نتایج جستجو برای: 4 dioxane
تعداد نتایج: 1304616 فیلتر نتایج به سال:
A microcosm study was conducted to assess two biostimulation strategies (relative to natural attenuation) to bioremediate 1,4-dioxane contamination at a site in west Texas. Dioxane concentrations were relatively low (<300 μg/L), which represents a potential challenge to sustain and induce specific degraders. Thus, biostimulation was attempted with an auxiliary substrate known to induce dioxane-...
The title compound, C(13)H(11)FO(4), was prepared by the reaction of 2,2-dimethyl-1,3-dioxane-4,6-dione and 4-fluoro-benz-alde-hyde in ethanol. The 1,3-dioxane ring adopts an envelope conformation. The crystal structure is stabilized by weak inter-molecular C-H⋯O hydrogen bonds.
The benzyl ring of the title compound, C(17)H(15)NO(4), is twisted away from the plane defined by five atoms of the dioxane ring by 34.83 (4)°. The dioxane ring exhibits a half-boat conformation, with the C atom between the dioxane O atoms 0.571 (8) Å out of the plane through the remainder of the ring. An intra-molecular N-H⋯O hydrogen bond may contribute to the stabilization of the planar conf...
The title compound, C(13)H(12)ClNO(4), is approximately planar, with a dihedral angle of 8.23 (4)° between the mean plane of the amino-methyl-ene unit and the planar part of the dioxane ring. The dioxane ring has a half-boat conformation, in which the C atom between the dioxane O atoms is -0.464 (8) Å out of the plane of the other five atoms. In the mol-ecule there is an intra-molecular N-H⋯O h...
In the title compound, C(10)H(20)O(4), the dioxane ring adopts a chair conformation. The tert-butyl group occupies an equatorial position, and is staggered with respect to the O atoms of the dioxane ring. In the crystal, mol-ecules are connected by O-H⋯O hydrogen-bonds into zigzag chains of R(4) (4)(8) and R(2) (2)(12) ring motifs that run parallel to the a axis.
Silybum marianum is a medicinal plant used widely for treating liver diseases. The silymarin, a mixture of three flavolignan isomers namely silybin (1), silydianin (2), and silychristin (3) is an active constituent of the plant. However, silybin containing 1, 4-dioxane ring is the most potent antihepatotoxic agent. In contrast, other isomers do not possess 1, 4-dioxane ring, and thus do not exh...
Exploiting chemical cooperation between Na and Fe(II) within the bimetallic base [dioxane ⋅ NaFe(HMDS)3] (I), (dioxane=1,4-dioxane, HMDS=N(SiMe3)2) selective ferration of fluorobenzene, 1-fluoronaphthalene, 1,4-difluorobenzene, 1,2,4-trifluorobenzene, 1,3,5-trifluorobenzene, 1-bromo-3,5-difluorobenzene, 3-fluoroanisole 3,5-difluoroanisole has been realized, affording sodium ferrates Na(HMDS)(2-...
Treatment of 5,8-dihydroxy-1-tetralone (9) with either 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) in refluxing benzene or silver (I) oxide in refluxing 1,4-dioxane afforded juglone (5-hydroxy-1,4-naphthoquinone) (1) in good yield. With manganese dioxide in dioxane the tetralone gave a mixture of juglone and naphthazarin (5,8-dihydroxy-1,4-naphthoquinone) (3), the proportion of naphthazarin...
In the crystal structure of the title compound, (C(5)H(6)N)(2)[UCl(4)O(2)]·C(4)H(8)O(2), the pyridinium cations occupy general positions and the anions and the solvent dioxane mol-ecule are located on centres of inversion. The dioxane mol-ecules are connected to two symmetry-related pyridinium cations via O-H⋯O hydrogen bonding. There are additional inter-molecular C-H⋯Cl contacts, which are in...
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