New Congeners of 1-Picryl-2-phenyl-2-(para-picramidophenyl)-diazenium Betaine whose Picramido Groups Are Replaced by 4-Cyano-2,6-dinitrophenyl Analogs

• Autorzy: Covaci I.
• Języki publikacji: EN

Abstrakty

EN

By analogy with our previously described 1-picryl-2-phenyl-2-(para-picramidophenyl)- diazenium betaine (4a), three new congeners were synthesized in which either one, or the other, or both of the picryl groups have one 4-nitro group replaced by a cyano group. The spectral properties of these new compounds are described, and they prove that the cyanodinitrophenyl group behaves like a slightly less powerful electron-withdrawing group than a picryl group. The dipotassium salt of 1-picryl-2-phenyl-2-(4-picrylaminophenyl)- hydrazine (5a) forms a supramolecular complex, 13, with 18-crown-6 ether, which can be mono- or dialkylated with methyl iodide, resulting in a monomethyl and dimethyl derivative 14 and 15, respectively. The monomethyl derivative, 14, has the methyl attached to the diarylamino nitrogen atom, since oxidation by potassium permanganate converts it into a stable hydrazylic radical, 17.Abyproduct in the synthesis of betaine 4a, when an excess of DPPH is used over N-methoxypicramide, was proved to be 2-(4-methoxyphenyl)-2-phenyl-1-picrylhydrazine, 12. In order to avoid the formation of such byproducts and to allow simpler purification procedures, it is recommended to use equimolar ratios of reactants, in the presence of potassium permanganate.

Słowa kluczowe

EN

betaines; stable free radicals; crown compounds; NMR spectra; hydrazine derivatives

• Wydawca: Polskie Towarzystwo Chemiczne
• Czasopismo: Polish Journal of Chemistry
• Rocznik: 2001
• Tom: Vol. 75, nr 10
• Strony: 1427--1440

Twórcy

autor

Covaci I.

• 1Roumanian Academy, Institute "I.G.Murgulescu" of Physical Chemistry, Laboratory of Supramolecular Chemistry and Interphase Processes, Splaiul Independentei 202, 77408, Bucharest, Roumania