Microwave assisted one pot synthesis of a series of trifluoromethyl substituted spiro [indole–triazoles]

A series of trifluoromethyl substituted spiro [3H-indole-3,3′-[3H-1,2,4]triazoles]-2(1H)-ones have been synthesized in 85–90% yield by one pot environmentally benign microwave induced techniques involving the condensation of 3-arylimino-2H-indol-2-ones (III) with thiosemicarbazide (IV) using montmorillonite as solid support. This 3-arylimino-2H-indol-2-ones (III) was synthesized in situ by the reaction of fluorinated indole-2,3-diones (I) and fluorinated anilines (II). The advantages obtained by the use of microwave irradiation were demonstrated.