Butyl Ketone

Methyl n butyl ketone is o colorless liquid, freely soluble in alcohol ond ether but very slightly soluble in water. 

---

Methyl n-butyl ketone Methyl n.butyl carbinol... 

Use the apparatus detailed in Section 111,20. Dissolve 100 g. (123 ml.) of methyl n-butyl ketone (2-hexanone) (Section 111,152) in 750 ml. of ether and add 150 ml. of water. Introduce 69 g. of clean sodium in the form of wire (or small pieces) as rapidly as possible the reaction must be kept under control and, if necessary, the flask must be cooled in ice or in running water. When all the sodium has reacted, separate the ethereal layer, wash it with 25 ml. of dilute hydrochloric acid (1 1), then with water, dry with anhydrous potassium carbonate or with anhydrous calcium sulphate, and distil through a fractionating column. Collect the fraction of b.p. 136-138°. The yield of methyl n-butyl carbinol (2-hexanol) is 97 g. 

Thus if R = n-propyl (ethyl n-propylacetoacetate), methyl n-butyl ketone is produced. The preparation of this ketone is described in Section 111,152 under Ethyl Aceioacetate. 

For the preparation of methyl n butyl ketone and methyl n amyl ketone by another method, see Section 111,152. 

Cool the mixture and decant the solution from the sodium bromide wash the salt with two 20 ml. portions of absolute alcohol and add the washings to the main solution. Distil off the alcohol, which contains the slight excess of n-propyl bromide used in the condensation, through a short fractionating column from a water bath. The residue A) of crude ethyl n-propylacetoacetate may be used directly in the preparation of methyl n-butyl ketone. If the fairly pure ester is required, distil the crude product under diminished pressure and collect the fraction boihng at 109-113727 mm. (183 g.) (R). 

To prepare methyl n-butyl ketone, add the crude ester (A) or the redistilled ethyl n-propylacetoacetate B) to 1500 ml. of a 5 per cent solution of sodium hydroxide contained in a 4-litre flask equipped with a mechanical stirrer. Continue the stirring at room temperature for... 

Separate the ketone layer from the water, and redistil the lattCT rmtil about one third of the material has passed over. Remove the ketone after salting out any dissolved ketone with potassium carbonate (5). Wash the combined ketone fractions four times with one third the volume of 35-40 per cent, calcium chloride solution in order to remove the alcohol. Dry over 15 g. of anhydrous calcium chloride it is best to shake in a separatory funnel with 1-2 g. of the anhydrous calcium chloride, remove the saturated solution of calcium chloride as formed, and then allow to stand over 10 g. of calcium chloride in a dry flask. Filter and distil. Collect the methyl n-butyl ketone at 126-128°. The yield is 71 g. 

Solvents used for dewaxing are naphtha, propane, sulfur dioxide, acetone—benzene, trichloroethylene, ethylenedichloride—benzene (Barisol), methyl ethyl ketone—benzene (benzol), methyl -butyl ketone, and methyl / -propyl ketone. Other solvents in commercial use for dewaxing include /V-methylpyrrolidinone, MEK—MIBK (methyl isobutyl ketone), dichloroethane—methylene dichloride, and propfyene—acetone. 

Methyl /-butyl ketone [1634-04-4] (pinacolone) has been prepared in 74% yield by reaction of / f/-amyl alcohol with formaldehyde in the presence of strong acid catalyst (78,79). 

Equilibrium constants measured at 20—25°C, except isopropyl /-butyl ketone which was measured at 35°C. 

Hexanone Methyl n-butyl ketone 127 CsHijO p-Xylene 1,4-Dimethylbenzene 71 QHio... 

Fig. 7.3. Crystal structures of some lithium etiolates of ketones. (A) Unsolvated hexameric enolate of methyl t-butyl ketone (B) tetrahydrofuran solvate of tetramer of enolate of methyl r-butyl ketone (C) tetrahydrofuran solvate of tetramer of enolate of cyclopentanone (D) dimeric enolate of 3,3-dimethyl-4-(r-butyldimethylsiloxy)-2-pentanone. (Structural diagrams are reproduced from Refs. 66-69.) by permission of the American Chemical Society and Verlag Helvetica Chimica Acta AG.

The facility with which a-cleavage occurs in solution depends on the stability of ttae adical fragments that can be ejected. Dibenzyl ketone, for exan le, is readify cleav jjiboto-lytically. Similarly, r-butyl ketones undergo a-cleavage quite readify on p ioCo in solution. ... 

---