An Efficient, Catalyst- and Solvent-Free Synthesis of imidazo[1,2-a]pyridines and 2,4-disubstituted thiazoles on Grinding

Abstract

An efficient synthesis of imidazo[1,2-a]pyridines and 2,4-disubstituted thiazoles in excellent yield under catalystand solvent-free conditions at room temperature on grinding has been developed. The important features of this method are that it is reasonably fast, very clean, high yielding, simple workup and environmentally benign.

Solvent- and catalyst-free synthesis of imidazo[1,2-a]pyridines under microwave irradiation

“…The typical procedure for the synthesis of these compounds involves a condensation reaction of an α-bromocarbonyl compound with 2-aminopyridine derivatives in neutral, weak basic organic solvents at elevated temperature. [16][17][18][19][20][21][22][23][24] These compounds were also synthesised by using solid support catalysts such as Al 2 O 3, 25 and TiCl 4 . 26 Other methods have…”

TCCA-Promoted Solvent-Free Chemoselective Synthesis of Thiosulfonates on Grinding

“…In recent years, significant articles have appeared reporting solid-state reactions by grinding. [7][8][9] Most of these reactions were carried out at room temperature in an absolutely solventfree environment using only a mortar and pestle, and a common merit of these processes is that they are efficient, economical, and environmentally friendly.…”

“…As a part of our continuing interest in the synthesis of sulfurcontaining compounds using green chemistry, 9,12,13 we report here a new and simple TCCA-promoted solvent-free chemoselective synthesis of thiosulfonates by oxidation of disulfides under mild conditions.…”

Solvent-Free Synthesis of 3,5-di(Hetero)Aryl-1,2,4-Thiadiazoles by Grinding of Thioamides under Oxidative Conditions

“…In recent years, significant articles have appeared reporting solid-state reactions by grinding. [20][21][22][23][24] Most of these reactions are carried out at room temperature in a completely solventfree environment using only a mortar and pestle, and therefore the common merit of these processes is that they are efficient, economical, and environmentally friendly.…”