Electrophilic substitution of 1-methylindeno-1H-[2,1-b]pyridine

It is shown that electrophilic substitution of 1-methylindeno-1H-[2,1-b]pyridine takes place at the C9 atom in the case of acylation (acetylation, benzoylation, and formylation), bromination, and nitration. Data from the 13C NMR spectrum of this pseudoazulene confirm sp2 hybridization of the C9 atom. © 1983 Plenum Publishing Corporation.