholine is converted, in the presence of hydrogen and of a catalyst containing palladium as well as zinc, cadmium or manganese or a mixture of these, at from 150.degree. to 250.degree. C. under a pressure of from 1 to 200 bar.

Abstract: A process for the preparation of aralkylamines of the formula ##STR1## where R.sup.1 is hydrogen, an aliphatic hydrocarbon radical, a cycloaliphatic radical or alkoxy,R.sup.2, R.sup.3 and R.sup.4 are hydrogen or alkyl,X.sup.1, X.sup.2, X.sup.3 and X.sup.4 are hydrogen or alkyl,A is ##STR2## X.sup.5, X.sup.6, X.sup.7, X.sup.8, X.sup.9 and X.sup.10 are hydrogen or alkyl andn is 2, 3 or 4,by reacting a secondary amine with a carbonyl compound in the presence of hydrogen and of a hydrogenation catalyst which comprises palladium, mixed with zinc, cadmium, manganese and/or a rare earth metal oxide, on an inert carrier.