In a
1-l. three-necked flask, equipped with a
mechanical stirrer, a
reflux condenser, and a
thermometer (with bulb immersed in the liquid), are placed
100 g. (0.75 mole) of anhydrous aluminum chloride and
300 g. of carbon disulfide (Note
1). The suspension is cooled to 15–25°, and a solution of
60 g. (0.71 mole) of thiophene (p. 578) and
105 g. (0.75 mole) of benzoyl chloride in
225 g. of carbon disulfide is added through the condenser, with stirring, over a period of three and one-half hours (Note
2). The solution is allowed to warm up to room temperature, and stirring is continued for three more hours; the reaction mixture is then allowed to stand overnight. The mixture is refluxed on the
water bath for three and one-half hours, cooled, poured on ice, and extracted with
ether. The
ether extract is washed successively with
sodium carbonate solution and water, and then dried over
calcium chloride. The
ether is removed by distillation on the water bath, and the residue is distilled under reduced pressure. The yield of product boiling at
200–209°/30–40 mm. is
117–120 g. (
88–90 per cent of the theoretical amount). On crystallization from
1 l. of petroleum ether (b.p.
65–110°) there is obtained
110–112 g. of product melting at
52°. Another crystallization from
petroleum ether gives a product which melts at
55–56°. The loss on the second crystallization is about 10 per cent.