Octadecyl bromide

Octadecyl bromide, b384 Octadecyl iodide, i43 Octadecyl mercaptan, o4... 

Octadecyl bromide, b319 Oxtadecyl mercaptan, o4 2,3,4,6,7,8,9,10-Octahydropyrimido... 

Bromides. dodecyl Bromide and Chloro-phenyl)octadecyl Bromide. Conversion of the alcohol to the corresponding bromide is accomplished by Collins method (3). The respective bromides are purified by distillation in 84% yield, and by recrystallization from alcohol in 78% yield. 

Contaminants may arise from impure starting materials, incomplete reactions and secondary reaction products. A knowledge of these factors serves to limit the list of probable contaminants to a small number. Tentative identifications of some of the contaminants shown as minor peaks in the chromatograms were assigned by matching their retention times (or retention temperatures) with those of probable contaminants. In the case of the six carboxylic acids of Table II, the contaminants are known to be carboxylic acids, since the method of purification involves repeated precipitations as the ammonium salts. The tridecanedioc acid observed in the octadecanedioc acid (compound 10 of Table IV) is considered the source of the lower homolog impurity to-(p-chlorophenyl)-octadecyl bromide (compound 6 of Table IV). 

Octadecylmethyl sulfoxide (OMS) was prepared in the following manner 15 g of octadecyl bromide and 3.5 g of thiourea were dissolved in 150 cm3 of ethanol. The mixture was refluxed for 1 hr after which 100 cm3 of ethanol were removed by distillation. The residue, after cooling, was made alkaline by an ethanol/sodium hydroxide solution (5 g sodium hydroxide in a minimum volume of ethanol). Methyl iodide, 3.7 g, was then added, and the mixture was left to stand overnight. The resulting thioether was recovered by filtration and washed with cold ethanol. The thioether was dissolved in glacial acetic acid then small quantities of 20 vol % hydrogen peroxide, constituting the stoichiometric amount, were added over several hours. The product was precipitated with water, and the precipitate was collected by filtration. The crude product was washed successively with water, ice-cold ethanol, and a small quantity of diethyl ether it was finally dried at 70°C. OMS was purified by successive recrystallization from benzene purification was... 

The synthesis of required imidazolium salt l-decyl-2-methyl-3-octadecylimidazolium bromide was achieved by the reaction of l-decyl-2-methylimidazole with octadecyl bromide in ethyl acetate [32]. The contents were first stirred at room temperature for 2 h under nitrogen followed by the increasing of the temperature to 55°C overnight. A white precipitate of imidazolium salt was obtained on cooling, which was filtered, washed extensively with ethyl acetate, and dried at room temperature under reduced pressure. Figure 10.1 shows the chemical structure of the imidazolium salt. 

Preparation by partial alkylation of resacetophe-none with octadecyl bromide in the presence of potassium carbonate in refluxing acetone for 20 h [3493],... 

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