8-Aminoquinolines and the dithiazolium salt 1 give N-(8-quinolinyl)imi
nodithiazoles 4 which undergo an unusual type of thermal rearrangement
to give the new imidazo[5,4,1-ij]quinoline-4-thiones 6; it appears th
at the thione sulfur is delivered intramolecularly (9 --> 10).