Treatment of some 1-naphthylformamides (or formanilides) possessing a 2, 4, 5- trioxygenated phenyl substituent at the 2-position with POCl3 caused an unprecedented carbon insertion reaction into a benzene ring, producing 7-5 ring (azaazulene) systems as valence isomers of isoquinoline skeletons. Precise examination of this abnormal Bischler- Napieralski reaction (BNR) using various substrates led to the following scope and ...
