Methyl ethyl ketone purification

The ethyl cyanoacetate and methyl ethyl ketone were Eastman Kodak Company white label grade chemicals and were used without further purification. Commercial absolute ethanol was found to give a slightly better yield of the ammonium salt of the imide. 

Methyl n-amyl carbinol. 247, 254 Methyl n-amyl ketone, 482 Methylaniline (mono), pure, from commercial methylaniline, 562, 570 P-Methylanthraquinone, 728, 740 Methyl benzoate, 780, 781 p-Methyl benzyl alcohol, 811,812 Methyl benzyl ketone, 727, 735 Methyl y-bromocrotonate, 926, 927 2-Methyl-2-butene, 239 Methyl n-butyl carbinol, 247,255 Methyl n-butyl ether, 314 Methyl n-butyl ketone, 475, 481 4-Methylcarbostyril, 855 p-Methylcinnamic acid, 719 4-Methylcoumarin, 853, 854 Methyl crotonate, 926, 927 Methylethylacetic acid, 354, 358 Methylethylethynyl carbinol, 468 Methyl ethyl ketone, 335, 336 purification of, 172 Methyl n-hexyl ether, 314 Methyl n-hexyl ketone, 335, 336 Methyl n-hexyl ketoxime, 348 Methyl hydrogen adipate, 938 Methyl hydrogen sebacate, 938,939 4-Methyl-7-hydroxycoumarin, 834 Methyl iodide, 287 Methyl isopropyl carbinol, 247,255 Methyl 4-keto-octanoate, 936... 

Chemicals and Standard Solutions. Cyclohexanone, cyclohexanol, 1,3,5-trichlorobenzene, 1,2,4-trichlorobenzene, phenol, 4-methylphenol, 4-chloro-phenol, 1,2,3,4-tetrahydroisoquinoline, 1-chlorohexane, 1-chlorododecane, and 1-chlorooctadecane were obtained from Aldrich. Acetone, tetrahydrofuran, ethyl acetate, toluene, dimethyl sulfoxide, and methanol were obtained from J. T. Baker. Distilled-in-glass isooctane, methylene chloride, ethyl ether, and pentane were obtained from Burdick and Jackson. Analytical standard kits from Analabs provided methyl ethyl ketone, isopropyl alcohol, ethanol, methyl isobutyl ketone, tetrachloroethylene, dodecane, dimethylformamide, 1,2-dichlorobenzene, 1-octanol, nitrobenzene, 2,4-dichlorophenol, and 2,5-dichlorophenol. All chemicals obtained from the vendors were of the highest purity available and were used without further purification. High-purity water... 

Thin-layer chromatography on alumina,271 silica gel,139,271>272 cellulose,262,272 Avicel,250,262 and polyamide273 thin layers has extended considerably the applications of chromatography to the separation and purification of imidazoles. Polyamide layers are useful especially for the separation of imidazoles and their 1-methyl derivatives and (using methyl ethyl ketone as solvent) allows separation of the more polar co mpounds su ch as 1,3 -dimethylimidazolium iodide.2 7 3 Imidazolines have also been separated by thin-layer chromatography.274... 

The cyanohydrin synthesis of a-hydroxy acids is very often carried out without isolation or purification of the cyanohydrins. The various techniques for the preparation of the cyanohydrins are discussed elsewhere (method 390). Hydrolysis to the a-hydroxy acids is usually effected by heating with concentrated hydrochloric acid. Excellent directions are given for mandelic acid (52% over-all from benzaldehyde), a-methyl-a-hydroxybutyric acid (65% from methyl ethyl ketone), and eighteen dialkyl- and alkylphenyl-glycolic acids (60-80%). Sodium hydroxide solution is used in the preparation of /S-hydroxypropionic acid from the /S-hydroxy nitrile (80%). ... 

Methyl ethyl ketone (bp 80°) has excellent solvent properties similar to acetone and has the advantage of a somewhat higher boiling point. The methods of purification applicable to acetone may be used with this ketone also. 

Toluene, acetone and methyl ethyl ketone are, due to their cut-off values, not the first choice if UV detection is used to control the process. Tetrahydrofuran has to be avoided because for larger scale use it has to be stabilized with an anti-oxidant (butyl-ated hydroxytoluene) that will finally end up in the product, often making an additional purification step necessary. 

A number of differences nevertheless appear between the purification schemes of acetone and methyl ethyl ketone. The existence of a water/methyl ethyl ketone hetero-azeotrope (bpi.o 73.4°C, water content 11.3 percent weight) complicates the separation of the products. 

Isotactic polystyrene. Isotactic polystyrene was prepared by heating a 10% solution of styrene in benzene at 60° for 24 hours in the presence of a catalyst prepared in the presence of monomer from equimolar amounts of (C2H5)3A1 (heptane solution) and T1CI3-AA (heptane suspension). The reaction mixture was diluted with benzene and poured into an excess of isopropanol. The resulting precipitate was dissolved in warm methylene chloride. The solution was filtered and added to hot methyl ethyl ketone. The solution was concentrated and cooled to obtain the isotactic polymer in the form of a white powder that was washed with methyl ethyl ketone and dried under vacuum. Final purification was achieved by reprecipitation of the polymer from benzene solution into methanol, followed by drying at 60° under vacuum. 

Here the biotransformation (Fig. 19-6) is preferred over the chemical reduction with commercially available asymmetric catalysts (BH3- or noble-metal-based), since with the chemocatalysts the desired high enantiomeric excess (ee > 98%, 99.8% after purification) is not achievable. Since the ketone has only a very low solubility in the aqueous phase, 1 kg ketone is added as solution in 4 L 0.9 M H2SO4 to the bioreactor. The bioreduction is essentially carried out in a two-phase system, consisting of the aqueous phase and small droplets made up of substrate and product. The downstream processing consists of multiple extraction steps with methyl ethyl ketone and precipitation induced by pH titration of the pyridine functional group (pfCa = 4.66) with NaOH. The (R)-amino alcohol is an important intermediate for the synthesis of (1-3-agonists that can be used for obesity therapy and to decrease the level of associated type II diabetes, coronary artery disease and hypertension. 

The membranes used for ethanol purification are also suitable for dehydration of many other organic solvents, including methanol, isopropanol, butanol, methyl ethyl ketone, acetone, and chlorinated solvents. Commercial units use up to 12 stages with reheating between stages, and product water contents lower than 100 ppm can be obtained. 

Acetone is used to extract fats, oils, waxes, and resins from natural products, to dewax lubricating oils, and to extract certain essential oils. The pharmaceutical industry uses acetone to extract B-vitamin complexes, alkaloids, antibiotics and enzymes. Methyl ethyl ketone is used to dewax lube oil. Methyl isobutyl ketone is used to dewax mineral oil, refine tall oil, and in extractive distillation and separation of isopropyl alcohol from ethyl and butyl alcohols. The extraction and purification of antibiotics and other pharmaceutical products utilize MIBK. Methyl isobutyl ketone is used in the extraction of rosin from pine wood and the extraction of heavy metal ion complexes from water solutions. 

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