Methyl ethyl ketone, reduction

The p-substituted amino ketones can be reduced readily to the more stable P-dialkylamino alcohols, many of which are useful local anaesthetics. Thus the local anaesthetic Tutocaine is made from the Mannich base derived from formaldehyde, methyl ethyl ketone and dimethylamine, followed by reduction and conversion into the p-aminobenzoate ... 

The crude ketal from the Birch reduction is dissolved in a mixture of 700 ml ethyl acetate, 1260 ml absolute ethanol and 31.5 ml water. To this solution is added 198 ml of 0.01 Mp-toluenesulfonic acid in absolute ethanol. (Methanol cannot be substituted for the ethanol nor can denatured ethanol containing methanol be used. In the presence of methanol, the diethyl ketal forms the mixed methyl ethyl ketal at C-17 and this mixed ketal hydrolyzes at a much slower rate than does the diethyl ketal.) The mixture is stirred at room temperature under nitrogen for 10 min and 56 ml of 10% potassium bicarbonate solution is added to neutralize the toluenesulfonic acid. The organic solvents are removed in a rotary vacuum evaporator and water is added as the organic solvents distill. When all of the organic solvents have been distilled, the granular precipitate of 1,4-dihydroestrone 3- methyl ether is collected on a filter and washed well with cold water. The solid is sucked dry and is dissolved in 800 ml of methyl ethyl ketone. To this solution is added 1600 ml of 1 1 methanol-water mixture and the resulting mixture is cooled in an ice bath for 1 hr. The solid is collected, rinsed with cold methanol-water (1 1), air-dried, and finally dried in a vacuum oven at 60° yield, 71.5 g (81 % based on estrone methyl ether actually carried into the Birch reduction as the ketal) mp 139-141°, reported mp 141-141.5°. The material has an enol ether assay of 99%, a residual aromatics content of 0.6% and a 19-norandrost-5(10)-ene-3,17-dione content of 0.5% (from hydrolysis of the 3-enol ether). It contains less than 0.1 % of 17-ol and only a trace of ketal formed by addition of ethanol to the 3-enol ether. 

D) 4 -[N-Ethyi-1 "-Methyl-2 -(4" -Methoxyphenyl)Ethylamino]Butyi-3,4-Dimethoxybenzoate Hydrochloride 10.3 g of 4 -iodobutyl-3,4-dimethoxybenzoate and 11.0 g of N-ethyl-p-methoxyphenylisopropylamine (obtained by catalytic reduction of an alcoholic solution of an excess quantity (60%) of p-methoxy-phenyl-acetone, to which was added a 33% (weight-for-weight) aqueous solution of ethylamine, with Pt as a catalyst), were boiled in 200 ml of methyl ethyl ketone for 20 hours, cooled and the iodine ion was determined the reaction was found to be complete. Then the methyl ethyl ketone was evaporated in vacuo and the residue was dissolved in 300 ml of water and 30 ml of ether the layers were separated and the water layer was extracted twice more with 20 ml portions of ether. 

For a number of applications curing at room temperature is desirable. This so-called cold cure is brought about by using a peroxy initiator in conjunction with some kind of activator substance. The peroxy compounds in these cases are substances such as methyl ethyl ketone peroxide and cyclohexanone peroxide, which as used in commercial systems tend not to be particularly pure, but instead are usually mixtures of peroxides and hydroperoxides corresponding in composition approximately to that of the respective nominal compounds. Activators are generally salts of metals capable of undergoing oxidation/reduction reactions very readily. A typical salt for this purpose is cobalt naphthenate, which undergoes the kind of reactions illustrated in Reactions 4.6 and 4.7. 

An efficient method has been developed by Pozdnyakov and Spivakov . In alkaline solution pertechnetate, in contrast to perrhenate, is reduced by hydrazine sulfate. After reduction technetiiun is no more extracted by methyl ethyl ketone. The distribution coefficient of technetium is by a factor up to 2500 smaller than that of rhenium. 

Ketone, methyl a-chloroethyl, phytochemical reduction of, IV, 81 —, methyl ethyl, phytoohemical reduction of, IV, 83... 

Complexes (351), (353) and (354) will catalyse the hydrogenation (DMA, 60°C, 1 atm) of acrylamide to 1-aminopropane2263,2264 but are inactive for the hydrogenation of alkenes.2263 Compounds (351) and (354) catalyse the hydrogenation of methyl vinyl ketone to methyl ethyl ketone and the reduction of unsaturated carboxylic acids.2265... 

Preparation of secondary (or tertiary) carbinols from pyridines and an aldehyde (or a ketone) in the presence of magnesium or aluminum and mercuric chloride is known in pyridine chemistry as the Emmert reaction. 7 70 For example, dimethyl-2-pyridylcarbinol is obtained in this way from pyridine and acetone. When a mixture of pyridine and acetone is subjected to an electrolytic reduction in dilute sulfuric acid at lead electrodes, a mixture of two main products results, namely, 2-(2-hydroxy-2-propyl)-3-piperideine and 4-(2-hydroxy-2-propyl)piperidine. Analogous compounds are obtained with the use of methyl ethyl ketone as the reactant. The mixed electrolytic reduction of 2-methylpyridine and acetone affords 2-(2-hydroxy-2-propyl)-6-methyl-3-piper ideine (74) and 2-methyl-4-(2-hydroxy-2-propyl)-piperidine.71... 

Tetraalkyl- and tetraatyl-ethylene glycols (pinacols) are made by reduction of ketones with active metals such as sodium, magnesium, and aluminum. The reaction is only fair for aliphatic and alicyclic ketones. Acetone, methyl ethyl ketone, cyclopentanone, and cyclohexanone all give less than 0% yields of pinacols. Mixtures of ketones are reduced to unsymmetrical pinacols. An active zinc-copper couple has been employed in the reduction of several simple olefinic aldehydes to dieodiols, e.g., crotonaldehyde to dipropenyl glycol,... 

Solvent effects Birch reduction. 1,2-Dimethoxyethane (Glyme) and Dimethyl ether (see Naphthalene-Sodium), Dimethylformamide. Dimethyl sulfone. Dimethyl sulfoxide. Diphenyl sulfoxide. Ethylene glycol. N-EthylmorphoUne. Hexamethylphosphoric triamide. Methylal. Methylene chloride. Methyl ethyl ketone. N-Methyl-2-pyrrolidone. Nitrometbane. Nitrosyl chloride. Phenetole. Tetrahydrofurane. Tetramethylene sulfone. Tetramethylene sulfoxide. Triethanolamine. Triethyl phosphate. Trifluoroacetic acid,... 

Adkins and Krsek noted that certain a,/3-unsaturated carbonyl compounds undergo reduction rather than hydroforraylation. Thus crotonaldehyde and acrolein are reduced to n-butyraldehyde and propionaldehyde, respectively, and methyl vinyl ketone is reduced to methyl ethyl ketone. Orchin and co-workers found that if the reaction is carried out at a higher temperature (180-185°) the carbonyl group is reduced as well. Indeed application of the 0x0 reaction to an alcohol leads to homologation ... 

Montreuil and Shelef [81] studied the SCR reaction over ZSM-5/AI2O3 supported on a cordierite monolithic substrate. Various oxygenated hydrocarbons, such as methanol, ethanol, propanol, acetaldehyde, acetone, methyl ethyl ketone, and 1,4-dioxane were used as reductant at 755 K [81]. The reaction extent with the various organic compounds was compared with that obtained when using propene as reductant. Propene was the superior reductant. Methanol as a reductant showed a very low NO conversion, whereas propanol showed the highest activity, albeit lower than that of propene. Upon adding oxygen to the feed the difference between propanol and propene vanishes. 

Desulfurization of petroleum feedstock (FBR), catalytic cracking (MBR or FI BR), hydrodewaxing (FBR), steam reforming of methane or naphtha (FBR), water-gas shift (CO conversion) reaction (FBR-A), ammonia synthesis (FBR-A), methanol from synthesis gas (FBR), oxidation of sulfur dioxide (FBR-A), isomerization of xylenes (FBR-A), catalytic reforming of naphtha (FBR-A), reduction of nitrobenzene to aniline (FBR), butadiene from n-butanes (FBR-A), ethylbenzene by alkylation of benzene (FBR), dehydrogenation of ethylbenzene to styrene (FBR), methyl ethyl ketone from sec-butyl alcohol (by dehydrogenation) (FBR), formaldehyde from methanol (FBR), disproportionation of toluene (FBR-A), dehydration of ethanol (FBR-A), dimethylaniline from aniline and methanol (FBR), vinyl chloride from acetone (FBR), vinyl acetate from acetylene and acetic acid (FBR), phosgene from carbon monoxide (FBR), dichloroethane by oxichlorination of ethylene (FBR), oxidation of ethylene to ethylene oxide (FBR), oxidation of benzene to maleic anhydride (FBR), oxidation of toluene to benzaldehyde (FBR), phthalic anhydride from o-xylene (FBR), furane from butadiene (FBR), acrylonitrile by ammoxidation of propylene (FI BR)... 

Here the biotransformation (Fig. 19-6) is preferred over the chemical reduction with commercially available asymmetric catalysts (BH3- or noble-metal-based), since with the chemocatalysts the desired high enantiomeric excess (ee > 98%, 99.8% after purification) is not achievable. Since the ketone has only a very low solubility in the aqueous phase, 1 kg ketone is added as solution in 4 L 0.9 M H2SO4 to the bioreactor. The bioreduction is essentially carried out in a two-phase system, consisting of the aqueous phase and small droplets made up of substrate and product. The downstream processing consists of multiple extraction steps with methyl ethyl ketone and precipitation induced by pH titration of the pyridine functional group (pfCa = 4.66) with NaOH. The (R)-amino alcohol is an important intermediate for the synthesis of (1-3-agonists that can be used for obesity therapy and to decrease the level of associated type II diabetes, coronary artery disease and hypertension. 

Reasonable conversions of NPBA were observed when using ketones as solvents however, product analysis showed increased byproducts formation with the use of ketones. When acetone is used as solvent, GC/MS analysis identified 2-methylindoline and N-phenylisopropylamine as the two major byproducts, which are produced via a secondary reaction between aniline (product), acetone and hydrogen (reductive amination). Similar byproducts were observed when using methyl ethyl ketone (MEK) as a solvent. In a parallel experiment, about 13% of aniline reacted with acetone under the same reaction conditions except in the absence of a catalyst. Most of the reaction product, about 11%, is non-hydrogenated product 2-methylindoline (C9H11N). These results clearly demonstrate that ketones are the least preferred solvents for N-debenzylation due to the secondary reaction between the desired product and the ketones. 

A fairly good correlation between modulus reduction and gel volume is demonstrated in Figure 3 for a number of different HIPS and acrylonitrile-butadiene-styrene (ABS) materials. The gel volume was determined by the usual high speed centrifugation of the methyl ethyl ketone-acetone solution. 

---