Intramolecular cyclization of 1-(2-arylethyl)tetrahydro-6-hydroxy-1H-pyrimidin-2-thiones: effect of substituents on reactivity.

Convenient synthetic procedures for 1,2,3,6,7, 11b-hexahydro-4H-pyrimido[6, 1 -a] isoquinolin-4-thiones and 2,3,6,7,12,12b-hexahydro-1H-pyrimido[1',6':1,2]pyrido[3,4-b]indole-4-thiones have been developed. Structural factors which influence on a cascade cyclization process have been elucidated.