The ability of SnCl2.2H2O as catalyst to promote the Biginelli three-component condensation reaction from a diversity of aromatic aldehydes, ethyl acetoacetate and urea or thiourea is described. The reaction was carried out in acetonitrile or ethanol as solvents in neutral media and represents an improvement of the classical Biginelli protocol and an advantage in comparison with FeCl3.6H2O, NiCl2.6H2O and CoCl2.6H2O which were used with HCl as co-catalyst. The synthesis of 3,4-dihydropyrimidinones was achieved in good to excelent yields.

An In–SiO₂ composite was prepared by the sol–gel method and was applied as a heterogeneous Lewis acid catalyst in the multicomponent Hantzsch synthesis of symmetrical and non-symmetrical 1,4-DHPs. The Ca²⁺ channel blockers nifedipine and nemadipine B were synthesized in a single step through a solvent-free protocol.

A series of new hybrid fluorescent Biginelli compounds, including a Monastrol derivative, were designed and synthesized with good yields. The photophysical studies revealed dual fluorescence emission, attributed to excited enol forms (E*) and tautomeric (K*) species, respectively, due to the ESIPT mechanism. The cytotoxic activity of all compounds was evaluated against MCF-7, Caco-2 and PC3 cancer cell lines and PNT2 normal prostate cells. The fluorescent Monastrol derivative 8f was the most active with cytotoxic activity very similar to cisplatin, whereas derivative 8c was the most selective towards the PC3 prostate cancer cells. The confocal laser scanning microscopy images of PC3 and MCF-7 cancer cell lines were acquired after incubation of the fluorescent Biginelli hybrids 8c and 8f, respectively, demonstrating efficient cellular uptake of both compounds and strong fluorescence within the intracellular medium. These results show that the new hybrid 3,4-dihydropyrimidin-2-(thi)ones are dual-function bioactive compounds that act both as fluorescent probes and antineoplastic agents.

Monastrol is a small cell-permeable heterocyclic molecule that is recognized as an inhibitor of mitotic kinesin Eg5. Heterocyclic–fatty acid derivatives are a new class of compounds with a broad range of biological activities. This work describes a comparative study of the in vitro antitumoral activity of a series of new long-chain monastrol analogues against rat glioblastoma cells. The novel analogues C6-substituted monastrol and oxo-monastrol were synthesized via Biginelli multicomponent condensation of fatty β-ketoester in good yields using a simple approach catalyzed by nontoxic and free-metal sulfamic acid. Following synthesis, their in vitro antitumoral activities were investigated. Notably, all analogues tested were active against rat glioblastoma cells. Superior activity was observed by analogues derived from palmitic and stearic fatty acid chains; these compounds were the most potent molecules, showing 13-fold higher potency than monastrol with IC₅₀ values of 5.11 and 6.85 μM, respectively. These compounds could provide promising new lead derivatives for more potent antitumor drugs.