Amine Dealkylations with Acyl Chlorides

The use of cyanogen bromide to dealkylate tertiary amines is known as the von Braun reaction. More recently, the development of carbonochloridate (chloroformate) reagents to effect these N-dealkylations has reached such high yields and mild reaction conditions as to open up the possibility of using simple alkyl groups to protect secondary amines. If an acyl chloride moiety is introduced within the molecule containing the tertiary amine, either by reaction of an organic acid with thionyl chloride or by treatment of a diamine with phosgene, intramolecular cyclization-N-dealkylation results leading to novel products. 1. Introduction 2. Kinetic and Mechanistic Aspects 3. Isolation of the Intermediate Salts 4. N-Dealkylations 5. Cyclization-Dealkylation Reactions 6. Summary and Outlook