tert.-butyl lithium in pentane byproducts: hexamethyldistannane; under argon; reaction time: 1-48 h; at -78 or -100 ° C; to mixture of TMEDA and LiBu addn. (-78 °C) of C8H10 (all at once), cooling is finished; after 24 h solution is cooled to -78 °C and Me3SnCl was added;; addition of H2O at 0 °C; extraction (pentane); evaporation of pentane; distillation (vacuum); elem. anal.; further products;

tert.-butyl lithium in pentane addn. of Me2NC2H4NMe2 at -78°C to tert-BuLi in pentane (10 s), ayellow ppt. is obtained, warming to 25°C (dissolution of ppt.), then cooling to -78°C, addn. of Me3SnCl in pentane, hydrolysis; distn. (bath temp. 70°C/9 Pa), first fraction (39-47°C) contains ethylenediamine-compd. and the dimethylamino-compd. in the ratio53 : 47, the second fraction (49°C) contains only the ethylenediamine-compd., elem. anal.;