2,2 -dipyridyl-1,1 -dioxide

Fig.2 IR spectra of 4,4 -dipyridyl N,N -dioxide in the vo-h stretching region for the hydrated compound (black line, bottom) and the complex it gives with 1,4-DITFB (grey line, top). Hydration water disappears on complex formation...

The presumably weaker gold-methyl bond is preferentially cleaved, consistent with a primary attack by sulfur dioxide, followed by methyl migration . The 2,2 -dipyridyl sulfinato complexes of iron(II), of formula Fe(2,2 -CioH8N2)2[OS(0)R]2, undergo an irreversible transformation into the thermodynamically stable S-sulfinato derivatives Fe(2,2 -CioHsN2)2[S(02)R]2 by refluxing in pyridine . 

Preparative Methods generally, 2,2 -dipyridyl disulfide-A, A -dioxide is obtained by the oxidation of fV hydrox3fp3Tidine-2-thione (2-mercaptopyridine-1-oxide, thiohydroxamic acid). To a suspension of 42.3 g of )V hydroxypyridine-2-thione in water (300 mL) was added 30% hydrogen peroxide (35 mL). The reaction is slightly exothermic. The reaction mixture was stirred for 1 h with the tenqterature maintained at 45 °C. A white solid,... 

Alkyl and aryl pyridyl disulfide-W oxides are also effective sulfenylating agents. Thus, treatment under prolonged reaction time of 2,2 -dipyridyl disulfide-)V,) -dioxide with 2 equiv of thiol generates s)mimetrical disulfides and 7V hydroxy-2-thiopyridone as shown in eq 3. ... 

Preparation of Disulfides. Unsymmetrical alkyl and aryl P3nidyl disulfide-A oxides are prepared by the reaction of 2,2 -dipyridyl disulfide-A,)V-dioxide with various thiols in good yields (eq 2). 7V hydroxypyridine-2-thione is a by-product of this reaction. 

Reaction of an aryllithium with carbon dioxide leads to the corresponding carboxylic acid. Aromatic carboxylic acids are decarb-oxylated by heating a) without NaOH, b) with NaOH or c) with CU2O in dipyridyle (see Scheme 6). 

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