Abstract:
The invention relates to a method for producing aliphatic aldehydes of the general formula (I) by reacting aldehyde of the general formula (II) with an aldehyde of the general formula (III), where R1 is hydrogen or a methyl group, R2 is a straight-chain or branched alkyl radical having 1 to 4 carbon atoms, and the two X are each hydrogen or together are a further C-C bond, in the presence of an aldol condensation catalyst to form the substituted octenal of the general formula (I) and subsequently optionally hydration, either continuously or in batches, to form the corresponding octanal of the formula (I). The invention is characterized in that the aldehydes of the general formula III and II are used in a molar ratio of III:II between 1.4:1 and 0.6:1.
Abstract:
In a process for preparing carboxylic esters by transesterification, a first feed stream comprising a first carboxylic ester, e.g. methyl formate, is introduced at the side into a reaction column at a first inlet located between the top and the bottom of the reaction column and a second feed stream comprising a first alcohol, e.g. ethanol, is introduced at the side into the reaction column at a second inlet located above the first inlet and the feed streams are reacted in a reaction zone of the reaction column to form a second carboxylic ester and a second alcohol. The first alcohol has a higher molecular weight than the second alcohol. A product fraction comprising the second carboxylic ester and unreacted first carboxylic ester is taken off at an offtake located above the second inlet. A bottom fraction comprising the second alcohol and unreacted first alcohol is taken off at the bottom of the reaction column. The product fraction is separated by distillation at a pressure which is different from the pressure in the reaction column into second carboxylic ester and a fraction containing unreacted first carboxylic ester and the fraction containing unreacted first carboxylic ester is at least partly recirculated to the reaction zone.
Abstract:
The invention relates to a method for the production of cyclopentane derivatives of formula (I), in which R represents a C1-C10 alkyl group, characterized in that cyclohexanol or cyclohexene or mixtures of both compounds are reacted to 1-methyl-1-cyclopentene (first stage), a C1-C10 alkanol being added subsequently to the double bond of the 1-methyl-1-cyclopentene (second stage).
Abstract:
The subject matter of the present invention is a liquid composition containing a pesticide in a dissolved form, a non-ionic surfactant and a propionamide of Formula I given below. The invention further relates to a method for producing the composition according to the invention by contacting the pesticide, the non-ionic surfactant and the propionamide with each other. The invention also relates to the use of the composition according to the invention for producing an emulsion and to an emulsion containing water and to the composition according to the invention.
Abstract:
The invention relates to a method for the production of 1-methylcyclopentene by the thermal reaction of cyclohexanol or cyclohexene or mixtures of both compounds to 1-methylcyclopentene, characterized in that the obtained byproducts 3-methylcyclopentene and 4-methylcyclopentene (double bond isomers of 1-methylcyclopentene) are fed back to the reaction.
Abstract:
The invention relates to a method for producing m-substituted phenylalkanols of the formula (I), R1 denoting C1-C5-alkyl, and R2, R3, R4, and R5 independently denoting hydrogen or methyl, characterized in that a p-substituted phenylalkanol of the formula (II), where R1, R2, R3, R4, and R5 have the meanings given under formula (I), is isomerized in the presence of a Friedel-Craft catalyst to form an m-substituted phenylalkanol of the formula (I). The corresponding aldehydes known as fragrances and aroma chemicals can be formed as valuable products from the m-substituted phenylalkanols of the formula (I) by means of oxidation or dehydration.
Abstract:
The invention relates to a method for producing arylpropenes, in particular 1-methoxy-4-(1-propenyl)-benzene (anethole)1, by thermolysis of the corresponding 1,1-diarylpropanes.
Abstract:
In a process for purifying carboxylic esters such as ethyl formate, a carboxylic ester to be purified is distilled in the presence of an extractant, preferably by (a) allowing vapour of the carboxylic ester to be purified to ascend in a distillation column; (b) conveying the extractant in countercurrent to the vapour in an extractive distillation zone; (c) taking off pure carboxylic ester above the extractive distillation zone. The extractant is selected, for example, from among diols, polyols, open-chain or cyclic amides.
Abstract:
Procedimiento para la preparación de arilpropenos de la fórmula general (I) **(Ver fórmula)** en la cual k presenta los valores 0, 1, 2 o 3 y R1 se selecciona, independientemente entre sí, entre alcoxi de C1-C6, di-(alquil de C1-C6)-aminas e hidroxilo, el cual comprende la termólisis de al menos un compuesto de 1,1-diarilpropano de la fórmula general (II) **(Ver fórmula)** en la cual k y R1 presentan los significados antes mencionados, en donde el compuesto de la fórmula II se pone en contacto con al menos un catalizador,oxídico, ácido y sólido en la fase gaseosa en una zona de reacción.