Baeyer–Emmerling indole synthesis

Baeyer–Emmerling indole synthesis is a method for synthesizing indole from a (substituted) ortho-nitrocinnamic acid and iron powder in strongly basic solution.^[1][2] This reaction was discovered by Adolf von Baeyer and Adolph Emmerling in 1869.^{[3] [4]}

Baeyer-Emmerling indole synthesis

Baeyer–Emmerling indole synthesis
Named after	Adolf von Baeyer Adolph Emmerling
Reaction type	Ring forming reaction

Reaction mechanism

The reaction of iron powder with o-nitrocinnamic acid reduces the nitro group to a nitroso. The nitrogen then condenses with a carbon on the alkene chain with loss of a molecule of water to form a ring. Decarboxylation gives indole.

Baeyer-Emmerling indole reaction mechanism

See also

• Baeyer–Drewson indigo synthesis