Dispersion Distillation with reaction

First, /3-CD is dissolved in 20% NaOH aqueous solution, then EPI is dropped in with stiring. The mixture reacts for 1.5 h at room temperature, and then 200 kerosene which contains emulsifier (n (tween 20) n (span 80) = 1 3) is added and vigorously mixed for 5 min to make the water phase disperse. Finally, the reaction system is heated up to 60° C, stirring speed is reduced while continuing to react for 8 h. The product is filtered and washed with diluted hydrochloric acid, methanol, distilled water and acetone, respectively. After wash, the product is dried imder vacuum. 

Method 2. In the apparatus described above is placed 4.8-5.0g. ( 0.2 g.-atorn) of clean sodium and 8.0-8.2 g. ( 0.2 g.-atom) of clean potassium (Ilotes 3, 4). The flask is heated with a heat gun to form the low-melting alloy, and then 300-350 ml. of anhydrous ether is added from a freshly opened can. The stirrer is operated at full speed until the alloy is dispersed and then at a slower speed for the remainder of the reaction (Notes 5, 6). A mixture of 17.4 g. (0.1 mole) of diethyl succinate (Note 7), 44g. (0.4 mole) of chlorotrimethylsilane (Note 8), and 125 ml. of anhydrous ether is then added at a rate sufficient to keep the reaction under control (Note 14). The purple mixture is stirred for another 4-6 hours (Note 9) and then filtered and washed as above in a nitrogen dry-box (Note ll). The product is distilled as above forerun 0.5-2 g. to 80° (10 mm.) and then at 82-86° (10 mm.) as a colorless liquid, 13.8-16.1 g. (60-70%), 1.4323-1.4330 (Notes 15-19). 

Toluene is commonly used. It can be dried by molecular sieves or direct distillation from calcium hydride into the reaction flask. Solvent stored over calcium hydride for several days is usually sufficiently dry to decant directly into the reaction flask, but distillation gives more consistent results. Any solvent with a boiling point sufficiently high to melt sodium is satisfactory. The submitters have also used methyl-cyclohexane and xylene in acyloin condensations. After the sodium is dispersed, the high-boiling solvent can be removed and replaced with anhydrous ether (as noted by the submitters) or can be retained and used in combination with ether (checkers). 

The photocatalytic decomposition of water was carried out in a closed gas circulation system connected to a high-vacuum line. About 200 mg of a powdered catalyst was dispersed in pure distilled water and irradiated through a water filter with an Xe lamp operated at 400 W. Hydrogen and oxygen evolved in the gas phase were analyzed by a gas chromatograph which was directly connected to the reaction system. 

Catalysts have been bonded to insoluble polymers to allow, in principle, an appreciable simplification of PTC the catalyst represents a third insoluble phase which can be easily recovered at the end of the reaction by filtration, thus avoiding tedious processes of distillation, chromatographic separation and so on. This is of potential interest mainly from the industrial point of view, due to the possibility of carrying on both discontinuous processes with a dispersed catalyst and continuous processes with the catalyst on a fixed bed. This technique was named "triphase catalysis" by Regen (13,33,34). 

A mixture of the above diol, PHBA, p-TSA and "Aromatic 150" was heated under N2 in a 3-neck flask equipped with stirrer, Dean-Stark trap, condenser and thermometer. The PHBA/diol wt. ratio varied from 20/80 to 60/A0 0.2 wt. % of p-TSA was used. About 10 wt. % of "Aromatic 150" was used the amount was adjusted to maintain the temperature at 230 +/- 3°. Distillate (cloudy H2O) was collected in the Dean-Stark trap during 9 to 11 hr. The reaction mass was cooled to 115°, and MIBK was added to yield a solution (20/80 PHBA/ diol ratio) or dispersion (other PHBA/diol ratios) of the crude polyol. 

An interesting application of TSIL was developed by Zhang et al for the catalytic hydrogenation of carbon dioxide to make formic acid. Ruthenium immobilized on silica was dispersed in aqueous IL solution for the reaction. H2 and CO2 were reacted to produce formic acid in high yield and selectivity. The catalyst could easily be separated from the reaction mixture by filtration and the reaction products and the IL were separated by simple distillation. The TSIL developed for this reaction system was basic with a tertiary amino group (N(CH3)2) on the cation l-(A,A-dimethylaminoethyl)-2,3-dimethylimidazolium trifluoromethanesulfonate, [mammim] [TfO]. 

In a hood, to a well-stirred dispersion of 62 gm (1.35 moles) of methyl-hydrazine, 175 ml of chlorobenzene, and 20 gm of powdered, anhydrous sodium sulfate is added dropwise, with cooling, 61 gm (0.663 mole) of freshly distilled l-chloro-2-propanone. After the addition has been completed, the reaction mixture is stirred for 1 hr. The moist sodium sulfate is separated by filtration and the filtrate is distilled. The fraction boiling between 60°C and 64°C is collected as product, yield 16.8 gm (31 %) of a yellow liquid. On redistillation the boiling point is raised slightly to 61°-64°C, index 1.4300. 

Since many W-nitrosoaniline derivatives are liquids, suitable modifications have to be made for the isolation of the product. In many cases the nitrosation is carried out with a dispersion of A-substituted anilines in hydrochloric acid and crushed ice to maintain the low temperatures of the reaction. Concentrated hydrochloric acid and sodium nitrite solutions are then added in turn while maintaining temperatures between 0° and 10°C. The product may be isolated by extraction with suitable solvents, such as benzene [26] or ether [27, 28], followed by evaporation of the solvent and distillation of the product under reduced pressure. 

A 1-L, three-neck flask was fitted with dropping funnel, a small spinning-band column and a thermometer. Into it were placed a 40% dispersion of Na in mineral oil (38 g, 0.66 mol) and Irielhylene glycol dimethyl ether (375 mL) (freshly vacuum distilled from Na). The flask was heated in an oil bath to 120 CC and a manostat maintained the pressure at 80 Torr. A dry ice chilled trap was present in the line. Over 30 min, a solution of 2,2,4,4-tetramethyl-J,3-dichlorocyclobutanc (69 32 g, 176 mmol) in triethylene glycol dimethyl ether (50 mL) was added at a rate which maintained the internal temperature at 130-140 C. The reaction was moderately exothermic and the mixture turned bright blue. The product was distilled at... 

For the test protein, disperse 6.25 mg protein (1.0 mg nitrogen as determined by Kjeldahl method see unitbi.2) in 10 ml distilled water into a small reaction vessel or vial. Adjust the pH of the suspension with 0.1 N NaOH while stirring at 37°C. 

---