Abstract:
The invention relates to the use of chromen-4-one derivatives of the formula I where R1 and R2 may be identical or different and are selected from H, —C(═O)—R7, —C(═O)—OR7, alkyl groups, alkenyl groups, hydroxyalkyl groups and/or cycloalkyl groups and/or cycloalkenyl groups, R3 is H or alkyl groups, R4 is H or OR8, R5 and R6 are selected from —H, —OH, alkyl groups, alkenyl groups and hydroxyalkyl groups, and R7 is H, alkyl groups, a polyhydroxyl compound, such as, preferably, an ascorbic acid radical or glycosidic radicals, and R8 is H or alkyl groups, where at least two of the substituents R1, R2 and R4-R6 are different from H or at least one substituent from R1 and R2 is —C(═O)—R7 or —C(═O)—OR7, for the care, preservation or improvement of the general state of the skin or hair.
Abstract:
A process for hydrogenating an organic compound which has at least one carbonyl group, in which the organic compound is brought into contact in the presence of hydrogen with a shaped article which can be produced in a process in which (i) an oxidic material comprising copper oxide, aluminum oxide and at least one of the oxides of lanthanum, tungsten, molybdenum, titanium or zirconium is prepared, (ii) powdered metallic copper, copper flakes, powdered cement, graphite or a mixture thereof is added to the oxidic material, and (iii) the mixture resulting from (ii) is shaped to a shaped article.
Abstract:
A process for the hydrogenation of an organic compound containing at least one carbonyl group comprises bringing the organic compound in the presence of hydrogen into contact with a shaped body which can be produced by a process in which (i) an oxidic material comprising copper oxide, zinc oxide and aluminum oxide is made available, (ii) pulverulent metallic copper or pulverulent cement or a mixture thereof is added to the oxidic material, and (iii) the mixture resulting from (ii) is shaped to form a shaped body.
Abstract:
In a process for preparing alcohols by catalytic hydrogenation of carbonyl compounds over a catalyst comprising rhenium on activated carbon, the catalyst used comprises rhenium (calculated as metal) in a weight ratio to the activated carbon of from 0.0001 to 0.5, platinum (calculated as metal) in a weight ratio to the activated carbon of from 0.0001 to 0.5 and, if appropriate, at least one further metal selected from among Zn, Cu, Ag, Au, Ni, Fe, Ru, Mn, Cr, Mo, W and V in a weight ratio to the activated carbon of from 0 to 0.25, and the activated carbon has been nonoxidatively pretreated. It is also possible to prepare ethers and lactones if the hydrogen pressure is not more than 25 bar. In this case, the activated carbon in the catalyst may also have been nonoxidatively pretreated.
Abstract:
The invention relates to the use of chrome-4-one derivatives of the formula I where R1 and R2 may be identical or different and are selected from H, —C(═O)—R7, —C(═O)—OR7, alkyl groups, alkenyl groups, hydroxyalkyl groups and/or cycloalkyl groups and/or cycloalkenyl groups, R3 is H or alkyl groups, R4 is H or OR8, R5 and R6 are selected from —H, —OH, alkyl groups, alkenyl groups and hydroxyalkyl groups, and R7 is H, alkyl groups, a polyhydroxyl compound, such as, preferably, an ascorbic acid radical or glycosidic radicals, and R8 is H or alkyl groups, where at least two of the substituents R1, R2 and R4—R6 are different from H or at least one substituent from R1 and R2 is —C(═O)—R7 or —C(═O)—OR7, for the care, preservation or improvement of the general state of the skin or hair.
Abstract:
The present invention provides a process for preparing 2-cyclopentenones of the general formula: where R1 to R4 are each hydrogen atoms or are alkyl or alkenyl radicals having from 1 to 12 carbon atoms, cycloalkyl or cycloalkenyl radicals having from 5 to 7 carbon atoms, aralkylene or aryl radicals, by converting hexenedioic acids and/or their esters of the general formulae where R1 to R4 are each as defined above and R5 and R6 are each hydrogen atoms or are alkyl radicals having from 1 to 12 carbon atoms, cycloalkyl radicals having 5 or 6 carbon atoms, aralkyl or aryl radicals, at temperatures of from 150 to 450° C., over solid, oxidic catalysts, wherein the catalysts on an oxidic support material comprise from 0.01 to 5% by weight of at least one alkali metal oxide.
Abstract:
Preparation of alkanolamines having improved color quality by treating the alkanolamine with hydrogen in the presence of a hydrogenation catalyst at elevated temperature, by using, as hydrogenation catalyst, a heterogeneous catalyst comprising Re, Ru, Rh, Pd, Os, Ir, Pt and/or Ag and a support material chosen from the group consisting of activated carbon, alpha-aluminum oxide, zirconium dioxide and titanium dioxide, where the catalyst, in the case of activated carbon as support material, has a cutting hardness of at least 10 N, a side crushing strength of at least 30 N or a compressive strength of at least 25 N.
Abstract:
A process for hydrogenating an organic compound which has at least one carbonyl group, in which the organic compound is hydrogenated in the presence of a shaped article which contains (i) an oxidic material comprising copper oxide, aluminum oxide and lanthanum oxide, and (ii) powdered metallic copper, copper flakes, powdered cement, graphite or a mixture thereof, is provided.
Abstract:
In a process for preparing alcohols by catalytic hydrogenation of carbonyl compounds over a catalyst comprising rhenium on activated carbon, the catalyst used comprises rhenium (calculated as metal) in a weight ratio to the activated carbon of from 0.0001 to 0.5, platinum (calculated as metal) in a weight ratio to the activated carbon of from 0.0001 to 0.5 and, if appropriate, at least one further metal selected from among Zn, Cu, Ag, Au, Ni, Fe, Ru, Mn, Cr, Mo, W and V in a weight ratio to the activated carbon of from 0 to 0.25, and the activated carbon has been nonoxidatively pretreated. It is also possible to prepare ethers and lactones if the hydrogen pressure is not more than 25 bar. In this case, the activated carbon in the catalyst may also have been nonoxidatively pretreated.
Abstract:
A description is given of the use of asymmetrically substituted urea derivatives of the general formula (I) where R1 and R2 each independently are a linear or branched aliphatic hydrocarbon radical having 1 to 4 carbon atoms as accelerators in combination with dicyandiamide as latent hardener for epoxy resin systems based on unhalogenated or halogenated bisphenols of type A or F and also based on resorcinol or tetrakisphenylolethane. The advangages of the inventively proposed accelerator/hardener combination are, for example, the excellent reactivity and very good storage stability. Moreover, the mechanical properties of the resins cured accordingly are likewise outstanding.