3-Phenylquinolin-2-thione (1.4 g.) was added to a suspension of sodium hydride (0.68 g. of a 50% w/w dispersion in mineral oil) in dimethylformamide (10 ml.) at 0°-5°. When all the hydrogen had evolved, a slurry of 1-chloro-2-dimethylamino-2-methylpropane hydrochloride (1.1 g.) in dimethylformamide (10 ml.) was added and the mixture was stirred at ambient temperature for 20 hr. The mixture was then poured into ice-water (100 ml.) and extracted with ethyl acetate (3×30 ml.). The ethyl acetate extract was washed with brine (30 ml.) and then dried (MgSO4). The solvent was evaporated and the residual oil was chromatographed on basic alumina (125 g., Brockmann Grade III), eluted with increasing concentrations of methylene dichloride in petroleum ether. The eluate obtained with 10% v/v methylene dichloride in petroleum ether was evaporated, the residual oil was dissolved in diethyl ether (20 ml.), and ethereal hydrogen chloride was added until precipitation was complete. The mixture was filtered and the solid residue was crystallised from ethyl acetate to give 2-(2-dimethylamino-2-methylpropylthio)-3-phenylquinoline hydrochloride, m.p. 199°-201°.
