Synthesis,structure, and transformations of 1-aza-3-oxa-7-thiabicyclo[3.4.0]nonan-2-one

1-Aza-3-oxa-7-thiabicyclo[3.4.0]nonan-2-one was obtained by reduction of 3,4-dimethoxycarbonyltetrahydro-1,4-thiazine. The reduction of this product with lithium aluminum hydride led to 3-hydroxymethyl-4-methyltetrahydro-1,4-thiazine. The molecular and crystal structures of 1-aza-3-oxa-7-thiabicyclo[3.4.0]nonan-2-one were investigated by x-ray diffraction analysis.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1280–1285, September, 1986.     

Crystallographic parameters of 1-organylgermatranes

The crystallographic parameters and the translation groups of the elementary cells of the crystals of 1-methyl-, 1-ethyl-, 1-phenyl-, and 1--naphthylgermatranes have been determined by X-radiography. The volumes of the elementary cells (V), the number of molecules in them (N), the X-ray density of the crystals (x) and the packing coefficients for the molecules in the crystals (k) have been calculated from the linear and angular parameters.     

Structure and properties of 2,4a-dimethyl-4-phenyl-3-ethoxycarbonyl-5-oxo-4a,5-dihydro-4H-indeno[1,2-b]pyridine

The molecular and crystal structure of 2,3a-dimethyl-4-phenyl-3-ethoxycarbony-5-oxo-4a,5-dihydro-4H-indeno[1,2-b]pyridine has been determined, and its reduction and alkaline and acid hydrolysis reactions have been studied.Translated from Khimiya Geterotsiklicheskikh Soedineii, No. 10, pp. 1388–1392, October, 1984.     

Synthesis,properties, and X-ray diffraction study of 4-trifluoromethyl-6-phenyl-2-chloro-3-cyanopyridine

4-Trifluoromethyl-6-phenyl-2-chloro-3-cyanopyridine was synthesized, and its molecular-crystal structure was established. The chlorine atom was replaced by amino, mercapto, thiocyanato, and azido groups. The possibility of the direct amination of 4-trifluoromethyl-6-phenyl-3-cyano-2-pyridone by the action of hexamethylphosphoric triamide (HMPT) was demonstrated.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1233–1237, September, 1987.     

Molecular and crystalline structure of furfural diacetate nitration intermediate

X-ray crystallography established the structure of the acetyl nitrate adduct to furfural diacetate (H. Gilman and G.F. Wright (1930)) as trans-2-acetoxy-5-nitro-2,5-dihydro-2-furfural diacetate (1a). The furanoid ring is essentially planar, its geometry being similar to that of 2,5-dihydrofuran molecule, except for the interatomic distance C(3)-C(4) which is shorter than the corresponding length of double C-C bond in alkenes. The C(5)-N 1.52 Å bond significantly exceeds the standard C-N bond lengths in nitroalkanes and nitrobenzene.     

Structure of 1,1,3(RS),6,6,8(RS)-hexamethyl-cis-10b(SR),10c(SR)-perhydro-1H,6H-3a(SR), 5a(SR) 8a(SR), 10a(SR)-tetraazapyrene determined by X-ray diffraction methods. A semiempirical method of structure solution

The crystal and molecular structure of the title compound hexamethyl-perhy-drotetraazapyrene (I) has been determined by X-ray diffraction methods. The compound crystallizes in the triclinic system, space groupP¯1, with cell dimensionsa=7.715(1),b=10.580(2),c=11.926(2) Å, and=94.37(1)°,=104.87(1)°, and =107.27(1)°. Since the usual direct methods failed, the structure was solved by a semiempirical optimization of packing a model ofI in the unit cell, in terms of the van der Waals' intermolecular energy. The atomic parameters at the most energetically favored position were then refined by least squares against 2396 observed unique reflections, giving a finalR of 0.067. The semiempirical solution used here seems to be limited to particular cases. The molecule ofI consists of two fused piperazine and two fused hexahydropyrimidine rings, having slightly distorted chair conformations. The rings form a foldedcis-10b,10c system of almost exactC ₂ point group symmetry. The lone methyl groups in positions 3 and 8 (at the folding) are found to be axially attached. The geminal methyl groups in positions 1 and 6 are situated away from the folding.