Base-Mediated Syntheses of Di- and Trisubstituted Imidazoles from Amidine Hydrochlorides and Bromoacetylenes.
A new transition metal-free method for the preparation of substituted imidazoles from easy-to-handle amidine hydrochlorides and bromoacetylenes has been developed. The reactions proceed in air and use inexpensive K2 CO3 as base. Additions of 2,2'-bipyridine and water have beneficial effects on the product yields. Various di- and trisubstituted imidazoles have been prepared in good yields (up to 88 %).
Institut für Organische Chemie, RWTH Aachen University, Landoltweg 1, 52074 Aachen (Germany).
Xiao Yun
XY
Chen
Institut für Anorganische Chemie, RWTH Aachen University, Landoltweg 1, 52074 Aachen (Germany).
Ulli
U
Englert
Institut für Organische Chemie, RWTH Aachen University, Landoltweg 1, 52074 Aachen (Germany). Carsten.Bolm@oc.RWTH-Aachen.de.
Carsten
C
Bolm
alkynes; amidines; base; heterocycles; imidazoles