The synthesis of the new heterocycles pyrrolo [1', 2': 1, 2] pyrazino [6, 5-b] carbazoles was achieved by the intramolecular cyclisation of 2-(1-pyrrolyl) carbazole derivatives. These latter compounds were obtained by the Clauson-Kaas reaction starting from the corresponding 2-aminocarbazoles, obtained by reduction of 2-nitrocarbazoles. A study of this reduction has shown that the introduction of acetyl grouping in position 9 makes this ...