Synthesis and spectroscopic studies of some hydrogenated thiazolo[2,3-a]isoquinolines

Dihydro-5H-thiazolo[2,3-a]isoquinolinones (1–6) and tetrahydro-5H-thiazolo[2,3a]isoquinolines (7–12) have been prepared from 3,4-dihydroisoquinoline derivatives under the action of α-mercapto alkanoic acids or ethylene sulfide, respectively. In the synthesis of compounds 2 and 5 isothiocarbostril (13) and N-thioacetyl-β-phenylethylamine derivatives (14), respectively, were also used as substrates and treated with bromoacetic acid derivatives. Spectral characteristics (IR, 1H, 13C NMR and MS) of compounds 1–12 are presented.