Synthesis and Antileishmanial Activity of Indoloquinones Containing a Fused Benzothiazole Ring

Autor: Ricardo A. Tapia, Yolanda Prieto, Félix Pautet, Nadia Walchshofer, Monique Domard, M.E. Sarciron, Houda Fillion
Rok vydání: 2002
Předmět:
Zdroj: European Journal of Organic Chemistry. 2002:4005-4010
ISSN: 1099-0690
1434-193X
DOI: 10.1002/1099-0690(200212)2002:23<4005::aid-ejoc4005>3.0.co;2-l
Popis: 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 quinones 10 or the pentacyclic derivatives 11 or 12. The structural assignment was made by 2D NMR 1H-13C HMBC correlation performed on the major regioisomer 10a. In vitro antileishmanial assays showed that dimethoxyindole 2a and quinones 12a + 12b possess good inhibitory activity against two Leishmania sp. without any cytotoxicity towards a THP-1 cell line. (© Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)
Databáze: OpenAIRE
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