Bi<sub>2</sub>O<sub>3</sub>/FAp, a sustainable catalyst for synthesis of dihydro‐[1,2,4]triazolo[1,5‐a]pyrimidine derivatives through green strategy
Nagaraju Kerru, Lalitha Gummidi, Surya Narayana Maddila, Sandeep V. H. S. Bhaskaruni, Sreekantha B. Jonnalagadda
Abstract
The bismuth loaded on fluorapatite (Bi 2 O 3 /FAp) proved to be an excellent catalyst for the synthesis of novel dihydro‐[1,2,4]triazolo[1,5‐a]pyrimidine derivatives via a three‐component reaction involving the mixture of 1 H ‐1,2,4‐triazol‐5‐amine, ethyl cyanoacetate or ethyl acetoacetate, and different benzaldehydes in ethanol at room temperature. The catalyst material was characterized by X‐ray diffraction, Brunauer–Emmett–Teller surface area analysis, Fourier‐transform infrared, scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, and transmission electron microscopy techniques. The efficacy of Bi 2 O 3 /FAp as a heterogeneous catalyst was evaluated with the loading of different wt% of bismuth on FAp. The 2.5% bismuth on FAp performed extremely well as a catalyst with a high yield of products (92%–96%) in a short reaction time (25–35 min). The catalyst was recovered by simple filtration. It showed undiminished activity up to five runs. Simple work‐up, room temperature reaction, short reaction time, high yields, no column chromatography, and good reusability of catalyst are the merits of the proposed protocol. In addition, this process offers 100% carbon efficiency and 98% atom economy with noteworthy fiscal and environmental benefits.