Organic reaction in which indigo is prepared from 2-nitrobenzaldehyde and acetone
The Baeyer–Drewsen indigo synthesis (1882) is an organic reaction in which indigo is prepared from 2-nitrobenzaldehyde and acetone[1][2] The reaction was developed by von Baeyer and Viggo Drewsen [da] in 1880 to produce the first synthetic indigo at laboratory scale. This procedure is not used at industrial scale.[3]
![Baeyer-Drewson indigo synthesis](Https://upload.wikimedia.org/wikipedia/commons/thumb/c/ce/Baeyer-Drewson_indigo_synthesis.svg/593px-Baeyer-Drewson_indigo_synthesis.svg.png)
The reaction is classified as an aldol condensation. As a practical route to indigo, this method was displaced by routes from aniline.[4]
Mechanism
[edit]![Mechnaism of the Baeyer-Drewsen Indigo Synthesis](Https://upload.wikimedia.org/wikipedia/commons/thumb/7/7e/Baeyer-Drewsen_Indigo_Synthesis_Mechanism.svg/855px-Baeyer-Drewsen_Indigo_Synthesis_Mechanism.svg.png)
Note
[edit]In the English literature this reaction is sometimes called Baeyer–Drewson reaction, although the author of the original paper was spelled Drewsen.
References
[edit]- ^ Adolf Baeyer, Viggo Drewsen (1882). "Darstellung von Indigblau aus Orthonitrobenzaldehyd". Berichte der deutschen chemischen Gesellschaft. 15 (2): 2856–2864. doi:10.1002/cber.188201502274.
- ^ Helmut Schmidt (1997). "Indigo – 100 Jahre industrielle Synthese". Chemie in unserer Zeit. 31 (3): 121–128. doi:10.1002/ciuz.19970310304.
- ^ "Johannes Pfleger, Chemist". Evonik Industries. Archived from the original on 2014-05-24. Retrieved 2022-12-04.
- ^ Elmar Steingruber "Indigo and Indigo Colorants" Ullmann's Encyclopedia of Industrial Chemistry 2004, Wiley-VCH, Weinheim. doi:10.1002/14356007.a14_149.pub2