Ethanol-water-toluene mixture

Preparation of l9-Norandrost-A-ene-3, l-dionef A solution of 1.1 g of 10y5-cyano-19-norandrost-5-ene-3,17-dione bis-ethylene ketal in a mixture of 15 ml of ethanol and 15 ml of toluene is carefully added to a vigorously stirred suspension of 10 g of sodium in 150 ml of boiling toluene. The addition is regulated to maintain the reaction mixture at the boiling point of the solvent. Another 40 ml of anhydrous ethanol is then added at the same rate. The solution is cooled and the excess of sodium is decomposed by addition of 95% ethanol. The reaction mixture is then diluted with water, the toluene layer separated and the aqueous phase extracted twice with ether. The organic solution is washed with water, dried and evaporated to yield 1 g of an amorphous mixture of the bis-ethylene ketals of 19- norahd-rost-5- and -5(10)-ene-3,17-dione (Note 1). 

Ni(cod)2 (1.59g, 6.00mmol), 1,5-cyclooctadiene (531 mg, 5.00mmol), and 2,2 -bipyridyl (937 mg, 6.00 mmol) were dissolved in DMF (20 ml), in a Schlenk tube under argon. To the solution was added 2,5-dibromothiophene (1.21 g, 5.00 mmol) at room temperature. The reaction mixture was stirred at 60°C for 16 h to yield a reddish-brown precipitate. The reaction mixture was then poured into HCl-acidic methanol, and the precipitate of PT was separated by filtration. The precipitate was washed with HCl-acidic methanol, ethanol, hot toluene, a hot aqueous solution of EDTA (pH = 3.80), a hot aqueous solution of EDTA (pH = 9), and distilled water in this order and dried under vacuum to yield a reddish-brown powder of PT. 

Synthesis of biaryls (general procedure The diaryltellurium dichloride (50 mmol) is heated with degassed Raney nickeP (60 g) in diglyme (500 mL) for 8 h. The mixture is filtered while still hot, and the solvent evaporated (water pump). The residue is recrystallized from ethanol or toluene. 

At this time 270 ml. of toluene is added to the mixture and the condenser is changed for distillation. An azeotropic mixture of ethanol, toluene, and water is distilled at 75-78° with the bath at 105-110°. When the temperature begins to drop (Note 1), 525 ml. of commercial absolute ethanol is added and the mixture is again heated under reflux for 12-16 hours (Note 2). Again 270 ml. of toluene is added, and the azeotropic mixture is distilled until the vapor temperature falls to 68°. After the residue is cooled, the system is evacuated to 25-35 mm. and the remaining ethanol and toluene are distilled. 

A reactor containing 10 ml of toluene and 10 ml of aqueous Na2C03 was treated with the step 2 product (1.0 mmol), 2,7-dipinacol boron-9,9-di-octyl-fluoiene (1.0 mmol), tetrakis triphenylphosphine palladium (0.01 mmol), and 0.16 ml of tricaprylmethyl-ammonium chloride. The mixture was then treated with a few drops of bromobenzene and then refluxed for 1 hour and treated with a few drop of phenyl boronic acid and then further refluxed 15 hours and cooled. The mixture was diluted with toluene and isolated toluene layer washed with water. The mixture was filtered after adding 40 mg of the palladium scavenger 3-mercaptopropyl modified silica gel. The solution was then poured into methanol and a yellow polymer isolated. The polymer was redissolved in toluene and then purified using a short column of silica gel. The solution was rewashed with water, reprecipitated in ethanol, and 0.80 g of polymer isolated having an Mn of 32,800 Da. 

Even the traditional methods discussed in this chapter can be used for concentrated dispersions through contrast matching. For example, silica particles coated with silane coupling agents in a refractive index-matched mixture of ethanol and toluene can be used in combination with visible probe particles to study the dynamics of particles in dense systems. In the case of microemulsions (Chapter 8), selective deuteration of a component (oil, water, or surfactant) can be used in neutron scattering experiments even to measure the curvature of the oil-water interface. 

By the reaction of concentrated solutions of nickel acetate and Hacac in an ethanol-water mixture the bis-aqua adduct [Ni(acac)2(H20)2] is obtained. An improved synthesis of the same compound has been devised starting from NiO(OH) which was reduced with Hacac at room temperature.1549 The green anhydrous Ni(acac)2 derivative is obtained by azeotropic distillation with toluene of the aqua complex or by its sublimation in vacuo. 

I). A solution of trans-3-bromocinnamoyl chloride (12.3 g) in anhydrous toluene (150 ml) was added slowly with stirring to a solution of ethylamine (10 g) in dry ether (100 ml) at room temperature. The reaction mixture was heated at reflux for 1 hour, and the solvent and excess amine were then removed under reduced pressure. The residue was triturated with water, filtered, and recrystallized from ethanol-water to give trans-3-bromo-N-ethylcinnamamide, m.p. 89-90°C, as a white crystalline material. NMR and IR spectra as well as elemental analysis were consistent with the assigned... 

A solution 0.1 mole of 2-ethoxymethyleneacetoacetic acid 4-trifluoromethylanilide (30.1 g) in 60 ml of ethanol is added dropwise at 5-10°C to the mixture of 0.11 mole of hydroxylamine hydrochloride (7.65 g) in 50 ml of water and 0.11 mole of sodium hydroxide (4.4 g) in 10 ml of water. The mixture is heated under reflux for 15 min. The crystals which are precipitated after cooling are filtered off, washed with water and dried. 19.6 g (72.6% of theory) of crystalline 5-methylisoxazole-4-carboxylic acid 4-trifluoromethyl-anilide are thus obtained, melting point (after recrystallization from toluene) 166.5°C. 

The crude ester obtained in this way was then treated with a solution of 7.5 g of flaked sodium hydroxide in 67.5 ml of water. The mixture was introduced into a 250 ml spherical flask, equipped with a condenser, and then the reaction medium was slowly brought to 60°-70°C. This temperature was maintained for 3 hours, whereafter the mixture was cooled to about 50°C and the ethanol which had formed and the residue of n-propanol were eliminated under a pressure of 70 mm Hg. The solution thus obtained was cooled to 20°C and acidified, while stirring, by addition of 26.25 g of 36% hydrochloric acid. During this operation, the temperature of the reaction medium was kept below 40°C by cooling. Stirring was continued for 30 minutes, whereafter the mixture was left standing for 30 minutes. The oily layer of di-n-propyl cyanacetic acid was decanted and the aqueous phase extracted with 35 ml of toluene. The extract in toluene was then added to the decanted di-n-propyl cyanacetic acid, whereafter the solution in toluene was washed, in a separation funnel, with a solution of 1.5 g of sodium chloride in 14 ml of water. The toluenic phase was decanted and the toluene distilled under atmospheric pressure. 

The reactor is an enameled apparatus with an agitator and a water vapour jacket. The production of sodium dihydroxyphenylsilanolate is carried out in butanol and toluene or ethanol and toluene medium at 35-50 °C. The consumption of other components is calculated by the amount of the loaded condensation product. After loading the product of condensation, the reactor is filled with toluene and butanol (or ethanol and toluene) from batch boxes 10 and 11. The ratio of the solvents should be 1 1.4 to obtain 10% silanol solution. The calculation takes into account toluene contained in the product of hydrolytic condensation. The loaded mixture is agitated in the reactor for 30 minutes after that it receives 20% alkali solution from batch box 12 at agitation. The reaction forms sodium dihydroxydiphenylsi-lanolate and water. 

E. Does the Polyurethane Foam Dissolve Place a small piece of cured foam from one of your preparations above in a vial or small bottle, cover with acetone, and cap. Periodically shake the mixture over a period of at least 30 minutes and observe. At the discretion of the teacher try dissolving samples of your polyurethane foam in other solvents as available (e.g., water, ethanol, hexane, toluene). 

Prelab Exercise Predict what a plot of temperature vs. volume of distillate will look like for the simple distillation and the fractional distillation of (a) a cyclohexane-toluene mixture, (b) an ethanol-water mixture. 

B) Simple Distillation of an Ethanol-Water Mixture. In a 500-mL round-bottomed flask place 2(X) mL of a 20% aqueous solution of ethanol. Follow the procedure (above) for the distillation of a cyclohexane-toluene mixture. Discontinue the distillation after 50 mL of distillate have been... 

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