Methyl isopropyl ketone (CAS NO.: ), which is also known as , 3-methyl-, could be produced through the following synthetic routes.

In a 1.5-l. round-bottomed Pyrex flask, fitted with a dropping funnel, an efficient mechanical stirrer, and a thermometer, is placed 176 g. (2 moles) of tert.-amyl alcohol (redistilled, b.p. range 0.5°). The flask is surrounded by a water bath, and the temperature of the alcohol is held at 50–60° while 320 g. (103 cc., 2 moles) of bromine is slowly added with stirring during about two hours. The stirring is continued for a few minutes until the bromine color has disappeared.

To the reaction flask containing the crude trimethylethylene dibromide is added 540 cc. of water, and the flask is fitted with a long reflux condenser and a mercury-sealed stirrer. The mixture is refluxed with stirring for three to five hours until hydrolysis is practically complete. The reflux condenser is then replaced by a condenser for distillation, and the crude methyl isopropyl ketone is removed from the reaction mixture by direct distillation, with stirring, until the temperature rises and the oil nearly stops coming over (about one and one-half hours), or until the oil coming over is heavier than water. The residue in the flask can be distilled to yield about 380 cc. of constant-boiling hydrobromic acid.

To the distillate, consisting of a yellow oil with a small lower water layer, powdered sodium carbonate (about 10 g.) is added, and the mixture is shaken until the water layer is alkaline and nearly saturated. The layers are separated, and the oil is refluxed for about sixteen hours with 20 g. of powdered potassium carbonate and 5 cc. of water. The oily layer is again separated and dried over about 6 g. of anhydrous calcium chloride or potassium carbonate. It is then placed in a flask containing 2 g. of dry sodium carbonate and distilled through an efficient column. The yield of methyl isopropyl ketone boiling at 92–94°is about 102 g. (59 per cent of the theoretical amount). The product is slightly yellow.