Solvent-free synthesis of imidazo[1,2-a]pyrimidine-3-carbonitriles and 1,2,4-triazolo[4,3-a]pyrimidines under the catalytic performance of TiO2-[bip]-NH2+ C(NO2)3− as a novel nanocatalyst

Abstract

In this article a simple method is reported for the promotion of the synthesis of imidazo[1,2-a]pyrimidine-3-carbonitriles and 1,2,4-triazolo[4,3-a]pyrimidines derivatives via three component one-pot condensation of various aromatic aldehydes, malononitrile and 2-aminobenzimidazole or 3-amino-1,2,4-triazole using TiO2-[bip]-NH2+ C(NO2)3− as a new efficient nano-catalyst. All the products which were obtained under mild and solvent-free conditions were identified with the comparison of their physical properties and spectral data with the authentic samples. The structure of the prepared catalyst was characterized using Fourier transform infrared spectroscopy (FT-IR), energy dispersive X-ray analysis (EDX), field emission scanning electron microscopy (FESEM), thermo gravimetric analysis (TGA) and X-ray diffraction (XRD). The significant features of this procedure are short reaction times, high yields of the products, ease of separation of the products and easy preparation of the catalyst. Also the catalyst can be recycled and reutilized for several cycles in the studied reactions.