Acetone-chloroform-methanol mixture

To a suspension of lithium aluminum hydride (2.87 g, 76 mmol) in tetrahydrofuran (125 ml), a solution of triethyl 1,1,2-ethanetricarboxylate (9.2 ml, 9.85 g, 40 mmol) in tetrahydrofuran (25 ml) was added dropwise with stirring over 2 hours. The inorganic salts were filtered off and washed with ethanol (100 ml). The filtrate and washings were combined and the solvent was evaporated under reduced pressure to afford a colourless oil (4.85 g). To a suspension of this oil in acetone (100 ml) 2,2-dimethoxypropane (25 ml) and p-toluenesulphonic acid monohydrate (2.3 g, 12 mmol) were added. The mixture was stirred for 1 hour. The resulting solution was neutralised with Amberlite IR 45 (methanol washed), filtered and the solvent evaporated under reduced pressure. The residue was purified by column chromatography on silica gel, eluting with chloroform-methanol mixtures (40 1 and 25 1) to afford 5-(2-hydroxyethyl)-2,2-dimethyl-l,3-dioxan as a colourless liquid (3.01 g, 47%). 

Figure 3.10 shows typical RCM for nonideal mixtures involving azeotropes. For the mixture ace tone/heptane /benzene (plot a) there is only one distillation field. The problem seems similar to a zeotropic system, except for the fact that the minimum boiler is a binary azeotrope and not a pure component. With the mixture acetone/chloroform/toluene (plot b) there is one distillation boundary linking the high-boiler with the low-boiler azeotrope. Consequently, there are two distillation regions. Similar behavior shows the plot c, with two azeotropes. The mixture acetone/chloroform/methanol (plotd) has four azeotropes (3 binaries and 1 ternary) displaying a behavior with four distillation regions. 

Schematic DRDs are particularly useful in determining the implications of possibly unknown ternary saddle azeotropes by postulating position 7 at interior positions in the temperature profile. Also note that some combinations of binary azeotropes require the existence of a ternary saddle azeotrope. As an example, consider the system acetone (56.4°C), chloroform (61.2°C), and methanol (64.7°C) at 1-atm pressure. Methanol forms minimum-boiling azeotropes with both acetone (54.6°C) and chloroform (53.5°C), and acetone-chloroform forms a maximum-boiling azeotrope (64.5°C). Experimentally there are no data for maximum- or minimum-boiling ternary azeotropes for this mixture. Assuming no ternary azeotrope, the temperature profile for this system is 461325, which from Table 13-18 is consistent with DRD 040 and DRD 042. However, Table 13-18 also indicates that the pure-component and binary azeotrope data are consistent with three temperature profiles involving a ternary saddle azeotrope, namely, 4671325, 4617325, and 4613725. All three of these temperature profiles correspond to DRD 107. Calculated residue curve trajectories for the acetone-chloroform-methanol system at 1-atm pressure, as...

At the end of six hours, the ethane/propane is vented and a 3 1 chloroform/methanol solution is injected to the system, dissolving the surfactant, water, and unreacted monomer. The polymer, which is insoluble in the chloroform/methanol mixture, is collected by filtration, washed with additional chloroform/ methanol and acetone, dried under vacuum, and weighed. The average molecular weight of the polymer (M ) is measured using static light scattering (see for example (12)] of dilute solutions of the polymer in water. 

Cerebrosides have been isolated from Phycomyces blakeslearus (3), a fungus often found on animals dung, by extraction of mycelia with acetone and chloroform/methanol mixtures and purified on a silicic acid column, followed by a Florisil column. The bases obtained after hydrolysis were all phytosphingosine homologs ranging in length from C17 to C22. Palmitic,stearic, oleic, linoleic and hydroxy palmitic acids were the major fatty... 

Coral-like clusters from pyridine + acetone, mp 230-240 with sintering at 180-190. [ ]Jf —10.8 (c = 2 in pyridine). Practically insol in water, cold methanol, acetone, cold acetic acid, ether, acetonitrile. Soluble in pyridine, chloroform, hot methanol, hot acetic acid. Dissolves readily in chloroform + methanol mixtures of high chloroform content. 

Finally, Figure 9.4d illustrates a more complex situation, the mixture acetone/ chloroform/methanol, with four azeotropes (three binaries and one ternary). There are four distillation regions. Note that the ternary azeotrope is a saddle. 

Figure 9.6 shows the RCM for the mixture acetone/chloroform/methanol, for which the class is 311-S. The first digit represents the max-azeotrope acetone/chloroform, the second the minimum-azeotrope chloroform/methanol, the third the minimum-azeotrope acetone/methanol. The letter S signifies the ternary saddle azeotrope. More RCMs are presented in Perry (1997), from a total of 125 configurations. 

A very interesting mixture is presented in Figs. 5.2-18 and 5.2-19. The mixture acetone/chloroform/methanol exhibits two binary minimum azeotropes, one binary... 

Fig. 5.2-19 Distillation lines of the system acetone/chloroform/methanol at a pressure of 1 bar. The boundary distillation lines, which run between the minimum and the maximum azeotropes, respectively, divide the mixture into four fields with different starting and endpoints of distillation lines...

Electrospinning was carried out using an 8 wt%/v PLA solution mixed with each of three PCL solutions, namely, 9wt%/v HMW PCL solution, 15wt%/v HMW PCL solution, and 15 wt%/v LMW PCL solution. PLA and PCL solutions were mixed at different blend ratios of 1/0, 3/1, 1/1, 1/3, and 0/1 with three solvents, consisting of a DCM /DMF mixture at a blend ratio of 3/1, a chloroform/methanol mixture at 2/1 and a chloroform/acetone mixture at 2/1, along with the calculated PLA/PCL fiber compositions. Table 8.2. The mixing process continued at room temperature in a benchtop orbital shaking incubator for about 3 h. 

Polar lipids are only sparingly soluble in hydrocarbon solvents but most polar lipids dissolve in more polar solvents such as methanol, ethanol, or chloroform. Chloroform-methanol mixtures dissolve most polar lipids but polyphosphoinositides or lyso-phospholipids are poorly soluble in this solvent mixture. Water-methanol mixtures may dissolve significant amounts of the most polar lipids such as gangliosides. Acetone is a poor solvent for phospholipids but glycolipids are more soluble in this solvent. 

An important publication by Kost et al. (63JGU525) on thin-layer chromatography (TLC) of pyrazoles contains a large collection of Rf values for 1 1 mixtures of petroleum ether-chloroform or benzene-chloroform as eluents and alumina as stationary phase. 1,3- and 1,5-disubstituted pyrazoles can be separated and identified by TLC (Rf l,3>i y 1,5). For another publication by the same authors on the chromatographic separation of the aminopyrazoles, see (63JGU2519). A-Unsubstituted pyrazoles move with difficulty and it is necessary to add acetone or methanol to the eluent mixture. Other convenient conditions for AH pyrazoles utilize silica gel and ethyl acetate saturated with water (a pentacyanoamine ferroate ammonium disodium salt solution can be used to visualize the pyrazoles). 

Acrylamide [79-06-1 ] M 71.1, m 84°, b 125°/25mm. Crystd from acetone, chloroform, ethyl acetate, methanol or benzene/chloroform mixture, then vac dried and kept in the dark under vac. Recryst from CHCI3 (200g dissolved in IL heated to boiling and filtered without suction in a warmed funnel through Whatman 541 filter paper. Allowed to cool to room temp and kept at -15° overnight). Crystals were collected with suction in a cooled funnel and washed with 3(X)mL of cold MeOH. Crystals were air-dried in a warm oven. [Dawson et al. Data for Biochemical Research, Oxford Press 1986 p. 449.]... 

The new lipid occurred only in the plasma hpids of newborns and was not present in membrane hpids of red cell membranes or platelets. Total lipids were extracted from plasma and from red blood cell membranes and platelets. A total lipid profile was obtained by a three-directional PLC using silica gel plates and was developed consecutively in the following solvent mixtures (1) chloroform-methanol-concen-trated ammonium hydroxide (65 25 5, v/v), (2) chloroform-acetone-methanol-ace-tic acid-water (50 20 10 15 5, v/v), and (3) hexane-diethyl ether-acetic acid (80 20 1, v/v). Each spot was scraped off the plate a known amount of methyl heptadecanoate was added, followed by methylation and analysis by GC/MS. The accmate characterization of the new lipid was realized using NMR technique. 

The most critical decision to be made is the choice of the best solvent to facilitate extraction of the drug residue while minimizing interference. A review of available solubility, logP, and pK /pKb data for the marker residue can become an important first step in the selection of the best extraction solvents to try. A selected list of solvents from the literature methods include individual solvents (n-hexane, " dichloromethane, ethyl acetate, acetone, acetonitrile, methanol, and water ) mixtures of solvents (dichloromethane-methanol-acetic acid, isooctane-ethyl acetate, methanol-water, and acetonitrile-water ), and aqueous buffer solutions (phosphate and sodium sulfate ). Hexane is a very nonpolar solvent and could be chosen as an extraction solvent if the analyte is also very nonpolar. For example, Serrano et al used n-hexane to extract the very nonpolar polychlorinated biphenyls (PCBs) from fat, liver, and kidney of whale. One advantage of using n-hexane as an extraction solvent for fat tissue is that the fat itself will be completely dissolved, but this will necessitate an additional cleanup step to remove the substantial fat matrix. The choice of chlorinated hydrocarbons such as methylene chloride, chloroform, and carbon tetrachloride should be avoided owing to safety and environmental concerns with these solvents. Diethyl ether and ethyl acetate are other relatively nonpolar solvents that are appropriate for extraction of nonpolar analytes. Diethyl ether or ethyl acetate may also be combined with hexane (or other hydrocarbon solvent) to create an extraction solvent that has a polarity intermediate between the two solvents. For example, Gerhardt et a/. used a combination of isooctane and ethyl acetate for the extraction of several ionophores from various animal tissues. 

Isolation of Sesquiterpene Lactones. The ether extract was evaporated and dissolved in 952 ethanol. Then an equal volume of 42 aqueous lead acetate was added. After 1 hour the mixture was filtered to remove precipitated chlorophyll and phenolic products and the ethanol removed under vacuum. The aqueous layer was extracted with chloroform giving a dark colored oil from which the sesquiterpenes were isolated by a combination of chromatographic procedures, i.e., LH-20 gel permeation, silica gel using both packed columns and thin layer plates. A variety of solvents were also used to purify the individual sesquiterpene lactones, e.g., benzene-acetone (1 1), ethyl acetate, chloroform-methanol (9 1). On thin layer chromatographic plates, spots were visualized by spraying with 22 aqueous KMn04 solution. 

It is commonly known that lipids, carbohydrates, and glycolipids are present in the Golgi apparatus (27). The determination of the components that react with the ZIO mixture was carried out by removing each component from tissues before incubation in the ZIO mixture. After lipid extraction by acetone (14), chloroform-methanol (15), or propylene oxide (27), no osmium-zinc precipitates could be detected in structures that normally reacted with ZIO. Blumcke et al. (15) summarized the nature of the lipids that react with the ZIO mixture as follows lipids and lipoproteins of cell membranes, neutral fat droplets (41), and lipid globules of type II pneumocytes and alveolar macrophages were, however, not as electron dense as the normally reactive lamellae containing highly unsaturated fatty acids. 

Mixtures of phosphoglycerides can be separated using a chloroform-methanol-water mixture, the proportions of which may be varied to suit the sample constituents (e.g. 65 25 4). Acetone is sometimes included in the solvent and silver nitrate-impregnated plates can be used. Acetic acid (1-4%) is also a useful additive to effect the separation of neutral phosphoglycerides... 

Since the early delipidation procedure was applied initially to the whole serum (815) and later to the isolated serum lipoproteins (818), many other methods of delipidation have been reported [see reference (816) for review], employing mixtures of organic solvents (ethanol-ethyl ether chloroform-methanol, acetone, etc.) or detergents (sodium dodecyl or decyl sulfate, Triton X-100, Nonidet, etc.). Techniques for delipidation have not been standardized, nor is there a comprehensive comparative assessment of the various proposed methods presently avail-... 

D. 1,4-Di-O-benzyl-L-threitol. The crude ketal is dissolved in methanol (300 mL), 0.5 N hydrochloric acid (30 idL) is added, and the resulting mixture Is heated to reflux. Acetone and methanol are slowly distilled off (Note 29). Additional methanol (50 mL) and 0.5 N hydrochloric acid (20 mL) are added and the mixture Is kept at room temperature until ketal hydrolysis Is complete. The mixture Is diluted with saturated sodium bicarbonate solution (500 mL) and extracted with ether (3 x 500 mL). The ether extracts are combined, dried over anhydrous magnesium sulfate, and filtered. Removal of volatile material under reduced pressure gives crude l,4-di-0-benzy1-L-threitol as a pale yellow solid. This solid is recrystallized twice from chloroform/hexanes, to provide 59-65 g (195-215 mmol, 57-63% yield) of pure diol, up 54-55 C (Notes 30 and 31). Concentration of the mother liquors from the recrystallizations gives a yellow solid which is chromatographed on 70-230 mesh silica gel 60 (500 g) (Note 32), and eluted with 50% ethyl... 

Virginiamycin is a mixture of two components designated Mi and Si, which are both cyclic polypeptides. It is soluble in methanol, ethanol, acetic acid, ethyl acetate, acetone, chloroform, and benzene but is practically insoluble in water and dilute acid. It also dissolves in alkalis but is rapidly deactivated. 

Figure 13.23. Examples of vapor-liquid equilibria in presence of solvents, (a) Mixture of-octane and toluene in the presence of phenol, (b) Mixtures of chloroform and acetone in the presence of methylisobutylketone. The mole fraction of solvent is indicated, (c) Mixture of ethanol and water (a) without additive (b) with 10gCaCl2 in 100 mL of mix. (d) Mixture of acetone and methanol (a) in 2.3Af CaCl2 ip) salt-free, (e) Effect of solvent concentration on the activity coefficients and relative volatility of an equimolal mixture of acetone and water (Carlson and Stewart, in Weissbergers Technique of Organic Chemistry IV, Distillation, 1965). (f) Relative volatilities in the presence of acetonitrile. Compositions of hydrocarbons in liquid phase on solvent-free basis (1) 0.76 isopentane + 0.24 isoprene (2) 0.24 iC5 + 0.76 IP (3) 0.5 iC5 + 0.5 2-methylbutene-2 (4) 0.25-0.76 2MB2 + 0.75-0.24 IP [Ogorodnikov et al., Zh. Prikl. Kh. 34, 1096-1102 (1961)].

Chemically cleaned silicon wafers (lxl cm2 pieces) were treated with 9-[AM3-triethoxysilylpropyl)amino]-9-oxononanoic acid methyl ester in toluene (20 ml of a 2% solution) at room temperature under nitrogen overnight. The wafers were then thoroughly washed with chloroform, methanol, and acetone in that order, and suspended in dimethylformamide (DMF 10 ml) containing lithium iodide (1 g). The mixture was refluxed for several hours. The wafers were recovered and washed several times with distilled water, once with sodium carbonate (1% aq., 10 ml) and again with distilled water. Finally, the wafers were rinsed with acetone and stored in a vacuum desiccator under nitrogen. 

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