Background:
A wide variety of dihydropyrimidins (DHPMs) exhibit pharmacological and
biological activities. Herein, an efficient one-pot synthesis of some 3, 4-dihydropyrimidin-2(1H)-one
derivatives is reported using Fe3O4 @SiO2–Pr-INH.
Objective:
Recently, several catalysts have been used to improve the Biginellis-reaction. However, some of
these catalysts have imperfections. Herein, a convenient method for the synthesis of 3, 4-dihydropyrimidin-
2(1H)-ones and their sulfur derivatives using Fe3O4 @SiO2–Pr-INH is reported.
Materials and Methods:
Firstly, the catalyst was synthesized through a simple four-step method. The Fe3O4
MNPs were synthesized using the chemical co-precipitation method, coated with a layer of silica using TEOS,
and then functionalized with CPTMS. Subsequently, a nucleophilic substitution of Cl by isoniazid resulted in
the formation of the magnetic Fe3O4@SiO2–Pr-INH. After the preparation and characterization of
Fe3O4@SiO2–Pr-INH, its catalytic activity was studied in the synthesis of 3, 4-dihydropyrimidin-2(1H)-one
derivatives. Following the optimization of the reaction conditions, several 3, 4-dihydropyrimidin-2(1H)-one
derivatives were synthesized by the reaction of ethyl acetoacetate or acetylacetone, thiourea or urea and
aromatic aldehydes at 80 °C under solvent-free conditions.
Results:
Isoniazid-functionalized Fe3O4 magnetic nanoparticles (Fe3O4@SiO2–Pr-INH) were prepared using
Fe3O4 with silica layer and their surface was modified with isoniazid. They were characterized successfully by
infrared spectroscopy, powder X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray
spectroscopy and were used for the synthesis of some 3, 4-dihydropyrimidin-2(1H)-one derivatives as
catalysts. Aromatic aldehydes with electron-donating or electron-withdrawing groups afforded 3, 4-
dihydropyrimidin-2(1H)-ones and their sulfur derivatives in good to excellent yields in short reaction times.
Conclusion:
Isoniazid-functionalized Fe3O4 magnetic nanoparticles (Fe3O4@SiO2–Pr-INH) were used as an
efficient catalyst for Biginelli-type synthesis of 3, 4-dihydropyrimidin-2(1H)-ones and 3, 4-dihydropyrimidin-
2(1H)-thiones in good to excellent yields and short reaction times. It is noteworthy that this method has several
advantages such as simple experimental procedures, the absence of solvent, environmentally benign process,
stability and reusability of the catalyst.
Hybrid magneto-optical mode converter made with a magnetic nanoparticles-doped SiO2/ZrO2 layer coated on an ion-exchanged glass waveguide