Octyl Bromide

In a 500 cc. round-bottom flask are placed 240 g. of hydro-bromic acid (48 per cent), 62 g. of concentrated sulfuric acid, and 71 g. of M-oclyl alcohol (b. p. 135-140° at 100 mm.). The mixture is boiled under reflux for three and a half hours. The solution is diluted with water and the bromide layer is separated, washed once with a little cold concentrated sulfuric acid, then with water and finally with dilute sodium carbonate solution, The crude yield is 102 g. this is dried over a little calcium chloride and distilled. The product is collected at iyh 200 and amounts to 96 g. (91 per cent theory). 

In a 5-I. round-bottom flask are placed 1200 g. of bromine and 1300 g. of crushed ice. The bromine is reduced with sulfur dioxide as already directed under (A) Hydrobromic Acid. In place of the above reduction mixture, there may be used a mixture of 2500 g. of aqueous 48 per cent hydrobromic acid and 750 g. of concentrated sulfuric acid. 

of trimethylene glycol (b. p. 210-215°) and 1200 g. of concentrated sulfuric acid are next added in the order given, the sulfuric acid being added slowly. The mixture is refluxed during a period of three hours and is then subjected to distillation until no water-insoluble product appears in the distillate (about one hour). 

The trimethylene bromide is purified as directed under w-Butyl Bromide. A yield of 1088 g. boiling at 162-165° (90 per cent theory) is obtained. In a number of experiments, the lowest yield obtained was 88 per cent, whereas the maximum obtained was 95 per cent. 

Sodium Bromide Method. The yields of trimethylene bromide by the sodium bromide method as described under w-Butyl Bromide are slightly lower than those given above. Thus, from I3S° S- °f water, 1545 g. of sodium bromide, 456 g. of trimethylene glycol, and 2500 g. of sulfuric acid, a yield of mo g. of crude product is obtained, from which, after purification and distillation, a yield of 1030 g. of bromide (85 per cent theory) is obtained. 

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R-Octyl bromide [111-83-1] M 193.1, b 201.5 , df 1.118, n 1.4503. Shaken with H2SO4, washed with water, dried with K2CO2 and fractionally distd. 

In place of K-octyl iodide other derivatives such as w-octyl bromide, n-octyl />-toluenesulfonate, and w-octyl chlorosulfonate can be substituted the submitter reports that the yields of octanal in these cases are comparable. 

Alkylation of several substituted benzoic acid salts with n-octyl bromide was performed under solvent-free PTC with excellent yields (95 %) within a very short reaction time [93] (2-7 min). Oil bath heating (A) led to yields equivalent to those produced under the action of microwave irradiation, which thus revealed only thermal effects in the range of temperature used (145-202 °C) (Eq. 39). 

Conversely, when n-octyl bromide was used with the less reactive terephthalate species, which constitutes a slow-reacting system , the yield was raised from 20 to 84% under the action of microwaves compared with A, which can be attributed to a later TS along the reaction coordinates (Eq. 40). 

The synthesis of octylthiocyanate by reaction of n-octyl bromide with KSCN, and its subsequent isomerization to isothiocyanate, have been realized by use of TBAB under the action of MW irradiation. The effect of inorganic solid supports was studied (Si02, K10, graphite, NaCl) (Eq. 64). 

Octyl bromide, b385 Octyl chloride, c204 Octyl cyanide, n95 Octyldimethylamine, d649 Octyl ether, d729 Octyl iodide, i44 Octyl sulfide, d730 Oleic acid, oil... 

This procedure illustrates a process which is general for 1,1-diphenyl substituted hydrocarbons. Diphenylmethane has been alkylated3 with benzyl chloride, benzhydryl chloride, a-phenyl-ethyl chloride, /3-phenylethyl chloride, isopropyl chloride, 2-ethylbutyl bromide, and re-octyl bromide in yields of 99, 96, 97, 88, 86, 96, and 99%, respectively. 

Octupolar materials, 17 453 Octyl bromide, physical properties of, 4 351t... 

A detailed study of the formation of n-octyl ethers under solidrliquid two-phase conditions in the absence of an added solvent has been reported [10], Potassium alkoxides tend to produce higher yields of the ethers than do the corresponding sodium derivatives, but octene is the major product in the reaction of 1-bromooctane with potassium t-butoxide. High temperatures also tend to promote the preferential formation of octene and slightly higher yields of the ethers are obtained using n-octyl tosylate in preference to n-octyl bromide. p-Fluorinated acetals have been prepared either under basic catalytic liquidrliquid or solidrliquid conditions from the fluori-nated alcohol and dichloromethane [11] with displacement of the fluorine atoms. 

The above considerations should bear some relationship with the stereochemistry of the reaction. As indicated earlier (8ection 2 Hebert et ai, 1985), in the reaction of anthracene anion radicals with optically active 2-octyl bromide, racemization is mostly observed together with a small but distinct amount (ca. 10%) of inversion. In the context of the ET-8n2 mixed mechanism sketched above, this can be rationalized in terms of a minor contribution of the latter pathway that would not detectably affect the overall rate constant of the reaction. The weakness of the bonded interactions in the transition state derives from the relatively poor affinity of the alkyl radical for the aromatic hydrocarbon. This is consistent with the fact that in those of the radical-anthracene pairs that were not favourably oriented for the 8, 2 reaction to occur, the alkyl radical escapes from the... 

Cyclohexyl xanthate has been used as a model compound for mechanistic studies [43]. From laser flash photolysis experiments the absolute rate constant of the reaction with (TMS)3Si has been measured (see Table 4.3). From a competition experiment between cyclohexyl xanthate and -octyl bromide, xanthate was ca 2 times more reactive than the primary alkyl bromide instead of ca 50 as expected from the rate constants reported in Tables 4.1 and 4.3. This result suggests that the addition of silyl radical to thiocarbonyl moiety is reversible. The mechanism of xanthate reduction is depicted in Scheme 4.3 (TMS)3Si radicals, initially generated by small amounts of AIBN, attack the thiocarbonyl moiety to form in a reversible manner a radical intermediate that undergoes (3-scission to form alkyl radicals. Hydrogen abstraction from the silane gives the alkane and (TMS)3Si radical, thus completing the cycle of this chain reaction. 

In a 50 ml flask fitted with a reflux condenser 5.5 g (0.0189 mol) of tributylstannane (tributyltin hydride) is added to 3.5g (0.018mol) of octyl bromide. An exothermic reaction ensues. Cooling is applied if the temperature rises above 50°. After 1 hour the mixture is distilled, giving 80% yield of octane and 90% yield of tributyltin bromide. 

The selective hthiation of 2-hexanone phenylaziridinyl-lEl-hydrazone 127 with LDA and subsequent alkylation with 8-(tert-butyldimethylsilyloxy)octyl bromide gave (Z)-hydrazone 128 in 65% yield. Its LDA-catalyzed selective decomposition followed by hydrolysis of the silyl ether yielded (Z)-9-tetradecen-l-ol, which was acetylated to afford the target compound 129 in 80% yield with a complete regioselectivity and a cisitrans ratio of 99.6/0.4. 

Fig. 1. Solubility of perfluorochemicals (PFCs) in water decreases rapidly with increasing molecular weight. The solubility of F-octyl bromide used in injectable oxygen carriers is 5x10- mol/l.

Fig. 2. (a) X-ray image of the bowels of an adult patient filled with F-octyl bromide (the bromine atom makes the compound radioopaque, hence clear on the radiograph). Courtesy Alliance Pharmaceutical Corporation (b) Lungs of an infant patient filled with the same material. From Ref. [17], with permission. 

Fig. 4. Synthesis of F-octyl bromide by bromination of F-octyl iodide produced by telo-merization of tetrafiuoroethyiene, the monomer of Teflon . F-octyl iodide is the precursor of numerous fiuorosurfactants.

Fig. 5. Intravascular half-life U/2 of an emulsion of F-octyl bromide Oxygent AF0144) in humans as a function of dose administered.

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