Synthesis,Spectroscopic Studies and X-ray Analysis of (<Emphasis Type="Italic">E</Emphasis>)-2-(2-Fluorophenyl)-3-(6-Nitrobenzo[d][1,3]dioxol-5-yl) Acrylic Acid

Abstract  

In the solid-state structure of the title compound, C₁₆H₁₀FNO₆, the configuration about the C=C double bond is E. The compound crystallized in the triclinic system, having space group P-1 with unit cell dimensions a = 5.829(10) ?, b = 8.801(16) ?, c = 13.543(3) ?, α = 87.753(15)°, β = 81.945(15)°, γ = 86.342(14)°. The structure of the molecule is V-shaped and in the crystal the molecules are linked to form inversion dimers connected by pairs of C–H···O hydrogen bonds.     

Structures of Two (<Emphasis Type="Italic">E</Emphasis>)-3-Substituted Cinnamoylbenzotriazole 1-Oxides

Abstract  

The molecule of (E)-3-(3-MeOC₆H₄CH=CHCO)-benzotriazole 1-oxide, 2, has a very near planar structure, while the 2-nitrophenyl ring is rotated out of the plane of the remaining atoms in (E)-3-(2-O₂NC₆H₄CH=CHCO)-benzotriazole 1-oxide, 1. The nitrogen oxide bond lengths in 1 and 2 are 1.258 (6) and 1.2683 (15) ?, respectively, and are in the region found for related compounds. There are no strong intermolecular hydrogen-bonds in either compound, instead there are weak C–H···O intermolecular hydrogen-bonds and π···π stacking interactions in 1, and C–H···O, C–H···π, and π···π stacking interactions in 2. Different three-dimensional arrays are generated in each case. Compound 1 crystallises in the orthorhombic space group Pna2₁, with a = 25.061 (2) ?, b = 3.6997 (2) ?, c = 14.2623 (12) ? and Z = 4. Compound 2 crystallises in the triclinic space group P-1, with a = 5.7297 (3) ?, b = 10.8440 (6) ?, c = 11.4965 (6) ?, α = 89.689 (3)°, β = 76.019 (3)°, γ = 75.047 (3)°, Z = 2.     

6-Chlorothieno[2,3-<Emphasis Type="Italic">e</Emphasis>]-1,4,2-dithiazine-3(2<Emphasis Type="Italic">H</Emphasis>)-thione-1,1-dioxide,Ammonium Salt Sesquihydrate: Synthesis,Crystal Structure and Density Functional Calculations

Abstract  

The title compound crystallizes in the monoclinic space group C2/c space group, with unit cell dimensions of a = 15.6684(3) ?, b = 7.3974(2) ?, c = 21.2669(5) ?; β = 106.7770(10)° (Z = 8). In the title compound, NH₄ ⁺·C₅HClNO₂S₄ ^–·1.5 H₂O, the 1,4,2-dithiazine ring adopts a distorted half-chair conformation. The structure displays several cooperative intermolecular N/O–H···N/O/S hydrogen-bonding interactions, giving rise to a two-dimensional layers packing motif. The layers are built up from seven component entities formed via extensive intermolecular N/O–H···N/O/S hydrogen bonds involving 6-chlorothieno[2,3-e]-1,4,2-dithiazine-3(2H)-thione-1,1-dioxide anions, ammonium cations and water molecules. The geometry of the title compound was fully optimized using a Density functional B3LYP/6-31G(d) and B3LYP/6-31+G(d) methods and the results were consistent with experimental values. The binding energy and associated basis set superposition as well as the thermodynamic quantities were calculated.     

Crystallographic and Conformational Analysis of [(<Emphasis Type="Italic">E</Emphasis>)-2-[(3-Chlorophenylimino)methy])-4-methoxyphenol]

Abstract  The crystal structure of C₁₄H₁₂ClNO₂ was determined by X-ray analysis. It crystallizes in the triclinic space group Pc with a = 12.5346(10) ?, b = 4.5101(3) ?, c = 12.0534(11) ?, α = 90.00o, β = 113.669(6)o, γ = 90.00o, Z = 2, Dx = 1.393 mg/m³, μ (MoK_α) = 0.298 mm⁻¹. The title compound is photochromic and molecule is non-planar. It adopts a phenol–imine tautomeric form with a strong intramolecular O–H···N hydrogen bond and a strong intermolecular C–H···O hydrogen bond. Minimum energy conformations AM1 were calculated as a function of the three torsion angles θ1(C10–C9–N1–C8), θ2(C9–N1–C8–C1) and θ3(N1–C8–C1–C6), varied every 10°. As in the X-ray experiment results, molecule has an angle that makes it non-planar between two aromatic rings in AM1 optimized geometry. Graphical Abstract  Molecular and crystal structure of [(E)-2-[(3-chlorophenylimino)methy])-4-methoxyphenol], C₁₄H₁₂ClNO₂, have been determined by single crystal X-ray diffraction study, and conformational analysis of the title molecule with respect to the selected torsion angle has been achieved by AM1 semi-empirical calculations.      

Crystal Structure and Conformational Analysis of 4-[(<Emphasis Type="Italic">p</Emphasis>-<Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-Dimethylamino)Benzylidene]-2-Phenyloxazole-5-One

Abstract  

Molecular and crystal structure of 4-[(p-N,N-dimethylamino)benzylidene]-2-phenyloxazol-5-one, C₁₈H₁₆N₂O₂, have been determined by single crystal X-ray diffraction study. The title compound is monoclinic, with a = 12.1704(23) ?, b = 3.9810(5) ?, c = 30.9603(56) ?, β = 101.176(15)°, Z = 4, D _x = 1.32 g/cm³, μ(Mo Kα) = 0.087 mm⁻¹, and space group is P12₁/c1. The structure was solved by direct methods and refined to a final R = 0.047 for 3166 reflections with I > 2σ(I). The crystal structure is stabilized by C–H⋯O and C–H⋯N type intra-molecular, C–H⋯O type inter-molecular interactions. To enlighten the flexibility and the geometric isomerism (E or Z) of the title compound, the selected torsion angle is varied from −180 to 180° in every 10° separately and molecular energy profile is calculated and analyzed.     

Crystal Structure and Spectroscopic Properties of <Emphasis Type="Italic">trans</Emphasis>-Dibromobis(1,2-ethanediamine)chromium(III) Perchlorate

Abstract  

The crystal structure of trans-[Cr(en)₂Br₂]ClO₄ (en = 1,2-ethanediamine) has been determined by a single-crystal X-ray diffraction study at 150 K. The complex crystallizes in the space group P[`1] P\overline{1} of the triclinic system with two mononuclear formula units in a cell of dimensions a = 6.853(4), b = 8.109(5), c = 12.475(8) ?, α = 81.006(10)°, β = 77.005(10)° and γ = 74.981(10)°. The Cr atom is in a slightly distorted octahedral environment, coordinated by four nitrogen atoms of two en ligands and two bromine atoms in trans axial positions. The mean Cr–N(en) and Cr–Br bond lengths are 2.079(3) and 2.4743(10)?, respectively. The five-membered rings are in stable gauche conformations with N1–Cr1–N2 and N3–Cr2–N4 angles of 82.81(11)° and 83.67(11)°, respectively. The crystal packing is stabilized by a network of N–H···O and N–H···Br hydrogen bonds. The infrared and electronic absorption spectra are consistent with the results of X-ray crystallography.     

Synthesis,Characterization and Antibacterial Activity of <Emphasis Type="Italic">N</Emphasis>-(2,3,4-Trimethoxy-6-methylbenzylidene)-2-methyl-benzenamine

Abstract  The title compound N-(2,3,4-trimethoxy-6-methylbenzylidene)-2-methyl-benzenamine (C₁₈H₂₁NO₃, M _r = 299.36) was synthesized and characterized by elemental analysis, IR spectra and single crystal X-ray diffraction. The crystal belongs to monoclinic, space group P2₁/n, with a = 7.2804(5), b = 8.5909(9), c = 26.117(3) ?, β = 92.056(2)°, V = 1,632.4(3) ?³, Z = 4, D _c = 1.218 g cm⁻³, λ = 0.71073 ?, μ(Mo Kα) = 0.083 mm⁻¹, F(000) = 640. The final refinement gave R = 0.0497, wR(F ²) = 0.1157 for 2,879 observed reflections with I > 2σ(I). X-ray diffraction analysis reveals that the dihedral angle between the two phenyl rings is 25.9 (2)°. The molecule adopts a trans configuration about the central C=N functional bond. The crystal structure is stabilized by C–H…O hydrogen bonds and π–π stacking interactions. The title compound possesses moderate antibacterial activity. Graphical Abstract  The title compound N-(2,3,4-trimethoxy-6-methylbenzylidene)-2-methyl-benzenamine (C₁₈H₂₁NO₃, M _r = 299.36) was synthesized and characterized by elemental analysis, IR spectra and single crystal X-ray diffraction. The crystal belongs to monoclinic, space group P2₁/n, with a = 7.2804(5), b = 8.5909(9), c = 26.117(3) ?, β = 92.056(2)°, V = 1,632.4(3) ?³, Z = 4, D _c = 1.218 g cm⁻³, λ = 0.71073 ?, μ(Mo Kα) = 0.083 mm⁻¹, F(000) = 640. The final refinement gave R = 0.0497, wR(F ²) = 0.1157 for 2,879 observed reflections with I > 2σ(I). X-ray diffraction analysis reveals that the dihedral angle between the two phenyl rings is 25.9 (2)°. The molecule adopts a trans configuration about the central C=N functional bond. The crystal structure is stabilized by C–H…O hydrogen bonds and π–π stacking interactions. The title compound possesses moderate antibacterial activity.      

Crystal Structure of 2-<Emphasis Type="Italic">Exo</Emphasis>-Phenyl-2,3,4,5-Tetrahydro-1,4-Epoxinafto[1,2-b]azepine

Abstract  

The title compound, C₂₀H₁₇NO, crystallizes in the orthorhombic P2₁2₁2₁ space group with unit cell parameters a = 7.6903(7) ?, b = 18.979(2) ?, c = 19.753(2) ?, with two crystallographically independent molecules in the asymmetric unit, which differ from one another in the slight rotation of the phenyl ring; this allows the formation of three internal hydrogen bonds, two of the type C–H···N and one of the type C–H···O, in one of the molecules, in contrast with only two of the type C–H···N in the other. The compound is rich in aromatic π rings and therefore the crystal packing is entirely dominated by cohesive weak C–H···π interactions among neighboring molecules producing an efficient packing with 71.2% of occupied space.     

Structural Studies of the 1:1 Complex of <Emphasis Type="Italic">o</Emphasis>-3,4-Dimethyltetrathiafulvalene (<Emphasis Type="Italic">o</Emphasis>-Me<Subscript>2</Subscript>TTF) and 1,2,4,5-Tetracyanobenzene (TCNB)

Abstract  

The synthesis and crystal structure of the 1:1 complex o-Me₂TTF-TCNB is reported. The complex crystallizes in the triclinic space group P-1 with a = 6.920(1) ?, b = 7.928(2) ?, c = 17.453(4) ?, α = 100.53(3)°, β = 99.66(3)°, and γ = 97.32(3)°. The bond length of the central C=C bond in o-Me₂TTF is 1.342(2) ?, indicating a neutral state for the o-Me₂TTF donor.     

Synthesis,Characterization and Crystal Structure of (<Emphasis Type="Italic">S</Emphasis>)-2-(2-Hydroxynaphthalen-6-yl)-<Emphasis Type="Italic">N</Emphasis>-((pyridin-4-yl)methyl) Propanamide

Abstract  

The synthesis, characterization and crystal structure of the title compound, (S)-2-(2-hydroxynaphthalen-6-yl)-N-((pyridin-4-yl)methyl) propanamide, is described. The salt is enantiomerically pure and crystallize in the orthorhombic P2₁2₁2₁ chiral space group with a = 7.9174(13) ?, b = 11.1583(18) ?, c = 11.2600(18) ?. Each molecule is linked to four neighboring molecules through the O–H···O and N–H···N hydrogen bonds into a supramolecular helical chain. The O–H···O and N–H···N hydrogen bonds lead to 24-membered open rings. Chains are further connected into layers via extensive interchain H···O and H···C short contacts.     

Synthesis,Characterization and Antibacterial Activity of <Emphasis Type="Italic">N</Emphasis>-(<Emphasis Type="Italic">N</Emphasis>-Acetic Acid-yl-Phthalimide-5-yl) Maleamic Acid Dihydrate

Abstract  

The compound N-(N-acetic acid-yl-phthalimide-5-yl) maleamic acid (C₁₄H₁₀N₂O₇, M _r  = 318) was synthesized and its structure was characterized by elemental analysis, ¹H NMR and IR spectra. The single crystal of the title compound (C₁₄H₁₄N₂O₉, M _r  = 354.27) was cultured and its structure was determined by single crystal X-ray diffraction. The crystal belongs to monoclinic system, space group P21/c with a = 14.3859(19), b = 12.5835(18), c = 8.6934(15) ?, β = 102.824(2)°, V = 1534.5(4) ?³, Z = 4, D _c  = 1.534 g cm⁻³, μ(Mo Kα) = 0.131 mm⁻¹, F(000) = 736. The final refinement gave R = 0.0652, wR(F ²) = 0.1239 for 2,703 observed reflections with I > 2σ(I). X-ray diffraction analysis reveals that the asymmetric unit of the title compound contains one N-(N-acetic acid-yl-phthalimide-5-yl) maleamic acid molecule and two water molecules. One of the two water molecules is disordered. The phthalimide group is essentially planar. The crystal structure of the title compound is stabilized by N–H…O and O–H…O hydrogen bonds interactions. The compound N-(N-acetic acid-yl-phthalimide-5-yl) maleamic acid possesses moderate antibacterial activity.     

Structure of a New Bioactive Agent Containing Combined Antibacterial and Antifungal Pharmacophore Sites: 4-{[(<Emphasis Type="Italic">E</Emphasis>)-(5-Bromo-2-hydroxyphenyl)methylidene]amino}-<Emphasis Type="Italic">N</Emphasis>-(5-methyl-1,2-oxazol-3-yl)benzenesulfonamide

Abstract  

The title compound (3), C₁₇H₁₄BrN₃O₄S, is a Schiff base compound of 5-bromosalicylaldehyde (1) and sulfamethoxazole (2). The structure of (3) was determined by spectral (IR, ¹H and ¹³C NMR), elemental analyses and X-ray diffraction data. Compound (3) crystallizes in the monoclinic space group C2/c, with a = 31.936(3), b = 6.2571(5), c = 16.903(1) ?, β = 94.867(8), V = 3365.5(5) ?³, Z = 8. In the molecule of compound (3), the molecule is bent at the S atom with a C–SO₂–NH–C torsion angle of −86.3(3)°. Pairs of molecules, related by inversion centres, form intermolecular N–H···N hydrogen bonds to produce a dimer. An intramolecular phenolic O–H···N hydrogen bond is also formed. Intermolecular hydrogen bonding and π–π stacking hold the molecules together. The average distance between stacked benzene ring planes is 3.625(2) ?.     

Synthesis,Crystal Structure and Thermal Properties of <Emphasis Type="Italic">N</Emphasis>-Acetyl-3-(2-furyl)-5-ferrocenyl-2-pyrazoline and <Emphasis Type="Italic">N</Emphasis>-Acetyl-3-(2-thienyl)-5-ferrocenyl-2-pyrazoline

Abstract  

Two novel ferrocenyl substituted N-acetyl-2-pyrazolines, N-acetyl-3-(2-furyl)-5-ferrocenyl-2-pyrazoline (3) and N-acetyl-3-(2-thienyl)-5-ferrocenyl-2-pyrazoline (4), have been synthesized and characterized by FTIR, ¹H-NMR, ¹³C-NMR techniques, elemental analysis and X-ray structure analysis. Thermal properties of these compounds have been determined by TGA, DTA and DSC analysis. Compound 3 (C₁₉H₁₈N₂O₂Fe) crystallizes in the monoclinic space group P21/c and Z = 4, with a = 8.6970(4) ?, b = 18.4725(9) ?, c = 11.0041(5) ?, β = 110.942(3)°. Compound 4 (C₁₉H₁₈N₂OSFe) crystallizes in the orthorhombic space group Fdd2 and Z = 16, with a = 84.242(2) ?, b = 13.5416(5) ?, c = 5.9405(2) ?, β = 90°. In terms of crystal packing, each compound shows different molecular arrangement, which are stabilized by C–H···O intermolecular weak hydrogen bonds, and/or C–H···π interactions.     

One Dimensional Hydrogen Bonded Arrangement in New Schiff-Base Compound (<Emphasis Type="Italic">E</Emphasis>)-2-(2,5-dimethoxybenzylideneamino)phenol (1): Synthesis,Characterization, Crystal Structure and Conformational Studies

Abstract  

New Schiff-base compound (E)-2-(2,5-dimethoxybenzylideneamino)phenol (1) was synthesized and characterized by elemental analyses, FT-IR and ¹H-NMR spectroscopy and single crystal X-ray diffraction. Molecular orbital calculation has been carried out for 1 by using HF method at 6-31G basis set. The title compound 1 crystallizes in monoclinic system, space group C2/c, with a = 19.4581(13) ?, b = 9.5805(5) Ǻ, c = 13.8431(7) Ǻ, β = 93.471(2)°, V = 2575.9(3) Ǻ³ and Z = 8. In the crystal structure two molecules are stabilized by a pair of intermolecular O1–H1···N1ⁱ hydrogen bonds. The dimeric units are further linked via C6–H6···O3ⁱⁱ hydrogen bond.     

Structure of Triammonium <Emphasis Type="Italic">fac</Emphasis>-Trichloridotrioxidorhenate(VII) Chloride with <Emphasis Type="Italic">C</Emphasis><Subscript>3<Emphasis Type="Italic">v</Emphasis></Subscript> Crystallographic Symmetry of the Complex Anion

Abstract  

The unstable crystals of triammonium fac-trichloridotrioxidorhenate(VII) chloride have been obtained from ammonium rhenate(VII) solution in concentrated hydrochloric acid. The crystal structure consists of fac-trichloridotrioxidorhenate(VII) anions, chloride anions and ammonium cations. Each fac-trichloridotrioxidorhenate(VII) anion and each chloride anion lies in special position of 3m site symmetry (cell parameters: a = 9.026(3) Å; c = 7.690(4) Å; space group: P6₃ mc). The ammonium cation lies in special position of m site symmetry. The following anion geometrical parameters of the fac-trichloridotrioxidorhenate(VII) anion have been obtained: Re–O bond length of 1.720(2) Å, Re–Cl bond length of 2.5428(9) Å, the bond angles: O–Re–O of 103.5(1)° and Cl–Re–Cl of 79.8(1)°.     

Crystallographic and conformational analyses of zwitterionic form of (<Emphasis Type="Italic">E</Emphasis>)-2-methoxy-6-[(2-morpholinoethylimino)methyl]phenolate

The single crystal X-ray diffraction analysis of the title compound, C₁₄H₂₀N₂O₃, reveals that the structure is adapted to its zwitterionic form and centrosymmetric dimers are formed by N⁺–H···O⁻ type ionic weak hydrogen bonds in the crystal structure. The title compound crystallizes in the triclinic space group P−1 with a = 5.9255(13) ?, b = 9.853(3) ?, c = 12.248(3) ?, α = 101.793(19)°, β = 94.941(17)°, γ = 104.36(2)°, Z = 2, D_x = 1.308 g/cm³, μ (Mo-K_α) = 0.092 mm⁻¹. The structure was solved by direct methods and refined to a final R = 0.0371 for 2183 reflections with I > 2σ (I). The crystal structure is stabilized by N⁺–H···O⁻ type intra-molecular hydrogen bonds and N⁺–H···O⁻ type packing interactions referred to as weak hydrogen bonds. To elucidate conformational flexibility of the title molecule, the selected torsion angle is varied from −180° to +180° in every 10° separately and then molecular energy profile is calculated and construed. In addition, charge-population analysis of the crystallographically observed structure confirms its zwitterionic form.     

Synthesis and Crystal Structure of a New Schiff Base 4-[(2-hydroxy-benzylidene)-amino]-<Emphasis Type="Italic">N</Emphasis>-(5-methyl-isoxazol-3-yl)-benzenesulfonamide

Abstract  The structure of the title compound (C₁₇H₁₅N₃O₄S)₂ the schiff base, bis(N-(5-methyl-3-isoxazolyl)-4-[(2-hydroxy benzylidene)-amino]) benzene sulfonamide was elucidated by H¹, C¹³ NMR, UV–VIS and IR spectroscopic techniques. The X-ray structure was determined in order to establish the conformation of the molecule. The compound crystallizes in the triclinic space group P-1, with a = 11.419(1), b = 11.426(0), c = 13.316(1) ?, α = 71.94(2), β = 89.79(1), γ = 89.14(2)° and Z = 4. Two benzene rings and azomethine group are practically coplanar, as a result of intramolecular hydrogen bonds involving the hydroxy O atom and azomethine N atom. The component species further interact via N–H···N and C–H···O hydrogen bonds and π–π stacking interactions. Index Abstract  The title compound (C₁₇H₁₅N₃O₄S)₂, Schiff base, bis(N-(5-methyl-3-isoxazolyl)-4-[(2-hydroxy benzylidene)-amino]) benzene sulfonamide was synthesized by the condensation of 4-amino-N-(5-methyl-3-isoxazolyl) benzene sulfonamide (SMZ) and 2-hydroxy benzaldehyde (SA). Its structure was confirmed by single crystal X-ray diffraction analysis. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Desynchronization of Pedal Motion: Crystallographic and Theoretical Study of (<Emphasis Type="Italic">E</Emphasis>)-4-[(4-ethylphenyl)diazenyl]-2-methylphenol

Abstract  The single crystal X-ray diffraction analysis of the title compound, C₁₅H₁₆N₂O, reveals that its molecules exhibit whole-molecule disorder at both crystal lattice sites due to pedal motion in solid state. The compound crystallizes in the monoclinic space group P 2₁/c with a = 20.5504(14) ?, b = 10.8887(5) ?, c = 12.0191(8) ? and β = 96.927(5)°. While major pedal conformers of the compound in solid state are stabilized by intermolecular O–H···N type hydrogen bonds leading to the formation of C(7) chains at Site 1 and C(8) chains at Site 2 along [0 1 0] axis, C–H···π type intermolecular interactions between major and minor conformers also serve to stabilize minor pedal conformers. An interesting feature about the crystal structure is that pedal conformers at Site 1 have two different occupancy factors arising from desynchronization of pedal motion along [2 1 0] direction in crystal phase. Quantum chemical calculations at the B3LYP/6-31++G** level suggest that the desynchronization of pedal motions make more unstable pedal conformers at Site 1 than those at Site 2. Index Abstract  Molecular and crystal structure of (E)-4-[(4-ethylphenyl)diazenyl]-2-methylphenol, C₁₆H₁₈N₂O, indicate desynchronization of pedal motion and the quantum chemical calculations at level of B3LYP/6-31++G** suggest that desynchronization of pedal motions make more unstable pedal conformers.      

<Emphasis Type="Italic">Mangifera indica</Emphasis>: Crystal Structures of Two Cycloartane Type Triterpenoids Present in the Bark

Abstract  

Cycloart-23-ene-3-oxo-26-oic acid or Mangiferolic acid (C₃₀H₄₈O₃), compound 1 and Cycloart-23-ene-3β,25-diol (C₃₀H₅₀O₂) compound 2, were isolated from the bark of Mangifera indica. The structures of both compounds 1 and 2 were established by spectral and X-ray diffraction studies. Compound 1 crystallizes in the monoclinic space group P2₁ with unit cell parameters a = 8.416(1), b = 20.638(2), c = 17.203(2) Å, β = 91.779(2)°, Z = 2. Compound 2 crystallizes in the monoclinic space group C 2 with unit cell parameters a = 33.824(9), b = 7.413(2), c = 11.136(3) Å, β = 98.347(4)°, Z = 4. Both structures (1 and 2) were solved by direct methods and refined to R = 0.0511 and 0.0588, respectively. For compound 1, there are two independent molecules (1A and 1B) per asymmetric unit and one disordered trichloride methane molecule. For compound 2, there is positional disorder of the side chain at C17 beginning from C23 up to C27. All the rings of both steroid skeletons are trans connected. For structures 1A, 1B and 2, the six-membered rings A, B and C have a deformed chair, deformed chair and sofa conformations. The five-membered rings D adopt a half-chair conformation. In structure 1, there are two types of hydrogen bonds, the first type, the molecules 1A and 1B are linked by pairs of O(3A)–H···O(1B) and O3B H3B···O1A hydrogen bonds. In addition, both O(1A)–H and O(1B)–H hydroxyl groups participate in a second type of hydrogen bond involving the atoms O(2A) and O(2B) of adjacent molecules, respectively. In structure 2, there is a characteristic pattern observed in packing diagram is that both hydroxyl groups (O1–H and O2–H) participate as hydrogen bond donors and acceptors. In both structures 1 and 2, the hydrophobic part of the steroid nucleus is stabilized by C–H···O interactions and van der Waals forces.     

Structure and Antibacterial Activity of 3-(3,4-Dimethoxyphenyl)furan-2(5<Emphasis Type="Italic">H</Emphasis>)-ones

Abstract  

Crystalline hydrate of the title compound (5), C₁₉H₂₆N₂O₅·2(H₂O), was structurally characterized by single crystal X-ray diffraction. It crystallizes in monoclinic system space group P 21/c with a = 7.3987(7) ?, b = 17.8691(16) ?, c = 17.0022(13) ?, β = 112.944(3)°, V = 2070.0(3) ?³, Z = 4, R ₁ = 0.0592, wR ₂ = 0.1016, and T = 298(2) K. The X-ray structure determination revealed that the center furanone ring is nearly coplanar with 3,4-dimethoxybenzene ring, making a dihedral angle of 0.860(69)°. Two kinds of centrosymmetric tetramers characterized by graph-set motifs of R ₇⁸(36) and R ₄⁶(32) are formed through O–H···O, O–H···N and C–H···O hydrogen bonding interactions, which generate a sheet of edge-fused rings parallel to the (011) plane. These sheets are further linked into a three dimensional network by C–H···π interactions. Nine 3-(3,4-dimethoxyphenyl)furan-2(5H)-ones were synthesized and fully characterized by elemental analysis, MS and ¹H NMR. All of them were evaluated for antimicrobial activities against three Gram-positive organisms and a Gram-negative organism, and compound 5 was the most active against Staphylococcus aureus ATCC 25923.