Benzoquinone derived 1,3-dithiole-2-ones and thiones

The syntheses and structures of 1,3-dithiole and tetrathiafulvalene derivatives of benzoquinone have been investigated. This work extends earlier investigations of naphthoquinone analogues. The X-ray structures, NMR, IR, UV, mass spectra, and E⁰ _1/2 values from cyclic voltammetry measurements are reported.Ab initio STO-6-31G calculations are used to correlate the cyclic voltammetry and UV data for selected compounds.     

4,5-Bis(benzylthio)-1,3-dithiole-2-thione compounds: crystal structures of [(p-XC6H4CH2)(p-XC6H4CH2)dmit: X=Y=OMe; X=Y=NO2; and X=OMe, Y=NO2]

4,5-Bis(benzylthio)-1,3-dithiole-2-thiones, [(p-XC₆H₄CH₂)(p-XC₆H₄CH₂)dmit: X=Y=OMe (2); X=OMe, Y=NO₂ (3); and X=NO₂] (4)] have been prepared from benzyl chlorides and [NEt₄]₂[Zn(dmit)₂]. Isostructural compounds, 2 and 3, crystallize in the triclinic space group (Z = 2) with a = 5.2920(10), b = 10.537(2), c = 18.961(4) Å, = 102.79(3), = 96.33(3), = 98.67(3)° for 2; a = 5.292(8), b = 10.528(12), c = 19.01(2) Å, = 102.74(9), = 96.26(11), = 98.56(11)° for 3. Compound 4 also crystallizes in the space group (Z = 4), with a = 9.296(8), b = 13.993(18), c = 16.186(4) Å, = 106.68(3), = 89.63(3), = 99.38(6)°. Molecular differences between 2 and 3, on one hand, and 4, on the other, arise in the disposition of the aryl rings relative to the dmit group. Short S---S contacts in 2 of 3.320(2) Å [S3---S3 ⁱ (symmetry operation: i: –x + 1, –y + 1, –z)] and in 3 of 3.314(5) Å [S3---S3 ⁱ (symmetry operation: i: –x + 1, –y, –z + 1)] link molecules into pairs. In 4, an S5A---S2B contact of 3.516(5) Å links two independent molecules, A and B, into bimolecular units, which are further connected into chains by S2A---S5B ⁱ contacts (symmetry operation: i: x, y, z – 1) at 3.569(5) Å. C–H---O hydrogen bonds are also present in 3 and 4.     

Synthesis of <Emphasis Type="Italic">E</Emphasis> Isomer and Crystal Structures of <Emphasis Type="Italic">E</Emphasis> and <Emphasis Type="Italic">Z</Emphasis> Isomers of 3-(2,5-Dimethoxyphenyl)-2-(4-methoxyphenyl)acrylonitrile

Abstract Details of the synthesis of the E isomer of 3-(2,5-dimethoxyphenyl)-2-(4-methoxyphenyl)acrylonitrile, and the X-ray crystal structures of both the E and Z isomers of this compound are presented. The E isomer crystallizes in the P2₁/c space group with cell parameters, a = 8.5659(17) ?, b = 16.399(3) ?, c = 11.224(2) ?, α = 90°, β = 95.27(3)°, γ = 90°and Z = 4. The Z isomer crystallizes in the Pca2₁ space group with cell parameters, a = 4.1223(8) ?, b = 19.113(4) ?, c = 19.453(4) ?, α = 90°, β = 90°, γ = 90° and Z = 4. Index Abstract Synthesis of E isomer and X-ray crystal structure determination of both E and Z isomers of 3-(2,5-dimethoxyphenyl)-2-(4-methoxyphenyl)acrylonitrile are presented.      

Synthesis,Separation and Crystal Structures of <Emphasis Type="Italic">E</Emphasis> and <Emphasis Type="Italic">Z</Emphasis> Isomers of 3-(2,5-Dimethoxyphenyl)-2-(4-Methoxyphenyl)Acrylic Acid

Abstract Synthesis, separation and X-ray crystal structures of E and Z isomers of 3-(2,5-dimethoxyphenyl)-2-(4-methoxyphenyl)acrylic acid are reported. Separation of E and Z isomers from a 1:1 mixture has been carried out by selective acidification of their sodium salts carefully controlling the pH of the solution. The structures of E and Z isomers were confirmed by determining crystal structures of these isomers using single crystal X-ray diffraction. The E isomer crystallizes in the P2₁/c space group with a = 11.493(2) ?, b = 5.5456(11) ?, c = 24.900(5) ?, α = 90°, β = 92.36(3)°, γ = 90°, Z = 4. The Z isomer crystallizes in the P2₁/c space group with a = 10.192(2) ?, b = 12.893(3) ?, c = 13.948(3) ?, α = 90°, β = 92.18(3)°, γ = 90°, Z = 4. Details of the synthesis and structural characterization and X-ray crystal structure determination of the title compounds are presented. Index Abstract Synthesis, Separation and Crystal Structures of E and Z Isomers of 3-(2,5-Dimethoxyphenyl)-2-(4-Methoxyphenyl)Acrylic Acid Balachandra Chenna, Bidhan A. Shinkre, Shweta Patel, Samuel B. Owens Jr., Gary M. Gray, Sadanandan E. Velu* Separation of E and Z isomers of 3-(2,5-dimethoxyphenyl)-2-(4-methoxyphenyl)acrylic acid from a 1:1 mixture has been carried out by selective acidification of their sodium salts and the structures of the individual isomers have been determined by X-ray single crystal diffraction.      

Crystal structures of 2,4,9-trimethyl-(3ar,4c,9c,9ac)-3a,4,9,9a-tetrahydro-benzo[?] isoindole-1,3-dione(endo), C15H17NO2 (1), and 2-methyl-(3ac,9ac)-3a,4,9,9a-tetrahydro-4r,9c-ethano-benzo[?]isoindole-1, 3-dione(endo), C15H15NO2 (2)

The title compounds crystallize in the space group P-1 (compound 1), with a = 7.198(2) Å, b = 7.965(2) Å, c = 12.707(2) Å, α = 72.05(1)^∘, β = 87.65(2)^∘, γ = 65.18(2)^∘ and Pbca (compound 2), with a = 8.156(3) Å, b = 13.177(3) Å, c = 22.742(4) Å. The chiral centers in both compounds C3a, C4, C9, C9a are either R, S, R, S or S, R, S, R (compound 1) and either R, R, S, S or S, S, R, R (compound 2) because of the centric space group.     

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.      

X-ray diffraction and total 1H and 13C NMR assignment of (RS)-5,6-dihydro-7,8-dimethoxy-5-methyl-6-(2-oxopropyl)-(2,3-methylenedioxyphenyl)-[c]-phenanthridine ((RS)-6-acetonyldihydrochelerythrine)

The X-ray diffraction structure of (RS)-5,6-dihydro-7,8-dimethoxy-5-methyl-6-(2-oxopropyl)-(2,3-methylenedioxyphenyl)-[c]-phenanthridine ((RS)-6-acetonyldihydrochelerythrine), isolated as an artifact from Bocconia Arborea, is reported. This compound crystallizes as orthorhombic system, space group Pna2₁, with a = 13.216(2) Å, b = 7.6547(10) Å, c = 20.096(3) Å. The phenanthridine central ring presents a distorted boat conformation, which gives rise to two planes with 21.30° between them. The acetonyl group at the six position forms weak C — H O and C — H -ring interactions. The title compound was completely characterized in solution by ¹H and ¹³C and 2D NMR experiments.     

The Synthesis and Structure of Two Novel <Emphasis Type="Italic">N</Emphasis>-(Benzothiazol-2-yl)benzamides

Abstract  Two novel benzothiazoles 2-chloro-N-(benzothiazol-2-yl)benzamide (1) and 2-chloro-N-(6-cyanobenzothiazol-2-yl)benzamide (2) were obtained in multistep synthesis. They were characterised by means of IR, ¹H- and ¹³C-NMR spectroscopy and also by single-crystal X-ray diffraction. The compound 1 crystallises with triclinic space group P , a = 9.5923(8) ?, b = 9.8583(8) ?, c = 13.8962(10) ?, α = 89.162(6)°, β = 77.741(7)°, γ = 80.064(7)°, V = 1264.5(2) ?³, Z = 4 and compound 2 crystallises as methanol solvate with monoclinic space group P 2₁/n, a = 7.5093(9) ?, b = 13.0211(14) ?, c = 16.032(2) ?, β = 92.717(10)°, V = 1565.9(3) ?³, Z = 4. Both crystal structures consist of discrete dimers connected into a three-dimensional network by intermolecular C–H···O and C–H···X (X = Cl or S) hydrogen bonds and by face-to-face π–π stacking interactions. Index Abstract  The synthesis and structure of two novel N-(benzothiazol-2-yl)benzamides. Irena Ćaleta, Dominik Cinčić, GraceKarminski-Zamola and Branko Kaitner. Hydrogen bonds and π–π interactions in N-(benzothiazol-2-yl)benzamides N-(benzothiazol-2-yl)benzamides.      

Synthesis and crystal structure of a novel 3D supramolecular complex [Na(DC18C6-B)][Ni(mnt)<Subscript>2</Subscript>]

A supramolecular complex [Na(DC18C6-B)][Ni(mnt)₂] (1) (DC18C6-B = cis-anti-cis-dicyclohexyl-18-crown-6, isomer B; mnt = maleonitriledithiolate) has been prepared and characterized by elementary analysis, FT-IR spectroscopy and X-ray single crystal diffraction. It crystallizes in triclinic, space group P1 with crystallographic data: a = 7.974(4) Å, b = 14.343(7) Å, c = 15.559(8) Å, α = 96.230(8)^∘, β = 100.361(8)^∘, γ = 93.849(9)^∘, V = 1733.2(15) ų, Z = 2, D_calcd = 1.408 g/cm³, F(000) = 766, R₁ = 0.0491, wR₂ = 0.1018. The formula unit contains one [Na(DC18C6-B)]⁺ complex cation and one [Ni(mnt)₂]⁻ complex anion, which are constructed into an infinite chain-like structure through Na–N bonds. The resulting chains crisscross on the [Ni(mnt)₂]⁻ complex anions and further assemble into an unusual 3D supramolecular framework via the weak interactions.