in not given tin compd. was heated at 65°C under vac.;

methyl iodide in N,N-dimethyl-formamide; toluene byproducts: (CH3O)2CO, CsI; (Ar); standard Schlenk technique; toluene (1 equiv.), MeI (2 equiv.) and CsF (1.4 equiv.) added to soln. of tin compd. (1 equiv.) in DMF under CO2 at 19°C; GC and NMR monitoring; not isolated;