Efficient one-pot synthesis of 3,4-dihydropyrimidin-2(1H)-ones catalyzed by a new heterogeneous catalyst based on Co-functionalized Na⁺-montmorillonite

Abstract

A facile and efficient solvent-free protocol for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones by using Co@imine-Na+-MMT as a new, environmentally friendly and reusable heterogeneous catalyst is reported.

One Pot Synthesis of Micromolar BACE-1 Inhibitors Based on the Dihydropyrimidinone Scaffold and Their Thia and Imino Analogues

“…5-Ethoxycarbonyl-4-((4-trifluoromethyl)phenyl)-6-methyl-3,4-dihydropyrimidine-2(1H)-one 4a [ 45 ]. From 4-trifluoromethylbenzaldehyde, ethylacetoacetate, urea; 0.266 g, 81%, m.p.…”

Biginelli Reaction: Polymer Supported Catalytic Approaches

“…After solvent free heterogeneous phase work up, excellent amounts of DHPMs were obtained. The recovered nanocatalyst was recycled for four consecutive cycles with almost consistent activity . The said hybrid nanocatalyst protocol highlighted the noticeable improvements over the classical Biginelli reactions.…”

“…The recovered nanocatalyst was recycled for four consecutive cycles with almost consistent activity. 249 The said hybrid nanocatalyst protocol highlighted the noticeable improvements over the classical Biginelli reactions. The short reaction time under solvent-free condition with excellent yields and recyclability of the catalyst makes the method creditable.…”

Chitosan-silica Sulfate Nano Hybrid: An Efficient Biopolymer Based-heterogeneous Nano Catalyst for Solvent-free Synthesis of 3,4-Dihydropyrimidine-2(1H)-one/thiones

“…4,9 Due to the problems associated with the classical Biginelli reaction such as harsh reaction conditions, low yields, and long reaction times and also regarding to the significance of DHPMs, hence the numerous reaction conditions using various Lewis and Brønsted acid catalysts have been developed so far. 5 To date, a plenty of homogeneous and heterogeneous catalysts such as nano BF 3 •SiO 2 , 10 Bi(III) supported on silica-coated Fe 3 O 4 nanoparticles, 11 TiCl 3 OTf-[bmim]Cl, 12 [TEAPS]H 2 PMo 12 O 40 , 13 CuCl 2 /HCl, 14 sulfated silica tungstic acid, 15 ErCl 3 •6H 2 O, 16 SnCl 2 /nano SiO 2 , 17 L-proline nitrate, 18 D-xylonic acid, 19 Fe(OTs) 3 •6H 2 O, 20 NiCl 2 •6H 2 O/ HCl, 21 Co@imine-Na + -montmorillonite, 22 dendrimer-attached phosphotungstic acid nanoparticles immobilized on nanosilica, 23 Ce(LS) 3 , 24 bentonite/PS-SO 3 H, 25 silica sulfuric acid, 26 HClO 4 •SiO 2 , 27 and the exchanged cations in an Algerian montmorillonite 28 under conventional heating, ultrasound and microwave irradiations as well as solvent-free conditions have been reported to achieve DH-PMs synthesis. 5 Although these protocols are accompa-nied with several advantages; however, they suffer from several defects such as the use of metal-based, corrosive, toxic, expensive, non-reusable, and moisture sensitive catalysts, tedious work-up and purification processes, environmental contaminations, the use of harmful organic solvents, inadequate yields, and also long reaction times.…”