文摘
Imines are important in biological chemistry and as intermediates in organic synthesis. An experiment for introductory undergraduate organic chemistry is presented in which benzaldehyde was condensed with p-methoxyaniline in toluene to give 4-methoxy-N-(phenylmethylene)benzenamine. Water was removed by azeotropic distillation using a Dean–Stark trap. The reaction was readily performed in one 3 h laboratory period, gave a crystalline product, and was easily followed visually by the amount of water collected. It demonstrated important concepts from second-year undergraduate organic chemistry, including equilibrium processes, condensation reactions, and imine formation. The experiment also gave students exposure to important laboratory techniques including azeotropic distillation, use of a water trap, and mixed-solvent recrystallization.
