Chichibabin reaction

The Tschitschibabin reaction (also Tschitschibabin amine reaction) is a nucleophilic aromatic substitution reaction for the production of 2- , 4-aminopyridines or -quinolines and was first described in 1914 by Alexei Evgenjewitsch Tschitschibabin .

In this case, in an activated for nucleophilic attack is heteroaromatic a hydrogen atom substituted. The nucleophilic substitution is carried out on heteroaromatics , the electron density of which is reduced by inductive and mesomeric effects .

mechanism

The reaction (here using the example of the synthesis of 2-aminopyridine substituted in the ortho- , meta- or para- position with the radical R ) proceeds according to an addition-elimination mechanism :

• In the first step from which it is sodium amide derived amide ion attached to the carbon atom, where the negative charge is stabilized by the nitrogen.
• In the next step, a hydride ion is split off , which is then protonated by the amino group to form hydrogen.
• Finally, the 2-aminopyridine is released from its anion by adding water.

See also

• Amination
• Name reaction
• Reaction mechanism

literature

• Jie Jack Li, (Foreword by EJ Corey): Name Reactions in Heterocyclic Chemistry II , Wiley-Verlag, 2011, ISBN 978-0-470-08508-0 .

swell

1. ↑ Entry on Tschitschibabin syntheses. In: Römpp Online . Georg Thieme Verlag, accessed on June 16, 2014.