Synthesis, Antitumor and Cytotoxic Activity of New Adamantyl O-Acylamidoximes and 3-Aryl-5-Adamantane-1,2,4-Oxadiazole Derivatives

O-Acylamidoxime and 1,2,4-oxadiazole derivatives were synthesized from adamantanecarbonyl chloride 1 and a diversity of arylamidoximes 2 a-k. First, O-acylamidoximes intermediates 3 a-k were synthesized and subsequent cyclization under microwave irradiation afforded 1,2,4-oxadiazol derivatives 4 a-k. Molar Heat of Reaction Calorimetry studies performed from O-acylamidoximes revealed influence of the substituent groups. A one-pot two-step methodology was also developed proving to be a viable protocol. Compounds were characterized by H-1 and C-13 Nuclear Magnetic Resonance (NMR) Spectroscopy, Elemental Analysis or High Resolution Mass Spectral Analysis, and subjected to cytotoxic studies in non-tumoral Vero cells and antiproliferative activity tests in six malignant cell lines. Our findings suggest that compounds 3 derivatives presented a concentration-dependent profile for chronic myeloid leukemia (K562) and acute promyelocytic leukemia (HL-60) cell.