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.     

Synthesis and Characterization of <Emphasis Type="Italic">N,N</Emphasis>-di(prop-2-ynyl)-<Emphasis Type="Italic">p</Emphasis>-toluidine

Abstract  

In order to investigate the intramolecular [4 + 2] cycloaddition, we prepared some new tertiary N-(5-substituted-2-furfuryl)-N-prop-2-ynyl-p-toluidines [Hergold-Brundić et al., Acta Cryst C56:e520, 2000; Mance and Jakopčić, Mol Divers 9:229, 2005; Mance, “unpublished results”] by the alkylation of secondary N-(5-substituted-2-furfuryl)-p-toluidines with the propargyl-bromide [Mance and Šindler-Kulyk, Synth Commun 26:923, 1996]. In the course of preparation of N-(5-methoxy-2-furfuryl)-N-prop-2-ynyl-p-toluidine [Mance, “unpublished results”], besides the main product (compound 1) (Scheme 1) we obtained N,N-di(prop-2-ynyl)-p-toluidine (compound 2) as the colourless crystals. The title compound 2, N,N-di(prop-2-ynyl)-p-toluidine, C₁₃H₁₃N, crystallizes in monoclinic C 2/c space group with unit cell parameters: a = 19.5319(9) ?, b = 7.5230(3) ?, c = 15.9000(7) ?, β = 112.554(5)°, V = 2157.64(18) ?³, Z = 8. The crystal structure is dominated by van der Waals forces only. The bond distances around amine N atom correspond to σ dominated bonds (1.467(2), 1.462(2) and 1.419(2) ?). The angles sum around amine N atom is in accord with sp³ hybridization (343°).     

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.     

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.     

Synthesis and Crystal Structure of (5-Methyl-3-phenyl-1<Emphasis Type="Italic">H</Emphasis>-pyrazol-1-yl)-[5-(<Emphasis Type="Italic">p</Emphasis>-tolylamino)-2<Emphasis Type="Italic">H</Emphasis>-1,2,3-triazol-4-yl]methanone

Abstract  

(5-Methyl-3-phenyl-1H-pyrazol-1-yl)-[5-(p-tolylamino)-2H-1,2,3-triazol-4-yl]methanone was synthesized and characterized by ¹H NMR, MS and IR spectra data. The structure of title compound was identified by X-ray diffraction. Compound, C₂₀H₁₈N₆O, Mr = 358.40, crystallizes in the triclinic space group P-1 with unit cell parameters a = 10.303(6), b = 12.489(7), c = 15.305(9) ?, α = 108.489(12), β = 101.920(11), γ = 96.971(13)°, V = 1790.0(17) ?³, Z = 4, Dx = 1.330 mg/cm³. The final R was 0.0520.     

An X-ray Crystallographic Study of 1,4-Di[(<Emphasis Type="Italic">E</Emphasis>)-2-(<Emphasis Type="Italic">p</Emphasis>-tolyl)-1-diazenyl]piperazine

Abstract  

The crystal structure of methyl 1,4-di[(E)-2-(p-tolyl)-1-diazenyl]piperazine (4) has been determined by single crystal X-ray diffraction analysis. The bis-triazene (4) adopts a normal chair conformation in the piperazine ring, with puckering parameters : φ₂ = −29(5)°, Q_T = 0.534(2) ? and θ₂ = 177.0(2)°. The crystal structure of 4 is compared with the structure of the triazene (2a) and the closely related bis-triazenes (3 and 5a). The piperazine ring of 2a and 4 adopt a typical chair conformation, whereas the piperazine ring of 3 adopts an unusual pseudo-boat conformation. Crystal data: 4 C₁₈H₂₂N₆, triclinic, space group P[`1] P\overline{1} , a = 6.8925(2) ?, b = 7.8574(3) ?, c = 16.8856(8) ?, α = 103.103(2)°, β = 90.528(2)°, γ = 101.776(2)° and V = 870.44 (6) ?³, for Z = 2.     

Synthesis,Characterization and Fluorescent Property of Two Mixed Ligand Coordination Polymers Constructed from 4-Cyclohexene-1,2-dicarboxylate and Nitrogen-Containing Ligands

Abstract  

Two new coordination polymers [Cd(1,2′-cy)(btx)_0.5H₂O]_n 1 and {[Ni(1,2-cy)(2,2′-bipy)(H₂O)₂]·3H₂O}_n 2 (1,2′-cy=4-cyclohexene-1,2-dicarboxylate, btx=1,4-bis(triazol-1-ylmethyl)benzene, 2,2′-bipy=2,2′-bipyridine) had been synthesized. Their structures were characterized by elemental analysis, IR, TG and X-ray single-crystal diffraction analysis. Crystal data for complex 1: Triclinic, space group P-1, a = 6.4303(13) ?, b = 10.399(2) ?, c = 11.713(2), α = 83.04(3)°, β = 81.87(3)°, γ = 83.84(3)°, and Z = 2. For complex 2: Orthorhombic, space group Pbcn, a = 15.613(3) ?, b = 13.970(3) ?, c = 21.290(4) ?, and Z = 4. Complex 1 exhibits an interesting two-dimensional wavelike covalent layer structure. When Ni salt was replaced by Cd salt, and reacts with 1,2′-cy and 2,2′-bipy, one-dimensional chain-like complex 2 was obtained. Furthermore, the fluorescent property of complex 1 was reported.     

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.     

Synthesis and Crystal Structures of Two Novel Complexes with <Emphasis Type="Italic">N</Emphasis>-[2-(5-Bromo-2-Hydroxybenzylideneamino)Ethyl]-4-Methylbenzenesulfonamide as Ligand

Abstract  

Two novel complexes constructed from the sulfonamide Schiff base ligand H ₂ L, N-[2-(5-bromo-2-hydroxybenzylideneamino)ethyl]-4-methylbenzene-sulfonamide, [Cu(HL)₂] (1) and [CuL(H₂O)] (2) are synthesized and characterized via X-ray single-crystal diffraction, elemental analysis, FT-IR and UV–Vis. 1 and 2 both form 1-D supramolecular architectures by π–π stacking interactions. 1 and 2 both crystallize in monoclinic, with space group C2/c and P2/c for 1 and 2, with unit cell parameters a = 27.640(18) ?, b = 7.907(5) ?, c = 17.945(14) ?, β = 118.27(2)°, V = 3454(4) ?³, Z = 4 for 1, and a = 16.758(5) ?, b = 7.272(2) ?, c = 15.080(4) ?, β = 106.334(5)°, V = 1763.6(9) ?³, Z = 4 for 2.     

<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 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) ?.     

Crystal Structure of 2-(2,2-Dibromovinyl)-1-methyl-1<Emphasis Type="Italic">H</Emphasis>-imidazole-4,5-dicarbonitrile

Abstract  

The crystal structure of 2-(2,2-dibromovinyl)-1-methyl-1H-imidazole-4,5-dicarbonitrile (C₈H₄Br₂N₄, Mr = 315.92) has been determined by single crystal X-ray diffraction analysis. The compound crystallizes in the monoclinic crystal system with space group P2₁/c and unit cell parameters: a = 15.144(2), b = 16.382(3), c = 8.267(1) ?, β = 95.76(2)^o and Z = 8. The final reliability index is 0.0297 for 2505 observed reflections. The two molecules of 2-(2,2-dibromovinyl)-4,5-dicyano-1-methylimidazole are localized in independent part of unit cell. The crystal packing is stabilized by C–H···N hydrogen bonds and Br···N intermolecular interactions.     

X-Ray Crystallographic Structure and Absolute Configuration of the Cyclic Di-amino Acid Peptide: Cyclo(<Emphasis Type="SmallCaps">l</Emphasis>-HomoCySH-<Emphasis Type="SmallCaps">l</Emphasis>-HomoCySH)

Abstract  

The cyclic di-amino acid peptide cyclo(l-homoCySH-l-homoCySH) [(3S, 6S)-3, 6-bis(2-sulfanylethyl) piperazine-2,5-dione, C₈H₁₄N₂O₂S₂, crystallizes in the orthorhombic space group P2₁2₁2₁ with unit cell parameters a = 6.1509(2) ?, b = 18.0217(9) ?, c = 29.6166(14) ?, V = 3283.0(2) ?³, Z = 12 (3 molecules, A, B and C, per asymmetric unit), D _c = 1.422 g cm⁻³ and a linear absorption coefficient of 0.464 mm⁻¹. The crystal structure determination was carried out with MoKα X-ray data measured at 120(2) K. In the final refinement cycle the data/restraints/parameter ratios were 5595/0/385 and goodness-of-fit on F ² = 1.084. Final R indices for [I > 2sigma(I)] were R1 = 0.0746, wR2 = 0.1356 and R indices (all data) R1 = 0.1092, wR2 = 0.1529. The largest electron density difference peak and hole were 0.526 and −0.445e ?⁻³. The DKP rings in all three molecules are essentially, and unusually, planar and the C=O oxygen atoms are co-planar with the ring in each case. Ring atom rms deviations, including the =O groups, are 0.0668, 0.0658 and 0.0656 ? in molecules A, B and C, respectively. Details of the molecular geometry are compared with the compound cyclo(Gly-Gly) (Degeilh R, Marsh RE Acta Cryst 12:1007, 1959) and in addition some cyclic di-amino acid peptides in which the DKP rings have more puckered boat conformations.     

Crystal and Molecular Structures of Di-1-Adamantylthiophosphinic Chloride, <Emphasis Type="Italic">P</Emphasis>,<Emphasis Type="Italic">P</Emphasis>-Diphenyl-<Emphasis Type="Italic">N</Emphasis>-Benzyl Phosphinothioic- and Selenoic- Amides

Abstract  Synthesis and X-ray structural determination of three phosphorus compounds are reported. (3b) is monoclinic P2(1)/c with a = 11.852(1), b = 12.825(1), c = 12.445(1) ?, β = 103.693(1)o; (4a) and (4b) are monoclinic P2(1)/n with a = 12.1422(16), b = 9.0860(12), c = 14.845(2) ?, β = 96.498(3)o for (4a), and a = 12.2714(16), b = 9.2812(12), c = 14.800(2) ?, β = 97.176(2)o for (4b). They all exhibit distorted tetrahedral geometry about the P atom. Ph₂P(X)NHC₇H₇ (X=S (4a) and X=Se (4b)) show typical P–S and P–Se double bond distances and P–N single bonds, while P–S bond in 1-Ad₂P(S)Cl (3b) is comparable to P–S single bonded probably due to the largeness of 1-adamantyl groups. Graphical Abstract  Synthesis and X-ray structural determination of 1-Ad₂P(S)Cl (3b), Ph₂P(S)NHC₇H₇ (4a) and Ph₂P(Se)NHC₇H₇ (4b) are reported.      

Hydrogen-Bonded Molecular Ladders and Interlaced Networks in Complexes Built of V-Shaped Molecules 4,4′-Isopropylidenediphenol or 4,4′-Oxydibenzoic Acid with 4,4′-Bipyridine

Abstract  

The title compounds, C₁₀H₈N₂·C₁₅H₁₆O₂ (1) and C₁₀H₈N₂·C₁₄H₁₀O₅ (2), were synthesized by 4,4′-bipyridyl and two similar V-shaped molecules. The two complexes both crystallized in the same space group P2₁/n with the crystal cell parameters: a = 16.0536(3) ?, b = 6.42730(1) ?, c = 21.2717(4) ?, β = 102.330°, V = 2144.21(7) ?³, Z = 4 in compound 1 and a = 7.45020(10) ?, b = 10.0784(2) ?, c = 26.9430(5) ?, β = 92.1140(10)°, V = 2021.67(6) ?³, Z = 4 in compound 2. Compound 1 forms regular molecular chains containing alternative 4,4′-bipyridyl and 4,4′-isopropylidenediphenol units; the molecular components are linked by two types of O–H···N hydrogen bonds. Additionally, every two neighboring chains are connected to be a ladder structure by means of weak C–H···O interactions. In compound 2, 4,4′-bipyridyl and 4,4′-oxydibenzoic acid first construct one-dimensional architecture by strong O–H···N hydrogen bonds, which are similar with the interactions in compound 1. Secondly, two types of weak C–H···O contacts formed between 4,4′-bipyridyl and the acid link one-dimensional chains to be interlaced three-dimensional hydrogen-bonded networks.     

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.     

Synthesis and Structure of (TMEDA)Cr(I)<Subscript>2</Subscript>(THF) and [(<Emphasis Type="Italic">N,N</Emphasis>-DMEDA)<Subscript>2</Subscript>CrI] I

Abstract  

The complexes (TMEDA)Cr(I)₂(THF) (1) and [(N,N-DMEDA)₂CrI] I (2) were synthesized and spectroscopically characterized (TMEDA = tetramethylethylenediamine, N,N-DMEDA = N,N dimethylethylenediamine). Complex 1 possesses square pyramidal geometry and crystallizes in spacegroup Pbca with crystal cell parameters a = 11.206(2) ?, b = 12.698(3) ?, c = 23.434(5) ?, V = 3,334.6(12) ?³ and Z = 4. Complex 2 also possesses square pyramidal geometry with a non-coordinated iodide counter anion and crystallizes in spacegroup P2₁/n with crystal cell parameters a = 9.4071(13) ?, b = 14.628(2) ?, c = 11.7516(16) ?, β = 98.904(2) ?°, V = 1,597.6(4) ?³ and Z = 4. Complex 2 has previously been incorrectly assigned as an octahedral complex based on spectroscopy.     

Synthesis and Crystal Structure of (<Emphasis Type="Italic">S</Emphasis>)-2-((<Emphasis Type="Italic">S</Emphasis>)-2-(<Emphasis Type="Italic">N</Emphasis>-Ts-Amino)-3-methylbutanoyl)-3-(1H-indol-3-yl)-6-phenyl-3,4-dihydro-1,2,4-triazin-5(2H)-one

Abstract  

The diastereoselective synthesis, NMR and X-ray structure of (S)-2-((S)-2-(N-Ts-amino)-3-methylbutanoyl)-3-(1H-indol-3-yl)-6-phenyl-3,4-dihydro-1,2,4-triazin-5(2H)-one—a potential antivirus agent are reported. The compound crystallizes in the triclinic space group P1 with unit cell parameters: a = 5.9259(6) ?, b = 9.6370(12) ?, c = 12.9541(9) ?, α = 109.210(9)°, β = 90.804(7)°, γ = 105.074(10)° and Z = 1.     

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.     

Synthesis,Crystal Structure,and Rotational Energy Profile of 3-Cyclopropyl-1,2,4-benzotriazine 1,4-Di-<Emphasis Type="Italic">N</Emphasis>-oxide

Abstract  

1,2,4-Benzotriazine 1,4-di-N-oxides are potent antitumor drug candidates that undergo in vivo bioreduction leading to selective DNA damage in the low oxygen (hypoxic) cells found in tumors. Tirapazamine (TPZ) is the lead compound in this family. Here we report on the synthesis, crystal structure, and conformational analysis of a new analog, 3-cyclopropyl-1,2,4-benzotriazine 1,4-di-N-oxide (3). Compound 3 (C₁₀H₁₀N₃O₂) crystallized in the monoclinic space group C2/c. Unit cell parameters for 3: a = 16.6306 (12), b = 7.799 (5), c = 16.0113 (11) ?, α = 90, β = 119.0440 (10), γ = 90, and z = 8.