In situ Raman monitoring of Michael addition for the synthesis of 1-substituted imidazoles intermediates with antiviral properties

Abstract

In situ Raman spectroscopy was used to assess the progress of the Michael addition reaction between imidazole and ethyl acrylate in dry media over basic carbon catalysts. N-substituted imidazoles and their derivatives obtained under these reaction conditions are pharmaceutically important due to their pharmacodynamic properties. Real-time Raman monitoring provides a non-invasive insight during the C–N coupling/Michael addition in the presence of basic catalysts. The progress of the reaction was monitored following the changes in intensity of the characteristic Raman bands. The results obtained by real-time Raman monitoring confirm the mechanism proposed for the reaction, the direct C–N coupling between imidazole and ethyl acrylate without the formation of any intermediate.