Showing papers on "Acetone published in 1968"
TL;DR: Evidence is presented that acetone produces its enhancement of aniline hydroxylation by a mechanism different from that of ethyl isocyanide.
112 citations
78 citations
TL;DR: Lomofungin is a new antibiotic which is extracted from the fermentation broth of Streptomyces lomondensis var.
Abstract: Lomofungin is a new antibiotic which is extracted from the fermentation broth of Streptomyces lomondensis var. lomondensis with methyl ethyl ketone and purified by crystallization. It is an acidic olive-yellow colored compound with a molecular formula C15H10N2O6 and a molecular weight of 314. It exhibits ultraviolet and visible absorption maxima at 221, 270, 311, 375 and 439mμ in 0.01N methanolic hydrochloric acid, and at 239, 265, 299, 342, 478 in 0.01N aqueous sodium hydroxide. Lomofungin does not melt below 320°C.It is soluble in dimethylformamide, alkaline water, acidic acetone and acidic methyl ethyl ketone but only slightly soluble in water, methanol, cyclohexane, acetone, ether or ethyl acetate.
55 citations
TL;DR: In this paper, a rate equation was derived on the basis of the Langmuir-Hinshelwood mechanism for liquid-phase hydrogenation of acetone over Raney nickel catalyst.
40 citations
TL;DR: In this article, the incorporation of reducing agent during the extraction of plant tissues with ethanol and acetone yielded extracts with higher content of total phenolics reacting with Folin-Denis reagent.
36 citations
34 citations
34 citations
TL;DR: In this paper, the rates of hydrogen abstraction by methyl radicals from the three different sites in ethanol have been measured by studying three isotopically different ethanols : CH3CH2OH, CH3 CD2 OH and CH3 CH2 OD.
Abstract: The rates of hydrogen abstraction by methyl radicals from the three different sites in ethanol have been measured by studying three isotopically different ethanols : CH3CH2OH, CH3 CD2 OH and CH3CH2 OD. Photolysis of acetone and acetone-d6 over the temperature range 130–250° has been used as the source of methyl radicals and velocity constants have been obtained for five elementary reactions.
Abstraction takes place from all three sites. The methylene group is the most reactive site in the molecule, and the methyl group the least. At 150°C, 75 % of the hydrogen comes from CH2, 20 % from OH and about 5 % from CH3. Arrhenius parameters for methyl radical attack based on Shepp's rate-constant for methyl radical combination are as follows : [graphic omitted] Isotope effects have been determined for the methylene and hydroxyl groups; at 150°, (kCH2/kCD2) is 6.3 and (kOH/kOD) is 3.2. The activation energy difference ECD2–ECH2 is somewhat greater than would be expected from the zero-point-energy difference, and tunnelling may contribute to this.
A hydrogen exchange reaction between acetone and the hydroxyl group of ethanol has been found to occur. Its importance is to limit the validity of abstraction studies to isotopically compatible systems. Such pairs are studied here.
31 citations
TL;DR: The anion-exchange characteristics of the platinum metals and gold in hydrochloric acid media are described and the conditions most suitable for quantitative separation are discussed.
29 citations
TL;DR: The protease from the fungus Endothia parasitica has been purified, by two methods, one leading to crystalline enzyme, which is maximally stable at pH 4 to 5, but quite unstable at pH 7.6.
28 citations
TL;DR: In this article, the 17O nm.r. technique was used to measure the rate of oxygen exchange of acetone in aqueous solution, in terms of the hydration-dehydration reaction of the carbonyl group and compared with those for formaldehyde and acetaldehyde.
Abstract: The rate of oxygen exchange of acetone in aqueous solution was measured by the 17O n.m.r. technique. Measurements were done in acetate, phosphate, borate and bicarbonate buffers. The H+ and OH–-catalysis rate constants were 16.5 and 55 M–1 sec–1 respectively. For the acetate and phosphate buffers, general acid but not general base catalysis was detected. The results in borate and bicarbonate buffers did not allow conclusions to be drawn regarding general catalyses in these buffers. The results are discussed in terms of the hydration-dehydration reaction of the carbonyl group and are compared with those for formaldehyde and acetaldehyde. Some measurements on the isotopic oxygen exchange of isopropylmethyl ketone and pinacolone with water are also reported.
TL;DR: An unidentified psychrophilic basidiomycete used valine and isoleucine as precursors to hydrocyanic acid (HCN) and two cyanogenic glucosides, linamarin and lotaustralin, were demonstrated in fungus cultures.
Abstract: An unidentified psychrophilic basidiomycete used valine and isoleucine as precursors to hydrocyanic acid (HCN). As probable intermediates in the pathway from valine and isoleucine two cyanogenic glucosides, linamarin and lotaustralin, were demonstrated in fungus cultures. The fungus contained two beta-glucosidases and an oxynitrilase which, acting together, were capable of releasing cyanide from both linamarin and lotaustralin. The two beta-glucosidases were purified and compared as to pH optimum, Michaelis constant, energy of activation, thermal stability, and substrate specificity. The products of methyl ethyl ketone cyanohydrin and acetone cyanohydrin dissociation by the oxynitrilase were demonstrated to be HCN together with methyl ethyl ketone and acetone, respectively. The oxynitrilase attacked aliphatic hydroxynitriles, but showed no activity on aromatic hydroxynitriles.
TL;DR: In this paper, it was shown that the combustion of simple ketones occurs mainly by propagation reactions which fall into three categories: the radical RCOCHR' formed by removal of a hydrogen atom from the ketone first adds on oxygen, then at least three different reactions take place:
TL;DR: In the temperature range 402-425 °C, propylene oxide in a toluene medium decomposes to form propionaldehyde (60-70%), acetone (14%), and free radicals (25%) as discussed by the authors.
Abstract: In the temperature range 402–425 °C, propylene oxide in a toluene medium decomposes to form propionaldehyde (60–70%), acetone (14%), and free radicals (25%). The ratio of products is invarient with...
TL;DR: Gas chromatographic analysis of milk cultures of three strains of Propionibacterium shermanii revealed the production of acetaldehyde, propionaldehyde, ethanol, and propanol by all strains as discussed by the authors.
TL;DR: In this paper, the rate of 2-propanol oxidation by chromic acid in aqueous acetone solutions has been found to be V'=k3 [Cr(VI)| [2-panol]ho, with the magnitude of k3 being over 700 times as great in 93.3% acetone as it is in water.
Abstract: The rate law for oxidation of 2-propanol by chromic acid in aqueous acetone solutions has been found to be V = k3 [Cr(VI)| [2-propanol]ho, with the magnitude of k3 being over 700 times as great in 93.3% acetone as it is in water. In other respects (primary deuterium isotope effect, Hammett "rho" value, and salt effects) the general features of the reaction strongly resemble those observed in aqueous acetic acid solutions.
TL;DR: These additives were found to increase considerably the extraction of protactinium in the cases of trilaurylamine, tributyl phosphate and isobutyl methyl ketone.
TL;DR: The extraction of silver, mercury, selenium, zinc, cobalt and iron with tridodecylamine and tributyl phosphate from hydrochloric acid solutions in aqueous methanol, ethanol and acetone is reported.
TL;DR: The solvent action of acetone on frozen sections of brain and other lipid-rich tissues has been assessed by quantitative and chromatographic techniques as mentioned in this paper, showing that acetone extracts free and esterified cholesterol, triglycerides and free fatty acids.
Abstract: The solvent action of acetone on frozen sections of brain and other lipid-rich tissues has been assessed by quantitative and chromatographic techniques. Under these histochemical conditions, acetone extracts free and esterified cholesterol, triglycerides and free fatty acids. Lecithin is not significantly extracted, while cephalins and sphingolipids are insoluble.
Patent•
23 Dec 1968TL;DR: It was shown that riboflavin (as lumiflavin and lumichrome) is sorbed by all resins with free phenolic groups, e.g. phenolsulphonic and phenolcarboxylic ion exchangers or a simple resin of resorcinol and formaldehyde.
TL;DR: In this article, the formation and further reactions of the methylperoxy radical are discussed in relation to its thermochemistry, with emphasis on the possible role of hydroperoxides in combustion reactions.
Abstract: Methyl radicals produced by the photolysis of acetone have been allowed to react with oxygen and the kinetics of the reaction studied over a range of conditions from 200 to 400°C. The results of earlier workers have been confirmed, and between 200 and 300 °C, the reaction is of the third order with a rate constant of approximately 10–31 cm6 molecule–2 sec–1 which decreased slightly with increasing temperature. Among the products of the reaction below 300°C, methyl hydroperoxide has been definitely identified and estimated quantitatively. Also, the major decomposition product of methyl hydroperoxide at room temperature is methanol. The formation and further reactions of the methylperoxy radical are discussed in relation to its thermochemistry, with emphasis on the possible role of hydroperoxides in combustion reactions.
Patent•
29 May 1968
TL;DR: In this paper, a process for the manufacture of bis-phenol by the catalytic condensation of a phenol with a ketone wherein the catalyst employed is a modified water-insoluble cationexchange resin containing a plurality of sulphonic acid groups, some of which have been converted to alkyl mercaptoamine salt groups by partial neutralization of the resin with an alkyal mercaptosamine.
Abstract: 1,183,564. Bisphenols. DOW CHEMICAL CO. 29 May, 1968, No. 25744/68. Heading C2C. [Also in Division C3P] A process is disclosed for the manufacture of a bis-phenol by the catalytic condensation of a phenol with a ketone wherein the catalyst employed is a modified water-insoluble cationexchange resin containing a plurality of sulphonic acid groups, some of which have been converted to alkyl mercaptoamine sulphonic acid salt groups by partial neutralization of the resin with an alkyl mercaptoamine. A preferred catalyst is a sulphonated styrene-divinylbenzene copolymer modified by partial neutralization with 2-mercaptoethylamine. The preparation of bisphenol A is described. Other suitable starting materials are phenol, o- and m-cresol, o- and m-chlorophenol, o-bromophenol, o-sec.- butylphenol, o t - butylphenol, 2,6 - dibromophenol, 2,6 - di - t - butylphenol, 6 - chloro - o - cresol and o-phenylphenol, acetone, methylethyl ketone, methylisobutyl ketone, acetophenone, cyclohexanone and 1,3-dichloroacetone.
TL;DR: In this article, the results were successfully interpreted on the basis of the Langmuir-Hinshelwood mechanism with the assumption that the catalyst surface is fully covered with the adsorbed species of hydrogen and ketone during the reaction.