in dichloromethane (inert atmosphere); addn. of the Sn-N compound in CH2Cl2 at -30°C, a 2nd portion at -60°C to (D6)Me2SnBr2 in CH2Cl2, slow warming to room temp. within 12 h; condensing the volatiles into a cooled trap in vacuo, removal of CH2Cl2 and Me3SnBr by distn. in vacuo, treatment of the residue with CH2Cl2, crystn. at -20°C; elem. anal.;