A butyl ether

It is now known1 that trialkyl phosphates will indeed alkylate phenols. The idea has been extended2 to the production of methyl ethers from alcohols and trimethyl phosphate, and of a butyl ether according to the equation... 

Another commonly used cyclodextrin Capfi oiulfobutylether ofi-CD (SBE-ft-CD), is a polyanionicp-cyclodextrin derivative with a sodium sulfonate salt separated from the lipophilic cavity by a butyl ether spacer group, or sulfobutylether. BotfHBGPand sulfobutylether qf-CD (SBE-p-CD) are widely used cyclodextrins for solubility-enhancing purpose. 

The reaction of either cis- or trans-1 with potassium /-butoxide in tetrahydrofuran at 25 °C leads to a /-butyl ether (2), apparently arising by attack of /-butoxide ion on an intermediate l,4-di-/-butylmethylenecyclopropene. If the reaction is carried out at low temperature and the volatile materials are distilled directly into a cold trap, the cyclopropene can be trapped, albeit in low yield (10 %), by added cyclopentadiene or detected directly by low-temperature NMR23. In a related example, a l,l-dihalo-2-bromo-3-methylcyclopropane (2a) leads to products which are also apparently derived through an intermediate 1 -chloro-3-methylenecyclopropene which undergoes nucleophilic addition (See Ref. 80). 

This polymer has a butyl ether group at one end and a hydroxyl group at the other end. 

Tetrachlorostannane (0.19-0.29 mol) is added dropwise to a butyl ether solution of methymagnesium iodide prepared from methyl iodide (1.59 mol) and magnesium (2.06 g. atom) at room temperature. Only gentle refluxing should occur during this step which requires 2-2.5 h to complete. The reaction mixture is heated under steady reflux (85-95 °C) for Ih and then allows to stand for several hours. The crude product is distilled from the reaction mixture, and a mixture of tetramethylstannane and butyl ether, distilling at 85-95 °C, is obtained. Tetramethylstannane (85-91%) is isolated by the fractional distillation of the mixture. 

The remaining components are common to many refinery streams, and thus isobutene and w-butenes may be derived from either source. Isobutene is generally recovered from the butadiene-free raffinate by chemical means. For example, by contacting the mixture with 65% sulphuric acid, r-butanol is formed in the acid phase, from which fairly pure isobutene (for butyl rubber ) may be regenerated. Alternatively, the isobutene within the mixed C4 stream may be converted directly to the dimer and trimer by contact with solid acidic catalysts, to viscous polybutenes by treatment with Lewis acid catalysts, or to a /-butyl ether (section 12.9.3). The reported 1993 U.S. production of isobutene was about 500 kt, but this refers only to isolated material (including dehydration of Arco s co-product /-butanol) derivatives possibly consumed 7-8 Mt in the U.S. compared with roughly 2Mt in Europe. 

Rat et al. (2011) reported simultaneous formation of glycosylation, esterifieation and a butyl ether resulting in substitution of a glucuronic acid trisaccharide. This substitution was easily performed in one step under microwave irradiation. 

MTBE Methyltert-butyl ether. Used as a gasoline additive. 

A small residue of di- -butyl ether, b.p. 142°, remains in the flask. 

Di-n-butyl ether. Technical n-butyl ether does not usually contain appreciable quantities of peroxides, unless it has been stored for a prolonged period. It should, however, be tested for peroxides, and, if the test is positive, the ether should be shaken with an acidified solution of a ferrous salt or with a solution of sodium sulphite (see under Diethyl ether). The ether is dried with anhydrous calcium chloride, and distilled through a fractionating column the portion, b.p. 140-141°, is collected. If a fraction of low boiling point is obtained, the presence of n-butyl... 

This preparation is an example of the use of di-M-butyl ether as a solvent in the Grignard reaction. The advantages are it is comparatively inexpensive, it can be handled without excessive loss due to evaporation, simple distillation gives an ether free from moisture and alcohol, and the vapour does not form explosive mixtures with air. n-Butyl ether cannot, of course, be employed when the boiling point of the neutral reaction product is close to 140°. 

Prepare a Grignard reagent from 24 -5 g. of magnesium turnings, 179 g. (157 ml.) of n-heptyl bromide (Section 111,37), and 300 ml. of di-n-butyl ether (1). Cool the solution to 0° and, with vigorous stirring, add an excess of ethylene oxide. Maintain the temperature at 0° for 1 hour after the ethylene oxide has been introduced, then allow the temperature to rise to 40° and maintain the mixture at this temperature for 1 hour. Finally heat the mixture on a water bath for 2 hours. Decompose the addition product and isolate the alcohol according to the procedure for n-hexyl alcohol (Section 111,18) the addition of benzene is unnecessary. Collect the n-nonyl alcohol at 95-100°/12 mm. The yield is 95 g. 

The crude bromide contains a little unchanged alcohol and is said to contain some n-butyl ether (b.p. 141°). The former is removed by washing with concen. trated hydrochloric acid and this purification process is satisfactory for most purposes. Both the alcohol and the ether are removed by washing with 11-12 ml. of concentrated sulphuric acid the butyl bromide is not affected by this reagent. 

An alternative method for isolating the n-butyl ether utilises the fact that n-butyl alcohol is soluble in saturated calcium chloride solution whilst n-butyl ether is slightly soluble. Cool the reaction mixture in ice and transfer to a separatory fimnel. Wash cautiously with 100 ml. of 2-5-3N sodium hydroxide solution the washings should be alkaline to litmus. Then wash with 30 ml. of water, followed by 30 ml. of saturated calcium chloride solution. Dry with 2-3 g. of anhydrous calcium chloride, filter and distil. Collect the di-n-butyl ether at 139-142°. The yield is 20 g. 

Compounds which dissolve in concentrated sulphuric acid may be further subdivided into those which are soluble in syrupy phosphoric acid (A) and those which are insoluble in this solvent (B) in general, dissolution takes place without the production of appreciable heat or colour. Those in class A include alcohols, esters, aldehydes, methyl ketones and cyclic ketones provided that they contain less than nine carbon atoms. The solubility limit is somewhat lower than this for ethers thus re-propyl ether dissolves in 85 per cent, phosphoric acid but re-butyl ether and anisole do not. Ethyl benzoate and ethyl malonate are insoluble. 

Separations based upon differences in the chemical properties of the components. Thus a mixture of toluene and anihne may be separated by extraction with dilute hydrochloric acid the aniline passes into the aqueous layer in the form of the salt, anihne hydrochloride, and may be recovered by neutralisation. Similarly, a mixture of phenol and toluene may be separated by treatment with dilute sodium hydroxide. The above examples are, of comse, simple apphcations of the fact that the various components fah into different solubihty groups (compare Section XI,5). Another example is the separation of a mixture of di-n-butyl ether and chlorobenzene concentrated sulphuric acid dissolves only the w-butyl other and it may be recovered from solution by dilution with water. With some classes of compounds, e.g., unsaturated compounds, concentrated sulphuric acid leads to polymerisation, sulphona-tion, etc., so that the original component cannot be recovered unchanged this solvent, therefore, possesses hmited apphcation. Phenols may be separated from acids (for example, o-cresol from benzoic acid) by a dilute solution of sodium bicarbonate the weakly acidic phenols (and also enols) are not converted into salts by this reagent and may be removed by ether extraction or by other means the acids pass into solution as the sodium salts and may be recovered after acidification. Aldehydes, e.g., benzaldehyde, may be separated from liquid hydrocarbons and other neutral, water-insoluble hquid compounds by shaking with a solution of sodium bisulphite the aldehyde forms a sohd bisulphite compound, which may be filtered off and decomposed with dilute acid or with sodium bicarbonate solution in order to recover the aldehyde. 

Quach, D. T. Giszkowski, N. A. Einlayson-Pitts, B. J. A New GG-MS Experiment for the Undergraduate Instrumental Analysis Laboratory in Environmental Ghemistry Methyl-f-butyl Ether and Benzene in Gasoline, /. Chem. Educ. 1998,... 

Isobutyl alcohol [78-83-1] forms a substantial fraction of the butanols produced by higher alcohol synthesis over modified copper—zinc oxide-based catalysts. Conceivably, separation of this alcohol and dehydration affords an alternative route to isobutjiene [115-11 -7] for methyl /-butyl ether [1624-04-4] (MTBE) production. MTBE is a rapidly growing constituent of reformulated gasoline, but its growth is likely to be limited by available suppHes of isobutylene. Thus higher alcohol synthesis provides a process capable of supplying all of the raw materials required for manufacture of this key fuel oxygenate (24) (see Ethers). 

Capacity Limitations and Biofuels Markets. Large biofuels markets exist (130—133), eg, production of fermentation ethanol for use as a gasoline extender (see Alcohol fuels). Even with existing (1987) and planned additions to ethanol plant capacities, less than 10% of gasoline sales could be satisfied with ethanol—gasoline blends of 10 vol % ethanol the maximum volumetric displacement of gasoline possible is about 1%. The same condition apphes to methanol and alcohol derivatives, ie, methyl-/-butyl ether [1634-04-4] and ethyl-/-butyl ether. 

Some isopentane is dehydrogenated to isoamylene and converted, by processes analogous to those which produce methyl /-butyl ether [1634-04-4] (MTBE) to /-amyl methyl ether [994-05-8] (TAME), which is used as a fuel octane enhancer like MTBE. The amount of TAME which the market can absorb depends mostly on its price relative to MTBE, ethyl /-butyl ether [637-92-3] (ETBE), and ethanol, the other important oxygenated fuel additives. 

High temperature steam reforming of natural gas accounts for 97% of the hydrogen used for ammonia synthesis in the United States. Hydrogen requirement for ammonia synthesis is about 336 m /t of ammonia produced for a typical 1000 t/d ammonia plant. The near-term demand for ammonia remains stagnant. Methanol production requires 560 m of hydrogen for each ton produced, based on a 2500-t/d methanol plant. Methanol demand is expected to increase in response to an increased use of the fuel—oxygenate methyl /-butyl ether (MTBE). 

Dehydrogenation of Tertiary Amylenes, The staiting material here is a fiaction which is cut from catal57tic clacking of petroleum. Two of the tertiary amylene isomers, 2-methyl-l-butene and 2-methyl-2-butene, are recovered in high purity by formation of methyl tertiary butyl ether and cracking of this to produce primarily 2-methyl-2-butene. The amylenes are mixed with steam and dehydrogenated over a catalyst. The cmde isoprene can be purified by conventional or extractive distillation. 

The dehydrogenation of 2-butanol is conducted in a multitube vapor-phase reactor over a zinc oxide (20—23), copper (24—27), or brass (28) catalyst, at temperatures of 250—400°C, and pressures slightly above atmospheric. The reaction is endothermic and heat is suppHed from a heat-transfer fluid on the shell side of the reactor. A typical process flow sheet is shown in Figure 1 (29). Catalyst life is three to five years operating in three to six month cycles between oxidative reactivations (30). Catalyst life is impaired by exposure to water, butene oligomers, and di-j -butyl ether (27). 

Like //-butyUithium, j iZ-butyUithium is infinitely soluble in most hydrocarbons, such as pentane and hexane. Its solutions in hexane are flammable and pyrophoric and therefore should be handled like //-butyUithium (96,100). j iZ-ButyUithium also is very soluble in ethers, but the ether solutions must be kept cold because ether cleavage is more rapid than in the presence of //—butyUithium (122). j iZ-ButyUithium has a t 2 of 2 d at 25°C in di-//-butyl ether and of 1 d at 25°C in di-//-hexyl ether. 

Until 1982, almost all methyl methacrylate produced woddwide was derived from the acetone cyanohydrin (C-3) process. In 1982, Nippon Shokubai Kagaku Kogyo Company introduced an isobutylene-based (C-4) process, which was quickly followed by Mitsubishi Rayon Company in 1983 (66). Japan Methacryhc Monomer Company, a joint venture of Nippon Shokubai and Sumitomo Chemical Company, introduced a C-4-based plant in 1984 (67). Isobutylene processes are less economically attractive in the United States where isobutylene finds use in the synthesis of methyl /i / butyl ether, a pollution-reducing gasoline additive. BASF began operation of an ethylene-based (C-2) plant in Ludwigshafen, Germany, in 1990, but favorable economics appear to be limited to conditions unique to that site. 

AlkoxyaLkyl hydroperoxides are more commonly called ether hydroperoxides. They form readily by the autoxidation of most ethers containing a-hydrogens, eg, dioxane, tetrahydrofuran, diethyl ether, diisopropyl ether, di- -butyl ether, and diisoamyl ether (10,44). From certain ethers, eg, diethyl ether (in the following, R = H R = 35 — CH2CH2), the initially formed ether hydroperoxide can yield alcohol on standing, or with acid treatment... 

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