Patent ID: 6936733

Claim:
A process for the industrial preparation of a disulfide of formula (I) in which n represents an integer between 0 and 2, said process comprising the following steps: (a) providing a solution containing a compound of formula (II) in which Hal represents a halogen atom, and reacting the formula II compound with a thioacetate of the formula CH 3 C(O)SM in which M represents sodium or potassium to form a thioacetate alkane sulfonate intermediate; (b) reacting the thioacetate intermediate from step (a) with a base to remove the acetate moiety and form a sodium mercaptoalkanesulfonate intermediate of formula III HS—CH 2 CH 2 —(CH 2 ) n —SO 3 Na (III); (c) adjusting the pH of the solution by adding an acid; (d) reacting the intermediate sodium mercaptoalkanesulfoflate of formula III with oxygen to yield the formula (I) disulfide; and (e) adding ethanol to the formula I disulfide obtained in step (d), followed by heating to dissolve the precipitates, then cooling and washing the resulting solid with ethanol.