Silica-gel Catalyzed Facile Synthesis of 3,4-Dihydropyrimidinones

A Green Approach for the Synthesis of 2,4-Dihydro-pyrimidinones Using PTSA

“…Several methods improved the procedure using phosphorus pentoxide-methanesulfonic acid 4 , potassium ter-butoxide (t-BuOK) 5 , ammonium dihydrogen phosphate 6 , silica-gel 7 , mesoporous molecular sieve MCM-41 8 , cyanuric chloride 9,10 , nano-BF 3 ⋅SiO 2 silica gel supported polyphosphoric acid 11 , zirconium(IV) chloride 12 , and indium(III) bromide 13 14 have been employed for this transformation.…”

Synthesis, Characterization, and Catalytic Behavior of Bamboo Rice Husk Ash

“…There are a variety of heterogeneous catalysts such as alumina, titania, zirconia, zeolite, clay, and silica that have been successfully employed in several organic transformations to minimize wastage, which is a cause of environmental pollutions . Among them, silica has been successfully used to catalyze various organic transformations with excellent yields of the products . In this connection, here we report the development of an efficient protocol for the synthesis of tetrahydro‐4 H ‐chromene‐3‐carbonitrile using silica derived from bamboo rice husk ash (BRiHA‐SiO 2 ) as catalyst.…”

Microwave-Assisted Synthesis and Biological Evaluation of Dihydropyrimidinone Derivatives as Anti-Inflammatory, Antibacterial, and Antifungal Agents

“…Due to the remarkable biological utilization, the pyrimidinones attract many researchers as well as academicians. Recently, several methods improved the procedure using phosphorus pentoxide-methanesulfonic acid [ 4 ], potassium ter -butoxide ( t -BuOK) [ 5 ], ammonium dihydrogen phosphate [ 6 ], silica-gel [ 7 ], mesoporous molecular sieve MCM-41 [ 8 ], cyanuric chloride [ 9 ], nano-BF 3 · SiO 2 [ 10 ], silica gel-supported polyphosphoric Acid [ 11 ], zirconium(IV) chloride [ 12 ], and indium(III) bromide [ 13 ] as catalysts. However, some of these one-pot procedures generally require strong protic or Lewis acids, prolonged reaction times, and high temperature.…”