Bougault reaction

The Bougault reaction is a name reaction in organic chemistry and enables the synthesis of indene derivatives . J. Bougault first reported this reaction in 1915.

Overview reaction

The Bougault reaction takes place in two steps. First, the reaction with sodium ethanolate takes place , which is followed by a reaction with sulfuric acid.

Reaction mechanism

In the proposed reaction mechanism, the β-arylpropionic ester 1 reacts with sodium ethoxide to form a reactive anion, which enters into a condensation reaction with diethyl oxalate . The resulting glyoxylate ester 2 then reacts with sulfuric acid in a cyclization reaction to form the desired indole derivative 3 .

Sulfuric acid can also be used to protonate 2 , in order to suppress undesired side reactions.

application

The Bougault reaction is used in the synthesis of indenes , dihydronaphthalenes and naphthalene derivatives .

Individual evidence

↑ ^a ^b ^c ^d Zerong Wang: Comprehensive Organic Name Reactions and Reagents . John Wiley & Sons, Inc., Hoboken, NJ, USA 2010, ISBN 978-0-470-63885-9 , doi : 10.1002 / 9780470638859 .
↑ ^a ^b ^c ^d E. C. Horning, John Koo: Glyoxylate Cyclizations. Methoxybenzsuberenes 1 . In: Journal of the American Chemical Society . tape 73 , no. December 12 , 1951, p. 5830-5831 , doi : 10.1021 / ja01156a110 .

↑ Louis F. Fieser, Emanuel B. Hershberg: The Synthesis of Phenanthrene and Hydrophenanthrene Derivatives. I. The Bougault Reaction . In: Journal of the American Chemical Society . tape 57 , no. October 10 , 1935, p. 1851-1854 , doi : 10.1021 / ja01313a027 .

[:0-1] Zerong Wang: Comprehensive Organic Name Reactions and Reagents . John Wiley & Sons, Inc., Hoboken, NJ, USA 2010, ISBN 978-0-470-63885-9 , doi : 10.1002 / 9780470638859 .

[:1-2] E. C. Horning, John Koo: Glyoxylate Cyclizations. Methoxybenzsuberenes 1 . In: Journal of the American Chemical Society . tape 73 , no. December 12 , 1951, p. 5830-5831 , doi : 10.1021 / ja01156a110 .

[3] Louis F. Fieser, Emanuel B. Hershberg: The Synthesis of Phenanthrene and Hydrophenanthrene Derivatives. I. The Bougault Reaction . In: Journal of the American Chemical Society . tape 57 , no. October 10 , 1935, p. 1851-1854 , doi : 10.1021 / ja01313a027 .