Toluene → Isobutylbenzene

Participants

Reaction Conditions

Reaction Steps

A 1-L Parr autoclave provided with a high shear turbine-type impeller was charged with 4.3g of NaK (an alloy having a K content of 78% by weight) and 428g of toluene. The mixture was heated to 160° C. under normal agitation, i.e., an agitator tip speed of 1.5 m/sec.; and the agitator tip speed was then increased to 5.7 m/sec. The mixture was agitated at this speed for 15 minutes, after which the temperature was increased to 190° C. Then 160 g of propene was fed over a period of 30 minutes while the temperature was maintained below 200° C. with cooling and the pressure below 2.8 MPa by regulating the propene feed rate. The autoclave was kept at 190° C. for one hour, and agitation was then slowed to normal. The NaK was deactivated by the addition of 12 g of isopropanol and 142 g of water. Analysis of the organic phase by gas chromatography showed that the reaction resulted in conversion to isobutylbenzene at the rate of 0.975 mol/hr. This compares with a conversion rate of only about 0.75 mol/hr. when diatomaceous earth- or potassium carbonate-supported NaK is employed as the catalyst and normal agitation conditions are maintained throughout the reaction.

Provenance & Evidence