Synthesis and Antileishmanial Activity of Indoloquinones Containing a Fused Benzothiazole Ring

✍ Scribed by Ricardo A. Tapia; Yolanda Prieto; Félix Pautet; Monique Domard; Marie-Elizabeth Sarciron; Nadia Walchshofer; Houda Fillion

• Publisher: John Wiley and Sons
• Year: 2002
• Tongue: English
• Weight: 116 KB
• Volume: 2002
• Category: Article
• ISSN: 1434-193X
• DOI: 10.1002/1099-0690(200212)2002:23<4005::aid-ejoc4005>3.0.co;2-l

✦ Synopsis

Pyrazinoindoloquinone 6 was synthesized by alkylation of ethyl 4,7-dimethoxyindole-2-carboxylate (1), followed by cyclization of the N-bromoethyl derivative 2b in the presence of ammonia. Oxidative demethylation of 2b and of the oxopyrazinoindole 3 with silver(II) oxide furnished quinones 5b and 6. Reduction of 3 with lithium aluminium hydride in dioxane provided 4, which was oxidized to afford 7. Quinones 5b, 6, and 7 were then treated in situ with the thiazole o-quinodimethane 9 to afford regioisomeric mixtures of the tetracyclic [a] Facultad