Baeyer diarylmethane synthesis
The Baeyer diarylmethane synthesis , named after the German chemist Adolf von Baeyer , is a name reaction from the field of organic chemistry and was first described in 1872. The Baeyer diarylmethane synthesis is essentially an electrophilic aromatic substitution and enables the production of diarylmethane from an aldehyde and an aromatic compound .
Overview reaction
Aromatic compounds ( benzene in the example ) can be converted to diphenylmethane with an aldehyde ( formaldehyde in the example ) via an acid-catalyzed condensation reaction .
The reaction also takes place with substituted aromatics.
Reaction mechanism
The following mechanism is described in the literature:
In the first step of the diarylmethane synthesis, the aldehyde ( 1 ) is protonated with an acid . On the thus formed carbocation , an aromatic compound 2 , under annulment of the aromaticity attack. Through elimination of water and subsequent electron rearrangement, rearomatization occurs with the formation of the carbocation 3 . In the second step, there is renewed electrophilic substitution on the aromatic, which ultimately results in diphenylmethane ( 4 ).
Individual evidence
- ↑ A. Baeyer: About the compounds of aldehydes with phenols In: Ber. German Chem. Ges. 5, 1872, pp. 280-282, doi: 10.1002 / cber.18720050186 .
- ↑ A. Baeyer: About the compounds of aldehydes and alcohols with aromatic hydrocarbons. Fourth communication. In: Ber. German Chem. Ges. 6, 1873, pp. 220-224, doi: 10.1002 / cber.18730060183 .
- ^ A b Zerong Wang: Comprehensive Organic Name Reactions and Reagents , Wiley, 2009, ISBN 978-0-471-70450-8 , pp. 132-135.