Resumo:
Synthetic strategies play an important role in the development of sustainable methodologies, aiming to reach important molecules. Thus, the use of multicomponent reactions, one pot and telescopic syntheses, can be applied in this aspect. Diethyl ethoxy-methylene malonate is an important electrophile for the synthesis of polyfunctionalized heterocycles, and can be used in different types of chemical transformations, as well as it is an attractive building block in the synthesis of carbonyl compounds. The present work had as purpose to investigate the reactivity of 2-amino-heterocycles against diethyl ethoxy-methylene malonate, precursors of β-enaminodicarbonyl compounds via a three-component reaction. The β-enaminodicarbonyl compounds were synthesized with yields ranging from 75% to 90%, beginning with 2-aminopyridines derivatives, diethyl malonate and triethyl orthoformate, an unprecedented condition for the synthesis of these molecules. Furthermore, cyclic products were accessed using these reactants under mild conditions, reaching pyrido-pyrimidinone nuclei via telescopic reaction. Hence, the tricomponent and telescopic reactions were more efficient and more environmentally sustainable methodologies being useful to achieve new molecules without the need to synthesize, isolate and purify intermediates.
