in not given slow addn. of a slurry of LiNMe2 to an organotin chloride soln. (under an inert atmosphere, under anhydrous conditions), stirring for 2 h at room temp.,; flash evapn., removing of both solvents and product, leaving small amount of solid residue, distn. of reaction mixt. without sepn., solvents are distilled off, distn. at reduced pressure;