Methyl f-butyl

Various 4-, 5-, or 4,5-disubstituted 2-aryIamino thiazoles (124), R, = QH4R with R = 0-, m-, or p-Me, HO C, Cl, Br, H N, NHAc, NR2, OH, OR, or OjN, were obtained by condensing the corresponding N-arylthiourea with chloroacetone (81, 86, 423), dichloroacetone (510, 618), phenacyichloride or its p-substituted methyl, f-butyl, n-dodecyl or undecyl (653), or 2-chlorocyclohexanone (653) (Method A) or with 2-butanone (423), acetophenone or its p-substituted derivatives (399, 439), ethyl acetate (400), ethyl acetyl propionate (621), a- or 3-unsaturated ketones (691), benzylidene acetone, furfurylidene acetone, and mesityl oxide in the presence of Btj or Ij as condensing agent (Method B) (Table 11-17). 

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,... 

Extraction of water with methylene chloride, removal of water from extract, volume reduction to 5 mL after solvent exchange to methyl-f-butyl ether... 

Salanitro JP, LA Diaz, MP Williams, HL Wisniewski (1994) Isolation of a bacterial culture that degrades methyl f-butyl ether. Appl Environ Microbiol 60 2593-2596. 

Principles and Characteristics Although early published methods using SPE for sample preparation avoided use of GC because of the reported lack of cleanliness of the extraction device, SPE-GC is now a mature technique. Off-line SPE-GC is well documented [62,63] but less attractive, mainly in terms of analyte detectability (only an aliquot of the extract is injected into the chromatograph), precision, miniaturisation and automation, and solvent consumption. The interface of SPE with GC consists of a transfer capillary introduced into a retention gap via an on-column injector. Automated SPE may be interfaced to GC-MS using a PTV injector for large-volume injection [64]. LVI actually is the basic and critical step in any SPE-to-GC transfer of analytes. Suitable solvents for LVI-GC include pentane, hexane, methyl- and ethylacetate, and diethyl or methyl-f-butyl ether. Large-volume PTV permits injection of some 100 iL of sample extract, a 100-fold increase compared to conventional GC injection. Consequently, detection limits can be improved by a factor of 100, without... 

Etherol A process for making oxygenated fuels (e.g., methyl f-butyl ether) from C4-C6 hydrocarbons by reacting them with methanol over an acid resin catalyst in a fixed bed reactor under mild conditions. Developed by BP with Erdoel Chemie and first used in a refinery at Vohburg, Germany, in 1986. Four units were operating and one was under construction in 1988. 

Generally, dissolved aromatics may be found quite far from the origin of a spill, but entrained hydrocarbons may be found in water close to the petroleum source. Oxygenates such as methyl-f-butyl ether (MTBE) are even more water soluble than aromatics and are highly mobile in the environment. 

One method (EPA 8020) that is suitable for volatile aromatic compounds is often referred to as benzene-toluene-ethylbenzene-xylene analysis, although the method includes other volatile aromatics. The method is similar to most volatile organic gas chromatographic methods. Sample preparation and introduction is typically by purge-and-trap analysis (EPA 5030). Some oxygenates, such as methyl-f-butyl ether (MTBE), are also detected by a photoionization detector, as well as olefins, branched alkanes, and cycloalkanes. 

Thermodynamic consistency of data on solutions can be tested by plotting In (71/72) against Xi and seeing whether the area between Zi = 0 and 0.5 is equal and opposite in sign to the area between 0.5 and 1.0. Such a plot is indicated in Figure 16.5 for solutions of methyl f-butyl ether and chloroform at 313.5 K (5). 

TABLE 17.3. Vapor Pressure and Composition for Solutions of Methyl f-Butyl Ether and Acetonitrile at 313.15 K. 

Initiating a remarkable series of papers in 2008-2009, Grubbs and Whited reported the formation of an Ir(I) carbene complex, 44, from the reaction of methyl f-butyl ether (MTBE) with Ozerov s (PNP)lrH2 (PNP = [N(2-P Pr2-4-Me-C6H3)2] ) and NBE [121-127]. C-H addition to (PNP)lr presumably occurs followed by... 

Wallington, T.J., Dagaut, P., Liu, R., and Kurylo, MJ. Gas-phase reactions of hydroxy radicals with the fuel additives methyl f-butyl ether and f-butyl alcohol over the temperature range 240-440 K, Environ. Sci. TechnoL, 22(7) 842-844, 1988c. Wallington, T.J. and Japar, S.M. Atmospheric chemistry of diethyl ether and ethyl ferf-butyl ether. Environ. Sci TechnoL, 25(3) 410-415, 1991. 

Various studies on the fate of the gasoline additive methyl-f-butyl ether (MTBE) have shown that it can be oxidized to t-butyl-formate (TBF) which happens particularly in the atmosphere ... 

Methyl f-Butyl Ether. MTBE is produced by reaction of isobutene and methanol on acid ion-exchange resins. The supply of isobutene, obtained from hydrocarbon cracking units or by dehydration of tert-butyl alcohol, is limited relative to that of methanol. The cost to produce MTBE from by-product isobutene has been estimated to be between 0.13 to 0.16/L ( 0.50—0.60/gal) (90). Direct production of isobutene by dehydrogenation of isobutane or isomerization of mixed butenes are expensive processes that have seen less commercial use in the United States. 

Tennakoon et al. (465) have studied, by conventional 13C NMR, the catalyzed conversion of 2-methylpropene (isobutene) to t-butanol (R = H) or to methyl-f-butyl ether i.e., 2-methyl-2-methoxy-propane (R = CH3) by... 

The rate constants for the reactions between OH and a range of ethers and hydroxy ethers have been reported at 298 K233 as well as those for reactions between dimethyl ether and methyl f-butyl ether over the range 295-750 K.234 Data from the former study show deviations from simple structure-activity relationships which were postulated to arise due to H-bonding in the reaction transition states.233 The atmospheric lifetime of methyl ethyl ether has been determined to be approximately 2 days.235 Theoretical studies on the H-abstraction from propan-2-ol (a model for deoxyribose) by OH have been reported using ab initio methods (MP2/6-31G ).236 The temperature dependence (233-272 K) of the rate coefficients for the reaction of OH with methyl, ethyl, n-propyl, n-butyl, and f-butyl formate has been measured and structure-activity... 

MTBE methyl f-butyl ether THF tetrahydrofuran EA ethyl acetate C6H12. cyclohexane DIPE diisopropyl ether DMF dimethylformamide. 

Methyl alcohol FIGURE 1 Manufacture of methyl-f-butyl ether. 

Common Diethyl ether Methyl f-butyl ether 4-Ethoxy- ... 

Only structures of type (11) can bear a substituent at nitrogen, and few reactions have been reported. However, the protected amino acids (81) may be generated from their methyl, f-butyl, or trimethylsilyl esters by treatment with strong acid or water (77JA7363). 

HPLC grade hexane and HPLC grade methyl-f-butyl ether 2.0 ml/min... 

In a particular experiment, p-cresol (23.54 g, 0.22 mol), methyl-f-butyl ether (19.36 g, 0.22 mol) and a silica/zirconia catalyst (3.5 wt%) were heated at 100°C for 3 hours. After cooling, 13.0 g of the product, 2-t-butyl-p-cresol was obtained, and 10.78 g of p-c resol was left unreacted. The FW of the product = 164 g/mol. Calculate the atom economy, yield, selectivity, carbon efficiency, and environmental factor. 

A newly developed isobutene recovery is based on its selective and quantitative etherification into methyl f-butyl ether (MTBE) by treatment of the C4 stream with methanol in the presence of a cation-exchange resin (e.g., Amberlyst 15), followed by catalytic splitting of the isolated ether [43-45]. MTBE was, and still is, primarily produced as a high-octane blending component for unleaded gazoline. 

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