Abstract: Disclosed is a composition of (1) a substituted benzaldehyde having the general formula ##STR1## where X is a leaving group in the ortho or para position, (2) a mercaptide having the general formula MSR' in an amount about stoichiometric to about 20 mole % in excess of stoichiometric with the amount of said substituted benzaldehyde, where M is an alkali metal and R' is alkyl or haloalkyl from C.sub.1 to C.sub.8 or aryl, aralkyl, or alkyl from C.sub.6 to C.sub.12, (3) sufficient water to dissolve said mercaptide and MX, (4) about 0.1 to about 5 mole %, based on said substituted benzaldehyde, of a phase transfer catalyst, and (5) 0 to about 100 wt %, based on total composition weight, of a water-immiscible organic solvent. Heating the composition to a temperature between about room temperature and 100.degree. C. results in the formation of a substituted mercapto-benzaldehyde.

Abstract: Disclosed is a method of making a substituted diphenyldisulfide from a substituted thiophenol. A two phase reaction mixture is prepared which comprises a substituted thiophenol having the general formula ##STR1## hydrogen peroxide, water, an organic solvent, a basic salt that will give a pH between about 7 and about 10, and an optional flocculating agent. In the formula, R is selected from the group consisting of halogen, alkyl from C.sub.1 to C.sub.6, alkoxy from C.sub.1 to C.sub.6, or nitro. After the exothermic reaction is complete, the reaction mixture is cooled to crystallize the substituted diphenyldisulfide product. The symmetrical product precipitates preferentially over the unsymmetrical product, thereby enhancing the purity of the product over the purity of the starting material. Optionally, the organic solvent and the aqueous phase are recycled.