133591-33-0Relevant articles and documents
Isomeric Ellipticines. Part 1. Synthesis of two Linear Isomers of the Antitumour Alkaloid Ellipticine
Alunni-Bistocchi, Giovanni,Orvietani, Pierluigi,Mauffret, Olivier,Antri, Said El,Deroussent, Alain,et al.
, p. 2935 - 2942 (2007/10/02)
Two linear isomers of the parent 5,11-dimethyl-6H-pyridocarbazole ellipticine 1a, belonging to the 6H- and 10H-pyridocarbazoles series and their methoxylated derivatives, have been synthesized by three different methods using the Skraup reaction and the Fischer-Borsche cyclization.One of these (method A) afforded an angular monomethyl-7H-pyridocarbazol 9 instead of the expected linear 6H-isomer 8a on cyclisation of 5,8-dimethyl-6-hydrazinoquinoline 21 with cyclohexanone via the Fischer-Borsche indol synthesis.The two other methods (B and C) afforded the desired linear isomers 7 and 8 when the Skraup reaction was performed with aminocarbazoles 26 or with tetrahydroaminocarbazoles 17 and 27 respectively, followed by aromatization of the A ring.Oxidized species were isolated after the aromatization step in method C and were tentatively assigned structures 30-33.