Synthesis, characterization, and investigation the catalytic potential of diammonium phosphate modified with bismuth for the one-pot synthesis of 3,4-dihydropyrimidin-2(1H)-ones through a three-component reaction: An in-depth evaluation using green metrics

A straightforward synthesis of a novel catalyst, bismuth phosphate (Bi(NO3)3/DAP), was achieved using a coprecipitation method. The resulting material underwent thorough characterization employing various techniques, including X-ray diffraction, FTIR, scanning electron microscopy (SEM), and EDX. We investigated the application of Bi(NO3)3/DAP as a catalyst in the 3,4-dihydropyrimidin-2(1H)-ones reaction between urea, ethyl acetoacetate, and various aldehydes. The results demonstrated that the catalyst exhibited excellent catalytic performance, leading to the production of products with impressive yields (89-97 %) in just 15 min in an ethanol medium. Additionally, the heterogeneity of the reaction was confirmed through a hot filtration test. Notably, this catalyst presents notable benefits, such as its easy recovery and ability to be reused for a minimum of five successive cycles, a simple work-up procedure, and the attainment of high product yields. A sustainability evaluation based on green metrics using the E-factor, atom economy (AE), reaction mass efficiency (RME), and optimum efficiency (OE) revealed that the use of a catalyst in the Biginelli reaction enhances environmental sustainability.