Acetone, also

With aldehydes, primary alcohols readily form acetals, RCH(OR )2. Acetone also forms acetals (often called ketals), (CH2)2C(OR)2, in an exothermic reaction, but the equiUbrium concentration is small at ambient temperature. However, the methyl acetal of acetone, 2,2-dimethoxypropane [77-76-9] was once made commercially by reaction with methanol at low temperature for use as a gasoline additive (5). Isopropenyl methyl ether [116-11-OJ, useful as a hydroxyl blocking agent in urethane and epoxy polymer chemistry (6), is obtained in good yield by thermal pyrolysis of 2,2-dimethoxypropane. With other primary, secondary, and tertiary alcohols, the equiUbrium is progressively less favorable to the formation of ketals, in that order. However, acetals of acetone with other primary and secondary alcohols, and of other ketones, can be made from 2,2-dimethoxypropane by transacetalation procedures (7,8). Because they hydroly2e extensively, ketals of primary and especially secondary alcohols are effective water scavengers. 

Acetone also reacts with diphenylamine, in the presence of acid, to form a variety of condition-dependent products (5). Excess amine and a small amount of strong acid catalyst at 100—150°C give 2,2-[4,4 -(dianilino)diphenyl]-propane [2980-26-9] (6). With a large amount of hydrochloric acid at 250°C in the presence of excess diphenylamine, the main product is 9,9-dimethylacridan [6267-02-3]. 

Geranyl acetones also reacts with vinyl Grignard reagent to produce nerohdol directly (192). 

Dodecyltrimethylammonium chloride [112-00-5] M 263.9, m 246 (dec). Dissolved in MeOH, treated with active charcoal, filtered and dried in vacuo [Waldenburg J Phys Chem 88 1655 1984], or recrystd several times from 10% EtOH in acetone. Also repeatedly crystd from EtOH/ether or MeOH. [Celia et al. 7 Am Chem Soc 74 2062 7952.]... 

Separated from retinol by column chromatography on water-deactivated alumina with hexane containing a very small percentage of acetone. Also chromatographed on TLC silica gel G, using pet ether/isopropyl ether/acetic acid/water (180 20 2 5) or pet ether/acetonitrile/acetic acid/water (190 10 1 15) to develop the chromatogram. Then recrystd from propylene at low temperature. 

Sodium azide [26628-22-8] M 65.0, m 300°(dec, explosive), pK 4.72 (for HN3). Crystd from hot water or from water by the addition of absolute EtOH or acetone. Also purified by repeated crystn from an aqueous solution saturated at 90° by cooling it to 10°, and adding an equal volume of EtOH. The crystals were washed with acetone and the azide dried at room temperature under vacuum for several hours in an... 

Methanol has a considerably higher boiling point than its alkane relatives, methane and ethane, consistent with significant intermolecular forces. Ammonia dissolves readily in acetone, also consistent with significant intermolecular forces. 

See Chromic acid Acetone, also Chromium trioxide Acetic acid... 

As depicted in Scheme 11, ylides 39 derived from 4-methyl-[l,2,3]triazolo[l,5- ]pyridine react with Michael acceptors, which, upon nucleophilic attack at C3 and ring opening, lead to nucleophilic displacement of nitrogen. The intermediate diradical led to a mixture of compounds, including alkenes and a cyclobutane derivative when methyl acrylate was used, and the indolizine 40 with methyl propiolate as the electrophile <1998T9785>. Heating 4-methyl triazolopyridine with benzenesulfonyl chloride in acetone also confirmed decomposition via a radical pathway. 

Oral administration of acetone has been reported to potentiate the neurotoxicity caused by oral exposure to the /2-hexane metabolite 2,5-hexanedione in rats (Ladefoged et al. 1989, 1994). Oral exposure to acetone alone in rats at 650 mg/kg/day resulted in a statistically significant decrease in motor nerve conduction velocity after 6 weeks co-exposure to acetone and 2,5-hexanedione resulted in greater effects than those seen with 2,5-hexanedione alone (Ladefoged et al. 1989). It is possible that acetone may potentiate /2-hexane neurotoxicity by decreasing body clearance of 2,5-hexanedione (Ladefoged and Perbellini 1986). Acetone also influences the action of many chemicals by its induction of the cytochrome P-450 isozyme CYP2E1 (Patten et al. 1986). /2-Hexane is metabolized by P-450 isozymes... 

Benzoylacetone. — C6H5.CO.CH2.CO.CH3 is prepared in an analogous way from acetophenone and ethyl acetate according to the procedure of Claisen, Ber., 1905, 38, 695. The yield may be as much as 75 per cent of the theoretical. The cheaper converse method—action of sodamide on ethyl benzoate and acetone—also succeeds in this case, although it fails when sodium or sodium ethoxide is used as condensing agent. In general the use of sodamide is to be preferred in the synthesis of 1 3-diketones. 

As a solvent, acetone is used in varnishes, lacquer, cellulose acetate fiber, cellulose nitrate (an explosive), and as a carrier solvent for acetylene in cylinders. Acetylene is stored at about 225 psi but is so explosively reactive that as an extra precaution the cylinder is filled with asbestos wool soaked in acetone. Acetylene is extremely soluble in acetone, and the asbestos keeps it from sloshing around when the cylinder is half empty. Acetone also is used in smaller volumes for the manufacture of pharmaceuticals and chloroform (the anesthetic). 

Most of what you read in the previous section about acetone also applies to methyl ethyl ketone (MEK). The processes for making MEK can be broadly categorized into by-product and on-purpose the more popular processes are the same—they just start with larger molecules, and the applications are much the same. 

The MNDO method has been employed " to study the acid-catalysed rearrangement of propylene 1,2-glycol. Propanaldehyde was found to be the major product with a small amount of acetone also being produced. The solid-state pinacol rearrangement of l,l,2-triphenylethane-l,2-diol has been performed over various solid... 

Acetone was detected in diesel fuel at a concentration of 22,000 pg/g (Schauer et al., 1999). Identified as an oxidative degradation product in the headspace of a used engine oil (10-30W) after 4,080 miles (Levermore et al., 2001). Acetone also was detected in automobile exhaust at concentrations ranging from 0.09 to 4.50 mg/m (Grimaldi et al, 1996) and in cigarette smoke at concentrations ranging from 498 to 869 mg/m (Euler et al., 1996). 

Photolysis of acetone also contributes significantly to its loss and is the dominant loss process in the upper troposphere (Gierczak et al., 1998 see Section J.3). 

In this regard, it is well to remember the role which the wall plays on the nature of the products obtained from gas phase oxidation. There is certainly common agreement that walls and wall reactions are important in this respect. For example, Hay et al. (11) have shown the importance of the walls in determining the nature and composition of the oxygenated products from 2-butane + 02 at 270°C. Cohens study on the photo-oxidation of acetone also illustrates this point (10). He found that if acetone is photolyzed by itself in a quartz vessel, the normal products—methane, ethane, carbon monoxide, and methyl ethyl ketone— are produced. 

Acetone also reduces the solubility of lactose, upon which a procedure to recover lactose from whey is based (Kerkkonen et al. 1963). Acetone is added to concentrated whey (18 to 20% lactose) in amounts sufficient to precipitate some of the impurities. After these are filtered out, the gradual addition of acetone to over 65% allows recovery of 85% of the lactose during a 3.5 hr period. The yield of lactose and rapidity of crystallization are influenced by the rate of acetone addition. 

At first thought one might attribute the disappearance of the OH band to a displacement of the OH groups from the surface or to a reaction of the type that Sidorov observed with methyl alcohol. Kurbatov and Neui-min (42) found, however, that acetone also caused the surface OH bands of silica aerogel to disappear. Moreover, this disappearance was easily reversible, and the OH band reappeared when the acetone was removed by freezing into a liquid nitrogen trap. 

The formation of 5-S-L-cysteinylmethyluracil maybe taken as an indication that under these conditions photoexcited acetone also abstracts an H-atom from the methyl group of Thy or (less likely) that RS- is also capable of undergoing this reaction. The observation of 5-S-L-cysteinylmethyl-5,6-dihydrouracil is less easily explained. An exomethylene precursor as discussed above for the reaction of CH2OH with Thy could, in principle, account for it. Detailed mechanistic studies are, however, missing. 

Practically insoluble in water, soluble in 3 parts of alcohol (95%), in 20 parts of chloroform, in 20 parts of solvent ether and in 6 parts of acetone also soluble in solutions of alkali hydroxides (3). 

The Williamson synthesis, using a sodium phenoxide and allyl bromide in methanol solution, is more rapid than the procedure using acetone and potassium carbonate and gives good results.16-36 441 66 Aqueous acetone also has been used as the reaction medium with allyl bromide and sodium hydroxide this method likewise is rapid and sometimes leads to better yields than the procedure using potassium carbonate and acetone.34 Allylation of 2-hydroxy-l,4-naphthoquinone has been carried out by treating the silver salt, in benzene, with allyl bromide 84 some C-alkylation as well as O-alkylation was observed. 

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