A Facile Oxidation of Tertiary Amines to Lactams by Using Sodium Chlorite: Process Improvement by Precise pH Adjustment with CO2

Abstract By using cheap and innocuous sodium chlorite, a series of tertiary amines have been oxidized to the corresponding lactams with good selectivity and high yield. In this method, neither transition-metal catalyst nor oxidant was used. In the oxidation step, the pH of the sodium chlorite was precisely adjusted to pH around 6 using CO2, such pH is a compromise between oxidative properties, chemical stability, and unwanted precipitation. In addition, buffer salts are not necessary, which allows this oxidation reaction to be performed under safe and environmentally benign conditions.