Fe(OTf)3-catalyzed practical synthesis of 2-trifluoromethylarylimidazoles from o-arylenediamines and hexafluoroacetylacetone
An iron-catalyzed practical synthesis of 2-trifluoromethylarylimidazoles through condensation of o-arylenediamines and hexafluoroacetylacetone followed by intramolecular addition and C–C bond cleavage in one-pot has been developed. A series of title compounds were obtained with up to 99% yield. This method is quite practical and suitable for scalable preparation due to simple experimental procedure and readily available reagents.
Cyclocondensation of N-(carbotrifluoromethyl)-ortho-arylenediamines leads to a series of 2-trifluoromethylarylimidazoles with good yields on montmorillonite K10 in 'dry media' under microwave irradiation within 2 min in a domestic oven. By conventional heating in the same conditions, no reaction is observed.