Extraction aliquat

Certain long-chain alkylammonium salts, notably tricaprylmethyl-ammonium chloride (Aliquat 336-S) and tri-Ao-octylamine hydrochloride (TIOA) are liquids, sometimes referred to as liquid anion exchangers, which can form extractable ion pairs or aggregates with anionic metal complexes in the... 

EDTA complexes of trivalent metals can be extracted successively with liquid anion exchangers such as Aliquat 336-S by careful pH control. Mixtures of lanthanides can be separated by exploiting differences in their EDTA complex formation constants. 

Lower molecular-weight quaternary ammonium halides, which partition across the two-phase system, transfer anions in measurable concentrations from the aqueous to the organic phase but, in contrast, many of the higher-molecular-weight quaternary ammonium halides with more than ca. 30 carbon atoms are virtually insoluble in aqueous media and their partition coefficients between aqueous and organic phases preclude the transfer of anions efficiently across the interface by the extraction process and yet catalysts, such as Aliquat 336 and Adogen 464, are extremely effective catalysts. 

The alkyl methanesulphonate (50 mmol), the appropriate potassium halide (50 mmol) and Aliquat (ll.27 g, 2.5 mmol) in H20 (5 ml) are stirred at ca. 100°C. The aqueous phase is separated and extracted with n-C,HI2 (50 ml). The combined organic solutions are washed sequentially with H20, cone. H2S04, and H20, dried (CaCl2), and fractionally distilled to yield the haloalkane [e.g. n-C8H,7CI (74%) from n-C8Hn0S02Me after 90 min n-C8HI7Br (73%) after 30 min n-C8H,7I (70%) after 20 min]. 

Method B from 1,3-benzoxathiol-2-ones NaHCO, (12.6 g, 0.15 mol) and Aliquat (1.5 g, 3.7 mmol) in H20 (35 ml) are added to the l,3-benzoxathio -2-one (0.05 mol) in CH2Br2(10 ml) and the mixture is refluxed for 3 h. Excess CH,Br2 (ca. 8 ml) is then allowed to distil and the reaction temperature is raised to ca. 100°C and maintained at this temperature until TLC analysis shows complete disappearance of the benzoxathi-olone. The reaction mixture is extracted with Et20 (2 x 25 ml) and the ethereal extracts... 

The amine or amide (50 mmol) and Aliquat (0.81 g, 2 mmol) in PhMe (20 ml) are stirred at 70-90 °C and diketene (6.73 g, 80 mmol) is added dropwise. The mixture is stirred for 8-10 h and then cooled, filtered, and evaporated. The residue is extracted with Et20 (3 x 25 ml) and the extracts are evaporated to yield the acetoacetylated product... 

Method B The heterocycle (8.5 mmol), K2C03 (1.2 g), powdered KOH (0.6 g) and TEBA-C1 or Aliquat (0.18 g, ca. 0.4 mmol) in CH,C12 (25 ml) are stirred under reflux for 6-8 h. The cooled mixture is filtered and the solid residue is extracted with hot CHjClj (2 X 100 ml). The combined organic solutions are evaporated to yield the A-alkyl derivative. 

Method E The imine (1 mmol), Aliquat (20 mg, 0.05 mmol), the alkylating agent (1.5 mmol), and powdered KOH (0.3 g) are intimately mixed at room temperature. The mixture is extracted with CH2C12 (10 ml) and the extract is filtered through silica and evaporated to yield the monoalkylated product. 

The a,P-unsaturated ketone (10 mmol) is stirred with the nitroalkane (40 mmol), K,CO, (0.7 g) and Aliquat (40 mg, 0.1 mmol) and the mixture is subjected to sonication at room temperature until the reaction is complete, as shown by GLC. The mixture is acidified with HC1 (1M) and extracted with Et20 (3 x 20 ml). The dried (MgS04) extracts are evaporated to yield the nitro ketone (>70%). 

Aqueous NaOH (4%, 4 ml) is added to the 3-acylcoumarin (l mmol), phenacyl bromide (0.2 g, 1 mmol) and Aliquat (10 mg, 0.02 mmol) in PhH (4 ml) at 25 °C and the mixture is stirred for 30 min and then poured into ice/H20 (50 ml). The aqueous mixture is neutralized with cone. HC1 and extracted with CHC1, (3 x 20 ml). The extracts are washed with H20, aqueous Na2C03 (sat. soln.), and H20, dried (Na2S04), and evaporated to yield the bicyclo[4.10]heptane derivative. 

Method B (liquiddiquid conditions) PhSeCHCl2 (0.24 g, 1 mmol), the organic substrate (1.25 mmol), Aliquat (8.1 mg, 0.02 mmol) and aqueous NaOH (50%, 1.5 ml) are sonicated for 90 min at room temperature. H20 (30 ml) is added and the aqueous mixture is extracted with CH2C 2 (3 x 20 ml). The combined extracts are dried (MgS04) and evaporated to yield the product. 

Aqueous NaOH (50%, 5 ml) is added dropwise over 1 h at -10 to -5°C to the appropriate l-((V-acetyl-/V-nitrosoaminomethyl)cycloalkan-l-ol, obtained by nitrosation of the 1 -(/V-acetylaminomethyl)cycloalkan-1 -ol (8.55 g, 50 mmol) with NOC1 [30], and Aliquat (2.3 g, 10 mmol) in the reactive substrate (100 ml). When the theoretical amount of N2 has been collected, the mixture is warmed to room temperature for 15 min and then diluted with brine (100 ml) and extracted with Et20 (4 x 30 ml). The ethereal extracts are dried (Na2S04) and fractionally distilled to yield the insertion adduct. 

The 2-bromoacetal (0.1 mol), prepared by the Dowex X8 (H+)-catalysed reaction of the diol with l-bromo-2,2-dimethoxyethane, is added to r-BuOK (16.8 g) and Aliquat (0.81 g, 2 mmol) in THF (150 ml) and the mixture is stirred at 80-90°C until the reaction is complete (2-4 h). n-C5H12 (4 x 200 ml) is added portionwise, with stirring after each addition, and the reaction mixture is then filtered through alumina. The filtrate is concentrated, H20 (5.5 ml) and AcOH (ca. 0.2 ml) are added to the residue, and the solution stirred at room temperature for 3 min. The aqueous mixture is extracted with Et20 (3 x 20 ml) and the extracts are dried (Na2S04) and evaporated to yield the diol half ester [e.g. AcO(CH2)2OH, 70% AcO(CH2),OH, 85% MeCH(OH)(CH2)2OAc, 80% MeCH(OAc)CH2CMe2OH, 85%]. 

Method B (solid liquid systems) The ester (10 mmol) is shaken with powdered KOH (2.8 g, 50 mmol) and Aliquat (0.48 g, l mmol) for 5 min at room temperature and then left at 85°C until TLC analysis shows the hydrolysis to be complete. The mixture is acidified with aqueous HCl and the acid (>90%) is collected (if solid) or extracted with Et20 or CH2Cl2 (if a liquid). 

Powdered KMn04 (1.2 mol) is added portionwise at <30°C over 2 h to the alkene (0.03 mol) and Aliquat (0.2 g, 0.5 mmol) in CH2C12 (n-C5H 2 or PhH) (100 ml) and AcOH (30 ml). The mixture is stirred at room temperature for 12 h and aqueous NaHSO, (5%, 100 ml) is then added. The aqueous phase is separated, acidified with concentrated HC1, and the carboxylic acid is collected (if it has precipitated), or the acidic solution is saturated with NaCI and extracted with Et20 (2x10 ml). Evaporation of the ethereal extracts yields the water-soluble carboxylic acid. 

Fig. 11.19 Distribution coefficients for lanthanide extraction with Aliquat 336 from nitrate (solid squares) and thiocyanate (solid circles) media. (From Ref. 1.)... 

Other applications of supported liquid membranes have been related to metal speciation. For example, recently a system for chromium speciation has been developed based on the selective extraction and enrichment of anionic Cr(VI) and cationic Cr(III) species in two SLM units connected in series. Aliquat 336 and DEHPA were used respectively as carriers for the two species and graphite furnace atomic absorption spectrometry used for final metal determination. With this process, it was possible to determine chromium in its different oxidation states [103]. 

Keywords. Cephalosporin antibiotics. Liquid membrane, Reactive extraction. Liquid-liquid ion extraction, Aliquat-336, HoUow-fiber membrane... 

The extraction of the Group IIB metals from aqueous solution is of obvious commercial importance and continues to be investigated.996-1000 The precise species which is extracted depends on the pH, but both Aliquat 336 and tri-n-butyl phosphate extract [ZnCl3]- from LiQ solution and [ZnCl4]2- from acidic media. 

The interaction of metallochromic indicators (Section 10.6.4) with metals has received a lot of attention since the resulting complexes are often solvent extractable. C. Woodward and H. Freiser73 have examined complexes of metals with sulfonated azo dyes with a view to their extraction by Aliquat-336. Vanadium in sea water can be determined at the 2 p.p.b. level by complexation with PAR (4-(2-pyridylazo)resorcinol) in the presence of CDTA and extracting the anion so formed into Zephiramine (tetradecyldimethylbenzylammonium chloride).74 The field has been reviewed up to 1971 by Ueno.2... 

In solvent extraction studies of various anions using Aliquat 336S, values of Kgx were obtained that showed a one-to-one correspondence between Kgj and electrode selectivity coefficients,... 

The so-called "trapped sites" of classical mobile-site, liquid ion exchanger electrodes belong to a category of compounds known as ion association extractants. Examples are long-chain diesters of phosphoric acid and tricaprylylmethylammonium (Aliquat) ions. The latter cation was studied extensively by Freiser and co-workers (1-3 ) in the design of anion sensors. 

Landgren, A. Liljenzin, J.O. Extraction behaviour of technetium and actinides in the aliquat-336/nitric acid system, Solvent Extr. Ion Exch. 17 (1999) 1387-1401. 

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