Abstract: The invention relates to a process for preparing 4-vinylcyclohexene, which comprises the steps

Abstract: The preparation of alkylaryl compounds takes place, inter alia, by a1) preparation of a C4-olefin mixture from LPG, LNG or MTO streams, b1) reaction of the C4-olefin mixture obtained in this way over a metathesis catalyst for the preparation of an olefin mixture comprising 2-pentene and/or 3-hexene, and optional removal of 2-pentene and/or 3-hexene, c1) dimerization of the 2-pentane and/or 3-hexene obtained in stage b1) over a dimerization catalyst to give a mixture comprising C10-12-olefins, and optional removal of the C10-12-olefins, d1) reaction of the C10-12-olefin mixtures obtained in stage a1) with an aromatic hydrocarbon in the presence of an alkylation catalyst to form alkylaromatic compounds, it being possible to add additional linear olefins prior to the reaction.

Abstract: A process prepares methacrylic acid from isobutane by subjecting isobutane to a partial catalytic dehydrogenation in the gas phase and charging an oxidation zone with the isobutenic product gas mixture after the components other than isobutane and isobutene have been substantially removed from the product gas mixture. The oxygen required to charge the oxidation zone is introduced accompanied by nitrogen.

Abstract: A process for preparing at least one partial oxidation and/or ammoxidation product of a hydrocarbon by partially dehydrogenating at least one saturated hydrocarbon H under heterogeneous catalysis and using the resulting product gas mixture A, which comprises the partially dehydrogenated hydrocarbon H, as such or in modified form for heterogeneously catalyzed partial oxidation and/or ammoxidation of the partially dehydrogenated hydrocarbon present in the product gas mixture A, said process including at least one mechanical separating operation inserted between the product gas mixture A and the heterogeneously catalyzed partial oxidation and/or ammoxidation.

Abstract: The invention relates to a process for preparing unsaturated nitrites from the corresponding alkanes which comprises the steps:

Abstract: C2-C30-alkanes are dehydrogenated in a process in which

Abstract: Partial oxidation products and/or ammoxidation products of an olefinic hydrocarbon A′ are prepared by a process in which said olefinic hydrocarbon is produced during normal operation by partial dehydrogenation and/or oxydehydrogenation of hydrocarbon A and fed in from another source during partial or complete nonoperation of the dehydrogenation and/or oxydehydrogenation.

Abstract: A process prepares methacrolein from isobutane by subjecting isobutane to a partial catalytic dehydrogenation in the gas phase and using the isobutenic product gas mixture to charge an oxidation zone in which the isobutene is oxidized to methacrolein in the gas phase with heterogeneous catalysis using molecular oxygen accompanied by molecular nitrogen as the oxygen source.

Abstract: In a process for the preparation of acrolein or acrylic acid or a mixture thereof from propane, the propane is subjected, in a first reaction stage, to a partial dehydrogenation under heterogeneous catalysis to give propene, of the components contained in the product gas mixture formed in the first reaction stage other than propene and propane at least a portion of the molecular hydrogen present is then separated off from said mixture and the product gas mixture is then used for the preparation of acrolein and/or acrylic acid by gas-phase catalytic propylene oxidation, molecular nitrogen being present for diluting the reaction gas mixture during the propylene oxidation.

Abstract: The invention relates to a method for the production of propene from a mixture (M1) essentially consisting of the following: ethylene (component E); hexenes (components H); optionally olefinic hydrocarbons (components K1a) different from ethylene and hexenes and optionally other inert hydrocarbons (components K1b). According to said method, the mixture (M1) is brought into contact with a metathesis catalyst at a temperature of 20 to 350° C., with the proviso that, as regards mixture (M1): the molar proportion of the sum consisting of 2-hexene and 3-hexene in components H is at least 4:1 to 99:1; the molar ratio between component E and the sum of components H and K1a is 1:1 to 100:1; the ratio between 2-hexenes and 3-hexenes is at least 2:1 as long as the 3-hexenes contained in the mixture are not simultaneously subjected to isomerization by means of which the proportion of 2-hexenes is correspondingly increased.

Abstract: In a process for preparing at least one partial oxidation and/or ammoxidation product of propylene, the propylene is obtained from crude propane by dehydrogenating and subjected in the presence of unconverted propane as a constituent of a gas mixture 2 which comprises a total C4-hydrocarbon content of ≦3% by volume to a heterogeneously catalyzed gas phase partial oxidation and/or partial gas phase ammoxidation.

Abstract: Process for preparing at least one partial oxidation and/or ammoxidation product of propylene, in which the propylene is produced from crude propane by dehydrogenation and is subjected to a heterogeneously catalyzed gas-phase partial oxidation and/or partial gas-phase ammoxidation in the presence of unreacted propane as constituent of a gas mixture 2 containing <1% by volume of 1-butene.

Abstract: In a process for the heterogeneously catalyzed dehydrogenation in one or more reaction zones of one or more dehydrogenatable C2-C30-hydrocarbons in a reaction gas mixture comprising them, with at least part of the heat of dehydrogenation required being generated directly in the reaction gas mixture in at least one reaction zone by combustion of hydrogen, the hydrocarbon or hydrocarbons and/or carbon in the presence of an oxygen-containing gas, the reaction gas mixture comprising the dehydrogenatable hydrocarbon or hydrocarbons is brought into contact with a Lewis-acid dehydrogenation catalyst which has essentially no Bronsted acidity.

Abstract: A process for regenerating a dehydrogenation catalyst comprises the steps (a)-(f):

Abstract: In a process for the preparation of acrolein or acrylic acid or a mixture thereof from propane, the propane is subjected, in a first reaction stage, to a partial dehydrogenation under heterogeneous catalysis to give propene, of the components contained in the product gas mixture formed in the first reaction stage other than propene and propane at least a portion of the molecular hydrogen present is then separated off from said mixture and the product gas mixture is then used for the preparation of acrolein and/or acrylic acid by gas-phase catalytic propylene oxidation, molecular nitrogen being present for diluting the reaction gas mixture during the propylene oxidation.

Abstract: Compounds of the formula I in which R1, R2, R3 and Ar have the meanings indicated in the claims, are suitable for the production of pharmaceuticals, for example for the prophylaxis and therapy of cardiovascular diseases such as high blood pressure, angina pectoris, cardiac insufficiency, thromboses or atherosclerosis. The compounds of the formula I have the ability to modulate the endogenous production of cyclic guanosine monophosphate (cGMP) and are generally suitable for the therapy and prophylaxis of disease states which are associated with a disturbed cGMP balance.

Abstract: The invention relates to methods for detecting a soluble guanylate cyclase whose heme iron is in the trivalent oxidation state, and to methods for finding chemical substances which stimulate the activity of a soluble guanylate cyclase when the heme iron of at least part of this soluble guanylate cyclase is oxidized to the trivalent state and also to diagnostic aids or kits for detecting a soluble guanylate cyclase with trivalent heme iron. Further, the invention relates methods for detecting a soluble guanylate cyclase lacking a heme group, and to methods for finding chemical substances which stimulate the activity of a soluble guanylate cyclase lacking a heme group.

Abstract: The invention relates to methods for detecting a soluble guanylate cyclase whose heme iron is in the trivalent oxidation state, and to methods for finding chemical substances which stimulate the activity of a soluble guanylate cyclase when the heme iron of at least part of this soluble guanylate cyclase is oxidized to the trivalent state and also to diagnostic aids or kits for detecting a soluble guanylate cyclase with trivalent heme iron. Further, the invention relates methods for detecting a soluble guanylate cyclase lacking a heme group, and to methods for finding chemical substances which stimulate the activity of a soluble guanylate cyclase lacking a heme group.

Abstract: The invention presents a subwoofer-loudspeaker box which is essentially built in one piece. This one-piece housing is completed with a separation wall (20) which can be inserted through an installation opening (12). An insertion frame (16) is installed on the inside wall (15) of the box housing (10) to establish the necessary seal between the volumes (28.1, 28.2) which are divided by the separation wall (20). A seal (29) is also provided for the peripheral edge (27) of the separation wall (20). The separation wall (20) is furthermore equipped with a cover plate (21) which closes the installation opening (12) as soon as the separation wall (20) reaches its final position in the box housing (10).

Abstract: Heteropolyoxometallates of tungsten, molybdenum and vanadium with a structurally defined micropore volume, a method of production by means of the hydrothermal reaction of the appropriate metal with an associated oxide, a diamine, phosphoric acid and water, and the use of the novel compounds as catalysts.