Cost-effective ionic liquid for environmentally friendly synthesis of 3,4-dihydropyrimidin-2(1H)-ones

Abstract

A simple, efficient and environmentally friendly process for synthesis of 3,4-dihydropyrimidinones using a onepot three-component condensation of aromatic aldehydes, b-dicarbonyl compounds, and urea/thiourea is discussed. The cost-effective, new generation ionic liquid (IL), tri-(2-hydroxyethyl) ammonium acetate was used as both solvent and catalyst. The reactions were carried out using both conventional heating and microwave energy. Application of IL technology with microwave energy represents an attractive and rapid alternative to the conventional acidÁbase catalyzed thermal processes.

Ionic Liquid Catalyzed 4,6-Disubstituted-3-Cyano-2-Pyridone Synthesis Under Solvent-Free Conditions

“…In the quest of developing mild, simple, environmentally friendly and solvent-free synthetic protocols, previously we have reported several reactions including hetero-Michael reaction [21], Knoevenagel condensation [22], Biginelli reaction [23] and Heck reaction [24] using ILs as recyclable catalytic system. As new generation ILs, a wide range of guanidine ionic liquids (GILs) have been synthesized and used as solvent as well as catalyst in the Henry reaction, aldol reaction, Heck reaction and for the synthesis of polysubstituted benzene [25][26][27][28][29][30].…”

Synthesis of 1-alkyl triazolium triflate room temperature ionic liquids and their catalytic studies in multi-component Biginelli reaction

“…In this context, several new reagents have been developed employing various ionic liquids as catalyst to carry out Biginelli reaction. [33][34][35][36][37] Particularly, ionic liquids such as [cmmim [[BF 4 ], 38 TMGT, 39 tri-(2-hydroxyethylammoniumacetate), 40 45 have been known to achieve this one-pot transformation.…”

Ionic liquid mediated one-pot synthesis of 6-aminouracils

“…As new generation ionic liquids, a wide range of guanidine ionic liquids (GILs) have been synthesized and used in many organic reactions such as the Henry reaction, aldol reaction and Heck reaction. [19][20][21][22] In the quest of developing simple, mild and environmentally friendly synthetic protocols, we have previously reported a hetero-Michael reaction, 23 a Knoevenagel condensation, 24 a Biginelli reaction 25 and a Heck reaction 26 using cost-effective ionic liquids as the recyclable solvent as well as the catalyst.…”