- Acidity and basicity of primary N-phenylnitramines: Catalytic effect of protons on the nitramine rearrangement
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Para-substituted N-phenylnitramines were prepared either by oxidation of diazonium salts or by nitration under alkaline or acidic conditions. Isotopic [15N-NO2] labelling indicated that the bands characteristic of the N-nitro group appear in the 1318-1323 and 1585-1607 cm-1 regions. In the nitrogen NMR spectra, the nitramino group gives two resonances at -193 ± 3 (NH) and -32 ± 3 ppm (NO2). The chemical shifts in proton and carbon NMR spectra are predictable, based on increments and the additivity rule. The spectral data indicate the lack of conjugation between the nitramino group and another substituent bound to the ring. It seems to contradict the well-known fact that substituents strongly (ρ = 4) influence the rate of nitramine rearrangement. The acidities of primary N-phenylnitramines (3.77 A B ≈ 21) are extremely low. Consequently, addition of protons to an intact nitramine molecule, as the preliminary step of the rearrangement, seems to be improbable. Migration of the N-nitro group precedes protonation; the latter process facilitates transformation of intermediates into stable final products. Copyright
- Daszkiewicz, Zdzislaw,Spaleniak, Grzegorz,Kyziol, Janusz B.
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p. 115 - 122
(2007/10/03)
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- Amidinoureas substituted in both the urea and amidino nitrogen positions
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A method of inducing blood pressure reduction in humans and mammals by administering 2,6-disubstituted phenyl N-alkyl amidinoureas in which the phenyl ring is additionally substituted by a hydroxy, alkoxy, aralkoxy, alkenyloxy, alkynyloxy, acyloxy or halo acyloxy group and a novel class of amidinourea compounds having pharmaceutical uses, including blood pressure lowering activity.
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- Substituted phenyl amidinoureas
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This invention relates to a method of lowering blood pressure in humans and mammals using 2,6-disubstituted phenyl amidinoureas in which the phenyl ring is additionally substituted by a hydroxy, alkoxy, aralkoxy, alkenyloxy, alkynyloxy, haloacyloxy, or acyloxy group and to novel 2,6-disubstituted phenyl amidinoureas which possess pharmaceutical properties, including blood pressure lowering activity.
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- Preparation of esters of phosphorus acids
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Esters of phosphorus acids are prepared by an improved process whereby aromatic alcohols and phosphorus halides are reacted at specified temperatures in the presence of amine catalysts thereby providing high yields of substantially pure esters and allowing preparation of selected halogen-containing mono- and di-esters of phosphorus acids wherein halogen is directly bonded to phosphorus having substantially no side reactant contamination. The phosphorus esters are useful as intermediates in the preparation of plasticizers, oil additives and functional fluids.
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