Isopropyl alcohol, from acetone ketones

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. 

Ketones and esters are required for C-type inks. Types of esters are ethyl acetate, isopropyl acetate, normal propyl acetate, and butyl acetate. From the ketone class, acetone or methyl ethyl ketone (MEK) can be used. The usual solvent for D-type inks are mixtures of an alcohol, such as ethyl alcohol or isopropyl alcohol, with either aUphatic or aromatic hydrocarbons. Commonly used mixtures are 50/50 blends by volume of alcohol and aUphatic hydrocarbon. 

Direct oxidation yields biacetyl (2,3-butanedione), a flavorant, or methyl ethyl ketone peroxide, an initiator used in polyester production. Ma.nufa.cture. MEK is predominandy produced by the dehydrogenation of 2-butanol. The reaction mechanism (11—13) and reaction equihbtium (14) have been reported, and the process is in many ways analogous to the production of acetone (qv) from isopropyl alcohol. 

Ulijn et al. identified an enzyme, capable of enantioselectively reducing the ketone, from their extensive collection of ADH variants further modification of the hit resulted in a biocatalyst that produces the desired (5)-alcohol in >99.9% ee at concentrations of 100 gL in a sofid-to-sofid biotransformation, where both starting material and product display only sparing solubility in the reaction medium. High conversions (>99%) are achieved by the substrate-coupled method, using 50 % v/v isopropyl alcohol concentrations to drive the reaction by continuous acetone removal (Scheme 1.55). The product can be easily isolated by filtration and washing. 

Ketones.have the characteristic -C- signature group imbedded in them. Acetone, CH3COCH3, comes from two different routes. It is a by-product in the cumene to phenol/acetone process. It is the on-purpose product of the catalytic dehydrogenation of isopropyl alcohol. Acetone is popular as a solvent and as a chemical intermediate for the manufacture of MIBK, methyl methacrylate, and Bisphenol A. 

While alcohols and acids are considered to be primary products (see Figure 4) ketones are probably formed in secondary reactions which only occur at higher temperatures 2). In Table II it can be seen that as the temperature increases, ketone production increases at the expense of alcohols up to a point after which both decrease (due to hydrogenation to hydrocarbons which under FT conditions are thermodynamically more stable (2), It has been suggested (2) that ketones result from the direct reaction between alcohols and surface carbon atoms and/or from the dehydrogenation of secondary alcohols (eg under high temperature FT conditions acetone and isopropyl alcohol are in thermodynamic equilibrium (2). 

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... 

Major markets as solvents and intermediates have made the ketones important commercial products lor many years. Acetone and mcthylethyl ketone have had the most impact on the chemical industry Acetone Is used s an intermediate In methyl isobutyl ketone, methyl methacrylate, diucelonc alcohol. ketone. hisphenol-A. phiwnc. and mesityl oxide Acetone is largely produced by dehydration of isopropyl alcohol In the production of phenol from cumene, acetone is produced as a by-product This mute to acetone has tended to control its price. 

The reduction of aldehydes and ketones is carried out very easily. The carbonyl compound and aluminum isopropoxide, prepared from aluminum and isopropyl alcohol, are heated in boiling isopropyl alcohol solution with provision for slow distillation until no more acetone is formed. The general equation may be represented as follows. 

More elaborate means have been described for removing the acetone by distillation with relatively little isopropyl alcohol. These include various columns such as a Vigreux13 or a modified Widmer column.10 They are to be recommended when the aldehyde or ketone boils Within 50° of isopropyl alcohol, but are unnecessary under other circumstances. A reflux condenser maintained at constant temperature by boiling methanol has been suggested.6 More convenient than this is the simple but effective partial condenser designed by Hahn.49 An easily constructed modification is illustrated in Fig. 3 (adapted from Organic Syntheses).60 The partial condenser is attached directly to the round-bottomed flask, and ethanol is placed in the inner condensing tube. The... 

Dehydrogenation or dehydration of alcohol to form ketones, e.g., acetone from isopropyl alcohol... 

It does not form, however, an addition-product with ammonia similar to that derived from aldehyde, but complex condensation products. When reduced by nascent hydrogen generated by the action of sodium amalgam on water, addition takes place as indicated above, and isopropyl alcohol is formed, but at the same time a dihydroxy alcohol, which contains six carbon atoms, is produced in appreciable quantities. This substance, called pinacol, is the first member of a series of such alcohols which are formed by the reduction of ketones. The equation for the reaction in the case of acetone is,... 

A major feature of acetone noted previously is that, along with isopropyl alcohol (IPA), it is considered a universal solvent. This means that acetone and IPA are fiilly miscible with a wide range of compounds within solvent classes such as alkanes, chlorinated alkanes, ketones, and—most inqiortantly— water. Consequently, for those support materials that are used as either NP or RP supports (e.g., cyanqiropyl, aminopropyl, diol), acetone (w IPA) may be used as a conversion solvent For example, to change a cyanopropyl colunm from a NP hexane/ dichloromethane mobile phase to a RP acetonitrile/water system, acetone (or IPA) is equilibrated with the column as an intermediate step. Note that buffers should never be present in any solution during the conversion step. If a buffer is in the mobile phase, then an identical mobile phase without the buffer must be equilibrated with the column prior to the conversion step. 

FIGURE 7 Generic solvent-exchange method, direct injection GC/FID. From bottom to top blank injection and GC volatiles test solution. Peaks I, methanol 2, n-pentane 3, ethanol 4, acetone 5 isopropyl alcohol 6, acetonitrile 7, methyl acetate 8, methylene chloride 9 methyl tertiary butyl ether 10, n-hexane 11, propanol 12, methyl ethyl ketone 13, ethyl acetate 14, sec-butanol 15, tetrahydrofuran 16, cyclohexane 17, hexamethyidisiloxane 18, benzene 19, n-heptane 20, butyl alcohol 21, 1,4-dioxane 22, methyl isobutyl ketone 23, pyridine 24, toluene 25, isobutyl acetate 26, n-butyl acetate 27, p-xylene 28, dimethylacetamide 29, solvent impurities. 

Some form of activated carbon is used in these processes rather than silica- and alumina-base adsorbents, because of carbon s selectivity for organic vapors in the presence of water. Typical solvents, which can be recovered from air streams by activated carbon, include hydrocarbons such as naphtha or petroleum ether methyl, ethyl, isopropyl, butyl, and other alcohols chlorinated hydrocarbons such as carbon tetrachloride, ethylene dichloride, and propylene dichloridc esters. such as methyl, ethyl, isopropyl, butyl, and amyl acetate acetone and other ketones ethers aromatic hydrocarbons such as benzene, toluene, and xylene carbon disulfide, and many other compounds. 

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