Efficient and eco-friendly synthesis of dihydropyrimidinones, bis(indolyl)methanes, and N-alkyl and N-arylimides in ionic liquids

Abstract

Dihydropyrimidinones, bis(indolyl)methanes, and N-alkyl and N-arylimides were synthesized efficiently under mild reaction conditions in the presence of two types of ionic liquids. In each section, effects of different ILs on the yield of reactions were investigated. The use of ionic liquids offer improvements for the synthesis of title compounds with regard to the yield of products, simplicity in operation, short reaction times and green aspects by avoiding toxic catalyst and organic solvents.

Three Component Reaction: An Efficient Synthesis of 3,4‐Dihydropyrimidin‐2(1H)‐ones and Thiones Using Heterogeneous Catalyst

“…7,8 The biological activity of some alkaloids isolated recently has been attributed to the dihydropyrimidinone moiety. 9 Dihydropyrimidinones have been prepared by employing protic acids, [10][11][12] Lewis acids, [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28] triflates, 29,30 microwave irradiation, [31][32][33][34] ionic liquids 35,36 and clays. 37,38 Unfortunately, many of these processes suffer major or minor limitations, such as drastic reaction conditions, low yields, expensive and toxic reagents, stoichiometric amounts of catalysts, strongly acidic conditions, long reaction time, and incompatibility with other functional groups.…”

Phosphotungstic Acid: An Efficient, Cost-effective and Recyclable Catalyst for the Synthesis of Polysubstituted Quinolines

“…In continuation of our ongoing interest in solvent-free synthesis [ 25 , 26 , 27 , 28 , 29 , 30 ], we herein report the use of phosphotungstic acid (H 3 PW) [ 3 ] as a catalyst in the synthesis of quinolines with excellent yields by the reaction of a variety of α-methyleneketones and 2-aminoaryl ketones under mild reaction conditions.…”

1‐Butyl‐3‐methylimidazolium Hydrogen Sulfate [bmim]HSO4: An Efficient Reusable Acidic Ionic Liquid for the Formylation of Alcohols

“…[4][5][6] Recently, acidic ionic liquids have been successfully used in these reactions due to their unique properties such as vapor-less feature and reusability. [5][6][7][8][9] O-Formylation could be the method of choice for protecting an alcoholic group in a complex synthetic sequence because deformylation can be affected selectively in the presence of acetate or other ester protecting groups. Further, if the alcoholic group is planned to be oxidized later in the synthetic scheme, the formylated alcoholic group need not be deprotected and direct oxidation under Oppenauer conditions can be realised.…”