Synthesis of two novel classes of tetracycles bearing tetrahydro ring system from benzothiazole: 7,8,9,10‐tetrahydrothiazolo[5,4‐a]acridine and 1,2,3,4‐tetrahydro‐12H‐benzothiazolo[2,3‐b] quinazolin‐12‐one

Novel 7,8,9,10‐tetrahydrothiazolo5,4‐a]acridine and 1,2,3,4‐tetrahydro‐12H‐benzothiazolo2,3‐b]‐quinazolin‐12‐one derivatives were synthesized in one step from the corresponding benzothiazoles. These two new tetracyclic skeletons were unambiguously characterized and are presently in pharmacological tests.