PROCEDIMIENTO PARA LA SINTESIS SELECTIVA DE DISULFUROS DE SILILALQUILO

LA INVENCION TRATA DE UN PROCEDIMIENTO PARA LA SINTESIS SELECTIVA DE DISULFUROS DE SILILALQUILO POR DESULFURACION DE LOS CORRESPONDIENTES POLISULFUROS CON AYUDA DE REACTIVOS NUCLEOFILICOS. Preparation of bis(silylalkyl)disulphanes of formula (R R R SiR )2S2 (I) comprises (1) reacting silylalkyl polysulphide(s) of formula (R R R SiR )2Sn (II) with a nucleophilic compound (III) of formula MCN (IIIA), M2SO3 (IIIB) or R R R P (IIIC) in an amount equimolar to the number of sulphur atoms to be removed from (II); (2) filtering the resultant solid; and (3) purifying (I). In the formulae, R -R , R -R = 1-8C alkyl and/or alkoxy, H or monovalent aryl, preferably phenyl, toluyl or benzyl; R = divalent 1-8C, preferably 2-4C alkylidene or a group of formula (IV); n = 3-20, preferably 3-10; and M = an alkali cation, optionally substituted ammonium ion or half alkaline earth or zinc ion. Preferably a mixture of (IIIA), (IIIB) and (IIIC) is used. Reaction is carried out in the presence of a solvent for (III) at a temperature between 20 degrees C and the b.pt. of the solvent, especially in a 2-phase system in the presence of a phase transfer catalyst.