p-Chlorobenzaldehyde (3.5 g., 0.025 mole) in ethanol (10 ml.) is added to a solution of 4-(o-chlorobenzyl)-4-phenyl-5-oxohexanoic acid (4.89 g., 0.015 mole) and sodium hydroxide (0.80 g., 0.03 mole) in water (50 ml.). The resulting mixture is heated on a steam bath for 24 hours. The reaction solution is cooled to room temperature, acidified with dilute hydrochloric acid (10 ml.), and the sticky solid which forms after scratching is filtered and air-dried, yield 7.0 g., m.p. 190°-213°C. Several recrystallizations from nitromethane, followed by a final recrystallization from acetonitrile, gives a light yellow solid with m.p. 223°-227°C.
