Indolopyridoquinazoline alkaloid

Later in 2001, Clark and coworkers [97] reported the isolation and structure characterization of an indolopyridoquinazoline alkaloid, 3-hydroxyrutaecarpine, (75) from Leptothyrsa sprucei. This study was particularly interesting in that the authors reported the substructural fragments 76-78, which were assembled prior to the final determination of the structure of 75. Long-range and H-... 

Sheen W-S, Tsai I-L, Teng C-M, Ko F-N, Chen I-S. Indolopyridoquinazoline alkaloids with antiplatelet aggregation activity from Zanthoxylum integrifolium. Planta Medic 1996 62 175-6. 

Danieli, B., P. Manitto, F. Ronchetti, and G. Russo New Indolopyridoquinazoline Alkaloids from Euxylophora paraensis. Phytochemistry 11, 1833 (1972). 

A successful simple appHcation of the quinazolinone aimelation is the short step synthesis of rutecarpine 16, an indolopyridoquinazoline alkaloid of Evodia rutaecarpa, from 2,3,4,9-tetrahydro-lH-j8-carbolin-l-one 80 via 2-azidobenzoyl derivative 81 (Scheme 18) [222]. Even after Kametani s practical iminoketene/amides condensation synthesis [227,228], many other synthetic routes to 16 and related systems utilizing Fischer indole synthesis [223-225] or cyclocondensation [65,226,229,230], etc. have been developed among these syntheses, above quinazolinone annelation route is one of the most facile and concise one. Recently very concise Pd-assisted biaryl coupling route to 16 as well as to luotonin A (26) and B (27) has been developed by Harayama et al. [231,232] (see Sect. 3.5). 

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