Pharmacokinetic study of loprinone hydrochloride, a new cardiotonic agent, in beagle dogs

Design, synthesis and anti-mycobacterial evaluation of imidazo[1,2-a]pyridine analogues

Based on the molecular hybridization strategy, thirty-four imidazo[1,2-a]pyridine amides (IPAs) and imidazo[1,2-a]pyridine sulfonamides (IPSs) were designed and synthesized. The structures of the target compounds were characterized using ¹H NMR, ¹³C NMR, LCMS, and elemental analyses. The synthesized compounds were evaluated in vitro for anti-tubercular activity using the microplate Alamar Blue assay against Mycobacterium tuberculosis H37Rv strain and the MIC was determined. The evaluated compounds exhibited MIC in the range 0.05-≤100 μg mL^-1. Among these derivatives, IPA-6 (MIC 0.05 μg mL^-1), IPA-9 (MIC 0.4 μg mL^-1), and IPS-1 (MIC 0.4 μg mL^-1) displayed excellent anti-TB activity, whereas compounds IPA-5, IPA-7 and IPS-16 showed good anti-TB activity (MIC 0.8-3.12 μg mL^-1). The most active compounds with MIC of <3.125 μg mL^-1 were screened against human embryonic kidney cells to check their cytotoxicity to normal cells. It was observed that these compounds were nontoxic (SI value ≥66). The ADMET characteristics of the final compounds were also predicted in silico. Further, using the Glide module of Schrodinger software, a molecular docking study of IPA-6 was carried out to estimate the binding pattern at the active site of enoyl acyl carrier protein reductase from Mycobacterium tuberculosis (PDB 4TZK). Finally, molecular dynamics simulations were performed for 100 ns to elucidate the stability, conformation, and intermolecular interactions of the co-crystal ligand and significantly active compound IPA-6 on the selected target protein. IPA-6, the most active compound, was found to be 125 times more potent than the standard drug ethambutol (MIC 6.25 μg mL^-1).

Design, synthesis and biological evaluation of 2-(3,4-dimethoxyphenyl)-6 (1,2,3,6-tetrahydropyridin-4-yl)imidazo[1,2-a]pyridine analogues as antiproliferative agents

Two series of forty five novel 2-(3,4-dimethoxyphenyl)-6-(1,2,3,6-tetrahydropyridin-4-yl) imidazo[1,2-a]pyridine analogues (IPA 1-22, IPS 1-22 and IP-NH) have been designed, synthesized and structures confirmed by ¹H NMR, ¹³C NMR, mass spectrometry. Furthermore, single crystal was developed for IPS-13. All the final derived conjugates were evaluated for their in vitro antiproliferative activity against a panel of diverse cancer cell lines viz., A549 (lung cancer), HeLa (cervical cancer), B16F10 (melanoma) and found to show potent anticancer activity on the tested cell lines. Many of them showed the IC₅₀ values in the range 2.0-20.0 µM. The most active compounds (IPA 5,6,8,9,12,16,17,19 and IPS 7,8,9,22) from IPA and IPS series were screened to determine their cytotoxicity on HEK-293 (human embryonic kidney) normal cell line and were found to be nontoxic to normal human cells. The molecular interactions of the derivatised conjugates were also supported by molecular docking simulations. These derivatives may serve as lead structures for development of novel potential anticancer drug candidates.

Electrochemical oxidative C–H/N–H cross-coupling for C–N bond formation with hydrogen evolution

We herein report an electrochemical oxidative C–H/N–H cross-coupling reaction in an undivided cell.

Catalyst free, C-3 functionalization of imidazo[1,2-a]pyridines to rapidly access new chemical space for drug discovery efforts

Multicomponent reactions (MCRs) are robust tools for the rapid synthesis of complex, small molecule libraries for use in drug discovery and development. By utilizing MCR chemistry, we developed a protocol to functionalize the C-3 position of imidazo[1,2-a]pyridine through a three component, decarboxylation reaction involving imidazo[1,2-a]pyridine, glyoxalic acid, and boronic acid.

Metal-free, efficient hydrazination of imidazo[1,2-a]pyridine with diethyl azodicarboxylate in neutral media

The first example of metal-free regioselective hydrazination of imidazo[1,2-a]pyridine with diethyl azodicarboxylate is accomplished. This procedure is chemically appealing due to the high degree of functional group tolerance and efficiency in expanding the molecular diversity.

Microwave-assisted synthesis of novel 2,3-disubstituted imidazo[1,2-a]pyridines via one-pot three component reactions

An expeditious one-pot, metal-free, three-component reaction of arylglyoxals, cyclic 1,3-dicarbonyls and 2-aminopyridines in the presence of molecular iodine under microwave irradiation is reported.

Iodine–triphenylphosphine mediated sulfenylation of imidazoheterocycles with sodium sulfinates

An efficient approach to sulfenyl imidazoheterocycles has been developed via iodine–triphenylphosphine mediated direct sulfenylation of imidazoheterocycles with sodium sulfinates under transition-metal-free conditions.

Efficient access to 2,3-diarylimidazo[1,2-a]pyridines via a one-pot, ligand-free, palladium-catalyzed three-component reaction under microwave irradiation

An expeditious one-pot, ligand-free, Pd(OAc)2-catalyzed, three-component reaction for the synthesis of 2,3-diarylimidazo[1,2-a]pyridines was developed under microwave irradiation. With the high availability of commercial reagents and great efficiency in expanding molecule diversity, this methodology is superior to the existing procedures for the synthesis of 2,3-diarylimidazo[1,2-a]pyridines analogues.