in ethanol byproducts: NaCl; soln. of triorganotin chloride treated with the org. compd., refluxed until clear soln. obtained (about 3h); bulk of ethanol removed by destillation, NaCl removed by filtration, thiophene-free benzene added, destillation continued, filtration/reflux repeated until all NaCl removed, solvent removed, residue dried (vacuum), recrystd. from ethanol, elem. anal.;