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Butanone, condensation

Terminal alkyne anions are popular reagents for the acyl anion synthons (RCHjCO"). If this nucleophile is added to aldehydes or ketones, the triple bond remains. This can be con verted to an alkynemercury(II) complex with mercuric salts and is hydrated with water or acids to form ketones (M.M.T. Khan, 1974). The more substituted carbon atom of the al-kynes is converted preferentially into a carbonyl group. Highly substituted a-hydroxyketones are available by this method (J.A. Katzenellenbogen, 1973). Acetylene itself can react with two molecules of an aldehyde or a ketone (V. jager, 1977). Hydration then leads to 1,4-dihydroxy-2-butanones. The 1,4-diols tend to condense to tetrahydrofuran derivatives in the presence of acids. [Pg.52]

Various 4-, 5-, or 4,5-disubstituted 2-aryIamino thiazoles (124), R, = QH4R with R = 0-, m-, or p-Me, HO C, Cl, Br, H N, NHAc, NR2, OH, OR, or OjN, were obtained by condensing the corresponding N-arylthiourea with chloroacetone (81, 86, 423), dichloroacetone (510, 618), phenacyichloride or its p-substituted methyl, f-butyl, n-dodecyl or undecyl (653), or 2-chlorocyclohexanone (653) (Method A) or with 2-butanone (423), acetophenone or its p-substituted derivatives (399, 439), ethyl acetate (400), ethyl acetyl propionate (621), a- or 3-unsaturated ketones (691), benzylidene acetone, furfurylidene acetone, and mesityl oxide in the presence of Btj or Ij as condensing agent (Method B) (Table 11-17). [Pg.233]

Methyl Isopropyl Ketone. Methyl isopropyl ketone [563-80-4] (3-methyl-2-butanone) is a colorless Hquid with a characteristic odor of lower ketones. It can be produced by hydrating isoprene over an acidic catalyst at 200—300°C (150,151) or by acid-catalyzed condensation of methyl ethyl ketone and formaldehyde to 2-methyl-l-buten-3-one, foUowed by hydrogenation to the product (152). Other patented preparations are known (155,156). Methyl isopropyl ketone is used as an intermediate in the production of pharmaceuticals and fragrances (see Perfumes), and as a solvent (157). It is domestically available from Eastman (Longview, Texas) (47). [Pg.493]

Biacetyl is produced by the dehydrogenation of 2,3-butanediol with a copper catalyst (290,291). Prior to the availabiUty of 2,3-butanediol, biacetyl was prepared by the nitrosation of methyl ethyl ketone and the hydrolysis of the resultant oxime. Other commercial routes include passing vinylacetylene into a solution of mercuric sulfate in sulfuric acid and decomposing the insoluble product with dilute hydrochloric acid (292), by the reaction of acetal with formaldehyde (293), by the acid-cataly2ed condensation of 1-hydroxyacetone with formaldehyde (294), and by fermentation of lactic acid bacterium (295—297). Acetoin [513-86-0] (3-hydroxy-2-butanone) is also coproduced in lactic acid fermentation. [Pg.498]

Aldol reaction of the campholenic aldehyde with 2-butanone gives the intermediate ketones from condensation at both the methyl group and methylene group of 2-butanone (Fig. 6). Hydrogenation results in only one of the two products formed as having a typical sandalwood odor (160). [Pg.423]

In the condensation of 2-butanone with citral, if the reaction temperature is kept at 0—10°C, higher yields of the isomethyl pseudoionones, which are the more thermodynamically stable isomers, are obtained. The aldol iatermediates have more time to equilibrate to the more stable isomers at the lower temperature. The type of base used and a cosolvent such as methanol are also very important ia getting a high yield of the isomethyl pseudoionones (168). [Pg.425]

Other Rea.ctlons, The anhydride of neopentanoic acid, neopentanoyl anhydride [1538-75-6] can be made by the reaction of neopentanoic acid with acetic anhydride (25). The reaction of neopentanoic acid with acetone using various catalysts, such as titanium dioxide (26) or 2irconium oxide (27), gives 3,3-dimethyl-2-butanone [75-97-8] commonly referred to as pinacolone. Other routes to pinacolone include the reaction of pivaloyl chloride [3282-30-2] with Grignard reagents (28) and the condensation of neopentanoic acid with acetic acid using a rare-earth oxide catalyst (29). Amides of neopentanoic acid can be prepared direcdy from the acid, from the acid chloride, or from esters, using primary or secondary amines. [Pg.103]

The synthesis starts by condensation of readily available optically active (R)-(+)-alpha-methylbenzylamine with 4-phenyl-2-butanone to form an imine which is itself reduced by hy-drogenolysis (Raney nickel) to give a 9 1 mixture of the (R,R)-amine and the (R,S)-amine (4). [Pg.20]

A. 2-Methyl-4-eihoxalylcyclopenlane-l,3,5-trione. A solution of sodium ethoxide is prepared in a 2-1. three-necked, round-bottomed flask fitted with a mercury-sealed stirrer, a reflux condenser carrying a drying tube, and a stopper by the addition of 69.0 g. (3 moles) of sodium to 950 ml. of absolute ethanol. The solution is cooled to 0-5° in an ice bath and stirred. The stopper is replaced by a dropping funnel, and a cold mixture (5-15°) of 108 g. (1.50 moles) of freshly distilled 2-butanone and 482 g. (3.30 moles) of diethyl oxalate (Note 1) is added gradually over a... [Pg.83]

MethyloU2-Butanol (2-Methyl-l,3-butanediol or a >Dioxy-/3-methylbutane). CH3.CH(OH).CH(CH2OH).CH3 mw 104.15, viscous oil, bp 200° 98—99° at 9mm. Sol in w, v sol in ale and eth. Can be prepd either by reduction of the corresponding aldehyde, 2-methylbutanol(3)-al-(l) with A1 amalgam (Ref 1), or by electrolytic reduction in 10% sulfuric acid of the corresponding ketone ale. In the latter case, methyl-2-butanone-3-ol-(l), obtained by the condensation of methylethylketone with formaldehyde, can be used. On nitration, it yields an expl dinitrate Refs 1) Beil 1,482,(250) 2)L.P.Kyria-kides, JACS 36, 535(1914)... [Pg.132]

The three-necked flask is charged with 750 ml. of formamide, 25 ml. of water, and 50 g. of ammonium chloride (Note 2). The mixture is heated to 180-190° in an oil bath, and 400 g. (3.02 moles) of 4,4-dimethoxy-2-butanone (Note 3) is added dropwise with stirring over the course of 6 hours (Note 4). The flow of cooling water in the reflux condenser should be adjusted to a rate such that the methanol and methyl formate formed during the reaction distil out (Note 5). After all the acetal has been added, heating is continued for 1 hour (Note 6). The mixture is allowed to cool and is poured into 1 1. of IN sodium hydroxide. The resultant solution is extracted with chloroform in a liquid-liquid extractor for 24 hours. The chloroform is separated, dried over sodium sulfate, and removed by distillation through a short column on a steam bath. [Pg.78]

Fluorenylamine, 40,5 Formaldehyde, reaction with diethyl malonate to form diethyl bis-(hydroxymethyl)malonate, 40,27 Formamide, condensation with 4,4-dimethoxy-2-butanone to give 4-methylpyrimidine, 43, 77 Formic acid, and hydrogen peroxide, with indcne, 41, 53... [Pg.114]

Reaction between Two Molecules of the Same Ketone. In this case, the equilibrium lies well to the left and the reaction is feasible only if the equilibrium can be shifted. This can often be done by allowing the reaction to proceed in a Soxhiet extractor (e.g., see OS I, 199). Two molecules of the same ketone can also be condensed without a Soxhiet extractor, by treatment with basic Al203. Unsymmetrical ketones condense on the side that has more hydrogens. (An exception is butanone, which reacts at the CH2 group with acid catalysts, though with basic catalysts, it too reacts at the CH3 group.)... [Pg.1220]

The one-step condensation to convert 2-butanone, ethyl cyano-acetate, and hydrocyanic acid to ethyl 2,3-dicyano-3-methyl-pentanoate is a modification of the procedure described by Smith and Horowitz 6 in which pyridine acetate was employed as the catalyst. Higson and Thorp 6 employed a two-step procedure in which butanone was converted to its cyanohydrin, which in turn was condensed with ethyl cyanoacetate. [Pg.101]

A 125 ml flask fitted with a magnetic stirring bar, a reflux condenser, a thermometer and a separatory funnel is charged with 7.2 g (9 ml, 0.1 mol) of 2-butanone (methyl ethyl ketone). From the separatory funnel a solution of 1.5 g (0.04 mol, 60% excess) of sodium borohydride in 15 ml of water is added dropwise with stirring at such a rate as to raise the temperature of the readion mixture to 40° and maintain it at 40-50°. Cooling with a water bath may be applied if the temperature rises above 50°. After the addition has been completed (approximately 30 minutes) the mixture is stirred until the temperature drops to 30°. It is then transferred to a separatory funnel and saturated with sodium chloride. The aqueous layer is drained and the organic layer is dried with anhydrous potassium carbonate. Distillation affords 5.5-6.0g (73-81%) of 2-butanol, b.p. 90-95°. [Pg.209]

Diastereomeric 2,2-disubstituted-tetrahydro-l,3-oxaxin-4-ones were synthesized from cw-2-hydroxy-l-cyclopentane- and -cyclohexanecarboxa-mides 132 by condensing them with nonsymmetric ketones, such as 2-butanone, 3-methyl-2-butanone, 3,3-dimethyl-2-butanone, or acetophenone (87T4565). The diastereomer product ratios are given in Table I. [Pg.370]

It is essential that the eluent is inert and does not react with the sample components or the adsorbent. It must be borne in mind that aliphatic ketones like acetone or butanone easily undergo condensation reactions on active adsorbents and thus change the elution behavior ol he chromatographic system. r... [Pg.209]

Additional insight into the factors affecting product structure was obtained by study of the condensation of 2-butanone with benzaldehyde.2... [Pg.61]

The results indicate that the product ratio is determined by the competition between the various reaction steps. Under base-catalyzed conditions, 2-butanone reacts with benzaldehyde at the methyl group to give l-phenylpent-l-en-3-one. Under acid-catalyzed conditions, the product is the result of condensation at the methylene group, namely, 3-methyl-4-phenylbut-3-en-2-one. Under the reaction conditions used, it is not possible to isolate the intermediate ketols, because the addition step is rate-limiting. These intermediates can be... [Pg.61]

In general, the product ratio of a mixed aldol condensation will depend upon the individual reaction rates. Most ketones show a pattern similar to butanone in reactions with aromatic aldehydes. Base catalysis favors reaction at a methyl position over a methylene group, whereas acid catalysis gives the opposite preference. [Pg.62]


See other pages where Butanone, condensation is mentioned: [Pg.122]    [Pg.70]    [Pg.62]    [Pg.131]    [Pg.122]    [Pg.70]    [Pg.62]    [Pg.131]    [Pg.425]    [Pg.277]    [Pg.2]    [Pg.127]    [Pg.24]    [Pg.129]    [Pg.185]    [Pg.56]    [Pg.78]    [Pg.10]    [Pg.149]    [Pg.42]    [Pg.70]    [Pg.691]    [Pg.294]    [Pg.296]    [Pg.1211]    [Pg.2]    [Pg.78]   
See also in sourсe #XX -- [ Pg.594 ]




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