Crystal Structure Of Ethyl Research Articles

Energetic Study of the Disordered Solvent in the Crystal Structure of an Isoxazole Derivative

In the crystal structure of ethyl (Z)-3-{[3-(3,5-dichloro-2,4,6-trimethylphenyl)isoxazol-4-yl]-2-butenylidene}carbazate–ethyl acetate solvate, C19H21Cl2N3O3.0.34-C4H8O2 (R 1 = 0.072, wR 2 = 0.228), the host molecules are linked by intermolecular N—H...N hydrogen bonds, giving rise to infinite channels which contain molecules of ethyl acetate. Packing potential energy calculations carried out for host–guest model crystals account for the disorder of the solvent molecules in the crystal state.

Crystal structure of ethyl 1-(2-hydroxy-4,6-dimethoxy)naphthyl-2-carboxylate,С10Нб(СООС2Н5)СбН2(ОН)(ОСН3)2

Crystal structure of ethyl 1-(2-hydroxy-4,6-dimethoxy)naphthyl-2-carboxylate,С10Нб(СООС2Н5)СбН2(ОН)(ОСН3)2

The Synthesis of Zinquin Ester and Zinquin Acid, Zinc(II)-Specific Fluorescing Agents for Use in the Study of Biological Zinc(II)

The syntheses of Zinquin ester [ethyl [2-methyl-8-(p- tolylsulfonylamino )-6-quinolyloxy]acetate] and the corresponding acid, both of which are zinc(II)-specific fluorophores , are described. 6-Methoxy-2-methyl-8-(p- tolylsulfonylamino ) quinoline (2) can be demethylated , with boron tribromide, to form either the expected phenol or a mixture of the phenol and the corresponding 5-bromo derivative depending upon the reaction conditions. These compounds react with ethyl bromoacetate to give the corresponding esters, as well as the 5-ethoxycarbonyl derivative formed by electrophilic substitution. Halogenation of the sulfonamide (2) occurs readily at the 5-position. The 5-iodo product undergoes a Heck coupling with ethyl acrylate . The crystal structures of ethyl [5-ethoxycarbonylmethyl-2-methyl-8-(p- tolylsulfonylamino )-6-quinolyloxy]acetate and [5-carboxymethyl-2-methyl-8-(p- tolylsulfonylamino )-6-quinolyloxy]acetic acid are described.

Formation of polyheterocyclic systems by reaction of 2-imino-4-methyl-2H-1-benzopyran-3-carbonitrile with active methylene compounds

2-Imino-4-methyl-2H-1-benzopyran-3-carbonitrile undergoes [1,5] tautomerism in solution to 2-amino-4-methylidene-4H-1-benzopyran-3-carbonitrile. Reaction with one equivalent of compounds containing a reactive methylene group affords simple 4-methylbenzopyran derivatives, and a methylidene derivative (of [1]benzopyrano[2,3-b][1,8]naphthyridine). Reaction with two and three equivalents of malononitrile affords derivatives of [1]benzopyrano[2,3,4-de]quinoline and [1]benzopyrano[2,3,4-de][1,6]-naphthyridine, which had previously been formulated as bicyclic benzopyran derivatives. The X-ray crystal structure of ethyl 3-amino-2-cyano-3-(2-imino-4-methyl-2H-1-benzopyran-3-yl)prop-2-enoate has been determined, showing the presence of two molecules in the asymmetric unit.

Synthesis and crystal structure of ethyl 1-benzyl-2-hydroxy-5-methyl-3-oxo-2-phenacyl-2,3-dihydropyrrole-4-carboxylate

Reaction of 5-phenyl-2,3-dihydro-2,3-furandione with ethyl 3-benzylamino-2-butenoate, resulting in ethyl 1-benzyl-2-hydroxy-5-methyl-3-oxo-2-phenacyl-2,3-dihydropyrrole-4-carboxylate and benzylamide ofN-benzoylpyruvic acid, was studied. The structure of the pyrrole derivative was confirmed by X-ray analysis.

Crystal structure of ethyl 4-methylthio-3-phenyl-2-thioxo-2,3-dihydro-1,3-oxazole-5-carboxylate

The title compound C13H13NO3S2 crystallizes in the triclinic space group\(P\bar 1\) (Z=2) with lattice constantsa=8.382(2),b=10.042(2),c=10.134(2) A, α=119.35(1)°, β=101.40(1)° and γ=90.54(1)°. The interplanar angle between the least squares planes of the 1,3-oxazoline ring and the phenyl ring amounts to 90.2°, thus hindering conjugation between the benzene and heterocyclic system. The observed bond parameters of the five-membered heterocycle suggest a significant contribution from a zwitterionic dipolar limiting structure [38.7(5)%] to the description of this ring system. The particular contributions of the resonance structures were estimated by calculations using the HOSE model on the base of the observed bond lengths.

Structure of a triazaoxatricyclodecadiene derivative. Partial disorder and a packing energy study

The crystal structure of ethyl 5-(2,6-dimethylphenyl)-2-methyl-3-oxa-4,8,9-triazatricyclo[5.3.0.0 2,6 ]deca-4,9-diene-8-carboxylate, C 18 H 21 N 3 O 3 (III), has been determined. The reaction between 2,6-dimethylbenzonitrile oxide (1) and ethyl 5-methyl-1,2-diazepine-1-carboxylate (II) gives rise to an anti tricyclo derivative with a rigid skeleton formed by 2-pyrazoline, cyclobutane and 2-isoxazoline planar rings. With respect to the central cyclobutane system, the bond lengths of which range from 1.539 (5) to 1.558 (5) A and the bond angles of which range from 89.7 (2) to 90.7 (2) o , the 2-pyrazoline and the 2-isoxazoline planes form dihedral angles of 116 and 112 o , respectively. The methyl group at the end of the ethyl carboxylate chain is disordered

Preparation and characterisation of organocobalt(III) complexes of tetraaza macrocyclic ligands. Crystal structures of ethyl- and propyl-cobalt(III) complexes of 3,7,11,17-tetraazabicyclo[11.3.1]heptadeca-1(17),13,15-triene

Several organocobalt(III) complexes of general formula tras-[CoR(L)(OH2)][ClO4]2 have been prepared in moderate yield using a photochemical route (L = a tetraaza macrocycle; R = Me, Et, Pr or Bu). The complexes have been isolated and characterised by microanalyses, 1H, 13C and 59Co NMR spectroscopies, and fast atom bombardment (FAB) mass spectrometry. Crystal structures of two of the complexes, trans-[CoR(L)(OH2)][ClO4]2(L = 3,7,11,17-tetraazabicyclo[11.3.1]heptadeca-1(17),13,15-triene; R = Et or Pr) establish the trans-geometry, with relatively long Co–O bond lengths of 2.121(3) and 2.29(3)Å respectively, showing the trans influence of the alkyl groups.

Trans Deformation of a carbon–carbon triple bond in response to incipient nucleophilic attack: the X-ray crystal structure of ethyl 3-(2-nitrophenyl)propynoate at 150 K

In the title compound 1 the electron-deficient alkyne bond shows a pronounced trans distortion in response to an adjacent electron rich nitro O atom, suggesting that the more favourable reaction coordinate for addition of nucleophiles to activated alkynes involves trans rather than cis addition.

Crystal structure of ethyl 3,4,6-tri- O-acetyl-2-deoxy-2-hydroxyimino-α- d- arabino-hexopyranoside

The crystals of the title compound, C 14H 21NO 9 ( M r 347.4), are orthorhombic, space group P2 12 12 1 with a = 8.998(2), b = 13.641(2), c = 14.027(3) Å, V = 1721.7(6) Å 3, and Z = 4; D c = 1.34 g.cm −3. The pyranoid ring has the distorted 4 C 1 conformation and the hydroxyimino group has the Z conformation.

Synthese von 3,3-Bis(alkylthio)-2-(2-thioxo-benzo-2H-1,3-thiazol-3-yl)-acryls�ure-Derivaten und Kristallstruktur des entsprechenden Ethyl 3,3-Bis(methylthio)acrylats

The 3,3-bis(alkylthio)-2-(2-thioxo-benzo-2H-1,3-thiazole-3-yl)acrylonitriles3a–e, the methyl and ethyl acrylates4 and5a–d, respectively, are prepared by dithiocarboxylation of the corresponding derivatives of acetic acid1a–c. The crystal structure of ethyl 3,3-bis(methylthio)-2-(2-thioxo-benzo-2H-1,3-thiazole-3-yl)acrylate5a has been determined by X-ray analysis.

The crystal structure of ethyl 5-methyl-1,2,3-triazino [5,4-b]-indole 4-carboxylate N(3)-oxide

Structure cristalline du compose du titre. Groupe d'espace monoclinique P2 1 /n. Molecule plane. La chaine laterale est approximativement trans et adopte une configuration en quinconce. Determination des operations de symetrie

The crystal structure of ethyl 5-methyl-l,2,3-triazino [5,4-b]-indole 4-carboxylate N(3)-oxide

Abstract The crystal structure of ethyl 5-methyl-l,2,3-triazino [5,4-b]-indole 4-carboxylate N(3)-oxide (II), (C13H12N4O3), has been detnrmined by X-ray diffraction techniques. The crystals are monoclinic, space-group P21/n, with a = 13.137 (1), b = 8.48 8(1), c = 12.70 9(1) Å and β = 116.63(2)°, Z = 4, Dc = 1.4278 g · cm−3. The crystal structure was solved by direct methods and refined by least-squares to R = 0.059 for 838 independent reflexions. The molecule is planar and the side-chain backbone is all-trans and presents a staggered conformation.

The crystal structure of ethyl 2,3-dideoxy-α- d- erythro-hex-2-enopyranoside

The crystal structure of ethyl 2,3-dideoxy-α- d- erythro-hex-2-enopyranoside, C 8H 14O 4, is orthorhombic, P2 12 12 1, with cell dimensions at 123 K [293 K] a = 11.220(2) [11.319(1)], b = 18.387(3) [18.458(2)], c = 8.509(2) [8.635(1)] Å, Z = 8. There are two symmetry-independent molecules in the asymmetric unit. In both molecules, the conformation is o H 5. The alkenic bond is almost exactly planar in one molecule, with C-1C-2C-3C-4 = +0.8°. In the other molecule, this torsion angle is +3.7°. The glycosidic torsion angle, O-5C-1O-1C-7, has normal exo-anomeric values of +71 and +64°. The conformation of the ethoxyl group is extended, with C-1O-1C-7C-8 = +162 and +170°. The primary alcohol group has different orientations, g/t on one molecule, g/g on the other. The characteristic glycosidic bond-shortening observed in the pyranosides is modified in this enopyranoside. Both the ring bond, O-5C-1, and the glycosidic bond, C-1O-1, are short, with distances ranging from 1.409 to 1.425 Å. Solution and solid-state c.p.-m.a.s., 13C-n.m.r. spectra are reported.

Crystal structure of ethyl pyruvate-2-methyl-4-chloro-phenyl hydrazone

Ethyl pyruvate-2-methyl-4-chloro-phenylhydrazone, C12H15N2O2Cl, is an important intermediate for the synthesis of ethyl-5-chloro-7-methyl indole-2-carboxy-late. Crystals are orthorhombic witha=6.99(4),b=23.75(6),c=17.05(6) Å and eight molecules per cell in the space group Cmca. The structure was solved by direct methods using film data and refined by block diagonal least squares method to anR-index of 0.052. The molecule occupies the space group mirror(m) special position. The stacking of the molecules is stabilized by van der Waal’s contacts.

The crystal structure of ethyl 2-imino-4-oxo-5-phenylimidazolidine-1-carboximidate

The zwitterionic nature of the five-membered ring in ethyl 2-imino-4-oxo-5-phenylimidazolidine-1-carboximidate is shown for the first time.

Dielectric Behavior and Crystal Structure of Ethyl and Vinyl Stearate

Measurements of the real (ε′) and imaginary (ε″) components of the complex dielectric constant have been made on ethyl and vinyl stearate and on mixtures of ethyl stearate in n-heneicosane at temperatures from +60° to —80°C and over a frequency range from 100 to 50 000 cps. A relaxation dispersion region, which was similar in shape and position for all samples, occurred below 0°C for the frequency range considered here. The magnitudes of the dispersions were found to be greater the more quickly the samples were frozen, and very much reduced for samples crystallized from acetone. Annealing of the solid samples at temperatures as low as 20 centigrade degrees below the freezing points resulted in a gradual decrease in polarization. Cooling curve data was obtained in order to supplement the above work. The results suggest that the molecular rotations involved in the observed solid state dispersions are associated with metastable crystal structures and that, in particular, the decrease in polarization with time is due to a gradual transformation in parts of the sample from a vertical to a tilted crystal structure.