RESCUE OF THE DEBUS-RADZISZEWSKI REACTION: PRACTICAL CLASS OF MULTICOMPONENT REACTIONS IN THE SYNTHESIS OF LOFIN

Multicomponent reactions are attractive for the development of bioactive substances, being a one-pot synthesis allows a quick and efficient synthesis, and allows the construction of a diversity of privileged structures. The Debus-Radziszewski reaction, a classic example of a multicomponent reaction for obtaining 2,4,5-tri-substituted imidazole, was used to compose a didactic sequence to be applied in undergraduate courses in the following disciplines: Organic Chemistry, Experimental Chemistry, Pharmaceutical Chemistry and Medicinal Chemistry. Thus, the classes were planned and applied, one theoretical and two experimental, the synthesis of lofin (2,4,5-triphenyl-1H-imidazole) and the characterization of the product. The Debus-Radziszewski reaction for the preparation the lofin, proved to be suitable for practical class of multicomponent reactions, as it uses accessible reagents and equipment, it is easy to do and the students can follow the progress of the reaction visually. In addition, the didactic sequence inserts students in a contextualized and interdisciplinary way in the practical chemistry procedures, employing a classic reaction, but with current perspectives of Organic and Medicinal Chemistry, such as the synthesis of the privileged fragments of bioactive compounds.

Keywords:
heterocycle; one-pot synthesis; organic chemistry class; medicinal chemistry class