109-64-8Relevant articles and documents
Process intensification-assisted conversion of α,ω-alkanediols to dibromides
Mekala, Shekar,Hahn, Roger C.
, p. 630 - 632 (2015)
The increasingly widespread applications of α,ω-dibromides motivated development of a scalable, inexpensive process to rapidly convert selected α,ω-alkanediols to the corresponding dibromides. Diols were heated with only 48% aq HBr and an organic solvent, using a Dean-Stark apparatus modified to fractionate the azeotropic distillate, thereby maintaining a higher HBr concentration and reaction rate in the pot. Intensified distillation also increased the reaction rate. Various other substrate, solvent, and parameter effects have been discovered and rationalized.
ANALYSE STRUCTURALE EN SERIE CYCLOBUTANIQUE. Partie 1. Derives monosubstitues et gem disubstitues du cyclobutane
Karimine, Mohamed,Galsomias, Jacqueline,Lere-Porte, Jean-Pierre,Petrissans, Jean
, p. 321 - 332 (1987)
Methylene bending mode analysis of some cyclobutane-d2 molecules reveals that in the dissolved state (solvent CCl4), bromocyclobutane occurs exclusively in a pseudo-equatorial form, whereas, under the same conditions, cyclobutanol and 1-bromocyclobutane carbonitrile exist both in pseudo-axial and pseudo-equatorial conformations.NMR spectroscopy confirms the results obtained for bromocyclobutane and leads to the conclusion that the pseudo-equatorial conformer is predominant in the case of cyclobutanol as well as in that of cyclobutane carbonitrile.A theoretical study of cyclobutanol in the gaseous state by the P.C.I.L.O. method gives results which are consistent with a pseudo-equatorial conformer.
Pulse Radiolysis Study on Radical Cations of Alkyl Bromides in Aqueous Solutions
Mohan, H.,Maity, D. K.,Mittal, J. P.
, p. 477 - 484 (1993)
The transient optical absorption bands formed on reaction of *OH radicals with 1,m-dibromoalkanes and n-alkyl bromides in acidic aqueous solutions have been assigned to intra-, , and inter-molecular, , radical cations, respectively.Depending upon R, these radical cations exhibit an optical absorption band in the 385-450 nm region.Increases in the chain length and electron-releasing power of R results in a red shift of λmax and a decrease in the lifetime.These radical cations are strong oxidants and oxidize various substrates with bimolecular rate constants of the order of 109 dm3 mol-1 s-1.
Method for preparing n-(γ(v)-bromoalkyl)phthalimides
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Page 3-4, (2008/06/13)
The invention concerns a procedure for preparation of N-(ω-bromoalkyl)phthalimides which consists of reacting potassium phthalimide with an α,ω-dibromoalkane without cosolvent, at a temperature from 50° C. to 130° C. by using a molar ratio of α,ω-dibromoalkane to potassium phthalimide from 2.5 to 6, then of removing excess α,ω-dibromoalkane, under reduced pressure at a temperature equal to 150° C. at most, of taking up the reaction medium again with a low boiling point alcohol at a temperature near that of the boiling point of said alcohol, of filtering at this temperature, of cooling the filtrate obtained and then of recovering the N-(ω-bromoalkyl)phthalimide.
Synthesis of 1,3-dibromopropane
Fel'dman, D. P.,Stonkus, V. V.,Shimanskaya, M. V.,Avot-s, A. A.
, p. 250 - 253 (2007/10/03)
A method for preparation of 1,3-dibromopropane from akrolein is proposed; it consists of alkylation of the starting compound, followed by catalytic reduction of the carbonyl group and bromination.
General Synthesis of Methyl- and Dimethyl-cyclobutanes from Simple 1,3-Diols by Phase Transfer Catalysis
Toeroek, Bela,Molnar, Arpad
, p. 801 - 804 (2007/10/02)
A general method is described for the preparation of methyl- and dimethyl-cyclobutanes from simple 1,3-diols.The key steps of the procedure are a phase transfer catalysed ring closure and the transformation of a carboxyl group to a methyl group.Phase transfer catalysis provides good yields in the synthesis of the cyclobutane skeleton.
Electron Spin Resonance Spectra and Structure of the Radical Cations of Dibromoalkanes and Monobromoalkanes
Hasegawa, Akinori,Symons, Martyn C. R.,Shiotani, Masaru
, p. 657 - 666 (2007/10/02)
The radical cations of dibromoalkanes containing two bromines separated by an alkyl chain, have been generated by exposing dilute solutions of the dibromoalkanes in freon to X-rays at 77 K.Two types of e.s.r. spectra were observed for these cations.The spectra obtained for Br(CH2)nBr, n = 1-7, show septet features characteristic of two equivalent Br nuclei.The coupling constant of the septet increases and reaches a plateau, with increased n in these dibromoalkanes.This indicates that a positive hole in these cations is shared, not by the two Br nuclei connected through ?-delocalization over the chain, but by the two Br nuclei directly bonded to each other, in accordance with conclusions recently drawn from e.s.r. studies of dichloroalkane cations.In contrast, the e.s.r. spectra obtained for Br(CH2)nBr, n > 7, are more complicated.When similar experiments were carried out with H(CH2)nBr, n > 7, analogous spectra were obtained, indicating that the spectra observed for these dibromoalkanes can be interpreted in terms of hyperfine interactions to only one of the two Br nuclei and to two nuclei with nuclear spins of 1/2.This result, considered together with the fact that similar cationic centres were detected for H(CH2)nBr, n > 3, and with the spectral change observed for Br(CH2)nBr and H(CH2)nBr cations in different matrices (CCl2FCClF2, CCl3F, and CCl4) indicates that cyclization also occurs for these cations, the positive hole being occupied in a three-centre bond comprising a Br nucleus, a C nucleus (four atoms away from the Br nucleus), and an H nucleus bonded to the C nucleus.
A CONVENIENT AND EFFICIENT METHOD FOR THE CONVERSION OF ALKYL CHLORIDES TO THE CORRESPONDING BROMIDES
Loupy, Andre,Pardo, Claude
, p. 1275 - 1282 (2007/10/02)
Reaction of representative alkyl chlorides (involving primary, secondary and tertiary substrates as also a dichloide) with stoechiometric amount of lithium bromide in the presence of a transfer agent (5percent Aliquat 336) without any added solvent, resulted in high conversions into the corresponding bromides under convenient and economical conditions.
SUBSTITUTED PHENOXY-AMINOPROPANOL DERIVATIVES
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, (2008/06/13)
Phenoxy-aminopropanol derivatives of the formula STR1 wherein R is lower alkyl, X is oxygen or sulfur, n is the integer zero or 1, Y is methylene, ethylene or propylene or, when n is zero, Y can also be a group of the formula EQU1 , wherein the double-bond is trans and the carbon atom marked with an asterisk is linked to Z, and Z is a 5-membered aromatic heterocyclic ring which contains one or more nitrogen atoms as the sole hetero atom (s), said heterocyclic ring is linked to Y via a nitrogen atom, and may be substituted by halogen, lower alkyl, lower alkoxy, aryl, cyano or carboxamido, or on adjacent carbon atoms by a group of the formula STR2 and pharmaceutically acceptable acid addition salts thereof are described. A process for the preparation of the compound of formula I and pharmaceutical preparations containing them are also described. The aforementioned compounds and salts possess β-adrenergic blocking activity and antihypertensive activity.
