Urea- Hydrogen Peroxide (UHP) Oxidation of Thiols to the Corresponding Disulfides Promoted by Maleic Anhydride as Mediator

Abstract

Urea-hydrogen peroxide (UHP) was used in the presence of maleic anhydride as mediator in a simple and convenient method for the oxidation in high yield of some thiols to the corresponding disulfides. Peroxymaleic acid formed in situ from the reaction of UHP with maleic anhydride has a key role in this oxidation. Performance of the reaction in various solvents showed that methanol was the solvent of choice at 0 oC. The products were isolated by simple filtration on silica gel.

A Comparative Study of Catalytic Activity of Fe, Mn and Cu Porphyrins Immobilized on Mesoporous MCM-41 in Oxidation of Sulfides

“…It is shown that the latter could be largely increased by the addition of different activators. [42][43][44] In large-scale bleaching applications and many synthetic oxidations, activation via formation of peroxycarboxylic acids [45][46][47][48][49][50] or with bicarbonate ion [51] can be a favored method. The effect of HOAc as activator in the catalytic oxidation of MePhS with UHP was investigated and the results are presented in Figure 5.…”

Synthesis of 2-Mercaptobenzimidazole and Some of its Derivatives

“…Step: Thiol compounds oxidize into disulfide easily, the weak oxidizing agent will be enough for oxidation depending on literature [24] Because the bond energy for (SH) group in thiole is (80 Kcal/mol) its very little from the bond energy for (OH) group in alcohols, therefore thiol possess ability on coupl oxidation whene it reacted with oxidizing agent to give disulfide.Oxidation of thiol compounds by hydrogen peroxide (30%) to give disulfide. As is shown below.…”

Fast and Highly Efficient Solid State Oxidation of Thiols

“…The filtrate was evaporated under reduced pressure and the resulting crude material was purified by flash chromatography on SiO 2 (eluent: CH 2 Cl 2 ) to afford bis 2-pyrimidine disulfide (95%); m.p = 132-135ºC (Lit. [24] The other substrates were treated similarly. Although a known compound, the analytical data for the product of entry 6 in Table 1 …”

“…Most reagents used are metal-based and toxic for the environment, while with others, such as halogens (Br 2 and I 2 ) and halogen containing reagents that are non-metallic, one encounters frequently difficulties in handling with the reagents and/or their separation from the products. In continuation of our recently reported work on the oxidation of thiols [23][24][25][26], herein we report a fast solid state method for controlled oxidation of the thiols to the corresponding disulfides using moist (10%) sodium periodate as an available, inexpensive and non toxic reagent.…”