green synthesis of pyrazol-chromeno[2,3-d]pyrimidinones using sba-pr-so3h as an efficient nanocatalyst

Hexagonal mesoporous silica (sba-15) was prepared and then functionalized by (3-mercaptopropyl)trimethoxysilane. the obtained 3-mercaptopropyl functionalized sba-15 (sba-pr-sh) was then oxidized using h2o2 in methanol under an acidic condition to give sulfonic acid functionalized mesoporous silica (sba-pr-so3h). the latter was characterized using different techniques (including tga, bet, bjh, chn, sem, and tem) and then used as a catalyst in organic synthesis. in the next step, sba-pr-so3h catalyzed the three-component reaction of pyrazolone, salicylaldehydes, and barbituric acid in water under reflux condition. through this procedure various pyrazolchromeno[2,3-d]pyrimidinone derivatives were obtained. the reaction conditions were completely green due to the use of water as a solvent and the presence of an environmentally benign catalyst.