Diverse synthetic approach for sulfur and nitrogen-containing spiroheterocycles from dimedone and their pharmacological evaluation

Novel spiro(3-hydroxy-5,5-dimethyl)-1,5’-(2’-substituated[1,3,4]-oxadiazole/thiadiazolo[3,2-c] thiazolines and 3-hydroxy-5,5-dimethyl-spiro[cyclohex-2-ene-thiazolo/thiazino[3,2-b]-s-tetrazine were prepared from previously reported hydrazone, semicarbazone, carbazone, and spiro-s-tetrazine intermediates derived from dimedone precursor. All the newly synthesized heterocycles have been characterized by analytical and spectral (¹H NMR and ^hC NMR) data and screened their in vitro antibacterial activity against gram negative bacteria Escherichia coli and gram positive bacteria Staphylococcus aureus. Some of the compounds showed moderate to good activities towards the bacteria chosen.