Iranian chemical communication 2423-4958 2 Issue 3, pp. 162-231, Serial No. 4 2014 07 01 Ag nanoparticle/melamine sulfonic acid supported on silica gel as an efficient catalytic system for synthesis of dihydropyrimidin thiones 180 186 778 EN Parya Nasehi Department of chemistry, Science and Research Branch, Islamic Azad University, Ahvaz, Iran Alireza Kiasat Department of chemistry, Science and Research Branch, Islamic Azad University, Ahvaz, Iran Mohammad Kazem Mohammadi Islamic Azad University , Ahvaz Branch Journal Article 2014 01 14 3,4-dihydropyrimidin-2(1H)-thiones were synthesized in the presence of Ag nanoparticle/melamine sulfonic acid (MSA) supported on silica gel. The reaction was carried out at 110 oC for 20 min under solvent free conditions. In all cases, the three component reaction proceeded smoothly to give the corresponding 3,4-dihydropyrimidin-2(1H)-thiones in moderate to good yield. We have found the best conditions are using 0.2 g MSA, 0.05 g Ag nanoparticle.SiO2 under solvent free conditions at 110 oC. This method have some advantages such as good yield, mild reaction conditions, ease of operation and work up, short reaction time and high product purity. In this work, we have investigated the application of Ag nanoparticle/MSA.SiO2 for synthesis of Biginelli – type condensation. https://icc.journals.pnu.ac.ir/article_778_c682a797f1c3b0ae09c658e4213392ec.pdf