Abstract:
A process for preparing homoallyl alcohols by catalysed reaction of alkenes with aldehydes or ketones, characterized in that the reaction is effected in the presence of noncovalently immobilized ionic liquid phase catalysts in the gas phase.
Abstract:
The invention relates to the use of cyclic carbonates of formula I or mixtures thereof in epoxy resin compositions, and epoxy resin compositions that contain such cyclic carbonates. In said formula R 1 and R 2 represent, independently of one another, hydrogen, C 1 -C 6 -alkyl, C 1 -C 4 -alkoxy-C 1 -C 4 -alkyl, C 5 -C 6 -cycloalkyl, phenyl, phenyl-C 1 -C 4 -alkyl, C 2 -C 6 -alkenyl or C 2 -C 6 -alkinyl, or R 1 and R 2 together represent a C 3 -C 11 -alkylene group; R 3 and R 4 represent, independently of one another, hydrogen, C 1 -C 6 -alkyl, C 1 -C 4 -alkoxy-C 1 -C 4 -alkyl, C 5 -C 6 -cycloalkyl, phenyl, phenyl-C 1 -C 4 -alkyl, C 2 -C 6 -alkenyl or C 2 -C 6 -alkinyl, or R 3 and R 4 together represent a C 4 -C 6 -alkylene group; or mixtures thereof, as an additive in epoxy resin compositions.
Abstract:
The present invention accordingly provides a process for preparing aldehydes of the formula (I) in which one, two or all three radicals of the group R 1 , R 3 and R 5 denote hydroxyl, and the radical or radicals of the group R 1 , R 3 and R 5 that do not denote hydroxyl are, independently of one another, hydrogen, C 1 -C 8 alkyl or C 6 -C 14 aryl, and R 2 and R 4 independently of one another are hydrogen, C 1 -C 8 alkyl, C 1 -C 8 alkoxy or C 6 -C 14 aryl, the process being characterized in that an aldehyde of the formula (II) in which one, two or all three radicals of the group R' 1 , R' 3 and R' 5 denote C 1 -C 8 alkoxy, and the radical or radicals of the group R' 1 , R' 3 and R' 5 that do not denote C 1 -C 8 alkoxy are, independently of one another, hydrogen, C 1 -C 8 alkyl or C 6 -C 14 aryl, and R 2 and R 4 have the definitions indicated under formula (I), is reacted at elevated temperature and elevated pressure in the presence of (C 1 -C 4 alkyl) 2 -amine, and the reaction product of the formula (I) is subsequently isolated.
Abstract:
The invention provides a process for preparing m- or p-substituted phenylalkanols of the formula (I) in which R 1 is m- or p-bonded to the phenyl ring and is C 1 -C 5 -alkyl, and R 2 , R 3, R 4 and R 5 are each independently hydrogen or methyl, which is characterized in that an unsubstituted phenylalkanol of the formula (II) in which R 2 , R 3 , R 4 and R 5 are each as defined for formula (I) is alkylated together with a C 1 -C 5 -alkyl halide of the formula (III) R 1 Hal (III), in which R 1 is as defined for formula (I) and Hal is halogen, in the presence of a Friedel-Crafts catalyst, to give an m- or p-alkyl-substituted phenylalkanol of the formula (I), then the reaction mixture is worked up and the desired m- or p-alkyl-substituted phenylalkanol of the formula (I) is removed, the remaining by-products formed are returned to the reaction mixture and these are isomerized in the presence of a Friedel-Crafts catalyst to give the desired m- or p- alkyl-substituted phenylalkanol. The m- or p-alkyl-substituted phenylalkanols of the formula (I) can be used to form, by oxidation or dehydrogenation, as products of value, the corresponding aldehydes, which are of interest as fragrances and aroma chemicals.
Abstract:
The invention relates to a method for producing enriched isopulegol by crystallizing the same out of a melt containing isopulegol. The invention particularly relates to a method for producing enantiomer-enriched n-isopulegol by means of melt crystallization, starting from optically active isopulegol having a smaller excess amount of enantiomers. Also disclosed is a method for producing menthol starting from enantiomer-enriched and/or diastereomer-enriched n-isopulegol which is obtained by melt crystallization.
Abstract:
PF 60020 17 The present invention relates to a process for preparing racemic or optically active menthol by catalytic hydrogenation of racemic or optically active isopulegol in the presence of hydrogen and catalysts which include nickel-, copper-, zirconium- and molybdenum-containing compounds. The present invention 10 specifically relates to a corresponding process for the continuous catalytic hydrogenation of L-isopulegol to L-menthol.
Abstract:
The invention relates to methods for preparing a reaction product containing aluminium, obtained during the production of isopulegol, by the cyclization of citronellal in the presence of complex compounds, said product containing at least one ligand of formula (I), in which: R1, R2, R3 are selected from hydrogen, halogen, nitro, C1-C8 alkyl, C1-C8 alkoxy, di(C1-C4 alkyl)amino and aryl; and R4, R5 are selected from halogen, nitro, C1-C8 alkyl, C1-C8 alkoxy, di-(C1-C4 alkyl)amino, aryl or heteroaryl. According to said method, a) the reaction product is separated by distillation into a top product enriched with isopulegol and a bottom product poor in isopulegol and b) the ligand of formula (I) is isolated from the bottom product. In addition, the invention relates to a method for producing isopulegol and to a method for producing menthol.