Chichibabin pyridine synthesis

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Not to be confused with Chichibabin reaction.

Chichibabin pyridine synthesis
Named after Aleksei Chichibabin
Reaction type Ring forming reaction
Identifiers
RSC ontology ID RXNO:0000526

The Chichibabin pyridine synthesis (

ketones, α,β-Unsaturated carbonyl compounds, or any combination of the above, with ammonia.[1] It was reported by Aleksei Chichibabin in 1924.[2][3]
Methyl-substituted pyridines, which show widespread uses among multiple fields of applied chemistry, are prepared by this methodology.[4]

Representative syntheses

The syntheses are presently conduced commercially in the presence of oxide catalysts such as modified

alumina (Al2O3) or silica]] (SiO2). The reactants are passed over the catalyst at 350-500 °C. 2-Methylpyridine- and 4-methylpyridine are produced as a mixture from acetaldehyde and ammonia. 3-Methylpyridine and pyridine are produced from acrolein and ammonia. Acrolein and propionaldehyde react with ammonia affords mainly 3-methylpyridine. 5-Ethyl-2-methylpyridine is produced from paraldehyde and ammonia.[5]

Mechanism and optimizations

These syntheses involve many reactions such as

Michael reactions
.

Chichibabin pyridine synthesis

Many efforts have been made to improve the method.[6][1] Conducting the reaction in the gas phase in the presence of aluminium(III) oxide.[4] zeolite (yield 98.9% at 500 K),[7]

From nitriles

Of the many variations have been explored. one approach employs nitriles as the nitrogen source. For example,

alkyne trimerization.[5]

See also

References

  1. ^
    doi:10.1021/ja01176a008
    .
  2. doi:10.1002/prac.19241070110
    .
  3. ISBN 978-3-540-40203-9
    .
  4. ^
    S2CID 93717043
    .
  5. ^
    ISBN 978-3527306732
    .
  6. doi:10.1021/ja01121a051
    .
  7. doi:10.1016/j.molcata.2008.10.010
    .
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