Sulfonic acid functionalized SBA-15 nanoporous material (SBA-Pr-SO3H) with a large pore size of 6 nm, a high surface area, high selectivity, and excellent chemical and thermal stability was applied as an efficient heterogeneous nanoporous acid catalyst in the reaction of isatin with pyrazolones under mild reaction conditions. A novel class of symmetrical spiro[indoline-3,4'-pyrano[2,3-c:6,5-c']dipyrazol]-2-one derivatives was successfully obtained in high yields. Comparison of these results with those reported in the literature shows that the current method is efficient, and results in better reaction times and yields of the desired products. Other advantages of this new method are its operational simplicity, easy work-up procedure, and the use of SBA-Pr-SO3H as a reusable and environmentally benign nanoreactor, such that the reaction proceeds easily in its nanopores. We also tested the antimicrobial activity of the prepared compounds using the disc diffusion method, and some of the synthesized compounds exhibited the best results against B. subtilis and S. aureus.

Sulfonic acid functionalized nanoporous silica (SBA-Pr-SO3H) with a pore size of 6 nm was synthesized using surface modification of Santa Barbara Amorphous (SBA-15). It is a solid acid hexagonally nano-reactor with high surface area and is reusable, high selective, non-corrosiveness which can easily isolate from the products. An efficient and green one-pot three component reaction was developed for the synthesis of pyrido[2,3-d]pyrimidine derivatives via a simple, mild and effective solvent free reaction of 4(6)-aminouracil, barbituric acid and aromatic aldehydes in the presence using SBA-Pr-SO3H. In this reaction, SBA-Pr-SO3H was an effective nano-catalyst which gave the products in good to high yields in a shorter reaction time compared to the other published reports. Some of the products were strong antibiotics against Bacillus subtilis and Staphylococcus aureus.