The 1H NMR spectra of a series of acridine‐derived Tröger's base analogs substituted at various positions were registered. Also the 1H NMR characteristics of the first heterocyclic asymmetric Tröger's base analog constituted of one acridine and one phenanthroline nucleus with the two corresponding symmetric Tröger's bases were compared. The analysis of the NMR data clearly shows that the chemical shifts
The heterocyclic aromatic amines 10-aminobenzo[b][1,7]phenanthroline 1 and 3-aminoacridine 2 react regioselectively with formaldehyde in acidic medium to yield the Tröger's base analogs 7 and 8.