The present invention relates to a novel process for oxidative esterification, generally for reaction of aldehydes with alcohols in the presence of oxygenous gases directly to give the corresponding ester in the presence of a heterogeneous catalyst, by means of which, for example, (meth)acrolein can be converted to methyl (meth)acrylate. The new catalyst has titanium dioxide as the main component of the support material. The catalysts are especially notable for high mechanical and chemical stability and for good catalytic performance even over very long periods. The process is an improvement in the catalyst service life, activity and selectivity over prior art catalysts which lose activity and/or selectivity relatively quickly in continuous operation in media having even a small water content.

A process for preparing methyl methacrylate by direct oxidative esterification of methacrolein has elevated yields compared to known processes. Methyl methacrylate (MMA) is used in large amounts for preparing polymers and copolymers with other polymerizable compounds. In addition, methyl methacrylate is an important synthesis unit for a variety of specialty esters based on methacrylic acid (MAA), which can be produced by transesterification with the appropriate alcohol. There is consequently a great interest in very simple, economic, and environmentally friendly processes for preparing methyl methacrylate. A superior workup of the reactor output from the oxidative esterification of methacrolein allows specific by-products to be isolated and then additionally converted to alkyl methacrylates, especially to MMA.

A process for preparing methyl methacrylate by direct oxidative esterification of methacrolein has elevated yields compared to known processes. Methyl methacrylate (MMA) is used in large amounts for preparing polymers and copolymers with other polymerizable compounds. In addition, methyl methacrylate is an important synthesis unit for a variety of specialty esters based on methacrylic acid (MAA), which can be produced by transesterification with the appropriate alcohol. There is consequently a great interest in very simple, economic, and environmentally friendly processes for preparing methyl methacrylate. A superior workup of the reactor output from the oxidative esterification of methacrolein allows specific by-products to be isolated and then additionally converted to alkyl methacrylates, especially to MMA.

The present invention relates to a method for total chemical synthesis of 9-cis-β-carotene (9CBC), and further provides stable formulations thereof.

The present invention relates to a method for total chemical synthesis of 9-cis-β-carotene (9CBC), and further provides stable formulations thereof.

The present invention relates to a novel process for oxidative esterification, generally for reaction of aldehydes with alcohols in the presence of oxygenous gases directly to give the corresponding ester in the presence of a heterogeneous catalyst, by means of which, for example, (meth)acrolein can be converted to methyl (meth)acrylate. The new catalyst has titanium dioxide as the main component of the support material. The catalysts are especially notable for high mechanical and chemical stability and for good catalytic performance even over very long periods. The process is an improvement in the catalyst service life, activity and selectivity over prior art catalysts which lose activity and/or selectivity relatively quickly in continuous operation in media having even a small water content.

The present invention relates to a novel process for oxidative esterification, generally for reaction of aldehydes with alcohols in the presence of oxygenous gases directly to give the corresponding ester in the presence of a heterogeneous catalyst, by means of which, for example, (meth)acrolein can be converted to methyl (meth)acrylate. The new catalyst has titanium dioxide as the main component of the support material. The catalysts are especially notable for high mechanical and chemical stability and for good catalytic performance even over very long periods. The process is an improvement in the catalyst service life, activity and selectivity over prior art catalysts which lose activity and/or selectivity relatively quickly in continuous operation in media having even a small water content.

A process for preparing methyl methacrylate by direct oxidative esterification of methacrolein has elevated yields compared to known processes. Methyl methacrylate (MMA) is used in large amounts for preparing polymers and copolymers with other polymerizable compounds. In addition, methyl methacrylate is an important synthesis unit for a variety of specialty esters based on methacrylic acid (MAA), which can be produced by transesterification with the appropriate alcohol. There is consequently a great interest in very simple, economic, and environmentally friendly processes for preparing methyl methacrylate. A superior workup of the reactor output from the oxidative esterification of methacrolein allows specific by-products to be isolated and then additionally converted to alkyl methacrylates, especially to MMA.

A process for preparing methyl methacrylate by direct oxidative esterification of methacrolein has elevated yields compared to known processes. Methyl methacrylate (MMA) is used in large amounts for preparing polymers and copolymers with other polymerizable compounds. In addition, methyl methacrylate is an important synthesis unit for a variety of specialty esters based on methacrylic acid (MAA), which can be produced by transesterification with the appropriate alcohol. There is consequently a great interest in very simple, economic, and environmentally friendly processes for preparing methyl methacrylate. A superior workup of the reactor output from the oxidative esterification of methacrolein allows specific by-products to be isolated and then additionally converted to alkyl methacrylates, especially to MMA.

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.