in neat (no solvent) byproducts: Me4Sn; heating of the react. mixt. at ca 60°C, then 1-2 d at room temp., treatment with hexane, filtration, evapg. of filtrate, adding of Me3SnCl, repeating of procedure; crystn. from benzene/hexane or ppn. with H2O from EtOH soln.; elem. anal.;

in benzene refluxing for 1 h, evapn., dissoln. in CHCl3, filtration; evapn., recrystn. from CH2Cl2/hexane; elem. anal.;