Dodecyl bromide

Submitted by E. Emmet Reid, John R. Ruhoei, and Robert E. Burnett. 

In order to obtain more efficient absorption of the hydrogen bromide, a small bulb is blown on the end of the inlet tube, and a number of pin holes are made in it by means of a small, white-hot tungsten wire. 

The dodecyl alcohol used was obtained by the fractionation of Lorol its boiling point was ig2.5 ig3.5°/ioo mm- or 15 i-i 52°/21 mm. If the alcohol is not of good quality, the yield is somewhat lower. It may also be prepared according to the procedure given in Org. Syn. xo, 62. 

The hydrogen bromide is conveniently prepared by the direct combination of hydrogen and bromine (p. 35). An excess of hydrogen is to be avoided since it causes loss of product by volatilization. 

The heat of the reaction maintains the alcohol at this temperature until the preparation is nearly completed. 

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Primary halides are more reactive than secondary compounds quaternary salt formation does not occur with tertiary halides, elimination always occurring to give the hydriodide and an olefln, Also, the larger the alkyl group the slower is the reaction this is shown by the very slow reaction of dodecyl bromide with quinoline, and even butyl iodide is much slower to react than methyl iodide. The longer chain primary halides commonly undergo elimination rather than cause quaternization for example, n-octyl and cetyl iodides give only the hydriodides when heated with 9-aminoacridine. ... 

S,N-Ditrityl-L-cysteine diethylamine salt Oxytocin Dodecyl bromide... 

The pioneering work on amphiphilic polyelectrolytes goes back to 1951, when Strauss et al. [25] first synthesized amphiphilic polycations by quaternization of poly(2-vinylpyridine) with n-dodecyl bromide. They revealed that the long alkyl side chains attached to partially quaternized poly(vinylpyridine)s tended to aggregate in aqueous solution so that the polymers assumed a compact conformation when the mole fraction of the hydrophobic side chains exceeded a certain critical value. Thus, Strauss et al. became the first to show experimentally the intramolecular micellation of amphiphilic polymers and the existence of a critical content of hydrophobic residues which may be compared to the critical micelle concentration of ordinary surfactants. They called such amphiphilic polyelectrolytes polysoaps [25],... 

Cordes et al995 carried out alkaline hydrolyses of p-nitrophenylhexanoate 55 (PNPH) in the presence of poly-4-vinylpyridine partially quaternized with dodecyl-bromide and ethylbromide (QPVP). They also found that the polyelectrolytes are increasingly effective as catalysts with an increasing ratio of dodecyl to ethyl groups, and the hydrophobic interactions are important in determining the catalytic efficiency. They observed the inhibitory effects of several gegen-anions fluoride ions are the weakest inhibitor, and nitrate is the strongest (F- < Cl < S04 [Pg.159]

N-dodecyl 3-carbamoyl pyridinium bromide (I) was prepared from vacuum-distilled n-dodecyl bromide (K K) and nicotinamide (Kodak) according to a published procedure (15) and identified... 

Method OP Neat n-dodecylphenyltellurium dibromide (0.53 g, 1.0 mmol) is heated at 230-250°C at 3 torr using a Kiigelrohr distillation apparatus. A colourless liquid distills which is identical to n-dodecyl bromide ( H NMR and GLC analysis) [0.25 g, (90%)]. (A red-brown residue seems to be mainly PhTeBr and on standing exposed to the ambient atmosphere solidifies to a grey solid PhTe(0)Br and the starting dibromide by IR and combustion analytical data.)... 

Disulphides, 1078 dialkyl, 496, 498 Dithizone, 955 Di-p-tolyl ketone, 930, 931 Dixon gauze rings, 97 n-Dodecane, 237 n-Dodecyl bromide, 282 n-Dodecyl chloride, 275 n-Dodecyl p-toluenesuiphonate, 825 Doebner reaction, 463, 465, 710, 711, 719... 

A mixture of 125 g. (0.5 mole) of w-dodecyl bromide (Note 1), 38 g. (0.5 mole) of thiourea, and 250 cc. of 95 per cent ethyl alcohol is refluxed on a steam cone for three hours (Notes 2, 3, and 4). A solution of 30 g. (0.75 mole) of sodium hydroxide in 300 cc. of water is added, and the mixture is refluxed for two hours. During this period the mercaptan separates as a pink to red oil. The layers are separated, and the aqueous layer is acidified with dilute sulfuric acid (7 cc. of concentrated acid to 50 cc. of water) and then extracted with one 75-cc. portion of benzene (Note 5). The extract is added to the crude mercaptan layer, and the whole is washed twice with 200-cc. portions of water and... 

An interesting class of polyeleclrolytes, denoted by polysoaps, is obtained by attaching soap-like molecules to the polymer chain. Such a polysoap is for instance produced by the quaternization of polyvinyl-pyridine with /r-dodecyl bromide. The polysoap molecules differ from ordinary poly electrolytes in that they may reach protein-like compactness in solution. They behave like prefabricated soap micelles and solubilize hydrocarbons and other compounds insoluble in water,... 

Hydroxypyridines are readily alkylated under a variety of conditions. Mitsunobu reaction with alcohols occurs selectively at oxygen in the presence of PPh3 and DEAD in THF at room temperature <2003TL725>. The 3-hydroxy group may be selectively alkylated in the presence of aliphatic hydroxyl groups. Pyridine 104 is alkylated at the aromatic position with dodecyl bromide in the presence of potassium carbonate in DMF at 95 °C <20030BC644> (Equation 70). 

The use of methyl alcohol prevents, to a large extent, the formation of troublesome emulsions. Less than 0.1 g. of dodecyl bromide dissolves in 100 cc. of 50 per cent methyl alcohol at room temperature. 

The above method for preparing w-dodecyl bromide is an adaptation of that of Ruzicka1 and has been published recently.2 It is thought to present some advantages in ease of manipulation and quality of product over the older method involving the action of aqueous hydrobromic acid on the alcohol in the presence of sulfuric acid.3... 

Almost three decades ago, Strauss and co-workers 18) carried out classic work on polysoaps (23) comprised of poly-4-vinylpyridine which had been quatemized on up to 38 % of the nitrogens with n-dodecyl bromide those nitrogens that escaped reaction with n-dodecyl bromide were then derivatized with ethyl bromide. Now addition of KBr to an aqueous solution of a polyelectrolyte normally decreases the viscosity. This is not true for the 38 % polysoap (23) where the viscosity increases with... 

Decomposition of Dodecyl Phenyl Tellurium Dibromide under Vacuum1 0.53 g (1.0 mol) of dodecyl phenyl tellurium dibromidc is placed in a Kugelrohr distillation apparatus and is heated at 230—250°/3 torr. The colorless liquid distillate is dodecyl bromide yield 0.25 g (90%). 

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