To a solution of
65 g. (0.25 mole) of ethyl sebacate (p. 277) in
800 cc. of absolute ethyl alcohol (Note
1) contained in a
3-l. round-bottomed flask, to which is attached a
60-cm. bulbed reflux condenser protected by a
calcium chloride drying tube, is added
70 g. (3 gram atoms) of sodium in large pieces in one lot. The somewhat vigorous reaction is easily kept under control by immersing the entire flask in a mixture of crushed ice and water. In a short time the reaction has subsided somewhat; the flask is then removed from the cooling mixture, and the reaction is allowed to proceed without external cooling. Reduction is completed by heating the mixture on a
steam bath until all the
sodium has dissolved. The partly cooled mixture is diluted with 300 cc. of water and heated on the steam bath until no more alcohol distils. The remaining small amount of alcohol is removed by gently applying suction from a
water pump. The residue is diluted with about 600 cc. of hot water, and the mixture is allowed to cool without being disturbed. The separated oil solidifies to a solid cake from which the lower aqueous layer is easily decanted. The solid is washed once with a little cold water, drained as completely as possible, and dried by heating in the flask on a steam bath under reduced pressure. The residue is extracted with four successive
250-cc. portions of hot benzene. The united extract is clarified with a little charcoal, filtered, and concentrated to a volume of about 60 cc. About
200 cc. of alcohol is added; the solution is filtered, concentrated to about 60 cc., and mixed with an equal volume of hot
benzene. On slow cooling the mixture sets to a solid mass of large crystals, which are filtered and washed with
ether. The yield of this product, which melts at
72–74° (corr.), is
32–33 g. (
73–75 per cent of the theoretical amount) (Note
2), (Note
3), and (Note
4).