Diphenylether

Deriv (+)-8,10-Diacetylusnic acid, pale yellow needles (MeOH), mp 202 °C, [a]g + 200 (CHCl3,c 1.00), from (+)-usnic acid with AC2O-H2SO4 at room temperature in 5 h StL (+)-Usnic acid Evernia prunastri (L.) Ach., (-)-usnic acid Cladonia stellaris (Ach.) Pouzar et Vezda 

StL Asahinea chrysantha (Tuck.), W.Culb. et C.Culb., Parmelia birulae Elenk. 

Deriv Methyl P-collatolate, needles (MeOH), mp 75 °C, from P-coUatolic acid with the calculated amount of CHjNj at 0°C. C. Collatolone, needles (EtOH), mp 142 °C, by boiling of P-collatolic acid with formic acid StL Asahinea chrysantha (Tuck.) W.Culb. et C.Culb., Asahinea scholanderi (Llano) W.Culb. et C. Culb. 

Deriv Methyl epiphorellate I, mp 135-137 °C (acetone-n-pentane), from epiphorellic acid I with CH2N2 

Needles (EtOH-H O), mp 250-251 °C React FeCl3 (CHClj-pyridine) green, NaOCl red IR (Nujol) 1680, 1726, 3280 cm  

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AROMATIC HYDROCARBONS FROM AROMATIC KETONES AND ALDEHYDES 1,1 -DIPHENYLETH ANE (I,l -Ethylidenebisbenzene)... 

The additional formation of PBDD from brominated diphenylether can be explained by a SET mechanism, see Scheme 3. 

Pfeifer F, HG Trtiper, J Klein, S Schacht (1993) Degradation of diphenylether by Pseudomonas cepacia Et4 enzymatic release of phenol from 2,3-dihydroxydiphenylether. Arch Microbiol 159 323-329. 

Chemicals that possess a common structural feature are called congeners. Some common examples are polychlorinated biphenyls (PCBs), polyaromatic hydrocarbons (PAHs), poly-brominated diphenylethers (PBDE) and chlorofluorocarbons (CFC). The common features... 

Lithium alkylamides (in situ generated from the amine and either n-BuLi or sec-BuLi) generally give higher yields under milder conditions. Thus, n-BuLi (5%) catalyzes the addition of primary and secondary amines to styrene to afford (-phenethy-lamines in moderate to good yields (e.g., Bq. 4.32) [155]. NH, and PhNHj, however, do not add to styrene under these conditions. a-Methylstyrene and 1,1-diphenyleth-ylene can also be hydroaminated. 

Similarly, toluene suspensions of the polystyrene housing of TV sets were examined by means of TPPy-FTMS (300-1200 K) [224], Diphenylether (DPE) was evidenced by peaks at m/z 141, 142 and 170 and decabromobiphenyl (DBBP) by m/z 943 and 864. Decabromodiphenyl ether (DBDPE) was recognised by thermal degradation products around m/z 800... 

Eljarrat E, De La Cal A, Larrazabal D, Fabrellas B, Femandez-Alba AR, Borrull F, Marce RM, Barcelo D (2005) Occurrence of polybrominated diphenylethers, polychlorinated dibenzo-p-dioxins, dibenzofurans and biphenyls in coastal sediments from Spain. Environ Pollut 136(3) 493-501... 

Danon-Schaffer MN (2010) Polybrominated diphenylethers in landfills from electronic waste. Faculty of graduate studies (chemical and biological engineering). Vancover, The University of British Columbia. Dr. phil 362... 

Takasuga T, Senthilkumar K, Takemori H, Ohi E, Tsuji H, Nagayama J (2004) Impact of fermented brown rice with Aspergillus oryzae (FEBRA) intake and concentrations of polybrominated diphenylethers (PBDEs) in blood of humans from Japan. Chemosphere 57 795-811... 

H. Thoma, G. Hauschulz, E. Knorr and O. Hutzinger, "Polybrominated Dibenzofurans (PBDF) and Dibenzodioxins (PBDD) from the Pyrolysis of Neat Brominated Diphenylethers, Biphenyls and Plastic Mixtures of these Compounds,"Chemosphere, JJi, 277(1987). 

Allchin CR, Law RJ, Morris S (1999) Polybrominated diphenylethers in sediments and biota downstream of potential sources in the UK. Environ Pollut 105 197-207... 

Hexanitrodiphenyloxid erhalt man durch Weiternitrierung der Di-, Tri-, Tetra- und Pentanitrosubstitutionsprodukte des Diphenylethers mit Mischsaure. 

The starting material is succinic dialkylester, which is easily obtained from maleic anhydride. Cyclization is accomplished with sodium alcoholate in a high boiling solvent or solvent mixture (such as diphenylether/diphenyl) to afford the succinylosuccinic dialkylester 54 ... 

J. 1998, Bioavailability of polychlorinated diphenylethers (PDPEs) in contaminated sediments Comparison of benthic organisms and semipermeable membrane devices (SPMDs). Organohal. Comp. 39 5-8. 

Another point worth mentioning is the selectivity of the electrogenerated electrophilic sulfur species toward aromatic substrates in the reaction with diphenylether and diphenylamine. In the first case, an internal ortho-cyclization yields in phenoxathiin, in the second, a para-substitution occurs [252] giving a linear product (8cheme 59). 

The thermal isomerizations of a number of cyclobutenes have also been studied in the liquid phase (Criegee ei a ., 1965). The rates of isomerization of cia- and [Pg.187]

The growth step procedures for the cycloaddition reaction are very simple. Combination of an ethynyl-substituted dendrimer and an excess of the cyclo-pentadienone in a refluxing solvent such as o-xylene, diphenylether, or methyl-naphthalene (with b.p. higher than 130 °C) typically results in quantitative conversion within 24 h. The refluxing of the solvent is necessary to accelerate the elimination of the carbon monoxide in the cycloaddition. The purity of the resulting compounds was checked by MALDI-TOF mass spectrometry which showed quantitative reaction, facilitating work-up. By repeated precipitation in methanol, the pure product can be isolated as white amorphous powders in yields higher than 90%. 

The fourfold cycloaddition of an excess of cyclopentadienone dendron 27 to the tetraethynyltetraphenylmethane 4 in diphenylether at 200°C affords dendri-mer 2 in 85% isolated yield, respectively (see Scheme 7). Dendrimer 2 corresponds to the second-generation polyphenylene dendrimer made by the divergent method [30]. It should be mentioned that while the addition of dendron 27 to the biphenyl core 9 takes two days the addition to the tetraphenylcore 4 takes one week. This can be explained by the higher mobiUty of the biphenylic core compared to the stiff tetrahedral core, which allows the proper orientation of the ethynyl functions for reactions with the bulky dendrons. 

Industrial organic pollutants Perfluorinated compounds (PFCs), polybrominated diphenylethers (PBDEs), new pesticides, and nanomaterials. 

Keywords Biotoxins, Coccidiostats, Food contaminants, LC-MS/MS, Nanomaterials antibiotics, Perfluorinated compounds. Pesticides, Polybrominated diphenylethers... 

Phenoxatellurium dichlorides are prepared by heating 2-phenoxyphenyl tellurium trichlorides or a mixture of equimolar amounts of TeCl4 and diphenylethers. ... 

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