Bromination

Preparation par deux methodes: 1) etherification par transfert de phase d'un polymere α,ω dielectrophile avec la p-hydroxyphenyl-2 oxazoline-2(I) 2) extension de chaine par transfert de phase d'un polymere α,ω diphenol avec le chlorure de methylene (II) ou polyetherification d'un bisphenol avec (II) en presence de (I)

... 35 (1994), p. 7055. Abstract | PDF (142 K) | View Record in Scopus | Cited By in Scopus (45). [8] BM Choudary, Y. Sudha and PN Reddy, Syn. Lett. (1994), p. 450. Full Text via CrossRef. [9] Y. Goldbery and H. Alper, J. Mol. Cat. 88 (1994), p. 377. ...

Photochemical excitation (λ> 300nm) of the decatungstate (nBu4N) 4W10O32, heterogenized with Amberlite IRA-900 and dispersed in a CH3CN/H2O mixture, causes the reductive activation of O2 to alkyl hydroperoxides. The light-assisted formation of these ...

Bromination of alkenes using a combination of potassium bromide and cerium (iv) ammonium nitrate (CAN) in a two phase system consisting of water and dichloromethane affords the corresponding dibromides in excellent yield. The reaction most likely involves ...

This review paper updates the previous literature in relation to the continued and developing use of stable isotope ratio analysis in samples which are relevant to forensic science. Recent advances in the analysis of drug samples, explosive materials, and samples derived from human and animal samples are discussed. The paper also aims to put the use of isotope ratio mass spectrometry into a forensic context and discuss its evidential potential.

1, 4-Dihydroxy-7, 8-dihydro-5H-benzo [a] cycloheptene-5, 9 (6H)-dione (7) was synthesised from hydroquinone and glutaric acid chloride via an acylation reaction. The reaction of dione (7) with bromine followed by treatment with NEt3 gave homonaphthazarin 8 as well as the ...

The influence of molecular weight on thermal transitions and on their thermodynamic parameters is discussed for a random thermotropic liquid crystalline copolyether based on the reaction of a 1:1 molar mixture of 1,5-dibromopentane and 1,7-dibromoheptane with 4,4′-dihydroxy-α-methylstilbene. Optimum phase transfer catalyzed polyetherification reaction conditions were established for the synthesis of polymers containing bromoalkane chain ends only over a wide variety of molecular weights. All these copolyethers present a crystalline and an enantiotropic nematic mesophase over the entire range of molecular weights studied. Both the thermal transitions and their thermodynamic parameters are strongly molecular weight-dependent up to Mn = 10,000–12,000, after which they remain constant. The enthalpies and entropies of isotropization of the copolyethers are higher than those of melting. This is in contrast to the same thermodynamic parameters of the corresponding homopolyethers. The entha...