Brine extraction

The Step 1 product (93 mmol) was suspended in 200 ml methyl alcohol and treated with 46 ml 6 M HC1 and 10% palladium on carbon (1.6 g), and then shaken 16 hours under 25psi hydrogen. The mixture was filtered through celite, then concentrated, and a white gum isolated. The residue was treated with 50 ml apiece 2 M NaOH and CHClj and then stirred 60 minutes. The aqueous phase was retreated with 5 ml 2M NaOH to pH 10 and then washed with 25 ml brine, extracted three times with 10 ml CHClj, dried with MgS04, and concentrated. The residue was dissolved in 320 ml warm diethyl ether and cooled to 4°C. A white solid was isolated by filtration, which was washed with a small portion of cold diethyl ether, and then air dried. A second product crop of 8 g was obtained by reducing the filtrate volume by 90%, so a total product yield of 79% was obtained. 

The product from Step 2 (1.49 mmol) was dissolved in 20 ml THE, 4ml IM NH4OH added, and the mixture stirred 6 hours at ambient temperature. Thereafter, it is poured into 200 ml brine, extracted twice with 100 ml EtOAc, washed, dried and concentrated. The residue was purified by flash chromatography using hexane/ethyl acetate, 9 1, and the product isolated as an orange resin having a keto-enol equilibrium of 3 1, respectively. 

A suitably thick salt layer is located at sufficient depth below the surface. This layer is drilled and water injected and brine extracted which excavates a cavern. Several stages are usually involved. Sometimes this brine is used for caustic-chlorine production. 

To a solution of (l/ )-[la,3a/f,4a,7aa]-4-(tm-butyldiiTiethylsiloxy)-7a-niethyl-l-[l-meth>l-2-(irimeihyl-siloxy)vinyl]hexahydroindane (14) (15.0 g, 38 mmol) in CHjClj was slowly added a solution of /V-fluoro-bis(phcnylsulfonyl)amine (26.0 g, 82 mmol) in CHjCl (250 niL) at 5 C. After stirring overnight at 25 C, the mixture was quenched with brine, extracted with EtOAc, washed with dil HCl and then brine, dried (Na SO ) and concentrated under reduced pressure. Chromatography (silica gel. EtOAc/hexaiies) gave 15 yield 5.93g (47%) (S-isoiner 30% and fJ-isomer 17%). 

SQM, as Eoote, initially selected a brine extraction location for its well field where the brine had the maximum potassium and the least sulfate for potash and lithium production, and later a location with the maximum sulfate content for potassium sulfate production (Fig. 1.57). Because of this the plants could initially use the simplest processes and have the lowest capital and operating costs. In the initial operation brine with up to 3400 ppm Li was pumped from the Salar in 40 wells, 28 m deep on a 200-500 m grid, which delivered up to 5280 m /hr of brine to the solar ponds. There were also 13 monitoring wells to follow any changes in the brine concentration and its depth from the surface. The ponds were lined with flexible PVC or reinforced hypalon membranes, and the brine flowed through the sections of the pond system in series. The initial salt ponds had an area of 1.16 million m followed by 3.36 million m for the sylvinite ponds, and later 1 million m of ponds were installed for lithium production. The plant employed 184 people, of which 120 were hired from the sparsely populated local area. Contractors were used to drill and maintain the weUs, harvest the salts, transport them to their respective stockpiles, and reclaim the sylvinite to feed the potash plant s conveyor belt. They also provided all of the miscellaneous trucking needed at the Salar, and transported the potash to Coya Sur or Maria Elena and the concentrated lithium chloride brine to the Salar de Carmen. SQM unloaded the brine and potash, and stacked the later material at its nitrate plants (Harben and Edwards, 1997). 

A member of the halogen group of elements, it is obtained from natural brines from wells in Michigan and Arkansas. Little bromine is extracted today from seawater, which contains only about 85 ppm. 

In a lOOmL round-bottomed flask fitted with a magnetic stirrer is placed a mixture of palladium (II) chloride (89mg, O.Smmol), p-benzoquinone (5.94g, 55mmol) and 7 1 dimethylformamide/water (20mL). To the solution, t-decene [substitute safrole for this compound) (7.0g, 50mmc4) is added in 10 min and the mixture is stirred at room temperature for 7h. The solution is poured into cold 3 normal hydrochloric acid (lOOmL) and extracted with 5 portions of ether. The extracts are combined and washed with three portions of 10% aqueous sodium hydroxide solution and a portion of brine, and then dried After removal of the solvent, the residue is distilled to give 2-decanone [P2P] yield 6.1g (78%). 

Bromo-2-nitrophenylacetic acid (26 g, 0.10 mol) was dissolved in a mixture of 50% HjSO (400 ml) and ethanol (600 ml) and heated to 90°C. Over a period of 1 h, zinc dust (26.2 g, 0.40 mol) was added. slowly and then heating was continued for 2 h. The excess ethanol was removed by distillation. The solution was cooled and filtered. The filtrate was extracted with EtOAc. The filtered product and extract were combined, washed with 5% NaCOj and brine and then dried (MgSO ). The solvent was removed in vacuo and the residue recrystallized from methanol to give 20.5 g (97% yield) of the oxindole. 

A solution of At-(tcrt-butoxycarbonyl)-6-methoxy-2-methylaniline (11.9 g, 50 mmol) was cooled to — 40°C and s-BuLi (96 ml of 1.3 M in cyclohexane. 125mmol) was added. The mixture was stirred at —45°C to —55°Cfor 30min and then allowed to warm slowly to — 15"C over 60 min. The yellow solution was recooled to —45 C and DMF (5.8 ml, 75 mmol) was added. After 5 min the reaction mixture was diluted with water (250 ml) and the product was extracted with EtOAc (2 x 150 ml). The extract was washed with w ater (200ml) and then concentrated in vacuo. The residue was dissolved in THF (100 ml) and 12 N HCl (2 ml) was added. The solution was stirred for 5 min at room temperature and then diluted with ether (250 ml). The solution was washed with water (250 ml), sat. aq. NaHCOj (250 ml), and brine (250 ml), dried (Na2S04) and evaporated. The product was purified by chromatography using 2% EtOAc in hexane for elution. The yield (9.3 g) was 75%. 

Phenyl-3-oxopropanoic acid (25 mmol) and EtjN (87.5 mmol) were dissolved in THF (150 ml) and cooled to —40°C. Ethyl chloroformate (27.5 mmol) was added dropwise to this solution and then the reaction mixture was stirred for 30 min at —20°C. Di-n-hexylamine (27.5 mmol) was added to the suspension and it was stirred at room temperature for an additional hour. The reaction mixture was diluted with water (100 ml) and extracted with ether (400 ml). The extract was washed with aq. 5% HCl (100 ml) and brine (2 X 100 ml) and dried over NajSO. The crude amide was obtained by removal of the solvent in vacuo and phenylhydrazine (25 mmol) was added. The mixture was heated to 100°C for 30 min. The residue was held in vacuo to remove the water formed and then powdered ZnCl2 (125 mmol) was added. The mixture was heated at 170"C with manual stirring for 5 min. The cooled residue was dissolved in acetone (100 ml) and diluted with ether (500 ml). Water (100 ml) was added. The organic layer was separated and washed successively with 5% aq. HCl (100 ml) and brine (2 x 100 ml) and dried over NajSO. The solvent was removed in vacuo, and the residue was recrystallized from EtOAc-hexane. The yield was 79%. 

A solution of benzyl indole-5-carboxylate(1.0g, 3.98 mmol) and methyl 4-(bro-momethyl)-3-methoxybenzoate (2.06 g, 7.97 mmol) in dry DMF (10 ml) was heated at 80°C for 24 h. The reaction solution was cooled, poured into water (100 ml) and the product extracted with EtOAc (3 x 75 ml). The extract was washed with water and brine and dried over MgSO, . The product was obtained by evaporation of the solvent and purified by chromatography on silica gel using 1 4 EtOAc/hexane for elution. The yield was 1.11 g (32%) and some of the indole (30%) was recovered unreacted. 

A solution of gramine (87,3 mg, 0,50 mmol) and 2-nitropropane (33.7 mg, 0.38 mmol) in CHjCN (3 ml) was treated with -Bu3P (18.6 mg, 0.l4mmol). The mixture was refluxed for 4 h. The solvent was removed in vacuo and the residue was acidified with 0.5N aq. HCl and extracted with 95 5 CHjClj-MeOH. The extract was washed with brine and dried (Na2S04). The solvent was removed in vacuo and the residue purified by TLC to yield 138.5 mg (99% yield) of the product. 

I2O5 (400 mg 1.20 mmol) was added to a solution of a cycloalka[b]indole (l.OOmmol) in 80% aqueous THF (25 ml). The mixture was stirred at room temperature and the solvent removed in vacuo. The residue was extracted into EtOAc and the extract washed with water, 5% NaS203, saturated NaHCOj and brine and dried over Na2S04. The solvent was evaporated and the residue purified by silica gel chromatography. 

The reaction is initiated with nickel carbonyl. The feeds are adjusted to give the bulk of the carbonyl from carbon monoxide. The reaction takes place continuously in an agitated reactor with a Hquid recirculation loop. The reaction is mn at about atmospheric pressure and at about 40°C with an acetylene carbon monoxide mole ratio of 1.1 1 in the presence of 20% excess alcohol. The reactor effluent is washed with nickel chloride brine to remove excess alcohol and nickel salts and the brine—alcohol mixture is stripped to recover alcohol for recycle. The stripped brine is again used as extractant, but with a bleed stream returned to the nickel carbonyl conversion unit. The neutralized cmde monomer is purified by a series of continuous, low pressure distillations. 

Magnesium sulfate heptahydrate may be prepared by neutralization of sulfuric acid with magnesium carbonate or oxide, or it can be obtained directly from natural sources. It occurs abundantly as a double salt and can also be obtained from the magnesium salts that occur in brines used for the extraction of bromine (qv). The brine is treated with calcium hydroxide to precipitate magnesium hydroxide. Sulfur dioxide and air are passed through the suspension to yield magnesium sulfate (see Chemicals frombrine). Magnesium sulfate is a saline cathartic. 

The I2 formed stays in solution, exerting a certain vapor pressure, and is extracted from the brine in a countercurrent air blow-out process. The extracted brine leaves the extraction tower and is discarded or reinjected into the wells to avoid sinking of the soil. The iodine-loaded air is then submitted to a cocurrent desorption process by means of an acidic iodide solution to which SO2 is added. By this solution the iodine is reduced to iodide by the following reaction ... 

AH metals come originally from natural deposits present in the earth s cmst. These ore deposits result from a geological concentration process, and consist mainly of metallic oxides and sulfides from which metals can be extracted. Seawater and brines are another natural source of metals, eg, magnesium (see Chemicals frombrine Magnesium and magnesium alloys Ocean raw materials). Metal extracted from a natural source is called primary metal. 

Table 1 gives the average metal content of the earth s cmst, ore deposits, and concentrates. With the exceptions of the recovery of magnesium from seawater and alkaU metals from brines, and the solution mining and dump or heap leaching of some copper, gold, and uranium (see Uranium and uranium compounds), most ores are processed through mills. Concentrates are the raw materials for the extraction of primary metals. 

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