Method of organo silicon compounds containing sulphur

Sulphur-contg. organosilicon cpds. Z-Alk-Sn-Alk-Z (I) (where Z =Si(R1)(R1)(R2) - Si(R1)(R2)(R2) or -Si(R2)(R2)(R2), R1 = 1-4C alkyl or phenyl, R2 = 1-8C (esp. 1-4C) alkyl or 5-8C cycloalkyl or 1-8C straight or branched alkylmercapto gp. Alk = opt. unsatd. straight or branched opt. cyclic 1-18C (esp. 1-6C or pref. 2 or 3C) hydrocarbon gp. and n = 2-6) are prepd. by reacting 2 mols. of a cpd. Z-alk-Hal where Hal = Cl, Br or I with 1 mol. of a cpd. Me2Sn in which Me = ammonium or metal atom, esp. alkali metal such as Na, pref. in an org. solvent such as acetone or an alcohol, at elevated temps. followed by filtering off the metal halide formed and distillation of the solvent under reduced pressure to leave the (I) as residue.