The well-ordered 2D hexagonal structure FDU-15 mesoporous polymer with the P6mm space group has been synthesized by soft template method.Novel sulfonic acid group-functionalized FDU-15 mesoporous polymer solid acid (FDU-SO3H) catalyst was successfully prepared through vapour-phase transfer sulfonation of FDU-15.Various techniques such as X-ray diffraction (XRD)

scanning electron microscopy (SEM) and elemental analysis have been adopted to track the functionalization processes

and to characterize the physicochemical properties of the FDU-SO3H.The FDU-SO3H catalyst was tested in the Biginelli reactions of aromatic aldehydes

ethyl acetoacetate and urea (or thiourea) under solvent-free conditions.In order to find the optimal reaction conditions for the FDU-SO3H catalyst

the effects of additive sequence

solvents

reaction substrates in the Biginelli reaction have been investigated.3

4-Dihydropyrimidinones/thiones and their derivatives have been synthesized under the optimum reaction conditions.A high yield of 3

4-dihydropyrimidin-2(1H)-ones as 91% was achieved when Biginelli reaction of benzaldehyde

ethyl acetoacetate and urea was carried out at 90 ℃ for 1 h under solvent-free conditions.The FDU-SO3H catalyst exhibited similar catalytic activity even after four cycles for Biginelli reaction of benzaldehyde

ethyl acetoacetate and urea.The possible mechanisms of Biginelli reaction have been discussed.The experimental results verified that the FDU-SO3H was able to act as a highly active

eco-friendly

stable and resusable heterogeneous catalyst.