F-octyl bromide

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.

Keywords /f-octyl bromide, benzoic acid, Aliquat 336, microwave irradiation, //-octyl benzoate... 

A candidate PFC was eventually identified that had a shorter organ-retention time than would have been predicted on the sole basis of its MW and was amenable to producing stable emulsions. This PFC was 1-n-F-octyl bromide (PFOB, 1). PFOB had initially been investigated because the radiopacity provided by its bromine atom allowed its use as a contrast agent. ... 

Table 3 Physical properties of F-octyl bromide (PFOB, 1) and F-decalin (FDC, 6)...

CsF added to tetra- -butylammonium bromide or Aliquat 336, the mixture stirred for 5 min, n-octyl bromide added, stirring continued for 5 min, and allowed to react for 40 h - n-octyl fluoride. Y 77%. Work-up is easy and reagents readily available yields are high from satd. chlorides and bromides (incl. benzylic), but aromatic bromides were more resistant. F.e. and with tetra-n-butylammonium fluoride, also from tosyla-tes, and comparison with other heterogeneous methods s. G. Bram et al., Synth. Commun. 18, 1661-7 (1988) review of solid-liq. phase transfer catalysis without solvent s. Bull. Soc. Chim. France 1989, 247-51. 

For the F-66E/PFHB emulsion, Tcr was estimated to be about 12 min, in close agreement with the rapid mass transfer observed experimentally. Excellent agreement with experiment was also observed for the molecular diffusion of perfluoro-octyl bromide (Tcr 3 h), hexadecane (rcR 520 h), and the absence of ripening observed for triolein (Tcr w 4 years) emulsions. 

A mixture of (R)-2-octyl methanesulfonate, KCI, Iricaprylmethylammonium diloride, and water stirred and heated 1.5 hrs. at 100° (+)-(S)-2-dilorooctane. Y 74% optical purity 89.2%. Also bromides and fluorides, iodides with race-mization, and f. phase transfer catalysts, s. D. Landini, S. Quid, and F. Rolla, Synthesis 1975, 430 phase transfer catalysis, review, s. M. M kosza, Pure Appl. Chem. 43, 439 (1975). 

Sodium telluride and ditelluride are readily generated in situ from Te by reduction with thiourea dioxide, and subsequent treatment with alkyl halide provides the corresponding dialkyl tellurides and ditellurides. E Thiourea dioxide and NaOH in 1 1 water/THF added to Te under N2, the mixture refluxed for 1 h, n-octyl halide and a little cetyltrimethylammonium bromide in THF added, and refluxing continued for 1 h - dioctyl telluride. Y 85%. The method is cheap, simple and does not require very dry conditions. F.e. and sym. ditellurides s. J.T.B. Ferreira et al., Synth. Commun. 19, 239-44 (1989) prepn. of Na2Te from ultra-pure Te-ingots/Na-naphthalenide, or from Te/Na and a little naphthalene, s. K.T. Higa, D.C. Harris, Organometallics 8, 1674-8 (1989). 

Depending of R substituent (methyl, ethyl, CH2CH2CI, Butyl, f-butyl, octyl), this reaction can take between 30 min. and 3 h under ultrasonic activation instead of 24h. by eating at 50°C. The N-alkylation is easy with bromide derivatives but far less with chlorides ones. So far, we realized nucleophilic substitution with 3-bromopropanol, and other radicals are imder study. 

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