Ra-Butyl bromide

The use of a modified sodium bromide-sulfuric acid method for the preparation of alkyl bromides is described in connection with the preparation of ra-butyl bromide. This method has been used also for the preparations of iso-amyl and trimethylene bromides, but, in general, the yields were found to be somewhat lower than those obtained with the hydrobromic-sulfuric acid method. 

Di-n-butyl ketone ra-Butyl bromide T ri-n-butyl earbinol 91... 

Cyclooctadiene (Aldrich Chemicals) was distilled from sodium and stored under argon. ra-Butyl bromide and 1.6 M ra-butyl lithium solution were purchased from Aldrich and used as received. Solvents used in the syntheses were dried with appropriate drying agents16 and freshly distilled under inert gas before use. All procedures are performed in an anhydrous, oxygen-free atmosphere using standard techniques for bench-top inert atmosphere reactions.17,18... 

FIG. 4 Viscosity curves for polyelectrolyte, 4-vinylpyridine/styrene copolymers quaternized with ra-butyl bromide, in nitromethane/dioxane mixture (numbers indicate weight ratio of nitromethane/dioxane). (From Ref. 16.)... 

Cathers GI, Fuoss RM. Polyelectrolytes. IV. Conductance of ra-butyl bromide addition compounds of 4-vinylpyridine-styrene copolymers in nitromethane-dioxane mixtures. J Polym Sci 1949 4 121-133. 

M-Butylbenzene has been prepared by the action of sodium (a) on benzyl chloride or bromide and w-propyl bromide without diluents,1 or (b) on n butyl bromide and bromobenzene without a solvent2 or in benzene 3 by a Clemmensen reduction of ra-butyr-ophenone 4 and by the action of benzylmagnesium chloride on M-propyl />-toluenesulfonate.5 Other procedures do not appear to be of preparative value. 

The residue from which no more alcohol can be distilled is treated with about 2 1. of water and shaken thoroughly. The upper layer of ra-butylmalonic ester is separated (Note 4) and distilled under diminished pressure from a 2- or a 3-I. Claisen flask. First a low-boiling portion is collected, consisting of alcohol, water, and butyl bromide then a small intermediate fraction of unchanged malonic ester comes over and finally w-butylmalonic ester boiling at i40-i45°/40 mm., i30-i35°/2o mm., and 235-24o°/76o mm. The first fractions amount to less than 100 cc., while the main fraction amounts to 860-970 g. (80-90 per cent of the theoretical amount). 

The Wittig reaction affords an invaluable method for the conversion of a carbonyl compound to an olefin, for example the conversion of benzalde-hyde and n-butyl bromide to a mixture of cis- and /ra/is-l-phenyl-2-n-propylethylene. 

As in organic chemistry where m values for bromides are rather lower than for chlorides, for example m — 0.92 for t-butyl bromide compared with m = 1.00 for t-butyl chloride, m values for cobalt(ra)-amine-bromide complexes are, at around 0.2, rather lower than for the analogous chlorides. Whereas in this work the effect of solvent structure on reaction rates has been used to gain further insight into reaction mechanisms, the opposite approach has also been used, in a study of aquation of tra/u-[Co(en)2Cl2]+ in alcohol-water mixtures, in which variation of rate with solvent composition has been used as a probe of solvent structure variation. Rates of aquation of both cis- and trans-[Co ea)2C have been determined in aqueous acetonitrile (0 < mole fraction MeCN < 0,104). For both complexes aquation rates decrease only slightly as the proportion of acetonitrile increases, with the cir-complex slightly more sensitive to solvent variation. The kinetic effects observed here are smaller than those observed in t-butyl alcohol-water solvent mixtures. ... 

In a detailed study of the reactions of MejSn with cis- or /ra/iy-4-t-butyl-cyclohexyl bromides in THF, mixtures of products were obtained with complete loss of stereochemical integrity at the carbon atom, thus implicating radical reactions (San Filippo Jr et al., 1978). Similar studies of MCjM" (M = Ge or Sn) with 4-alkylcyclohexyl bromides and the corresponding tosylates showed that the latter react with inversion of configuration, consistent with an 8, 2 mechanism, whereas the bromides react via a non-stereospecific process for which several possible pathways have been discussed (Kitching et al., 1978). 

Santos PS, Ando RA, Siqueira LJA, Bazito FC, Torresi RM (2007) The sulfur diojdde-l-butyl-3-methylimidazolium bromide interaction drastic changes in structural and physical properties. J Phys Chem B 111(30) 8717-8719. doi 10.1021/jp0743572... 

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