Sofa Conformation Research Articles

Crystal structure of (3E,5E)-3,5-bis-[4-(di-ethyl-aza-nium-yl)benzyl-idene]-1-methyl-4-oxopiperidin-1-ium trichloride dihydrate: a potential biophotonic material.

In the trication of the title hydrated mol-ecular salt, C28H40N3O(3+)·3Cl(-)·2H2O, the central heterocyclic ring adopts a sofa conformation, with the exocyclic N-C bond in an equatorial orientation. The dihedral angles between the planar part of this heterocyclic ring and the two almost flat side-chain fragments, which include the aromatic ring and bridging atoms, are 28.8 (1) and 41.1 (1)°. Both di-ethyl-aza-niumyl substituents have a tetra-hedral geometry, while the dihedral angles between the above-mentioned flat part of the aryl fragments and the imaginary planes drawn through atoms C-N-C of the di-ethyl-aza-niumyl substituents are 86.3 (2) and 80.4 (1)°, respectively. In the crystal, N-H⋯Cl hydrogen bonds link the cations and anions into [100] chains. The chains are cross-linked by numerous C-H⋯O and C-H⋯Cl inter-actions, generating a three-dimensional network. One of the chloride ions is disordered over two adjacent positions in a 0.895 (4):0.105 (4) ratio.

Crystal structure of 2-[9-(2-hy-droxy-phen-yl)-1,8-dioxo-1,2,3,4,5,6,7,8,9,10-deca-hydro-acridin-10-yl]acetic acid.

The title compound, C21H21NO5, crystallizes with two mol­ecules in the asymmetric unit. In each mol­ecule, the central 1,4-di­hydro­pyridine ring adopts a shallow sofa conformations (with the C atom bearing the phenol ring as the flap), whereas the pendant cyclo­hexene rings both have twisted-boat conformations. Each mol­ecule features an intra­molecular O—H⋯O hydrogen bond, which closes an S(8) ring. In the crystal, the mol­ecules are linked by O—H⋯O, C—H⋯O and C—H⋯π inter­actions, forming a three-dimensional network.

Crystal structure of 3-benzyl-1-[(1,2,3,4-tetra-hydro-naphthalen-1-yl-idene)amino]-thio-urea.

In the title compound, C18H19N3S, the dihedral angle between the planes of the benzene rings is 58.63 (8)°. The six-membered ring bonded to the thio­semicarbazide group (r.m.s. deviation = 0.038 Å) adopts a sofa conformation, with one of the methyl­ene-group C atoms as the flap. A short intra­molecular N—H⋯N contact is observed. In the crystal, mol­ecules are linked by weak N—H⋯S inter­actions to generate C(4) chains propagating in the [010] direction, with adjacent mol­ecules related by glide symmetry.

Crystal Structure Analysis of Methyl-3-phenyl-3H-chromeno[4,3-c]isoxazole-3a(4H)-carboxylate

AbstractThe crystal structure of the potential active methyl-3-phenyl-3H-chromeno[4,3-c]isoxazole-3a(4H)-carboxylate(C 18 H 15 NO 4 ) has been determined from single crystal X-ray diffraction data. In the title compound crystallizes in theorthorombic space group P2 1 2 1 2 1 with unit cell dimension a=9.8320 (17) A, b=9.9890 (18) A and c= 15.588 (3)A [α=90°,β= 90 o and γ= 90 o ]. In the structure chromene, isoxazole and carboxylate are almost coplanar each other. All geometricalparameters revelled that chromene ring of pyran ring adopt sofa conformation. The crystal packing is stabilized byintermolecular C-H...O and C-H...N hydrogen bond interaction.Keywords: Chromene, Pyran, Single Crystal Structure, X-ray diffraction 1. Introduction Chromenes constitute one of the main class of natu-rally occurring oxygen heterocycles, which posses sev-eral biological and pharmacological properties such asanti-coagulant, anti-sterility, anti-viral, anti-fungal, anti-inflammatory, cardionthonic, anti-diabetic, spasmolytic,diuretic, anti-anaphylactic, anti-cancer activities

Crystal structure of 2-acetyl-5-(3,4-di-meth-oxy-phen-yl)-6-eth-oxy-carbonyl-3,7-dimethyl-5H-thia-zolo[3,2-a]pyrimidin-8-ium chloride.

The title mol­ecular salt, C21H25N2O5S+·Cl−, crystallizes with two ion pairs in the asymmetric unit. The cations have similar conformations (r.m.s. overlay fit = 0.40 Å), with one of them showing disorder of the terminal methyl group of the ester in a 0.72 (2):0.28 (2) ratio. In the first cation, the 3,4-dimeth­oxy-substituted phenyl ring subtends a dihedral angle of 88.38 (7)° with the pyrimidine ring and 6.79 (8)° with the thia­zole ring. The equivalent data for the second cation are 89.97 (3) and 6.42 (7)°, respectively. The pyrimidine ring adopts a sofa conformation in each cation. In the crystal, the components are linked by N—H⋯Cl hydrogen bonds, generating isolated ion pairs. The ion pairs are are linked by C—H⋯O inter­actions, generating a three-dimensional network. In addition, a weak C—H⋯π inter­action is observed.

Crystal structure of ethyl 4-(2-fluoro-phen-yl)-6-methyl-2-sulfanyl-idene-1,2,3,4-tetra-hydro-pyrimidine-5-carboxyl-ate.

The title compound, C14H15FN2O2S, crystallizes with two mol­ecules in the asymmetric unit. In each mol­ecule, the pyrimidine ring adopts a sofa conformation with the sp 3-hybridized C atom forming the flap and the fluoro-substituted ring in an axial position. In the crystal, mol­ecules are linked via N—H⋯S hydrogen bonds, forming chains of R 2 2(8) rings along [100]. In one independent mol­ecule, an intra­molecular C—H⋯O hydrogen bond is observed.

Crystal structure of 4-(6-bromo-4-oxo-4H-chromen-3-yl)-2-methyl-amino-3-nitro-pyrano[3,2-c]chromen-5(4H)-one chloro-form monosolvate.

In the title compound, C22H13BrN2O7·CHCl3, the pyran ring adopts a shallow sofa conformation with the C atom bearing the bromo­chromene system as the flap [deviation = 0.291 (3) Å]. The dihedral angle between the pyran fused-ring system (all atoms; r.m.s. deviation = 0.032 Å) and the bromo­chromene ring system (r.m.s. deviation = 0.027 Å) is 87.56 (9)°. An intra­molecular N—H⋯O hydrogen bond closes an S(6) ring. The Cl atoms of the solvent mol­ecule are disordered over two sets of sites in a 0.515 (6):0.485 (6) ratio. In the crystal, inversion dimers linked by pairs of N—H⋯O hydrogen bonds generate R 2 2(12) loops. The packing also features C—H⋯O and very weak π–π [centroid–centroid separation = 3.960 (2) Å] inter­actions, which link the dimers into a three-dimensional network.

Crystal structures and conformational analyses of three pyranochromene derivatives.

The title compounds, C27H20O6, (I) [systematic name: methyl 7-oxo-14-phenyl-1H,7H,14H-pyrano[3,2-c:5,4-c']dichromene-14a(6bH)-carboxyl-ate], C24H22O5, (II) [systematic name: methyl 1-oxo-6-phenyl-2,3,4,12b-tetra-hydro-1H,6H-chromeno[3,4-c]chromene-6a(7H)-carboxyl-ate], and C25H23N3O4, (III) [systematic name: 6-(4-ethyl-phen-yl)-2,4-dimethyl-1,3-dioxo-2,3,4,12b-tetra-hydro-1H,6H-chromeno[4',3':4,5]pyrano[2,3-d]pyrimidine-6a(7H)-carbo-nitrile], are pyran-ochromene derivatives. The central pyran rings (B) of compounds (I) and (III) adopt half-chair conformations, whereas that of compound (II) adopts a sofa conformation. The pyran rings (A) of the chromene ring systems of compounds (II) and (III) adopt half-chair conformations, while that of compound (I) adopts a sofa conformation. The mean plane of the central pyran rings (B) make dihedral angles of 70.02 (6), 61.52 (6) and 69.12 (7)°, respectively, with the mean planes of the chromene moieties (C+A) of compounds (I), (II) and (III). The bicyclic coumarin ring system (C+A+B+E) in compound (I) is almost planar (r.m.s. deviation = 0.042 Å). The carbo-nitrile side chain in compound (III) is very nearly linear, with the C-CN angle being 176.6 (2)°. The cyclo-hexene ring (E), fused with the central pyran ring (B) in compound (II) adopts a sofa conformation. In the mol-ecular structures of compounds (II) and (III), there are C-H⋯O short contacts, which generate S(7) ring motifs. In the crystal structures of the title compounds, mol-ecules are linked by C-H⋯O hydrogen bonds, which generate mol-ecular sheets parallel to the ab plane, with R 4 (3)(28) loops in (I), inversion dimers with R 2 (2)(10) loops in (II) and chains along [010] with R 2 (2)(12) ring motifs in (III). In the crystal structures of (I) and (III), there are also C-H⋯π inter-actions present, leading to the formation of a three-dimensional framework in (II) and to sheets parallel to (101) in (III).

Crystal structure of (1R,2S,4R,7R,8S,9R)-3,3-dichloro-8,9-epoxy-4,8,12,12-tetramethyltricyclo[5.5.0.0(2,4)]dodecane.

The title compound, C16H24Cl2O, is built up from two fused six- and seven-membered rings which bear a di­chloro­cyclo­propane group and an ep­oxy group, respectively. In the mol­ecule, the six-membered ring adopts an envelope configuration with the C atom linking the ep­oxy ring at the flap, while the seven-membered ring adopts a boat–sofa conformation.

Crystal structure of ethyl 2-acetyl-3,7-dimethyl-5-(thio-phen-2-yl)-5H-thia-zolo[3,2-a]pyrimidine-6-carboxyl-ate.

In the title compound, C17H18N2O3S2, the pyrimidine ring adopts a shallow sofa conformation, with the C atom bearing the axially-oriented thio­phene ring as the flap [deviation = 0.439 (3) Å]. The plane of the thio­phene ring lies almost normal to the pyrimidine ring, making a dihedral angle of 79.36 (19)°. In the crystal, pairs of very weak C—H⋯O hydrogen bonds link the mol­ecules related by twofold rotation axes, forming R 2 2(18) rings, which are in turn linked by another C—H⋯O inter­action, forming chains of rings along [010]. In addition, weak C—H⋯π(thio­phene) inter­actions link the chains into layers parallel to [001] and π–π inter­actions with a centroid–centroid distance of 3.772 (10) Å connect these layers into a three-dimensional network.

Crystal structure of ethyl 4-(2-meth-oxy-phen-yl)-6-methyl-2-sulfanyl-idene-1,2,3,4-tetra-hydro-pyrimidine-5-carboxyl-ate.

In the title compound, C15H18N2O3S, the hydro­pyrimidine ring adopts a sofa conformation with the methine C atom as the flap. The benzene ring is almost perpendicular to the mean plane of the hydro­pyrimidine ring, making a dihedral angle of 85.51 (8)°, and the meth­oxy O atom lies over the centre of the pyrimidine ring. In the crystal, weak N—H⋯S inter­actions form a zigzag chain running along the b-axis direction.

Crystal structure of anagyrine perchlorate.

The title mol­ecular salt, C15H21N2O+·ClO4 −, crystallizes with four cations (A, B, C and D) and four anions in the chiral unit cell (space group P21). The alkaloid was isolated from the aerial parts of Genista Hispanica collected in the Samarkand region of Uzbekistan. Each cation is protonated at the N atom that bridges the alkaloid rings C and D. In each cation, ring A is almost planar and ring B adops a sofa conformation with the methyl­ene group bridging to the C ring as the flap. Rings C and D adopt chair conformations with a cis ring junction in all four cations. In the crystal, A+B and C+D dimeric pairs linked by pairs of N—H⋯O hydrogen bonds are observed, which generate R 2 2(16) loops in each case. The dimers are consolidated by weak aromatic π–π stacking inter­actions between the A rings [centroid–centroid distances = 3.913 (3) and 3.915 (3) Å].

Crystal structure of ethyl 6-(2-fluoro-phen-yl)-4-hy-droxy-2-sulfanyl-idene-4-tri-fluoro-meth-yl-1,3-diazinane-5-carboxyl-ate.

In the title compound, C14H14F4N2O3S, the central di­hydro­pyrimidine ring adopts a sofa conformation with the C atom bearing the 2-fluoro­benzene ring displaced by 0.596 (3) Å from the other five atoms. The 2-fluoro­benzene ring is positioned axially and bis­ects the pyrimidine ring with a dihedral angle of 70.92 (8)°. The mol­ecular conformation is stabilized by an intra­molecular O—H⋯O hydrogen bond, generating an S(6) ring. The crystal structure features C—H⋯F, N—H⋯S and N—H⋯O hydrogen bonds, which link the mol­ecules into a three-dimensional network.

Crystal Structure Theory and Applications of 14-Ethoxy-4,6,-dimethyl-8.12- dioxa-4.6-diazatetracyclo [8.8.0.02,7.013,18]octadeca-13,15,17-triene-3,5-dione

AbstractIn view of the growing medicinal importance of chromene and its derivatives, the single crystal X-ray diffraction studywas carried out for the potential active 4,6-dimethyl-9-phenyl-8,12-dioxa-4,6-diazatetracyclo [8.8.0.02,7.013,18]octadeca-2(7),13,15,17-tetraene-3,5,11-trione-2-ethoxyphenyl (2E)-but-2-enoate (C 18 H 20 N 2 O 5 ). In the title compound are twomolecules exist in the asymmetric unit. It crystallizes in the monoclinic space group P2 1 /c with unit cell dimensiona=14.608(3) A, b=12.845(3) and c= 17.781(4) [alpha & gamma=90 o beta=91.233(5) o ]. Both pyran and pyran ring of thechromene moiety adopts sofa conformation in the molecule A & B. The crystal structure is stabilized by intramolecularC-H...O hydrogen bond interaction.Keywords: Pyran; Chromene; Sofa Conformation; Single Crystal Structure; X-ray Diffraction (XRD) 1. Introduction The chromene moiety regularly appears as a principalstructural component in various biologically importantorganic compounds such as flavonoids, natural alka-loids, tocopherols and anthocyanins

Crystal structure of ethyl 2-cyano-3-[(1-eth-oxy-ethyl-idene)amino]-5-(3-meth-oxy-phen-yl)-7-methyl-5H-1,3-thia-zolo[3,2-a]pyrimidine-6-carboxyl-ate.

In the title compound, C22H24N4O4S, the central pyrimidine ring adopts a sofa conformation with the ring-junction N atom displaced by 0.2358 (6) Å from the mean plane of the remaining ring atoms. The 3-meth­oxy­phenyl ring, at the chiral C atom opposite the other N atom, is positioned axially and is inclined to the thia­zolo­pyrimidine ring with a dihedral angle of 83.88 (7)°. The thia­zole ring is essentially planar (r.m.s. deviation = 0.0034 Å). In the crystal, pairs of weak C—H⋯O hydrogen bonds link mol­ecules related by twofold rotation axes to form R 2 2(8) rings, which in turn are linked by weak C—H⋯N inter­actions, forming ribbons along [-110]. In addition, π–π stacking inter­actions [centroid—centroid distance = 3.5744 (15) Å] connect the ribbons, forming slabs lying parallel to (001).

Crystal structure of ethyl 6-methyl-2-sulfanylidene-4-(thiophen-2-yl)-1,2,3,4-tetrahydropyrimidine-5-carboxylate

In the title compound, C12H14N2O2S2, the di­hydro­pyrimidine ring adopts a sofa conformation, with the C atom bearing the thienyl ring lying above the plane of the five remaining approximately coplanar (r.m.s. deviation = 0.0405 Å) atoms of the ring. The dihedral angle between the five near coplanar atoms of the ring and the thienyl ring is 89.78 (11)°. In the crystal, mol­ecules are linked into a supra­molecular chain along [100] via N—H⋯O(carbon­yl) hydrogen bonds. Inversion-related chains are linked into double chains via N—H⋯S(thione) hydrogen bonds. The three-dimensional architecture also features meth­yl–thienyl C—H⋯π inter­actions.

Crystal structure of methyl 1-methyl-3,5-diphenyl-7-tosyl-3,6,7,11b-tetra-hydro-pyrazolo-[4',3':5,6]pyrano[3,4-c]quinoline-5a(5H)-carboxyl-ate.

In the title compound, C35H31N3O5S, the piperidine ring adopts an envelope conformation, with the methine C atom as the flap, and the pyran ring adopts a sofa conformation. The mean planes of these two rings are almost normal to one another, making a dihedral angle of 85.96 (5)°. The two phenyl rings, one attached to the pyrazole ring and the other to the pyran ring, are inclined to one another by 65.41 (11)°. They are inclined to the mean planes of the rings to which they are attached by 12.59 (11) and 70.09 (9)°, respectively. There is an intra­molecular C—H⋯π inter­action involving the tosyl­ate methyl group and the phenyl ring attached to the pyrazole ring. In the crystal, mol­ecules are linked by C—H⋯π inter­actions, forming ribbons parallel to (10-2). The ribbons are linked by slipped parallel π–π inter­actions involving inversion-related pyrazole rings [inter-centroid distance = 3.672 (2) Å], forming slabs parallel to (001). A preliminary report of this structure has been published [Bakthadoss et al. (2014 ▶). Eur. J. Org. Chem. pp. 1505–1513].

Crystal structure of ethyl 2-(2-fluoro-benzyl-idene)-5-(4-fluoro-phen-yl)-7-methyl-3-oxo-2,3-di-hydro-5H-1,3-thia-zolo[3,2-a]pyrimidine-6-carb-oxy-late.

In the title mol­ecule, C23H18F2N2O3S, the 4-fluoro-substituted and 2-fluoro-substituted benzene rings form dihedral angles of 88.16 (8) and 23.1 (1)°, respectively, with the thia­zole ring. The pyrimidine ring adopts a flattened sofa conformation with the sp 3-hydridized C atom forming the flap. In the crystal, pairs of weak C—H⋯O hydrogen bonds link mol­ecules related by twofold rotation axes, forming R 2 2(10) rings, which are in turn linked by weak C—H⋯N inter­actions to form chains of rings along [010]. In addition, weak C—H⋯π(arene) inter­actions link the chains into layers parallel to (001) and π–π inter­actions with a centroid–centroid distance of 3.836 (10) Å connect these layers into a three-dimensional network.

Crystal and Molecular Structure of 12-(2-Methoxyphenyl)-9-[(4-methylbenzene)sulfonyl]-22-oxo-13,21-dioxa-9-azapentacyclo [12.8.0.02,11.03,8.015,20]docosa-1(14),3,5,7,15(20),16,18-heptaene-11-carbonitrile

The crystal structure of the title compounds with both coumarin and sulfonamide moieties were examined. These two groups have very special for their pharmaceutical and medicinal properties have been determined from single crystal X-ray diffraction data. In the title compound crystallizes in the monoclinic space group <TEX>$P2_1/c$</TEX> with unit cell dimension a=<TEX>$8.5775(4){{\AA}$</TEX>, b=<TEX>$24.9943(13){\AA}$</TEX> and c=<TEX>$13.7319(7){\AA}$</TEX> [alpha & gamma=<TEX>$90^{\circ}$</TEX> beta=<TEX>$103.558(2)^{\circ}$</TEX>]. In the structure The S1 atom shows a distorted tetrahedral geometry, with O1-S1-O2 [<TEX>$121.08(1)^{\circ}$</TEX>] and N1-S1-C5 [<TEX>$105.85(1)^{\circ}$</TEX>] angles deviating from ideal tetrahedral values are attributed to the Thrope-Ingold effect. The sum of bond angles around N1 (<TEX>$354.9^{\circ}$</TEX>) indicates that N1 is in <TEX>$sp^2$</TEX> hybridization. The Pyridine ring adopts boat conformation and pyran rings adopt a sofa conformation. Crystal structure is stabilized by C-H...O intra molecular hydrogen bond interactions.

Crystal structure of 1'-(2-methyl-prop-yl)-2,3-di-hydro-spiro-[1-benzo-thio-pyran-4,4'-imidazolidine]-2',5'-dione.

In the title compound, C15H18N2O2S, the 2,3-di­hydro-1-benzo­thio­pyran ring adopts a sofa conformation and the hydantoin ring is twisted with respect to the benzene ring at 78.73 (17)°. In the crystal, pairs of N—H⋯O hydrogen bonds link the mol­ecules into inversion dimers.