摘要:
The present invention relates to a process for preparing substituted 2-nitrobiphenyls and to specific 2-nitrobiphenyls. The invention further relates to a process for preparing 2-aminobiphenyls from such 2-nitrobiphenyls and to a process for preparing (het)arylamides of such 2-aminobiphenyls.
摘要:
The present invention relates to the use of cyclic carbonates of the formula I or a mixture thereof in epoxy resin compositions and also to epoxy resin compositions which comprise such cyclic carbonates. in which R1 and R2 independently of each other are hydrogen, C1-C6-alkyl, C1-C4-alkoxy-C1-C4-alkyl, C5-C6-cycloalkyl, phenyl, phenyl-C1-C4-alkyl, C2-C6-alkenyl or C2-C6-alkynyl, or R1 and R2 together are a C3-C11-alkylene group; R3 and R4 independently of each other are hydrogen, C1-C6-alkyl, C1-C4-alkoxy-C1-C4-alkyl, C5-C6-cycloalkyl, phenyl, phenyl-C1-C4-alkyl, C2-C6-alkenyl or C2-C6-alkynyl, or R3 and R4 together are a C4-C6-alkylene group; or mixtures thereof, as additives in epoxy resin compositions.
摘要:
The present invention relates to novel macrocyclic lactones, to processes for their preparation and to their use as fragrances and also to products comprising the novel macrocyclic lactones.
摘要:
The present invention relates to a process for preparing 4-cyclohexyl-2-methyl-2-butanol. The process comprises the following steps: a) reaction of styrene with isopropanol at elevated temperature to obtain 4-phenyl-2-methyl-2-butanol, and b) heterogeneously catalyzed hydrogenation of 4-phenyl-2-methyl-2-butanol over a catalyst suitable for ring hydrogenation of aromatics.
摘要:
The present invention relates to a particularly economic overall method for producing menthol, specifically for producing optically active, essentially enantiomerically and diastereomerically pure L-menthol and racemic menthol, starting from the starting material citral which is available inexpensively on an industrial scale. The method comprises the following steps a.1) catalytic hydrogenation of neral and/or geranial to give citronellal, b.1) cyclization of citronellal to isopulegol in the presence of an acidic catalyst, c.1) purification of isopulegol by crystallization and d.1) catalytic hydrogenation of isopulegol to give menthol.
摘要:
The present invention relates to a process for preparing 4,4′-[1-(trifluoromethyl)alkylidene]bis(2,6-diphenylphenols), in particular for preparing 4,4′-[1-(trifluoromethyl)ethylidene]bis(2,6-diphenylphenol), which comprises the self-condensation of cyclohexanone in the presence of a basic catalyst to form tricyclic condensation products, dehydrogenation of the resulting tricyclic condensation products in the presence of a supported transition metal catalyst in the condensed phase to form 2,6-diphenylphenol and reaction of the 2,6-diphenylphenol with a trifluoromethyl ketone. The invention further provides an improved process for preparing 2,6-diphenylphenol by aldol self-condensation of cyclohexanone.
摘要:
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).
摘要:
The present invention therefore relates to a process for preparing an aldehyde of the formula (I) where one, two or all three radicals from the group of R1, R3 and R5 are hydroxyl, and that radical or those radicals from the group of R1, R3 and R5 which are not hydroxyl are each independently hydrogen, C1-C8-alkyl or C6-C14-aryl, and R2 and R4 are each independently hydrogen, C1-C8-alkyl, C1-C8-alkoxy or C6-C14-aryl, which comprises converting an aldehyde of the formula (II) in which one, two or all three radicals from the group of R′1, R′3 and R′5 are C1-C8-alkoxy, and that radical or those radicals from the group of R′1, R′3 and R′5 which are not C1-C8-alkoxy are each independently hydrogen, C1-C8-alkyl or C6-C14-aryl, and R2 and R4 are each as defined for formula (I), at elevated temperature and elevated pressure in the presence of (C1-C4-alkyl)2-amine, and then isolating the reaction product of the formula (I).
摘要:
The present invention relates to a process for preparing 4-cyclohexyl-2-methyl-2-butanol. The process comprises the following steps: a) reaction of styrene with isopropanol at elevated temperature to obtain 4-phenyl-2-methyl-2-butanol, and b) heterogeneously catalyzed hydrogenation of 4-phenyl-2-methyl-2-butanol over a catalyst suitable for ring hydrogenation of aromatics.
摘要:
The present invention relates to a process for preparing enriched isopulegol by crystallization from a melt comprising isopulegol. The invention relates specifically to a process for preparing enantiomerically enriched n-isopulegol proceeding from optically active isopulegol having a relatively low enantiomeric excess by crystallization from the melt. The invention further relates to a process for preparing menthol proceeding from enantiomerically and/or diastereomerically enriched n-isopulegol prepared by crystallization from the melt.