REACTION OF ETHACRIDINE LACTATE WITH NITR OUS-ACID AND THE COLOR-STRUCTURE RELATIONSHIPS WITH ACRIDINE-DERIVATIVES .3. ANALYTICS OF ETHACRIDINE LACTATE

The identity test for ethacridine lactate with nitrous acid, prescribe d in several pharmacopeias, gives rise to a diazotization of the amino group in 6-position yielding the diazonium salt, which was isolated a s tetrafluoroborate and undoubtedly identified. In the same manner fro m proflavine the monodiazonium derivative results as tetrafluoroborate . These diazonium compounds are also responsible for the colour in the rest solutions following from a comparison of the UV/VIS spectra. Sem iempirical calculations with a series of acridine derivatives show a v ery good agreement of the theoretical and observed wavelengths of maxi mal absorption. Therefore, the solution owes its colour to the diazoni um chromophore and not to intermolecular interactions of the heteroaro matic ring systems.