Feist-Bénary reaction

The Feist-Bénary reaction or Feist-Bénary furan synthesis is a name reaction in organic chemistry . It is used for the synthesis of furan derivatives . The reaction is understood to be a base- catalyzed condensation of β-dicarbonyl compounds with α-halo-carbonyl compounds. As the base is ammonia or, alternatively, z. B. pyridine . The reaction was first presented in 1901 by the German chemist Franz Feist and further elaborated in 1911 by his compatriot Erich Bénary .

R ¹ , R ² = H, alkyl group; R ³ = alkyl or aryl group; R ⁴ = alkyl or alkoxyl group; × = Cl, Br or I

mechanism

The following illustration shows - based on literature data - a plausible reaction mechanism for this reaction:

Reaction mechanism of the Feist-Bénary reaction R ¹ , R ² = H, alkyl group; R ³ = alkyl or aryl group; R ⁴ = alkyl or alkoxyl group;

First, the β-dicarbonyl compound 1 is deprotonated under the action of a base - here ammonia . A proton transfer takes place, so that enol 2 is formed. This now attacks the carbonyl group of the α-halo-carbonyl compound 3 . The carbonyl compound 4 is formed . Hydrogen chloride is split off via an intermediate stage and dihydrofuranol 5 is formed . With elimination of water , the furan derivative 6 is finally formed from 5 with aromatization .

Individual evidence

↑ ^a ^b ^c ^d ^e Zerong Wang: Comprehensive Organic Name Reactions and Reagents, 3 Volume Set . John Wiley & Sons, Hoboken, New Jersey 2009, ISBN 978-0-471-70450-8 , pp. 1036-1037.
↑ ^a ^b ^c L. Kürti , B. Czakó: Stratigic Applications of Named Reactions in Organic Synthesis . Elsevier Academic Press, Amsterdam 2005, ISBN 978-0-12-429785-2 , p. 166.

[Wang_1036-1] Zerong Wang: Comprehensive Organic Name Reactions and Reagents, 3 Volume Set . John Wiley & Sons, Hoboken, New Jersey 2009, ISBN 978-0-471-70450-8 , pp. 1036-1037.

[Kürti_166-2] L. Kürti , B. Czakó: Stratigic Applications of Named Reactions in Organic Synthesis . Elsevier Academic Press, Amsterdam 2005, ISBN 978-0-12-429785-2 , p. 166.