An Easily Constructed Water Separator In many organic reactions, such as preparation af enamine, ketal and ester, i t is necessary to drive the equilibrium to completion by azeotropically distilling off the generated water. The most commonly used azeotropic mixture is benzenelwater, and the Dean-Stark trap is the standard piece of equipment used as the water separator.' However, this rather simple piece oiapparatus is not commonly available in the undergraduate laboratory. I have found a simple and inexpensive way to construct a water separator by using only two, readily available three-way connecting tubes (a) as shown in the figure. One open end of the apparatus is stoppered by a round-bottomed flask ( b ) .The receiving vessel (c) can be a graduated tube, a pear-shaped flask or a small additional funnel. We have used this device in preparation of the pyrrolidine enamine of cyclohexanone2 in 0.2 mole scale with satisfactory results. 'Bates, Robert B., and Schaefer, John P., "Research Techniques in Organic Chemistry," Prentice-Hall Inc., London, 1971. 2Manson, Richard S., "Advanced Organic Synthesis,'' Academic Press, New York, 1972,
Albert W. M. Lee Hong Kong Baptist College 224 Waterloo Road Kowloon, Hong Kong
Volume 60
Number 7
July 1983
595
