Patent ID: 7851657

Claim:
A process for preparing a product of formula (I), R—CH 2 —S—S—S—CH 2 —R (I), said process comprising: a) providing a solution of N-(trimethylsilyl)imidazole in an organic solvent; b) adding neat sulfur dichloride to said solution to provide a reaction mixture comprising diimidazolylsulfide; and c) without isolation, contacting the diimidazolylsulfide with a thiol reagent of formula RCH 2 SH to provide the product of formula (I); d) isolation of the product of formula (I); and e) purification of the isolated product by recrystallization from at least one crystallization solvent, wherein the product of formula (I) is a crystalline product; and wherein R is an optionally substituted aryl or an optionally substituted heteroaryl group.