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]isoquinoline (7-12) have been prepared from 3,4-dihydroisoquinoline derivatives under the action of a-mercapto alkanoic acids or ethylene sulfide, respectively. In the synthesis of compounds 2 and 5 isothiocarbostril (13) and N-thioacetyl-beta -phenylethylamine derivatives (14), respectively, were also used as substrates and treated with bromoacetic acid derivatives. Spectral characteristics (IR, H-1, C-13 NMR and MS) of compounds 1-12 are presented. (C) 2001 Elsevier Science Ltd. All rights reserved.