530-47-2Relevant articles and documents
REACTION OF FERVENULIN-4-OXIDE WITH ACETOACETIC ESTER HYDRAZONES
Azev, Yu. A.,Novikova, A. P.,Mudretsova, I. I.
, p. 1398 (1984)
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New sulfonyl derivatives of 2,2-diphenyl-1-picrylhydrazyl and their supramolecular complexes with crown ethers or kryptands
Ioni?ǎ, Petre,Cǎproiu, Miron T.,Balaban, Alexandru T.
, p. 935 - 941 (2007/10/03)
The synthesis of mono-and di-sulfonates 1 and 2 derived from DPPH was optimised (their notation is NaOSO2-DPPH and (NaOSO2)2-DPPH, respectively). The pKa values of the corresponding hydrazines 3 and 4 were determined. With crown ether 18-C-6, hydrophobic supramolecular complexes are formed by 3 and 4. The sodium monosulfonate 3 reacts with thionyl chloride yielding the sulfochloride ClSO2-DPPH-H (5). With alcohols or amines, 5 reacts readily leading to alkyl esters and sulfonamide derivatives, respectively: thus, valine afforded a well-characterized compound, and the corresponding free radical may be used as a spin label or as a colored redox indicator for peptide chemistry. Similarly, 4-aminoantipyrine forms a sulfonamide. The new compounds were characterised by elemental analysis, IR, UV-VIS, NMR and ESR spectroscopy, and by their complexation and transport data.