Síntese one pot de 1,3,4-oxadiazóis derivados de L-aminoácidos e benzoil-hidrazidas

Abstract

In the following work, a range of 1,3,4-oxadiazles 2,5-disubstituted 3 was prepared, using a one pot approach, from L-amino acids 1(a-e) and 2-benzoylhydrazides, using POCl3 as dehydrating agent. The study involved the reaction of L-amino protected amino acids (1a-e) and benzoyl hydrazide (2a-d) prepared in the conventional method using 1,4- dioxane as solvent and POCl3 as dehydrating agent, providing the products yields between 30-63%. The reactions to obtain the 1,3,4-oxadiazóis were also performed under microwave irradiation, in the absence of solvent and short reaction time, giving the products with moderate to good yields (42-72%). It was subsequently held a one pot synthesis of 1,3,4-oxadiazóis 2,5 - disubstituted from selenocysteine 1f, L-serine-derived, and benzoyl hydrazide (2a-d), carried out in conventional method and microwave irradiation, with yields of 50-66% and 47-54% respectively.