Methyl ethyl ketone, atmosphere

Peroxide-Ketazine Process. Elf Atochem in France operates a process patented by Produits Chimiques Ugine Kuhhnaim (PCUK). Hydrogen peroxide (qv), rather than chlorine or hypochlorite, is used to oxidize ammonia. The reaction is carried out in the presence of methyl ethyl ketone (MEK) at atmospheric pressure and 50°C. The ratio of H202 MEK NH2 used is 1 2 4. Hydrogen peroxide is activated by acetamide and disodium hydrogen phosphate (117). Eigure 6 is a simplified flow sheet of this process. The overall reaction results in the formation of methyl ethyl ketazine [5921-54-0] (39) and water ... 

Ergometrine crystallises, with solvent, from benzene in needles or from methyl ethyl ketone in prisms both forms have m.p. 162-3° (dec.). From ethyl acetate it crystallises at — 4° in thin, solvent-free plates, m.p. 160-1° (dec.), and at atmospheric temperature on concentration in vacuo in diamond-shaped plates, B.0-5EtAc, m.p. 130-2° (dec.), from which the combined solvent is not removed at 100° in vacuo. By crystallisation from acetone, Grant and Smith obtained a second form in long needles, m.p. 212° (dec.), which appears to be the more stable, since the form, m.p. 162-3°, tends to pass into it on keeping. Ergometrine has [o]d — 44° (CHCI3) - - 42-2° or + 62-6° (c = 1-7, EtOH) or... 

Among the reaction products, the oxime of methyl ethyl ketone was found. Under atmospheric pressure (flow system) and at a lower temperature (80°C), the same oxime (55) affords nonvinylated 2,3-dimethyl- and 2-(l-propenyl-2)pyrroles in low yield along with a larger amount of resin (—50%). In a run without acetylene carried out under even harsher conditions (100-110°C, 7 hr, atmospheric pressure), over 80% of the oxime 55 was recovered. 

Low molecular weight aldehydes and ketones are used in the manufacture of resins, dyes, esters, and other organic chemicals. Many ketones including acetone and methyl ethyl ketone are industrial solvents. Some of the compounds that are used commercially are presented in Table 2.1.1. Mary aldehydes and ketones are emitted into the atmosphere from chemical and combustion processes. Photochemical degradation of many organic substances also generates lower aldehydes and ketones. 

This process (see Figure 18.3) was invented by PCUK and is operated by AtoFina in France. The reaction is carried out in the presence of methyl ethyl ketone (MEK) at atmospheric pressure and 50°C. The molar ratio in the feed of hydrogen peroxide (H202) MEK NH3 is 1 2 4. 

On the other hand, Gavrilova and Gonikberg opened the furan ring with hydrogen, without the use of catalysts.213 The reaction is carried out at high temperature (350-375°) and at a pressure between 240 and 750 atmospheres, in the absence of a solvent. The following products are obtained from 2-methylfuran acetone, methyl ethyl ketone, methyl butyl ketone, methyl amyl ketone, acetophenone, methylpropylcarbinol, w-pentane, and water. The authors suggest that these products are formed by a free radical mechanism. 

The platinum metals Pt, Pd, Rh, Ir, Ru, Os, and Au The metals are present as their chlorides or sodium chloro-salts. The solvent used is methyl ethyl ketone containing 30 per cent (v/v) hydrochloric acid (d 118) it is freshly prepared. The solution is spotted on the paper strip and allowed to dry thoroughly in the air. The atmosphere in the separation vessel is saturated with respect to the... 

Ozonolysis of cis-3,4-Dimethyl-3 -hexene. A solution of cis-3,4-di-methyl-3-hexene (98% pure, Chemical Samples Co.) (1.12 grams, 10 mmoles) in 50 ml pentane was ozonized at — 62°C until the blue color of excess ozone was evident. A nitrogen stream was used to purge the solution of excess ozone. Pentane was then carefully distilled off at atmospheric pressure. A water aspirator (20 mm Hg) was then used to remove the ketone product. Treatment of this material with 10 ml of an 0.1 M solution of 2,4-dinitrophenylhydrazine gave 2.33 grams of crude 2,4-dinitrophenylhydrazone. The crude product was recrystallized and identified as the 2,4-dinitrophenylhydrazone of methyl ethyl ketone, mp 115-116°C. Yield of the ketone was 92% based on olefin used. 

The mesembrine alkaloids can be separated chromatographically by the ascending method on paper (Schleicher and Schuell 2042 b mgl), impregnated with a solution of formamide in acetone (1 4), with the solvent systems A (methyl ethyl ketone heptane = 2 3) and B (methyl ethyl ketone xylene = 1 1), in an atmosphere saturated with ammonia (12). After spraying with Dragendorff reagent an extract from /S. nama-quense showed at least nine alkaloids. The Rf values of the mesembrine alkaloids are given in Table II. 

Siloxane-based sealants cure either by condensation or addition reactions (22). One-package systems are available that cure in the presence of atmospheric moisture. The cross-linking reaction results in the elimination of either acetic acid or methyl ethyl ketone depending on the resin system. The more conventional two-package systems use metallic soaps such as dibutyl tin dilaurate to catalyze the cross-linking with the subsequent elimination of ethyl alcohol. Addition cures can also be accomplished with vinyl-containing polysiloxanes and a transition metal catalyst. 

A. Saturated compounds Aliphatic aldehydes and ketones such as acetaldehyde, propionaldehyde, aldol, acetone, methyl ethyl ketone, ethyl-acetoacetate, and acetonylacetone are hydrogenated by ruthenium at atmospheric conditions as illustrated in Table I, No. 1-10. 

This class of organic compounds is exemplified by acetone and its higher homologues. As for the aldehydes, photolysis and reaction with the OH radical are the major atmospheric loss processes (Atkinson, 1989). The limited experimental data available indicate that, with the exception of acetone (see Figure 5.11), photolysis is probably of minor importance. Reaction with the OH radical is then the major tropospheric loss process. For example, for methyl ethyl ketone the OH radical can attack any of the three carbon atoms that contain hydrogen atoms ... 

Ultra-thin epoxy films with thickness d p of 60, 125, 250, and 650 nm were spin-coated in C02-reduced, dried air (dew point -70 °G) from the appropriately diluted prepolymer solution in methyl ethyl ketone (MEK). After film preparation, the specimens were stored in the same atmosphere at about 23 °C for 72 h. This room temperature (RT) curing was followed by a post-curing" step at 120 °C in argon for 1 h. 

The cobaloxime(II) derivatives [Co(Hdmg)2(Ph3P)d and [CoCHdmgV pyal, where Htdmg is dimethylglyoxime, are catalysts for the oxidation of o-phenylenediamine (OPD) by atmospheric O2 at ambient temperature. In acetone, methyl ethyl ketone or cyclohexanone as solvents, cyclization to 2,2-disubstituted dihydrobenzimidazoles (DHB) is followed by... 

Methyl ethyl ketone-acetonitrile-water (MEK) (84 8 8). A mixture of MEK and water (3 2) is placed in bottom of chamber to provide a solvent satd. atmosphere Detection... 

Some partially miscible mixtures cannot be separated directly by this method. For example, methyl ethyl ketone and water are pai tially miscible and form an azeotrope at atmospheric pressure, but... 

Methyl Ethyl Ketone Methyl Chloride u u u u Satisfactory for use under atmospheric ... 

As stated in Chapter 7, the composition of an azeotrope varies with the distillation pressure. Thus, the azeotrope between ethanol and water contains 89.4 mol% ethanol at atmospheric pressure, 90.2 mol% ethanol at 380 mm Hg, and 92.0 mol% ethanol at 190 mm Hg absolute pressure [6]. Similarly, the azeotrope between methyl ethyl ketone and water contains 65.4 mol% MEKat atmospheric pressure, 70.0 mol% MEKat 350 mm Hg, and 72.2 mol% MEKat 200 mm Hg absolute pressure. Because MEK and water form two immiscible liquid phases upon condensation of the overhead, these two compounds can be separated by distilling each of these two phases separately. Because the azeotrope of ethanol and water is a single-phase liquid, separation of these two components can be achieved by distillation in two columns operating at different pressures in order to shift the azeotropic composition. 

The 2-butoxy, and 1-butoxy radicals formed in the reactions of 2-butyl and 1-butyl peroxy radicals with NO (path (d) and (j)), react with O2 to produce HO2 together with carbonyl compounds such as methyl ethyl ketone and butanal (path (g) and (1)), and complete the HO cycle. Under the typical NO concentrations in the polluted atmosphere, the formation rate of alkyl nitrates by the reactions of alkoxy radicals with NO2 is negligible, the recombination isomerization reaction by the alkylperoxy radicals with NO is the major pathway as the formation process of alkyl nitrate. 

Figure 22. Automatically generated atmospheric concentration profiles of acetone, methyl ethyl ketone, and diisobutyl ketone as they evaporated from a liquid mixture of these compounds. A neural network was used to detect when each component was present, and the concentration of each molecule was calculated by PLS regression. (One bad point can be seen for MEK.)...

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