A solution of
600 g. (4.9 moles) of isopropyl bromide (Note
3) in
300 cc. of dry ether is then added through the separatory funnel. The reaction begins after about 15 cc. of the solution has been added (Note
4). The solution is added at such a rate that the reaction mixture refluxes gently. It is well to arrange to cool the flask with running water if the refluxing becomes too vigorous. The addition of the
isopropyl bromide solution should require from three and one-half to four hours. The reaction mixture is refluxed on the
water bath for forty minutes after addition of the
isopropyl bromide solution is complete.
After addition of the
acetaldehyde solution is complete, the product is decomposed by pouring the reaction mixture onto 2 kg. of cracked ice. The excess
magnesium may be removed conveniently by decantation at this point. The basic magnesium halide is dissolved by addition of about
1 l. of 15 per cent sulfuric acid. The
ether solution is separated, and the aqueous layer is extracted with four
150-cc. portions of ether. The
ether solutions are combined, dried over
25 g. of calcined potassium carbonate, filtered, and fractionally distilled, using a
short column. The
methyl isopropyl carbinol distils at
110–111.5°. The fraction boiling at
37–109° should be dried and refractionated. The total yield is
210–215 g. (
53–54 per cent of the theoretical amount).