To a mixture of
292 g. (332 cc., 3.7 moles) of dry benzene and
116 g. (73.2 cc., 0.75 mole) of dry carbon tetrachloride (Note
1), in a
1-l. flask provided with a
reflux condenser having a
calcium chloride tube at its upper end, is added
100 g. (0.75 mole) of anhydrous aluminum chloride in lumps (Note
2). The flask is at once immersed in ice water to within 5 cm. of the top, and allowed to stand for twenty-four hours, the temperature of the water being allowed to rise to that of the room (Note
3).
One hundred and ten grams (153 cc., 1.48 moles) of anhydrous ether is added in small portions, through the condenser, the flask being shaken occasionally during the twenty minutes required for the addition.
The mixture is allowed to stand for twenty-four hours, and is then poured into a
5-l. flask containing 650 g. of ice and
25 cc. of concentrated hydrochloric acid.
One liter of benzene is then added, and the mixture heated on a
steam bath under a
return condenser. After gently boiling for five or ten minutes, the mixture is allowed to cool to 40–50°, when the
benzene layer is separated, washed with 700 cc. of warm water containing
25 cc. of concentrated hydrochloric acid, and distilled. After the
benzene has been removed under atmospheric pressure, the residue is transferred to a
300-cc. flask and distilled under reduced pressure, and a fraction boiling over the range
190–215°/10 mm. collected (Note
4). This weighs
135–160 g.; it solidifies on cooling. It is recrystallized from
550–650 cc. of ethyl alcohol (Note
5), and a colorless product, crystallizing in needles which melt sharply at
92°, is obtained. This is filtered off and washed twice with
30-cc. portions of fresh alcohol. The alcoholic mother liquor is concentrated and the residue distilled under reduced pressure, material which distils over at
190–200°/10 mm. being collected. This is recrystallized from
ethyl alcohol, and
6–7 g. more of pure material is thus obtained. The total yield of recrystallized product is
125–154 g. (
68–84 per cent of the theoretical amount).