No abstract

The synthesis of a new class of angular tetracyclic quinones is described. Our strategy involves Diels-Alder reaction of pyrroloquinolinequinone 9, generated in situ from pyrroloquinoline 8, and dienes. The required pyrroloquinoline 8 was prepared in four steps from commercially available compounds. All compounds were tested for trypanocidal activity in vitro against Trypanosoma cruzi epimastigotes.

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Fused pyridine derivatives R 0450 A Convenient Synthesis of Benzo[g]pyrrolo[3,2-c]quinoline-6,11-diones. -The title compound (VIII) is prepared in situ from pyrroloquinoline (VII). Due to its decomposition during purification, it trapped with dimethylbutadiene or pentadiene followed by aromatization in the presence of DBU. Tetracyclic diones (X), (XII) and (XIII) are obtained as new derivatives of the pharmacologically interesting heterocyclic skeleton. -(TAPIA*, R. A.; LOPEZ, C.; MORELLO, A.; MAYA, J. D.; VALDERRAMA, J. A.; Synthesis 2005, 6, 903-906; Fac. Quim., Pontif. Univ. Catol. Chile, Santiago 22, Chile; Eng.) -C. Herrmann 34-206

13C chemical shift assignment of several methyl substituted heterocyclic naphtho- and anthraquinones, including dihydronaphthofuranquinones, azaanthraquinones, benzopyrroloquinolinediones and benzothiophenoquinolinediones, are described. A deshielding effect due to a methyl group was observed over the neighbouring carbonyl carbon, in every case studied. 13C assignments were based on 2D experiments.