Acylation of 1-oxo-4-hydroxypyridazino[4,5-b]quinoxaline

Monoacyl and diacyl derivatives were obtained, depending on the reaction conditions, by reaction of 1-oxo-4-hydroxypyridazino[4,5-b]quinoxaline with acylating agents. Reductive acetylation leads to compounds with three acetyl groups. The structures of all of the compounds obtained were confirmed by their IR and UV spectra.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 407–410, March 1977.     

Methylation of 1-oxo-4-hydroxypyridazino[4,5-b]-quinoxaline

The methylation of 1-oxo-4-hydroxypyridazino[4,5-b]quinoxaline (I) with methyl iodide and diazomethane under various conditions was studied. The structures of the disodium and disilver salts of I were established by means of spectrophotometric methods of analysis.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1418–1420, October, 1973.     

Synthesis and crystal structure of the copper(II) valerate complex with nicotinamide

A coordination compound of copper(II) valerate with nicotinamide, [CuL(C₄H₉COO)₂]₂ (I), has been synthesized, and its crystal structure has been determined by X-ray crystallography. The crystals of I are triclinic: a = 9.1245(9) Å, b = 9.8572(6) Å, c = 11.0944(9) Å, α = 73.51(1)°, β = 79.917(6)°, γ = 72.161(7)°, Z = 2, space group $P\bar 1$ . In the centrosymmetric binuclear molecule of I, the copper atoms (Cu...Cu′, 2.621 Å) are linked through four bidentate chelating valerate ligands (av., Cu-O 1.969 Å). The coordination polyhedron of the Cu atom is a tetragonal pyramid with the nitrogen atom of the pyridine ring in the apical position at a longer distance (Cu-N, 2.190 Å).     

Coordinational compounds of 3<Emphasis Type="Italic">d</Emphasis>-metal phthalates with nicotinamide

Complexes of iron(II), cobalt(II), nickel(II), copper(II), and zinc with nicotinamide were synthesized. The compounds obtained were characterized by means of chemical analysis, conductometry, thermogravimetry, and by means of the IR and the diffuse reflection spectroscopy.