Synthesis of a novel series of pyrimido- and triazino{[}4,5-b] quinolines

New tetrahydropyrimido{[}4,5-b]quinolines, hexahydropyrimido{[}4,5-b] quinolines, a thioxohexahydropyrimido{[}4,5-b] quinoline, an octahydropyrimido{[}4,5-b] quinoline and a tetrahydro{[}1,2,3] triazino{[}4,5-b] quinoline have been synthesised. A series of S-alkyltetrahydroprimido{[}4,5-b] quinolines was obtained by the reaction of the thioxohexahydropyrimido{[} 4,5-b] quinoline with allyl bromide, propargyl bromide or with epichlorohydrin. All newly synthesised compounds were characterised by IR, (1)H, (13)C NMR and elemental analysis.