18617-40-8Relevant academic research and scientific papers
Dearomative (3+2) cycloaddition of 2-substituted 3,5-dinitropyridines and N-methyl azomethine ylide
Bastrakov, Maxim A.,Fedorenko, Alexey K.,Starosotnikov, Alexey M.,Kachala, Vadim V.,Shevelev, Svyatoslav A.
, p. 72 - 77 (2019/02/25)
[Figure not available: see fulltext.] 1,3-Dipolar cycloaddition of various 2-substituted 3,5-dinitropyridines and unstabilized N-methyl azomethine ylide has been studied. It was found that, depending on the nature of the substituent, the reaction results
2-alkoxy-3,5-diaminopyridine derivatives and their salts, and dye compositions for keratinous fibers containing the derivatives or salts
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, (2008/06/13)
A dye composition for keratinous fibers which contains a coupler and a developer are disclosed. The present coupler component is a novel 2-alkoxy-3,5-diaminopyridine derivatives of the formula (1): STR1 wherein R1 and R2 are the same or different from each other and independently represent a hydrogen atom, a lower alkanoyl group or a lower alkyl group which may be substituted by at least one hydroxyl group, and R3 is a lower alkyl group which may be substituted by at least one hydroxyl group, or a salt thereof; provided that R1 and R2 are not both a hydrogen atom or an acetyl group at the same time. The present 2-alkoxy-3,5-diaminopyridine derivatives are useful as couplers in dye compositions, and are capable of dyeing keratinous fibers such as hair in a bright blue color with excellent dyeability. Dye compositions containing the present compounds as a coupler show excellent resistance to discoloration, excellent resistance to shampooing and excellent resistance to friction.
Structure of 2-methoxy-3,5-dinitropyridine
Punte, G.,Rivero, B. E.,Cerdeira, S.,Nudelman, N. S.
, p. 298 - 301 (2007/10/02)
2-Methoxy-3,5-dinitropyridine, C6N3O5H5, crystallizes in the monoclinic system, space group P21/n, with cell parameters a = 7.496(5), b = 18.38(1), c = 6.068(2) Angstroem, β = 77.18(4) deg, V = 815(1) Angstroem3, and four molecules per unit cell.Its structure was solved by direct methods and refined by least-squares procedures to a final R = 4.99 percent, Rw = 5.42 percent, for 753 observed independent reflections.The molecule is not planar, a rotation of the methoxy and 3-nitro groups out of the pyridine ring (7 deg and 16 deg, respectively) is observed.The methoxy group is located syn to the ring nitrogen atom to avoid repulsion with the 3-NO2 group and adopts a geometry different from the mean reported in the literature for methoxyaromatic groups.Geometrical parameters suggested by Domenicano and Murray-Rust and Norrestam and Schepper are used to analyze substituent effects on the pyridine shape and the possible causes of non-additivity of substituent effects are discussed.The relation of molecular conformation with reactivity of the title compound with amines is examined.
1H and 13C NMR Studies of Substituted Nitropyridines and Nitrobenzenes
Nudelman, N. S.,Cerdeira, S. B.
, p. 507 - 511 (2007/10/02)
The 1H and 13C NMR spectra of 3-nitro-, 5-nitro- and 3,5-dinitro-2-methoxypyridines have been determined.The results show the preferred cis conformation for the 2-methoxy group, and the importance of steric repulsion between the oxygen atom of this group
