Meldrum's acid as an excellent catalyst for the facile, efficient and one-pot synthesis of N,3-diarylimidazo[1,2-a]pyridin-2-amines

Abstract

Using the three-component reaction between aryl glyoxals, arylamines, and 2-aminopyridine were synthesized N, 3-diarylimidazo[1,2-a]pyridin-2-amines and 3-aryl-N-(pyridine-2-yl)imidazo[1,2-a]pyridin-2-amines under catalyst-free conditions. Using these starting materials under the same conditions and in the presence of Meldrum's acid as catalyst gave only N, 3-diarylimidazo[1,2-a]pyridin-2-amines. It was observed for the synthesis of these products, Meldrum's acid as catalyst gave 72-89% yields in 1.5-2 hours as against 4-8 hours required to get 53-65 % yields under catalyst-free conditions.

Efficient one pot preparation of novel 1-oxo-3-aryl-1,5-dihydrobenzo[4,5]imidazo[1,2-a]pyridine-2-carboxylic acid derivatives in a green solvent

“…Given the biological activity of imidazo [1,2-a]pyridine-3-carboxamides, 33,34 we decided to synthesize benzo [4,5]imidazo [1,2-a]pyridine-2-carboxylic acids, which could be used as the precursor for the preparation of the corresponding lactam derivatives. In this regard, in continuation of our previous work on the development of multicomponent reactions for the synthesis of imidazo[1,2-a]pyridines, 35,36 we herein describe a facile and efficient strategy for the synthesis of 1-oxo-3-aryl-1,5-dihydrobenzo [4,5]imidazo [1,2a]pyridine-2-carboxylic acid derivatives via the one pot-three component reaction of 2-(1H-benzo[d]imidazol-2-yl)acetonitrile, aryl aldehydes, and Meldrum's acid in water at room temperature.…”

Synthesis, Characterization and Evaluation of Some Meldrum's Acid Derivatives as Lubricant Additives

“…Meldrum's acid is a powerful organic Chiron that is commonly utilized to produce natural products [10][11][12]. and heterocyclic compounds [13,14]. Meldrum's acid derivatives also exhibit a wide spectrum of biological activities; they act as antimicrobials [15][16][17], antituberculosis agents [18], antimalarial, and antioxidants [19].…”