A
500-ml., round-bottomed flask equipped with a
reflux condenser is charged with a solution of
25 g. of potassium hydroxide in
250 ml. of 95% ethanol, to which is added
16.6 g. (0.0498 mole) of methyl (trans-2-iodo-1-tetralin)carbamate (Note
1). The resulting mixture is heated under reflux on a stream bath for 2 hours, cooled, and added to 500 ml. of water. The clear, yellow solution is shaken three times with
100-ml. portions of diethyl ether. The
ether layers are combined, washed three times with 125-ml. portions of water and once with
125 ml. of a saturated sodium chloride, dried over
5 g. of anhydrous potassium carbonate, and filtered. The
ether is removed by distillation on a
steam bath, giving the crude imine as a yellow-brown oil (Note
2). The oil is transferred to a small flask, the container is rinsed with
ether, and the rinse is added to the distillation flask. The product is collected by distillation through a small Vigreux column with warm water circulating through the condenser to prevent crystallization of the product. The fraction boiling at
80–82° (0.15–0.25 mm.) is collected as a solid that forms in the receiver, yielding
4.9–5.1 g. (
68–70%) of the imine, m.p.
54–56° (Note
2); the IR spectrum has a band at 3205 cm.
−1 (NH) (Note
3).