Introduction of a Novel Brønsted Acidic Ionic Liquid Incorporated in UiO‐66 Nanocages for the Efficient Synthesis of Pyrimido[4,5‐d]Pyrimidines

Abstract

AbstractAn efficient, environmentally friendly and convenient route is described for the synthesis of pyrimido[4,5‐d]pyrimidines by using TEDA‐BAIL@UiO‐66 as a novel catalyst. In this procedure, a series of pyrimido[4,5‐d]pyrimidine derivatives were synthesized via the three‐component reactions of 6‐aminouracils, substituted aromatic aldehydes and urea or thiourea in the presence of triethylenediamine Brønsted acidic ionic liquid supported in Zr metal‐organic framework (TEDA‐BAIL@UiO‐66) as a novel catalyst under ultrasound irradiation. Excellent yields and no tedious separation procedures are the key advantages of the present method, which produced the desired products in high yields and short reaction times. Also, the catalyst was fully characterized by energy‐dispersive X‐ray spectroscopy (EDX), field emission scanning electron microscopy (FE‐SEM), Fourier transform infrared spectrophotometry (FT‐IR), X‐ray diffraction (XRD), Brunauer‐Emmett‐Teller (BET) and thermogravimetric analysis (TGA) analysis.