Evonik Roehm Gmbh

Roehm Gmbh & Co Kg

Jochen Ackermann

Hermann Siegert

Alexander May

Bernd Vogel

Soenke Broecker

Udo Gropp

Ruediger Carloff

Horst Hiltner

Hans-Rolf Rausch

Ingrid Lunt-Rieg

The present invention relates to processes for transesterification, comprising the steps of

Transesterification methods

Alpha-hydroxycarboxylic esters are prepared by a continuous process in which alpha-hydroxycarboxamide is reacted with an alcohol in the presence of a catalyst to obtain a product mixture which contains alpha-hydroxycarboxylic ester, ammonia, unconverted alpha-hydroxycarboxamide and alcohol, and catalyst; wherein reactant streams containing an alpha-hydroxycarboxamide, an alcohol and a catalyst are fed into a pressure reactor. The reactant streams are reacted with one another in the pressure reactor at a pressure in the range of 1 bar to 100 bar; and the product mixture is depleted in alcohol and ammonia by distilling off ammonia at a pressure which is constantly kept greater than 1 bar without the aid of additional stripping media. The continuous process can be employed particularly advantageously on the industrial scale.

Process for preparing alpha-hydroxycarboxylic esters

The present invention relates to a process for preparing carboxamides by hydrolysing carbonitriles in the presence of a catalyst comprising manganese dioxide, wherein the reaction mixture added to the catalyst comprising manganese dioxide has a pH in the range of 6.0 to 11.0 and the hydrolysis is performed in the presence of an oxidizing agent. The present invention further relates to a process for preparing alkyl (meth)acrylates, the process having a hydrolysis step according to the process described above.

Process for preparing carboxamides by hydrolysis carboxylic acid nitriles in the presence of a catalyst comprising manganese dioxide

The present invention relates to processes for preparing alkyl (meth)acrylates, comprising the steps of

Methods for producing alkyl(meth)acrylates

The invention relates to a process for continuous preparation of alkyl (meth)acrylates by transesterification of methyl (meth)acrylate using alcohols which are high-boiling relative to methanol. A particular workup technique achieves product qualities which have hitherto not been attained. Very high space-time and overall yields can also be achieved.

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Muehltal, Germany

Jochen Ackermann