General Papers ARKIVOC 2007 (xvi) 260-265
Experimental Section
General Procedure. All yields refer to the pure isolated products which were characterized by comparison with authentic samples (IR, 1H NMR, TLC, and mp).
Preparation of [Ag(bipy)2]S2O8
Bis(bipyridine)silver(II) peroxydisulfate was prepared according to the reported procedure.15 To a methanol solution of silver nitrate (0.51 g, 3 mmol), 2,2'-bipyridine (1.1 g, 7 mmol) was added and the bright yellow solution was allowed to stir at room temperature for 0.5 h. The solvent was removed and the yellow crystalline product ([Ag(bipy)2]NO3) was poured into an cooled aqueous solution of K2S2O8 (0.95 g, 3.5 mmol). After the solution has been left standing for 0.5 h, a brown crystalline compound was formed. The solution was filtered and the brown crystals was washed with cooled water and dried in vacuo. Yield 4.64 (76%). The product was characterized as [Ag(bipy)2]S2O8 based CHN elemental analysis, magnetic susceptibility, and UV-Vis spectroscopy. Anal. Calc. for AgC20H16N4O8S2: C, 39.23, H, 2.63, N, 9.15, Found: C, 39.44, H, 2.48, N, 9.07. µeff (BM, 298 K), 1.84. .max (nm)( e, lmol-1cm-1), 445 (1950).
General Procedure for the oxidation of organic substrates with [Ag(bipy)2]S2O8
To a solution of a substrate (1 mmol) in 10 ml wet acetonitrile, [Ag(bipy)2]S2O8 (0.5-3 mmol) was added and stirred at room temperature for 0.15-5 h. The progress of the reaction was monitored by TLC (CCl4:MeOH or n-heptane:ethylacetate). The reaction was left for 30 min to settle all inorganic residues and filtered. The solid was washed with acetonitrile (3×5 ml). The combined organic phases were evaporated and the crude product was purified by flash chromatography (silica gel). In the case of sulfonic acids, the oily crude products were isolated as their sodium salts on adding saturated sodium bicarbonate solution.
Acknowledgements
The authors are grateful to the Kermanshah Oil Refining Company and the Razi University Research Council for the financial support of this work. MJ is particularly grateful to Proferssors
H. Firouzabadi and P. Salehi for their valuable comments. References and Footnotes
1. Minisci, F.; Citterio, A.; Giordano, C. Acc. Chem. Res. 1983, 16, 27. 2. House, D. A. Chem. Rev. 1962, 62, 185. 3. Anderson, J. M.; Kochi, J. K. J. Am. Chem. Soc. 1970, 92, 1651. 4. Walling, C.; Camaioni, D. M. J. Org. Chem. 1978, 43, 3266. ISSN 1551-7012 Page 264 ©ARKAT USA, Inc.
