in dichloromethane to ClSnBu3 in CH2Cl2 is added AgSO3Me, mixt. is stirred at room temp. for 1 h; filtration, solvent is removed under reduced pressure, residue is heated at 0.01 mmHg, elem. anal.;

in toluene 1:2; azeotropic dehydration; boiling for 2-4 h; removal of solvent;