Skraup reaction

The Skraup synthesis was named after the Czech-Austrian chemist Zdenko Hans Skraup (1850-1910), and describes the synthesis of quinoline and its derivatives.

Reaction mechanism

α, β -unsaturated carbonyl compounds (aldehydes, ketones ) by an acid catalyzed addition reaction with aromatic amines to form quinoline. The carbonyl compounds required for the synthesis of α, β -unsaturated are often presented only in a separate step of the synthesis (eg crotonaldehyde from paraldehyde or acrolein from glycerol).

Only in the next step, the amine is added. Subsequently, the acid-catalyzed aldehyde condensation occurs with the aromatic nucleus and forms the dihydroquinoline.

Then the dihydroquinoline is dehydrated by nitrobenzene the aromatic quinoline, the nitrobenzene is reduced.

Variant

If the dihydroquinoline formed disproportionates to tetrahydroquinoline and quinoline derivative, so it is a Doebner -Miller synthesis.

Swell

• Organikum, German VEB Verlag der Wissenschaften, Berlin 1976
• A. Wollrab: Organic Chemistry: An Introduction for teacher training and minor students. Springer, 2002, pp. 984

• Name reaction