LAUSR

Abstract Herein, we report the one-pot cyclization of Biginelli Adduct, ethyl 4-(2-hydroxyphenyl)-6-methyl-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carboxylate ( I) to the oxygen-bridged adduct, ethyl 2-methyl-4-thioxo-3,4,5,6-tetrahydro-2 H -2,6-methanobenzo[ g ] [1,3,5]oxadiazocine-11-carboxylate ( II) in a high yield and purity under mild reaction condition using zinc(II) perchlorate hexahydrate as a highly efficient catalyst. The cyclic product ( II ) was characterized both in the solid state and in solution using FT–IR, 1 H NMR, and UV–visible spectroscopy. Theoretical calculations using density functional theory with B3LYP/6-311++G(d,p) level were used to further investigate the structure properties. DFT calculations (gas phase) revealed the stability of cyclic compound II (3.45 kcal/mol) than compound I . In addition, the anticancer activity of II was investigated using MCF-7 human breast cell line. The results revealed a moderate activity with 223.55 μg/ml IC 50 value.