SYNTHESIS OF 4,5-DISUBSTITUTED BENZO[C][2,7]NAPHTHYRIDINES BY COMBINED METALATION-PALLADIUM-CATALYSED CROSS-COUPLING STRATEGIES - PREPARATION OF 8H-PYRIDO[4,3,2-MN]ACRIDONE AS A MODEL OF CYSTODYTIN ALKALOIDS

摘要

A short and efficient synthesis of 8H-pyrido[4,3,2-mn]acridone is described. The strategy involves the preparation of 4-chloro-5-methylbenzo[c][2,7]naphtyridine, as key intermediate, by metalation and Palladium catalyzed cross-coupling reaction. A second cross-coupling reaction and subsequent oxydation by SeO2 led to the title compound. [References: 23]