Abstract: Methacrolein is prepared in a continuous process by a Mannich condensation reaction of formaldehyde with propanal. A methacrolein polymerization inhibitor is introduced during the production process and a part thereof is recycled back into the reactor where the Mannich condensation reaction is carried out.

Abstract: The invention relates to a process for preparing a carboxylic ester by reacting an aldehyde in the presence of an aluminum alkoxide, wherein the aluminum alkoxide is obtained either by reacting an aluminum hydride with an aldehyde or by reacting a different aluminum alkoxide with a carboxylic ester.

Abstract: Methacrolein is prepared in a continuous process by a Mannich condensation reaction of formaldehyde with propanal. A methacrolein polymerization inhibitor is introduced during the production process and a part thereof is recycled back into the reactor where the Mannich condensation reaction is carried out.

Abstract: The invention relates to a process for preparing a carboxylic ester by reacting an aldehyde in the presence of an aluminum alkoxide, wherein the aluminum alkoxide is obtained either by reacting an aluminum hydride with an aldehyde or by reacting a different aluminum alkoxide with a carboxylic ester.

Abstract: The invention relates to a process for preparing a carboxylic ester by reacting an aldehyde in the presence of an aluminum alkoxide, wherein the aluminum alkoxide is obtained either by reacting an aluminum hydride with an aldehyde or by reacting a different aluminum alkoxide with a carboxylic ester.

Abstract: The invention relates to a process for preparing a carboxylic ester by reacting an aldehyde in the presence of an aluminum alkoxide, wherein the aluminum alkoxide is obtained either by reacting an aluminum hydride with an aldehyde or by reacting a different aluminum alkoxide with a carboxylic ester.

Abstract: A method can prepare a carboxylic ester. The method includes reacting an aldehyde in the presence of an aluminium alkoxide applied to a support material.

Abstract: A method can prepare a carboxylic ester. The method includes reacting an aldehyde in the presence of an aluminium alkoxide applied to a support material.

Abstract: The present invention describes a process for dehydrating alpha-substituted carboxylic acids in the presence of water at high pressures while avoiding by-products.

Abstract: The present invention relates to a catalytic continuous process for producing methyl methacrylate, said process comprising the step of reacting methacrolein with oxygen and methanol in the presence of a heterogeneous noble-metal-containing catalyst in an oxidative esterification reaction to give methyl methacrylate, characterized in that the stationary concentration of the starting material methacrolein is equal to or less than 12% by weight based on the total weight of the reaction mixture in the reactor, and the ratio F between the total liquid volume within the reactor expressed in litres divided by the total weight of catalyst in the reactor expressed in kilograms is equal to or less than 4.

Abstract: The present invention relates to a process for preparing methyl methacrylate by a direct oxidative esterification of methacrolein with oxygen and methanol, which is conducted in the liquid phase at a pressure of 2 to 100 bar with a gold catalyst. According to the invention, the liquid phase is withdrawn continuously from the reactor and optionally enriched with oxygenous gas, the pH, after the withdrawal, is adjusted to a pH between 5 and 9 by means of addition of a basic solution and this liquid phase is conducted back into the reactor again to an extent of at least 50%.

Abstract: The present invention relates to a process for producing methyl methacrylate, comprising the following steps: A) producing methacrolein and B) reacting the methacrolein obtained in step A) in an oxidative esterification reaction to give methyl methacrylate, characterized in that the two steps A) and B) take place in a liquid phase at a pressure of from 2 to 100 bar, and step B) is carried out in the presence of a heterogeneous noble-metal-containing catalyst comprising metals and/or comprising metal oxides.

Abstract: The invention relates to a process for preparing ETBE from technical mixtures which comprise at least 1-butene, isobutene, n-butane and 2-butenes, by reacting the isobutene present, distillatively removing a fraction comprising 1-butene and isobutene and again reacting the isobutene present therein to give ETBE.

Abstract: The invention relates to a process for the selective, economically viable preparation of methacrylic acid and methacrylic esters starting from acetone cyanohydrin, wherein, in a first step, 2-hydroxy-2-methylpropionic acid is prepared by reacting acetone cyanohydrin with sulphuric acid in the presence of water and a suitable polar solvent and is isolated and methacrylic acid is subsequently prepared by ?-elimination of water starting from 2-hydroxy-2-methylpropionic acid.