Delépine reaction

The Delépine reaction is the <a href="/facts/Organic_synthesis/aprl6Iq7">organic synthesis</a> of primary <a href="/facts/Amine/JvfYJfP6">amines</a> (4) by reaction of <a href="/facts/Benzyl/kHmqYwqH">benzyl</a> or <a href="/facts/Alkyl/vmEk8X4v">alkyl</a> <a href="/facts/Halide/ujYu8kGD">halides</a> (1) with <a href="/facts/Hexamethylenetetramine/jnFrmG81">hexamethylenetetramine</a> (2) followed by <a href="/facts/Acid_(chemistry)/FySU18n1">acid</a> <a href="/facts/Hydrolysis/JTvwIHPs">hydrolysis</a> of the <a href="/facts/Quaternary_ammonium_salt/bNpF1goc">quaternary ammonium salt</a> (3). It is named after the French chemist <a href="/facts/Marcel_Del%25C3%25A9pine/4R4a3QFx">Stéphane Marcel Delépine</a> (1871–1965).

Advantages of this reaction are selective access to the primary amine without <a href="/facts/Side_reaction/HMJ8CYxH">side reactions</a> from easily accessible reactants with short reaction times and relatively mild reaction conditions. Downsides include that the reaction is often performed using <a href="/facts/Chloroform/gvzuJMXa">chloroform</a> as solvent, which is toxic, and poor <a href="/facts/Atom_economy/M8mPjCJw">atom economy</a>, including the formation of several <a href="/facts/Equivalent_(chemistry)/ksgd425g">equivalents</a> of <a href="/facts/Formaldehyde/Ck8RLfqk">formaldehyde</a> (a known carcinogen) during quaternary ammonium salt formation.
An example is the synthesis of 2-bromoallylamine from 2,3-dibromopropene.

Delépine reaction open-in-new

Delépine reaction