Methyl propyl ether, reaction

Addition of alcohol to alkenes hy alkoxymercuration-reduction produces ethers via Markovnikov addition. This addition is similar to the acid-catalysed addition of an alcohol. For example, propene reacts with mercuric acetate in aqueous THF, followed hy reduction with NaBFl4, to yield methyl propyl ether. The second step is known as demercuration, where Flg(OAc) is removed hy NaBH4. Therefore, this reaction is also called alkoxymercura-tion-demercuration. The reaction mechanism is exactly the same as the oxymercuration-reduction of alkenes. 

The constant for the decomposition of gaseous propionic aldehyde falls away steadily below about 80 mm., that for the decomposition of diethyl ether below about 150 mm., that for the decomposition of diethyl ether below about 300 mm. Several other ethers, dipropyl ether, methyl propyl ether and methyl ethyl ether behave in a similar manner. The velocity constant for the decomposition of azomethane also diminishes but not until lower pressures are reached for example at 290° C. k at 0-259 mm. has one-fourth of its value at 707-9 mm. In several reactions, such as the racemization of pinene, and the decomposition of gaseous acetone the falling off of the velocity constant has not actually been looked for. The decomposition of azoisopropane is unimolecular down to pressures of 0-25 mm. 

A study of the photo-sensitized ring-opening reactions of the radical cations (76) of arylcyclopropanes (75) with methanol, water, and cyanide nucleophiles suggests a three-electron 5k2 mechanism (Scheme 11).185 The isolated products are methyl propyl ethers, derived from nucleophilic attack of methanol on the radical cation (76). They were detected by UV-VIS spectroscopy and shown to react with nucleophiles by transient kinetic methods. The benzyl radical (77) reacts with the DCB radical anion to afford monoaromatic ether (78) by oxidation and protonation or the disubstituted ether (79) by addition of DCB. Regio- and stereo-selectivity of the substitution were complete regiochemistry and rate constant were profoundly effected by the electronic nature of the aryl substituents.186 Elsewhere, a combined ab initio and CIDNP study... 

METHYL PROPYL ETHER (557-17-5) Forms explosive mixture with air (flash point < -4°F/< -20°C). Able to form unstable peroxides. Violent reaction with strong oxidizers, permanganates, peroxides, ammonium persulfate, bromine dioxide, strong acids, acyl halides. Flow or agitation of substance may generate electrostatic charges due to low conductivity. 

The inflammable solvents most frequently used for reaction media, extraction or recrystallisation are diethyl ether, petroleum ether (b.p. 40-60° and higher ranges), carbon disulphide, acetone, methyl and ethyl alcohols, di-Mo-propyl ether, benzene, and toluene. Special precautions must be taken in handling these (and other equivalent) solvents if the danger of Are is to be more or less completely eliminated. It is advisable to have, if possible, a special bench in the laboratory devoted entirely to the recovery or distillation of these solvents no flames are permitted on this bench. 

Repeat this analysis for the reaction of phenyl methyl ether with HI leading to phenol and methyl iodide or methanol and phenyl iodide and involving protonated phenyl methyl ether as an intermediate. (Note In this case, the appropriate empty molecular orbital is LUMO+2 the LUMO is concentrated primarily on the CO bond.) Which reaction, with ethyl propyl ether or phenyl methyl ether, appears to be more likely to give selective ether cleavage ... 

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... 

Reactions of a-haloethers in aqueous medium has been reviewed recently . The reactions in water are extremely rapid and in general precise kinetic data is not available. For example, it is estimated that methyl chloromethyl ether undergoes hydrolysis 10 times faster than n-propyl chloride . The rapidity of the reactions of a-haloethers is attributed to resonance stabilization of the transition state according to the structures... 

The ketone, the hydrogenation catalysts and the ammonium salt are present in an aqueous solution which may also contain a suitable organic solvent or solvents inert to the reactants and the products formed by the reaction As examples of useful organic solvents, mention may be made of alcohols such as methanol, ethanol and propanol ethers such as ethyl ether, propyl ether and ethyl hexyl ether esters such as methyl acetate, ethyl formate and amyl acetate, and various acids and hydrocarbon solvents well known in the art. 

As seen in Scheme 14, molecular elimination processes (including cage disproportionation reactions) account for about half of the primary decomposition. This is in contrast to the behavior of the Isosteric ethers such as diethyl (177) and methyl n-propyl ethers (88), where these processes are rather less important (Schemes 6 and 7). It is not known whether the formaldehyde formed in reaction 4 (Scheme 14) incorporates the carbon atom from methylene or methyl. 

Figure 8-7. Correlation between equilibrium constant for esterification and solubility of water in the solvent. Equilibrium constant was defined as [Ester]/([Alcohol].[Acid]), for reactions at fixed water activity (close to 1). Solvents are bb, butyl benzoate be, bromoethane bk, dibutyl ketone bp, dibutyl phthalate bz, benzene ca, 1,1,1-trichloroethane cf, chloroform ct, carbon tetrachloride cy, trichloroethylene ee, ethyl ether ek, diethyl ketone ep, diethyl phthalate hd, hexadecane hx, hexane me, methylene chloride mk, methyl iso-butyl ketone nm, nitromethane oc, /so-octane pe, iso-propyl ether tl, toluene. Valivety et al...

Figure lll-B-7. Arrhenius plot of the rate coefficient for the reaction of NO3 with Ce ethers (di-n-propyl ether, DnPE di-isopropyl ether, DiPE ethyl rerr-butyl ether, ETBE and fert-amyl methyl ether, TAME). 

Simple alkyl radicals such as methyl are considered to be nonnucleophilic. Methyl radicals are somewhat more reactive toward alkenes bearing electron-withdrawing substituents than towards those with electron-releasing substituents. However, much of this effect can be attributed to the stabilizing effect that these substiments have on the product radical. There is a strong correlation of reaction rate with the overall exothermicity of the reaction. Hydroxymethyl and 2-hydroxy-2-propyl radicals show nucleophilic character. The hydroxymethyl radical shows a slightly enhanced reactivity toward acrylonitrile and acrolein, but a sharply decreased reactivity toward ethyl vinyl ether. Table 12.9 gives some of the reactivity data. 

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