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  • Author: Viktor Vrábel x
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Vrábel Viktor, Sivý Július and Šafař Peter

Abstract

The title compound, C17H32NO4I・H2O, is chiral molecule with seven stereogenic centres. The absolute configuration was assigned from the synthesis and confirmed by the structure determination. The central six-membered ring of the indolizine moiety and 1,4-dioxane ring adopt a chair conformation, with two atoms displaced by -0.530(3), 0.712(3) and -0.631(2), 0.602(2) Å, respectively, from the plane of the other four atoms. The conformation of the pyrrolidine ring is close to that of a envelope, with the flap atom displaced by -0.600(3) A from the plane through the remaining four atoms. The electron structure was calculated by the semiempirical quantum chemistry method PM3. The crystal structure of compound is stabilized by O-H・・・I and O-H・・・O hydrogen bonds.

Open access

Viktor Vrábel, Július Sivý, Ľubomír Švorc, Jan Světlík and Šafař Peter

Abstract

We report here the structure of new spiro-derivative, namely methyl (2R,4R)-4-(5-methylthiazol- 2-ylamino)spiro[chroman-2,2’-chromene]-3’-carboxylate, C23H20N2O4S, which crystallizes as racemate in the space group P-1. In this compound, the chromanone moiety consists of a benzene ring fused with a sixmembered heterocyclic ring which adopts a distorted half-chair conformation. The molecules are linked by a combination of N–H⋯N hydrogen bonds and weak C–H⋯O, C-H⋯S, C-H⋯π, inter- and intramolecular interactions resulting in a two-dimensional network in the crystal structure.

Open access

Viktor Vrábel, Július Sivý, Ľubomír Švorc, Jan Světlík and Štefan Marchalín

Abstract

We report here the crystal and electronic structure of a new spiro-derivative, namely methyl (2R,4S)- 4-(benzothiazol-2-ylamino)-8,8´-dimethoxyspiro[chroman-2,2´-chromene]-3´-carboxylate (I), C28H24N2O6S, which crystallizes as racemate in the space group C2/c. In this compound, the chromanone moiety consists of a benzene ring fused with a six-membered heterocyclic ring which adopts a distorted half-chair conformation. The molecules are linked by a combination of N-H∙∙∙N hydrogen bonds and weak C-H∙∙∙O, C-H∙∙∙S, C-H∙∙∙ π, inter- and intra-molecular interactions resulting in a two-dimensional network in the crystal structure.

Open access

Viktor Vrábel, Július Sivý, Peter Šafař and Štefan Marchalín

Abstract

The title compound, C13H15NO3S, is a chiral molecule with two stereogenic centres. Its absolute configuration was derrived from the synthesis and confirmed by structure determination. The expected stereochemistry of atoms C5 and C6 was confirmed to be S. The central N-heterocyclic rings are not planar and adopt a half-chair conformation. A calculation of least-squares planes showed that these rings are puckered in such a manner that the five atoms C1, C2, C3, C5 and N1 (second ring: N1, C6, C7, C10 and C11) are planar, while atoms C4 (C5) are displaced from these planes with the out-of-plane displacement of 0.582 (3) Å and 0,666 (2) Å in the second ring, respectively. Dihedral angle between the planes of the central N-heterocyclic rings is 40.0 (1)°. Crystal structure is stabilized by C—H···O hydrogen interactions.

Open access

Vrábel Viktor, Sivý Július, Šafař Peter and Marchalín Štefan

Abstract

The title compound, C11H16NOS・I, is chiral molecule with three stereogenic centres. The absolute configuration was assigned from the synthesis and confirmed by the structure determination. The central six-membered ring of the indolizine moiety adopts a half-chair conformation with atom displaced by 0.655 (2) A from the plane of the oder remaining five atoms. The pyrrolidine ring adopts an envelope conformation, with the greatest deviation from the mean plane of the ring being 0.646 (2) A for the bridgehead N atom. The crystal structure of the title compound is stabilized by O-H・・・I and C-H・・・O hydrogen bonds.

Open access

Viktor Vrábel, Július Sivý, Peter Šafař and Jozefína Žúšiová

Abstract

Molecules of the title compound, C13H21NO3, crystallize as single enantiomers with four stereogenic centres, their absolute configuration were confirmed by anomalous dispersion effects determined by diffraction measurements on the crystals. Conformations of the pyrrolidine and 1,3-oxolane rings are close to that of an envelope, with the flap atoms displaced by −0.205 (1) and −0.449 (1) Å, respectively, from the plane of the other remaining four atoms. The central six-membered ring of the indolizine moiety adopts a nearly perfect boat conformation, with two atoms displaced by 0.575 (1) and 0.603 (1) Å from the plane of the other remaining four atoms. Crystal structure of the title compound is stabilized by C−H···O hydrogen interactions.

Open access

Viktor Vrábel, Július Sivýb, Jan Světlíkc, Štefan Marchalínd and Šafař Peterd

Abstract

We report here the crystal and molecular structure of a new chromane-derivative, namely isopropyl( 2R*,3S*,4S*)-4-(benzo[d]thiazol-2-ylamino)-2-hydroxy-2-ethylchromane-3-carboxylate (I), C21H22N2O4S, which crystallizes as racemate in the space group C2/c. Its structure has been solved using X-ray diffraction data obtained at low temperature (100(2) K). In this compound, the chromane moiety consists of a benzene ring fused with a six-membered heterocyclic ring which adopts a distorted half-chair conformation. The molecules are linked by a combination of O-H∙∙∙N and N-H∙∙∙O hydrogen bonds, resulting in a twodimensional network which helps stabilizing the crystal structure of the compound (I). Dihedral angle between the chromane and benzothiazol rings is 80.6(1)0.

Open access

Viktor Vrábel, Július Sivý, Peter Šafař and Jozefína Žúžiová

Abstract

The molecules of the title compound, C11H16NS·I, crystallize as single enantiomer with two stereogenic centre, their absolute configuration were confirmed by anomalous dispersion effects in diffraction measurements on the crystals. The conformation of the pyrrolidine ring is close to that of an envelope, with the flap atom N1 displaced by 0.661 (2) A from the plane of the oder remaining four atoms. The central six-membered ring of the indolizine moiety adopt a half-chair conformation with atom C5 displaced by -0.686 (2) Å from the plane of the oder remaining five atoms. The crystal structure of the title compound is stabilized by C-H···I···H-C hydrogen interactions.