Pumice as a Novel Natural Heterogeneous Catalyst for the Designation of 3,4-Dihydropyrimidine-2-(1H)-ones/thiones under Solvent-Free Conditions

Abstract

In this study, pumice is used as a novel natural heterogeneous catalyst for the synthesis of 3,4-dihydropyrimidine-2-(1H)-ones/thiones via the one-pot multi-component condensation of aromatic aldehydes, urea/thiourea, and ethyl acetoacetate or acetylacetone in excellent yields (up to 98%). The physical and chemical properties of the catalyst were studied. Their geochemical analysis revealed a basaltic composition. Furthermore, X-ray diffraction showed that it is composed of amorphous materials with clinoptilolite and heulandites zeolite minerals in its pores. Moreover, pumice has a porosity range from 78.2–83.9% (by volume) and is characterized by a mesoporous structure (pore size range from 21.1 to 64.5 nm). Additionally, it has a pore volume between 0.00531 and 0.00781 m2/g and a surface area between 0.053 and 1.47 m2/g. The latter facilitated the reaction to proceed in a short time frame as well as in excellent yields. It is worth noting that our strategy tolerates the use of readily available, cheap, non-toxic, and thermally stable pumice catalyst. The reactions proceeded smoothly under solvent-free conditions, and products were isolated without tedious workup procedures in good yields and high purity. Indeed, pumice can be reused for at least five reuse cycles without affecting its activity.

Design, synthesis of novel Schiff bases as potential insecticidal agents against Spodoptera frugiperda (Lepidoptera: Noctuidae)

“…The same methodology was used to conduct control (check) tests without the tested substance. Larval mortality numbers were computed for a period of seven days following the exposure period [28][29][30][31][32][33]. After mortality was adjusted using Abbott's formula, probit analysis was performed [34].…”

Transition‐Metal‐Free Synthesis of N‐Heterocyclic Compounds via Multi‐Component Reactions

“…El-Lateef and his groups developed a one-pot multi-component condensation for the synthesis of pyrimidine derivatives 603 from aromatic aldehydes 1, urea/thiourea and ethyl acetoacetate or acetylacetone 307 (Scheme 119). [138] The reaction was catalyzed by using pumice as a novel natural heterogeneous catalyst under solvent-free condition and the synthesized compounds were isolated without tedious workup procedures with high purity with excellent yields of the products. The reaction mechanism proceeds via the activation of aromatic aldehyde 1 by the acidic catalyst (pumice is a volcanic rock composed of 70 % SiO 2 and 13 % Al 2 O 3 ).…”

“…El‐Lateef and his groups developed a one‐pot multi‐component condensation for the synthesis of pyrimidine derivatives 603 from aromatic aldehydes 1 , urea/thiourea and ethyl acetoacetate or acetylacetone 307 (Scheme 119). [138] …”

Nickel oxide nanoparticles as sustainable catalysts for efficient synthesis and anti-microbial evaluation of 2-amino-4H-pyran derivatives

“…Moreover, multi-component reaction are useful in organic synthesis [5,6] due to their higher yields, shorter reaction times, easier procedures, lower cost compared to multistep reactions in addition to an eco-friendly application [7][8][9][10]. Recently the use of catalysts has become very important in organic synthesis which plays a crucial role in the creation of fine compounds [11][12][13][14][15]. Today every scientific and technological discipline, including catalysis, has become very interested in transition metal nanoparticles [16][17][18].…”