Verfahren zur Synthese von Acryl- und Methacrylverhindungen durch Eliminierungs- und Austauschreaktionen in flüssiger Phase

Abstract

Synthesis of acryl- and methacryl derivatives via elimination and interchange reactions of suitable compounds are described.

Decarboxylation of maleic monoesters in a pyridine base/basic copper salts pyrolysis bath at 210 °C leads to the corresponding acrylic ester in quantitative yields. Thus, isopropyl- and isobutyl acrylates, which were previously prepared in relatively low yields via esterification of acrylic acid, can be synthethised in a single step. Since both the acrylates do not form azeotropic mixtures with most alcohols, special acrylates of higher alcohols can be obtained by transesterification.

Synthesis of methacrylic acid or methyl methacrylate is carried out by dehydration of α-hydroxy isobutyric acid at 260°C in an organic, polar, inert and high boiling point solvent, employing catalytic quantities of sodium hydroxide. This is achieved by reacting the molten acid or in acetic or methanolic acid solution.

The procedures described can be employed for continuous synthesis of acryl- and methacryl derivatives. Furthermore, these procedures do not contribute towards environmental pollution.