Magnesium chloride solution preparation

In preparation of MgCl2 from seawater, magnesium hydroxide, Mg(OH)2, is first precipitated from seawater by the addition of dolime or lime. This is then treated with hydrochloric acid to produce a neutralized magnesium chloride solution. The solution obtained is evaporated and converted into soHd magnesium chloride hexahydrate (60,61). 

Procedure. Prepare a standard magnesium chloride solution (0.05M) and a buffer solution (pH 10) see Section 10.72. Standard EDTA (0.05M) will also be required. 

It was very difficult to obtain the new compound of P d or P d as a solid salt, because a very small amount of P d or P d was present in very dilute aqueous solution. However, the preparation of a small volume of P d solution of relatively high concentration was successfully achieved by the following procedure the enrichment of phosphorus oxoacid species into a certain amount of an anion-exchange resin and the subsequent elution with a calculated volume of potassium chloride solution of a proper concentration. By adding small volumes of magnesium chloride solution and methyl alcohol to the resulting P d solution, 4 mg of magnesium salt of Pgd was obtained. 

Polymerization. Copolymers of tetrafluoroethylene/perfluoro(methyl vinyl ether) and the nitrile (1-4 mole ) have been prepared batch-wise in a stirred autoclave using an aqueous ammonium persulfate or ammonium persulfate-sodium sulfite redox couple system at 40°-100° C. The TFE/PMVE gas mixture was pressured, as required, to maintain the pressure and the nitrile pumped in solution in trichlorotrifluoro-ethane. After completion of the reaction, polymer was isolated from the latex (25-30 solids) by coagulation using ethanol and aqueous magnesium chloride solution. It was washed with alcohol/water solutions and dried at 70 °C in an oven under nitrogen. Mass balance indicated that most of the nitrile had been incorporated. 

Place 8 0 g. of magnesium turnings or ribbon and 80 ml. of the dry benzene in the flask. Prepare a solution of 9-0 g. of mercuric chloride in 50 ml. of the dry acetone, transfer it to the dropping-funnel, and then allow it to enter the flask slowly at first, and then more rapidly, so that the addition takes about 3-5 minutes. The reaction usually starts shortly after the initial addition of the mercuric chloride solution if it is delayed, it may then start vigorously, and the flask may have to be cooled in water to prevent escape of acetone through the condenser. 

Prepare a solution of benzyl magnesium chloride in a 2-litre three-necked flask from 24-3 g. of magnesium turnings, 600 ml. of sodium-dried ether and 126-5 g. (115 ml.) of redistilled benzyl chloride follow the experimental details given under n-Propylbenzene (Section IV,7). Cool the flask in running water or in ice water. Place a solution of 456 g. of n-butyl-p-toluenesulphonate (Section IV,198) in about twice its volume of anhydrous ether in the dropping funnel, and add it slowly with stirring, at such a rate that the ether just boils a white solid soon forms. The addition is complete after about 2 hours. Pour the reaction product... 

Chlorobenzene. Prepare a solution of phenyldiazonium chloride from 31 g. (30 -5 ml.) of aniUne, 85 ml. of concentrated hydrochloric acid, 85 ml, of water, and a solution of 24 g. of sodium nitrite in 50 ml. of water (for experimental details, see Section IV,60). Prepare cuprous chloride from 105 g. of crystallised copper sulphate (Section 11,50,1), and dissolve it in 170 ml. of concentrated hydrochloric acid. Add the cold phenyl diazonium chloride solution with shaking or stirring to the cold cuprous chloride solution allow the mixture to warm up to room temperature. Follow the experimental details given above for p-chlorotoluene. Wash the chlorobenzene separated from the steam distillate with 40 ml. of 10 per cent, sodium hydroxide solution (to remove phenol), then with water, dry with anhydrous calcium chloride or magnesium sulphate, and distil. Collect the chlorobenzene (a colourless liquid) at 131-133° (mainly 133°), The yield is 29 g. 

This product is sufficiently pure for the preparation of phenylacetic acid and its ethyl ester, but it contains some benzyl tso-cyanide and usually develops an appreciable colour on standing. The following procedure removes the iso-cyanide and gives a stable water-white compound. Shake the once-distilled benzyl cyanide vigorously for 5 minutes with an equal volume of warm (60°) 60 per cent, sulphuric acid (prepared by adding 55 ml. of concentrated sulphuric acid to 100 ml. of water). Separate the benzyl cyanide, wash it with an equal volume of sa+urated sodium bicarbonate solution and then with an equal volume of half-saturated sodium chloride solution- Dry with anhydrous magnesium sulphate and distil under reduced pressure. The loss in washing is very small (compare n-Butyl Cyanide, Section 111,113, in which concentrated hydrochloric acid is employed). 

Brine Preparation. Sodium chloride solutions are occasionally available naturally but they are more often obtained by solution mining of salt deposits. Raw, near-saturated brines containing low concentrations of impurities such as magnesium and calcium salts, are purified to prevent scaling of processing equipment and contamination of the product. Some brines also contain significant amounts of sulfates (see Chemicals FROMBRINe). Brine is usually purified by a lime—soda treatment where the magnesium is precipitated with milk of lime (Ca(OH)2) and the calcium precipitated with soda ash. After separation from the precipitated impurities, the brine is sent to the ammonia absorbers. 

Magnesium trisihcate is prepared by precipitation of a solution of sodium siUcate of the proper composition, ie, MgO to Si02 ratio equal to 1 1.5, using a solution of magnesium chloride or sulfate. The precipitate of the magnesium trisihcate is filtered, washed, and dried at a low temperature. 

Brine Preparation. Rock salt and solar salt (see Chemicals frombrine) can be used for preparing sodium chloride solution for electrolysis. These salts contain Ca, Mg, and other impurities that must be removed prior to electrolysis. Otherwise these impurities are deposited on electrodes and increase the energy requirements. The raw brine can be treated by addition of sodium carbonate and hydroxide to reduce calcium and magnesium levels to below 10 ppm. If further reduction in hardness is required, an ion-exchange resin can be used. A typical brine specification for the Huron chlorate ceU design is given in Table 6. 

The ammonium chloride solution is prepared by dissolving 50 g. of ammonium chloride in 150 cc. of water at 25-30°. The literature recommends the use of 30 per cent sulfuric acid for decomposing the magnesium compound when this is used, the yield drops to 50 -55 per cent, probably owing to the ready polymerization of the hydrocarbon in the presence of mineral acids. 

A solution of 6.3 g (0.9 moles) ethoxyacetylene in 50 ml ether is added dropwise during 30 min to a Grignard reagent prepared from 2.18 g (90 mg-atoms) magnesium and 9.81 g (90 mmoles) ethyl bromide. The reaction mixture is stirred for 1 hr at room temperature and then a solution of 3 g (9 mmoles) 3) -acetoxyandrost-5-en-I7-one in 50 ml dry ether is added dropwise. The mixture is refluxed for 1 hr and after cooling to 0° poured into 100 ml of an aqueous ammonium chloride solution. The aqueous solution is extracted with ether, and the organic extract is washed with ammonium chloride solution and water, dried, and evaporated. The residue is chromatographed on 130 g alumina (activity III). Elution with petroleum ether-benzene (1 1) yields, after crystallization from acetone-hexane, 1.27 g (35%) 3j5-acetoxy-17a-ethoxyethynylandrost-5-en-17) -ol mp 138-139° Ho -122°. 

Preparation of 4-aza-S-(N-methyl-4-piperidyll-10,11-dihydro-SH-dibenzo[a,d]cycloheptene-S-ol Add 17.4 g of N-methyl-4-chloropiperidine to a stirred mixture containing 3.2 g of magnesium, 20 ml of anhydrous tetrahydrofuran, 1 ml of ethyl bromide and a crystal of iodine. Reflux for two hours, cool to 30°-35°C and add a solution of 13 g of 4-aza-10,11 -dihydro-5H-dibenzo[a,d] cycloheptene-5-one in 25 ml of tetrahydrofuran. Stir for five hours, remove the solvent by distillation in vacuo and add 250 ml of ether. Add 100 ml of 10% ammonium chloride solution and extract the mixture with chloroform. Concentrate the chloroform solution to a residue and recrystallize from isopropyl ether obtaining 20 g of the carbinol,... 

A) Preparation of p-Hydroxy-p -Methoxybemhydrylidenecyclohexane To a Grignard solution prepared from 110 g of magnesium (4.5 mols) and 840 g of p-bromoanisole (4.5 mols) in one liter of anhydrous ether, there was added dropwise with vigorous agitation 307 g of p-hydroxyphenyl cyclohexyl ketone (1.5 mols) dissolved in one liter of anhydrous ether. Upon completion of the addition the reaction mixture was refluxed for 2.5 hours with agitation, and was then cooled. Thereupon 15 mols of ammonium chloride dissolved in 3 liters of water were added. The ethereal layer was separated, washed with water, dried over anhydrous sodium sulfate and distilled. Yield 370 g. BP 180° to 190°C at 0.1 mm. The substance was recrystallized from a mixture of carbon tetrachloride and petroleum ether. MP 145° to 146°C. 

Dithioglycerol is prepared in the following manner 1,537 parts of sodium monosulfide nonahydrate and 411 parts of powdered sulfur are dissolved with stirring in 1,345 parts of water. Magnesium hydroxide is precipitated in the stirred sodium trisulfide solution by adding successively 97 parts of sodium hydroxide dissolved in 180 parts of water and then slowly 246 parts of magnesium chloride hexahydrate dissolved in 180 parts of water. The... 

Preparation of 2-Cyclopropylcarbony/amido-5-Chlorobenzophenone To 400.5 g (1.73 mols) of 2-amino-5-chlorobenzophenone dissolved in 220 g (2.18 mols) of triethylamine and 3.5 liters of tetrahydrofuran is added cautiously 181 g (1.73 mols) of cyclopropane-carboxylic acid chloride. The reaction is refluxed 2 /2 hours and allowed to cool to room temperature. The solvent is then removed under vacuum to obtain 2-cyclopropylcarbonyl-amido-5-chlorobenzophenone as a residue which is dissolved in 1 liter of methylene chloride, washed twice with 5% hydrochloric acid, and then twice with 10% potassium hydroxide. The methylene chloride solution is then dried over anhydrous magnesium sulfate, filtered and the solvent removed under vacuum. The residue is recrystallized from 1,500 ml of methanol, charcoal-treating the hot solution to give 356 g of 2-cyclopropylcarbonylamido-5-chlorobenzophenone, MP 105° to 105.5°C (69% yield). 

To a solution of thienyl magnesium bromide prepared from 21.4 g of magnesium and 144 g of 2-bromothiophene are added 39.B g of ethyl 4-dimethylaminocyclohexylcarboxylate. The mixture is ailowed to warm to room temperature and stirred for an additional six hours. The reaction mixture is then decomposed with dilute ammonium chloride solution and extracted with ether. The combined ether extracts are extracted thoroughiy with 10% hydrochloric acid and the acid solution made alkaline with ammonium hydroxide. The aqueous solution is extracted with chloroform which is then washed with water, dried and evaporated to a residue in vacuo. Recrystallization of the residue from hexane yields Oi.O -dithienyl-4-dimethyl-aminocyclohexyl carbinol, melting point 156°C to 157°C after recrystallization from benzene. 

Note. Prepare by dissolving 25 g magnesium chloride (MgCl2,6H20) and 50 g ammonium chloride in 250 mL of water. Add a slight excess of ammonia solution, allow to stand overnight and filter if necessary. Acidify with dilute hydrochloric acid, add 1 mL concentrated hydrochloric acid and dilute to 500 mL. 

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