in toluene byproducts: HCl; at -78°C for 1 h, warm to room temp. refluxed for 1 week; solvent removed under vac., recrystn. from toluene/hexane or by very short-path distn. or sublimation under high vac., elem. anal.;

in toluene byproducts: 1,8-bis(dimethylamino)naphthalene hydrochloride; at -78°C under vac., allowed to warm with stirring to room temp., 30 min, chilled to ice temp., filtered under vac., solid washed with condensed solvent, removed the solvent by distn. under vac.; solid is byproduct, solvent heated to 45°C under continuous pumping, oily solid washed with warm heptane, dissolved in toluene, recrystd. with heptane, sublimed under vac.;