Diphenyl bromine

Isoxazole, 4-methyl-3,5-diphenyl-bromination, 6, 51 Isoxazole, 3-methyl-4-nitto-5-styryl-photolysis, 6, 14 Isoxazole, 3-methyI-5-phenyl-copper complexes ESR, 6, 7... 

Brominated Diphenyl Oxides. Brominated diphenyl oxides are prepared by the bromination of diphenyl oxide. They are often referred to as diphenyl ethers. Taken together, the class constitutes the largest volume of brominated flame retardants. They range ia properties from high melting sohds to hquids. They are used, as additives, ia virtually every polymer system. 

DecabromodiphenylOxide. Decabromodiphenyl oxide [1163-19-5] (decabrom) is the largest volume bromiaated flame retardant used solely as an additive. It is prepared by the bromination of diphenyl oxide ia neat bromine usiag AlCl as a catalyst (32). The bromination may also be carried out ia an iaert solvent such as methylene dibromide [74-95-3] (33). The commercially available grades are >98% decabromodiphenyl oxide with the remainder being the nonabromo species. 

Octabromodiphenyl Oxide. Octabromodiphenyl oxide [32536-52-0] (OBDPO) is prepared by bromination of diphenyl oxide. The degree of bromination is controlled either through stoichiometry (34) or through control of the reaction kinetics (35). The melting poiat and the composition of the commercial products vary somewhat. OBDPO is used primarily ia ABS resias where it offers a good balance of physical properties. Poor uv stabiUty is the primary drawback and use ia ABS is being supplanted by other brominated flame retardants, primarily TBBPA. 

Benzo[b]furan, 2,3-dihydro-2-phenyl-synthesis, 4, 697 Benzo[b]furan, 2,3-dihydroxy-tautomerism, 4, 37 Benzo[6]furan, 4,6-dimethoxy-acylation, 4, 606 Benzo[6]furan, 2,3-dimethyl-acetylation, 4, 606 bromination, 4, 605 photooxygenation, 4, 642 Benzo[b]furan, 5,6-dimethyl-2,3-diphenyl-applications, 4, 709 Benzo[b]furan, 1,3-diphenyl-vertical ionization potential, 4, 587 Benzo[b]furan, 2-ethoxy-5-hydroxy-synthesis, 4, 127... 

Imidazole, 2-amino-1 -methyl-4,5-diphenyl-tautomerism, 5, 368 Imidazole, 2-aroyl-mass spectra, 5, 360 synthesis, 5, 391, 402 UV spectra, 5, 356 Imidazole, 4-aroyl-synthesis, 5, 474 Imidazole, C-aroyl-UV spectra, 5, 356 Imidazole, aryl-nitration, 5, 396, 433 oxidation, 5, 433 Imidazole, 1-aryl-dipole moments, 5, 351 dearylation, 5, 449 ethylation, 5, 448 H NMR, 5, 353 hydroxymethylation, 5, 404 rearrangement, 5, 108 synthesis, 5, 390 thermal rearrangement, 5, 363 Imidazole, 2-aryl-chlorosulfonation, 5, 397 synthesis, 5, 475 Imidazole, 4-aryl-bromination, 5, 399 Imidazole, C-aryl-electrophilic substitution, 5, 432-433 nitration, 5, 433 Imidazole, N-aryl-reactions, 5, 448-449 structure, 5, 448-449 Imidazole, arylmercapto-... 

Isoxazole, 3,5-dimethyl-4-(p-nitrophenyl)-bromination, 6, 51 Isoxazole, 3,5-dimethyl-4-vinyl-oxidation, 6, 27, 54 Isoxazole, diphenyl-mass spectra, 6, 6-7 Isoxazole, 3,4-diphenyl-... 

Pyrazole, 1 -(2,4-dinitrophenyl)-3-methyl-bromination, S, 240 Pyrazole, 2,3-diphenyl-synthesis... 

Thieno[ 1,2,3]diazaborines, dihydro-bromination, 1, 656 deuteration, 1, 658 iodination, 1, 656 nitration, 1, 656 nucleophilic substitution copper-promoted, 1, 658 Thienodiazepines synthesis, 7, 595 Thieno[ 1,2]diazepines synthesis, 7, 598 Thieno[2,3-d][l, 2]diazepines synthesis, 4, 749 Thieno[3,2-d][l,2]diazepines synthesis, 4, 749 Thieno[ 1,3]diazepines synthesis, 7, 607 Thieno[ 1,4]diazepinones as anticonvulsants, 1, 170 Thieno[3,4-d][l,3]dioxol-2-one, 4,6-diphenyl-... 

The quantities of bromine and diphenyl sulflde must be adjusted according to the amount of alkoxide added. 

Bromine compounds are often used as flame retardant additives but 15-20ptsphr may be required. This is not only expensive but such large levels lead to a serious loss of toughness. Of the bromine compounds, octabromo-diphenyl ether has been particularly widely used. However, recent concern about the possibility of toxic decomposition products and the difficulty of finding alternative flame retarders for ABS has led to the loss of ABS in some markets where fire retardance is important. Some of this market has been taken up by ABS/PVC and ASA/PVC blends and some by systems based on ABS or ASA (see Section 16.9) with polycarbonates. Better levels of toughness may be achieved by the use of ABS/PVC blends but the presence of the PVC lowers the processing stability. 

It should, however, be noted that good flame retardancy is only achieved with the use of flame retardant additives and that some of the best of these, such as the brominated diphenyls and brominated diphenyl ethers, are restricted in their use in some countries. 

Bromination of the diphenyl indole derivative 316 with bromine in DMF or trimethylammonium bromide afforded the 7-bromo derivative 317. Reaction with allyl bromide or its derivatives gave A-allyl derivatives 318 that upon cyclization with palladium acetate gave 7,9-dimethoxy-l,2-diphenylpyrrolo[3,2,l-// ]quinoline derivatives 319 (92T7601) (Scheme 57). 

Bromodiphenyl has been obtained along with some of the ortho derivative from the bromination of diphenyl.1 However, according to Schlenk,2 the product so obtained is contaminated with some p, -dibromodiphenyl which is very difficult to remove. Bamberger obtained j>-bromodiphenyl from the action of benzene on solid p-bromobenzene diazoanhydride.3 The method described in the procedure has recently been described in the literature.4... 

The first report of the use of bromine for the oxidation of sulphoxides appeared in 1966116. Diphenyl sulphone was isolated in 0.5-1% yield when the sulphoxide was treated with bromine in aqueous acetic acid for several hours. The yield was increased to about 5% by quenching the reaction with sodium carbonate. A kinetic study117 of a similar reaction involving dimethyl sulphoxide showed no significant yield improvement but postulated that the mechanism proceeds via an equilibrium step forming a bromosulph-onium type intermediate which reacted slowly with water giving dimethyl sulphone as indicated in equation (35). 

Carboxylic acids, a-bromination of 55, 31 CARBOXYLIC ACID CHLORIDES, ketones from, 55, 122 CARBYLAMINE REACTION, 55, 96 Ceric ammonium nitrate [Ammonium hexa mtrocerate(IV)[, 55, 43 Chlorine, 55, 33, 35, 63 CHROMIUM TRIOXIDE-PYRIDINE COMPLEX, preparation in situ, 55, 84 Cinnamomtnle, a-phenyl- [2-Propeneni-tnle 2,3-diphenyl-], 55, 92 Copper(l) iodide, 55, 105, 123, 124 Copper thiophenoxide [Benzenethiol, copper(I) salt], 55, 123 CYCLIZATION, free radical, 55, 57 CYCLOBUTADIENE, 55, 43 Cyclobutadieneiron tricarbonyl [Iron, tn-carbonyl(r)4-l,3-cyclo-butadiene)-], 55,43... 

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