caa a22 4500 467991642 CHVBK 20180323112546.0 cr unu---uuuuu 170328e19900701xx s 000 0 eng 10.1007/BF00509712 doi (NATIONALLICENCE)springer-10.1007/BF00509712 Chemical properties of ylidene derivatives of azines. 4. Structures of the products of protonation and transformation of dihydroazinylidenecyanoacetic esters in concentrated sulfuric acid [Elektronische Daten] [I. Oleinik, O. Zagulyaeva, A. Denisov, V. Mamaev] It was demonstrated by UV and 13C NMR spectroscopy that in concentrated sulfuric acid ylidene derivatives of dihydropyridine (Ia) and dihydropyridazine (IIa) have aromatic structures Ib and IIb, while derivatives of dihydropyrimidines IIIa and IVa, dihydropyrazine Va, and dihydro-s-triazine VIa retain ylidene structures IIIb-VIb, respectively, which determines their greater stability in these solutions. When solutions of Ib-VIb in 95% H2SO4 were allowed to stand, they were converted to the corresponding azinylmalonic ester monoamides or azinylacetamides, depending on the reaction temperature. Plenum Publishing Corporation, 1991 Oleinik I. Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR, 630090, Novosibirsk aut Zagulyaeva O. Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR, 630090, Novosibirsk aut Denisov A. Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR, 630090, Novosibirsk aut Mamaev V. Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR, 630090, Novosibirsk aut Chemistry of Heterocyclic Compounds Kluwer Academic Publishers-Plenum Publishers 26/7(1990-07-01), 801-807 0009-3122 26:7<801 1990 26 10593 https://doi.org/10.1007/BF00509712 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00509712 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Oleinik I. Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR, 630090, Novosibirsk aut NATIONALLICENCE 700 1- Zagulyaeva O. Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR, 630090, Novosibirsk aut NATIONALLICENCE 700 1- Denisov A. Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR, 630090, Novosibirsk aut NATIONALLICENCE 700 1- Mamaev V. Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR, 630090, Novosibirsk aut NATIONALLICENCE 773 0- Chemistry of Heterocyclic Compounds Kluwer Academic Publishers-Plenum Publishers 26/7(1990-07-01), 801-807 0009-3122 26:7<801 1990 26 10593 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer