Extractable organic halide

TOX, EOX, AOX, and POX were determined in hospital waste sludge138 treated with 400 pg g 1 of hypochlorite. Ethanol is a solvent commonly used for extracting organic halides from sludge, but its extraction efficiency proved to be poor. 

Finally, the sum of those organic halides that are extracted from solids is defined as extractable organic halide (BOX) [154]. EOXs containing chlorine, bromine, or iodine are... 

The pulp and paper industry is the largest industrial process water user in the U.S.5 In 2000, a typical pulp and paper mill used between 15,140 and 45,420 L (4000 to 12,000 gal) of water per ton of pulp produced. 1 2 3 4 General water pollution concerns for pulp and paper mills are effluent solids, biochemical oxygen demand (BOD), and color. Toxicity concerns historically occurred from the potential presence of chlorinated organic compounds such as dioxins, furans, and others (collectively referred to as adsorbable organic halides, or AOX) in wastewaters after the chlorination/ extraction sequence. With the substitution of chlorine dioxide for chlorine, discharges of the chlorinated compounds have decreased dramatically. 

One can set up to do this using the competition between dimerization and halogen atom abstraction from RX to form the rhodium(III) halide complex. As a function of [RX], the product ratio is quite easily evaluated. From that, one can get the rate constant ratio but, knowing independently the rate constant for dimerization, it is possible to extract from those data rate constants for reactions of the rhodium(II) complex with these organic halides. The rate constants obtained are listed in Table I. 

Organic halides from organotellurium(IV) halides (typical procedures). Method To 1-chlorocyclohexyltellurium trichloride (0.35 g, 1.0 mmol) in dioxane (5 mL) is added f-BuOOH (70%, 0.26 g, 2.0 mmol) and the mixture stirred under reflux for 30 min, during which period a pale yellow solid precipitates. After cooling at room temperature, the precipitate is filtered off, and the filtrate poured into brine and then extracted with ether (3x30 mL). The ether extract is dried (MgS04), and GLC analysis reveals the presence of 1,2-dichlorocyclohexane (0.14 g (92%), cisitrans = 7 93) (using phenyl acetate as the internal standard). 

Organic halides are often excellent solvents and are particularly useful for recrystaUization and extraction. Methylene chloride (bp 41°) has solvent characteristics similar to those of ether and is heavier than water. The commercial material is satisfactory for most purposes, and if purification is desired, it may be washed with concentrated sulfuric acid and with water and then dried and distilled. Ethylene dichloride (bp 84°) is similar to methylene chloride in its solvent properties and may be purified in the same fashion. 

Ryu, Curran and their co-workers have achieved the fluorous hydroxymethyla-tion of organic halides using a catalytic quantity of a fluorous tin hydride [8] in the presence of sodium cyanoborohydride [10]. Interestingly, this fluorous reagent, as is usually the case for the related fluorous reactions [18], permits simple purification by a three-phase (aqueous/organic/fluorous) extractive workup. An example is given in Scheme 4-5. It should be noted that, unlike the cyclization-for-mylation sequence shown in the fourth equation in Scheme 4-3, the cyclization-hydroxymethylation sequence of the same substrate using a catalytic system was... 

The 17e metal-based radical Ta 3(CO)4(dppe) was formed via hydrogen atom extraction from TaIH(CO)4(dppe).659 In solution, this radical abstacted halogen atoms from many organic halides RX to give TaIX(CO)4(dppe). Ta°(CO)4(dppe) existed in solution as an equilibrium mixture of monomer and dimer [(dppe)(CO)3Ta](/i2-CO)2. The latter is the form stable in the solid state. While no crystal structures are available, DFT calculations indicated a stable pseudo-octahedral stereochemistry for the monomer and several possible (/i2-CO)2 structures for the dimer.656 Each of the latter featured linear, semi-bridging carbonyls supporting a weak, delocalized Ta—Ta interaction. 

A large number of fluorous tin reagents for use in palladium-catalyzed Stille cross-coupling reactions with organic halides or triflates have been developed. Reaction times can be reduced to just a few minutes when conducted with microwave heating. Three-phase extraction between water (top), dichloromethane (middle), and perfluorohexanes (FC-72) (bottom) allow the coupled product to be isolated from the dichloromethane and the resulting fluorinated tin chloride to be recovered from the FC-72 phase and recycled (Scheme 5.8.8). 

To an ice cold mixture of the organic halide (3 mmol) and carbon disulfide (6 mmol) in a test tube was added amine (6 mmol) and the mixture was stirred at 0 °C for 30 min, then warmed to room temperature where stirring was continued until the reaction was complete (reaction mixture solidified or monitored by TLC). The reaction was quenched by addition of water and was extracted with EtOAc, dried over anhydrous Na2S04, and evaporated to give NMR pure product. Further purification in some cases could be achieved by silica gel column chromatography eluted with petroleum ether and ethyl acetate or recrystallization to afford the pure dithiocarbamate. 

D.iii.a. Standard Phosphine-Assisted Protocol. The process is done with palladium complexes with hydrophobic phosphine ligands and aqueous solution or a slurry of inorganic base in a biphasic system in which benzene or toluene is the most frequently used solvent. Therefore, it is evident that the process should involve phase transfer, because the precatalyst and organic halide reside in the organic phase, while boronate must be extracted to the aqueous phase. The most probable answer to the question of how the... 

Most of the studies have been carried out in nonaqueous solvents, mainly because of the highest potential window available and because of the very low solubility of most organic halides in water. Even if, as a first consideration, the use of organic solvents is not encouraged at industrial scale, one of the possible strategies for the effective dechlorination of wastewaters is represented by reductive treatments in organic media following extraction of the pollutants from the refluence (by solvent extraction or by adsorption on a specific solid filter) [14]. 

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