Methyl ethyl ketone, condensation

Ketones do not condense readily with malonic ester. The condensation of acetone and diethyl malonate is brought about by heating for 24 hours with acetic anhydride and zinc chloride. The yield of diethyl isopropyl-idenemalonate is 52%. ° Under similar conditions methyl ethyl ketone condenses to the extent of only 19%. ° ... 

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). 

Methyl Isopropenyl Ketone. Methyl isopropenyl ketone [814-78-8] (3-methyl-3-buten-2-one) is a colorless, lachrymatory Hquid, which like methyl vinyl ketone readily polymerizes on exposure to heat and light. Methyl isopropenyl ketone is produced by the condensation of methyl ethyl ketone and formaldehyde over an acid cation-exchange resin at 130°C and 1.5 MPa (218 psi) (274). Other methods are possible (275—280). Methyl isopropenyl ketone can be used as a comonomer which promotes photochemical degradation in polymeric materials. It is commercially available in North America (281). 

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. 

Aldehydes and ketones such as acetaldehyde, ben2aldehyde, acetone, acetophenone, cyclohexanone, cyclopentanone, and methyl ethyl ketone have been condensed with CPD in the presence of alkaline agents to produce colored hilvene derivatives. A typical condensation with a ketone is depicted as follows ... 

A condensible blowdown tank, designed on a similar basis to that described above for phenol, may be provided in other services where a conventional condensible blowdown drum would not be acceptable (e.g., due to effluent water pollution considerations). Examples of such cases are methyl ethyl ketone (MEK) and dimethyl formamide (DMF). A suitable absorbing material is specified (e.g., a lube oil stock for MEK water for DMF), and the design must include consideration of maximum permissible operating temperatures to prevent excessive vapor evolution or the boiling of water. 

A mixture of 17.6 grams of p-n-butoxyacetophenone, 12.1 grams of piperidine hydrochloride, 4.5 grams paraformaldehyde, 0.25 cc concentrated hydrochloric acid, 52.5 cc nitro-ethane, 7.5 cc of 95% ethanol, and 15 cc of toluene was boiled under reflux for one hour, removing water formed in the reaction by means of a condensate trap. The mixture was then cooled. The crystals which formed were collected by filtration, washed with anhydrous ether and recrystallized from methyl ethyl ketone. The crystals thus obtained, which melted at 174°-175°C, were shown by analysis to be 4-n-butoxy-beta-piperidinopropiophen-one hydrochloride. 

Ethyl Propianyl-Pyruvate 36 grams of methyl ethyl ketone and 73 grams of ethyl oxalate are condensed in the presence of sodium ethylate, the reaction mixture being refluxed in an alcoholic medium. 28 grams of the desired product having a boiling point of 100° to 105°C/6 mm are obtained. 

In its manufacture, methyl ethyl ketone is condensed with ethylcyanoacetate to give ethyl-2-cyano-3-methyl-2-pentenoate. That, in turn, adds HCN to give ethyl-2,3-dicyano-3-methyl-pentanoate. Saponification and decarboxylation gives 2-methyl-2-ethyl succinonitrile. Heating with aqueous NH3 gives the diamide which loses NHj and cyclizes to ethosuximide. 

The 5-methyl-5-ethyloxazolidine-2,4-dione may be prepared by reacting methyl ethyl ketone with sodium cyanide and with ammonium thiocyanate followed by desulfurization. This intermediate may also be prepared by condensing a-hydroxy-a-methylbutyramide with ethyl chlorocarbonate or by condensing ethyl a-hydroxy-a-methylbutyrate with urea. Another method described (Traube and Aschar, Ber., 46, 2077-1913) consists in the condensation of ethyl a-hydroxy-a-methylbutyrate with guanidine followed by hydrolysis. 

In the manufacture of methyl ethyl ketone (MEK) from 2-butanol, the reactor products are precooled and then partially condensed in a shell and tube exchanger. A typical analysis of the stream entering the condenser is, mol fractions MEK 0.47, unreacted alcohol 0.06, hydrogen 0.47. Only 85 per cent of the MEK and alcohol are condensed. The hydrogen is non-condensable. 

Biacetyl monoxime has been prepared by the action of amyl nitrite on methyl ethyl ketone using sodium hydroxide1 or hydrochloric acid 2 as a condensing agent, and by melting nitroso-levulinic acid.3... 

The methyl ethyl ketone should not be allowed to stand any length of time between the addition of the hydrochloric acid and the treatment with ethyl nitrite, inasmuch as the acid causes a condensation of the ketone with itself, thereby lowering the yield of biacetyl monoxime. 

The preparative importance of the acyloins depends on the fact that they are intermediate products, from which many 1 2-diketones can be obtained. The simplest aromatic member of this group is benzil (anisil and furil are analogous) like its aliphatic prototype diacetyl CH3.CO.CO.CH3 (and like anhydrous glyoxal) it is yellow in colour. Diacetyl is obtained from methyl-ethyl ketone via the monoxime of the former compound (von Pechmann). It is remarkable that diacetyl condenses to p-xyloquinone. (Formulate). 

Extension of this condensation to mixed ketones (95) provided further confirmation for the above interpretation. Thus, methyl ethyl ketone and p-chlorophenylbiguanide gave successively the triazine derivatives (CXXVIII) and (CXXIX). The latter (CXXIX) was resolvable into its enantiomers by (+)-tartaric acid this observation supports the six-membered ring structure of (CXXIX) and, because of the very gentle conditions of its isomerisation, that of its isomer (CXXVIII). 

Condensation of3,5-Dimethoxybenzaldehyde with Methyl Ethyl Ketone. 1 mole of the aldehyde is mixed with 3 moles of ketone and a 7% NaOH solution. This mixture is heated to 70-80° for 4 hours. The resulting product is recrystallized from petroleum ether to give a 65% yield of white needles. Mp 70-71°. 

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°. 

In all processes an acyclic precursor, called a pseudoionone, pseudoirone, etc., is prepared by base-catalyzed condensation of citral or 6-methylcitral with acetone, methyl ethyl ketone, or allylacetone, as appropriate. 

In the methylionone synthesis, condensation of citral with methyl ethyl ketone results in a mixture of n-methyl- and isomethylpseudoionone, each of which may occur as one of four possible cis-trans isomers. 

Oxybis[2-(ethyleneoxy)-2 -hydroxy-1,1 -binaphthyl] (2.32 g, 3.61 mmol) and potassium carbonate (l.lOg, 7.96mmol) were placed in a 300mL round-bottomed flask equipped with a reflux condenser and a magnetic stirrer bar. Dry methyl ethyl ketone (142 mL) was then added and the mixture was refluxed on an oil bath for 1 h. To this solution, Af,Af-bis-(2-p-nitrobenzenesulfonyloxyethyl)-A -p-nitrobenzenesulfonamide dichloromethane complex (3.44g, 4.32 mmol) was added. 

B. 2-Iodoethyl benzoate. A mixture of 170 g. of anhydrous sodium iodide and 1.2 1. of methyl ethyl ketone (Note 2) is heated on a steam bath for 1 hour with occasional shaking in a 3-1. round-bottomed flask fitted with a water-cooled reflux condenser. 2-Chloroethyl benzoate (162 g., 0.88 mole) is added to the mixture, and heating is maintained for an additional 22-24 hours with occasional shaking. The mixture is cooled to room temperature and filtered through a 15-cm. Buchner funnel with suction. The inorganic salts on the filter are washed with 200 ml. of methyl ethyl ketone, and the filtrate is concentrated by distillation of about 1 1. of the solvent. The residue is poured into 1 1. of water contained in a separatory funnel, which is shaken, and the lower layer is withdrawn. The latter is washed successively with 200 ml. of 10% sodium bisulfite solution, 200 ml. of 5% sodium bicarbonate solution, and 100 ml. of water. It is dried with anhydrous magnesium sulfate (5-7 g.) and fractionated under reduced pressure. The yield of material boiling at 133 -136°/2.5 mm., 1.5820, is 190 -196 g. (78-81%). 

CH3.CO.C(CH2OH)2.CH3i mw 132.16, crysts, mp 54—59°, bp 121—125° at 9—14mm can be prepd by condensation of methyl ethyl ketone with 2 moles of formaldehyde in presence of an alkaline catalyst, such as 2N NaOH (Ref 3) It gives on nitration an explosive di-nitrate... 

Ethylene glycol in the presence of an acid catalyst readily reacts with aldehydes and ketones to form cyclic acetals and ketals (60). 1,3-Dioxolane [646-06-0] is the product of condensing formaldehyde and ethylene glycol. Applications for 1,3-dioxolane are as a solvent replacement for methylene chloride, 1,2-dichloroethane, 1,1,1-trichloroethane, and methyl ethyl ketone as a solvent for polymers as an inhibitor in 1,1,1-trichloroethane as a polymer or matrix interaction product for metal working and electroplating in lithium batteries and in the electronics industry (61). 1,3-Dioxolane can also be used in the formation of polyacetals, both for homopolymerization and as a comonomer with formaldehyde. Cyclic acetals and ketals are used as protecting groups for reaction-sensitive aldehydes and ketones in natural product synthesis and pharmaceuticals (62). 

Some of the chemistry developed by the industry more recently, to produce new monohydric alcohols, is just as interesting as the linalool chemistry. Sandalore, a recent new Givaudan chemical with a persistent, sandalwood odor is made according to the scheme in Figure 15 (9). Alpha-pinene, the starting material, is converted to the epoxide which is catalytically rearranged to campholen-ic aldehyde. Aldol condensation with methyl ethyl ketone followed by hydrogenation yields Sandalore . 

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