Potassium water-dioxane

Phase diagrams, at 25° C, were determined for potassium acetate-water-dioxane, potassium acetate-water-tetrahydro-furan, and potassium chloride-water-tetrahydrofuran. Potassium acetate exceeded potassium chloride in its capacity to stratify aqueous solutions of either dioxane or tetrahydro-furan. Kobsevs (1) investigations revealed that the greater the solubility of an alkali metal salt, the greater its salting-out effect. The relative order of the water solubilities of the salts studied are potassium acetate > > potassium chloride. More potassium acetate is required to cause stratification in aqueous dioxane than is necessary to obtain the same results in aqueous tetrahydrofuran. It is proposed that, in comparison to dioxane, tetrahydrofuran forms a weaker association with water and, hence, the cations can more easily break these bonds causing liquid-phase separation. 

It was also highly desirable to learn how to better control the salting-out effect in water-tetrahydrofuran systems so that extractions in this pair of mixed solvents could be performed. This present study of the phase relationships in some of the solvent systems used in aminosugar research includes the determination of the phase diagrams of the systems potassium acetate-water-dioxane, potassium acetate-water-tetrahydro-furan, and potassium chloride-water-tetrahydrofuran, and an attempt to provide a theoretical explanation for the experimental results. 

Specific Procedure. Table I provides a characteristic example of the data for the experimental observations in the system potassium acetate-water-dioxane, which data were used in plotting solubility curves at 25 °C and 85°C on a three-component, equilateral triangular graph (Figure 1). 

Table I. Solubility Curve and Tie-Line Data for the System Potassium Acetate—Water—Dioxane in Weight Percentage...

Figure 1. Isotherms of potassium acetate-water-dioxane in weight percent O, 25°C A, 85°C.

Salting-Out Effects Owing to Potassium Acetate. The system potassium acetate-water-dioxane (Figure 1, Table I) was investigated at temperatures of 25°C and 85°C. The salting-out isotherms are binodal curves and showed a very slight displacement toward the aqueous comer with an increase in temperature. 

Figure 4. Comparison of potassium acetate-water-dioxane and potassium acetate-water-THF plots O, dioxane A, THF...

A mixture of potassium permanganate and sodium periodate has also been used to cleave double bonds. This procedure, usually referred to as the Lemieux-von Rudloff reaction, can be carried out in several mixed solvent systems such as butanol and water, dioxane and water " or acetone and water. " It has also been claimed that the addition of phase transfer agents improves yields. 

As the VLB diagram (Fig. 16.28) shows, the water/ dioxane azeotrope is separated easily from both water and from the solvent. However, the laboratory techniques used for drying (molecular sieves, barium oxide, magnesium sulphate and potassium hydroxide) are all rather expensive without a recovery system. Chloroform is an effective azeotropic entrainer and its toxicity is not an automatic disqualification because dioxane itself needs to be handled with very great care. 

Alternatively, treat a solution of 3 9 g. of the 6is-diazo ketone in 50 ml. of warm dioxan with 15 ml. of 20 per cent, aqueous ammonia and 3 ml. of 10 per cent, aqueous silver nitrate under reflux in a 250 or 500 ml. flask on a water bath. Nitrogen is gently evolved for a few minutes, followed by a violent reaction and the production of a dark brown and opaque mixture. Continue the heating for 30 minutes on the water bath and filter hot the diamide of decane-1 lO dicarboxyhc acid is deposited on cooling. Filter this off and dry the yield is 3 -1 g., m.p. 182-184°, raised to 184-185° after recrystallisation from 25 per cent, aqueous acetic add. Hydrolyse the diamide (1 mol) by refluxing for 2-5 hours with 3N potassium hydroxide (4 mols) acidify and recrystaUise the acid from 20 per cent, acetic acid. The yield of decane-1 10-dicarboxyhc acid, m.p. 127-128°, is almost quantitative. 

The iodoform test. Dissolve 0 -1 g. or 5 drops of the compound in 2 ml. of water if it is insoluble in water, add sufficient dioxan to produce a homogeneous solution. Add 2 ml. of 5 per cent, sodium hydroxide solution and then introduce a potassium iodide - iodine reagent dropwise with shaking until a definite dark colour of iodine persists. Allow to... 

Acetylene and Potassium in Liquid Ammonia Potassium (40 g) is dissolved in 1 liter of dry liquid ammonia. Dry acetylene is then bubbled into the solution until the blue color is discharged. A solution of 15 g of estrone in 300 ml of dioxane is prepared and diluted with 300 ml of ether, cooled, and added to the potassium acetylide solution over a period of 10 min. The liquid ammonia is allowed to evaporate, an additional 500 ml of ether is added, and the mixture is allowed to stand overnight. About 3 liters of 5 % sulfuric acid is added and the organic layer separated. The water layer is re-extracted with fresh ether, and the combined ether extracts are washed twice with 5 % sodium carbonate solution, th6n several times with water, and finally evaporated under reduced pressure. The residue is dissolved in 150 ml of methanol, then an equal quantity of hot water is added and the mixture cooled. The precipitated solid is collected, washed with cold 60 % methanol and crystallized once from methanol-water to give 14.8 g (85%) of 17a-ethynylestradiol mp 143-144°. 

Hydroxy-B-homo-5a-cholestan-7-one acetate (54b) A solution of 3/3-hydroxy-5a-cholestan-7-one acetate (51b 5 g mp 146-148°) in dioxane-ethanol (100 ml, 1 1) is placed in a 250 ml three-necked flask equipped with a mechanical stirrer and thermometer and is cooled to 0° (iee-salt bath). Powdered potassium cyanide (7.3 g) is added portionwise with stirring. Acetic acid (8 ml) is then added dropwise with constant stirring over 30 min. The resultant mixture is stirred for 1 hr at 0° C and for an additional 2 hr at room temperature. It is then poured into ice water (200 g ice, 100 ml water) and after standing for 1 hr the precipitate is collected by filtration. The product is dissolved in ether (100 ml), the ether solution is washed with 5% sodium bicarbonate, water and dried over anhydrous sodium sulfate. The filtrate is evaporated at reduced pressure and the solid residue (5.1 g) is crystallized from ethyl acetate (30 ml) to yield 2.8 g of cyanohydrin (52b) mp 160-164° repeated crystallization from the same solvent gives a product mp 164-167°. An alternative method of isolation of the cyanohydrin is used when 100 g or larger quantities are worked up. The reaction mixture is poured directly into a mixture of ice water and sodium bicarbonate, the precipitate (mp 155-156°) is washed well with water, dried and used directly for the next step. 

A) A mixture of 333 parts of 4-(1 -piperazinyDphenol dihydrobromide, 11.2 parts of acetic acid anhydride, 42 parts of potassium carbonate and 300 parts of 1,4-dioxane is stirred and refluxed for 3 days. The reaction mixture is filtered and the filtrate is evaporated. The solid residue is stirred in water and sodium hydrogen carbonate is added. The whole is stirred for 30 minutes. The precipitated product is filtered off and dissolved in a diluted hydrochloric acid solution. The solution is extracted with trichloromethane. The acid aqueous phase is separated and neutralized with ammonium hydroxide. The product is filtered off and crystallized from ethanol, yielding 5.7 parts of 1 acetyl-4-(4-hydroxyphenyl)piperazine MP 181.3°C. 

In the flask are placed 200 cc. of dioxane, 100 g. (1.02 moles) of mesityl oxide, and a solution of 4.6 moles of potassium hypochlorite in 3 1. of water (Note 1), and the stirrer is started. The mixture becomes warm immediately, and within five minutes chloroform begins to reflux. When the reaction becomes very vigorous the stirrer is stopped and the flask is cooled with running water (Note 2). The stirring is resumed as soon as feasible and is continued for three or four hours, when the temperature of the mixture will have dropped to that of the room. Sodium bisulfite (about 5 g.) is then added to react with the excess hypochlorite (Note 3). 

For example, direct treatment of red phosphorus with potassium hydroxide in a mixture of dioxane and water with a phase-transfer catalyst (benzyltriethylammonium chloride) allows direct reaction with primary haloalkanes to form the trialkylphosphine oxide in moderate (60-65%) yield.1415 Allylic and benzylic halides are similarly reported to generate the corresponding tertiary phosphine oxides. When the reaction is performed with a,(o-dihalides, cyclic products are generated only with four- and five-carbon chains the third site... 

Thioetherification of PECH is feasibly performed in DA-solvents as already described in the patent (20J. For example, the highest substitution was obtained by the reaction of P(ECH-EO)(1 1 copolymer of epichloro-hydrin and ethylene oxide) and equimolar thiophenoxide in HMPA at 100°C for 10 h as DS 83% for sodium and 93% for potassium salts. The DS in our nucleophilic substitution was estimated by the elemental analysis as well as the titration of liberated chloride ion with mercuric nitrate (21). In the latter method, reacted medium was pretreated with hydrogen peroxide when the reductive nucleophiles which can react with mercuric ion were used. As described before for PVC, thiolation was also achieved conveniently with iso-thiuronium salt followed by alkaline hydrolysis without the direct use of ill-smelling thiolate. The thiolated PECH obtained are rubbery solids, soluble in toluene, methylene chloride, ethyl methyl ketone and DMF and insoluble in water, acetone, dioxane and methanol. 

Cabon tetrachloride, n-hexane, chloroform, ACN, acetone, THF, pyridine, acetic acid, and their various mixtures were applied as mobile phases for adsorption TLC. Methanol, 1-propanol, ACN, acetone, THF, pyridine and dioxane served as organic modifiers for RP-TLC. Distilled water, buffers at various pH (solutions of and dipotassium hydrogen phosphate or potassium dihydrogen phosphate) and solutions of lithium chloride formed the aqueous phase. Carotenoids were extracted from a commercial paprika sample by acetone (lg paprika shaken with 3 ml of acetone for 30 min), the solution was spotted onto the plates. Development was carried out in a sandwich chamber in the dark and at ambient temperature. After development (15 cm for normal and 7cm for HPTLC plates) the plates were evaluated by a TLC scanner. The best separations were realized on impregnated diatomaceous earth stationary phases using water-acetone and water-THF-acetone mixtures as mobile phases. Some densitograms are shown in Fig.2.1. Calculations indicated that the selectivity of acetone and THF as organic modifiers in RP-TLC is different [14],... 

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