Madelung synthesis

The Madelung synthesis is a chemical reaction that produces (substituted or unsubstituted) indoles by the intramolecular cyclization of N-phenylamides using strong base at high temperature.^{[1] [2]}

This method is essentially confined to the preparation of 2-alkinylindoles (not easily accessible through electrophile aromatic substitution) because of the vigorous reaction conditions.

References

1. ^ Madelung, W. (1 January 1912). "Über eine neue Darstellungsweise für substituierte Indole. I". Berichte der deutschen chemischen Gesellschaft 45 (1): 1128–1134. doi:10.1002/cber.191204501160. 
2. ^ Houlihan, William J.; Uike, Yasuyuki, Parrino, Vincent A. (1 October 1981). "Novel cycloaddition products formed by the modified Madelung indole synthesis". The Journal of Organic Chemistry 46 (22): 4515–4517. doi:10.1021/jo00335a039.