The solution of
benzylmagnesium chloride is cooled with running water, and
456 g. (2 moles) of n-butyl p-toluenesulfonate (Note
1) dissolved in about twice its volume of anhydrous
ether is then added slowly with stirring through the
separatory funnel at such a rate that the
ether just boils. The time required for the addition is about two hours. A white solid soon forms and the mixture assumes the consistency of a thick cream. Stirring is continued, without cooling, for about two hours, and the mixture is hydrolyzed by pouring onto crushed ice to which is then added about
125 cc. of concentrated hydrochloric acid (Note
2).
The
ether layer is separated and combined with a
200-cc. ether extract of the aqueous layer. The combined
ether solution is washed once with about 100 cc. of water and then dried by shaking for a few minutes with about
10 g. of anhydrous potassium carbonate. After filtration, the
ether is distilled on a
water bath. When practically all the
ether has been removed, about
5 g. of sodium, freshly cut and in thin slices, is added and the mixture is boiled for about two hours (Note
3). The solution is decanted and then distilled, using an
efficient fractionating column. The fraction boiling at
190–210° is collected. This on redistillation yields
74–88 g. (
50–59 per cent of the theoretical amount) of
n-amylbenzene boiling at
198–202° (Note
4).