C. Cochennec et al., NUCLEOPHILIC-ADDITION OF LITHIO DERIVATIVES TO 1-SUBSTITUTED BENZO[C]NAPHTHYRIDINES (2,9-DIAZAPHENANTHRENES), Journal of the Chemical Society. Perkin transactions. I, (8), 1995, pp. 979-984
Nucleophilic addition of lithio derivatives to 1-substituted benzo[c]
[2,7]naphthyridines and rearomatization of the intermediate dihydro co
mpounds with MnO2 gives good overall yields of product.