Indole-fused spirochromenes as potential anti-tubercular agents: design, synthesis and in vitro evaluation.

As part of an ongoing effort to develop new anti-tubercular agents, a series of novel indole-fused spirochromene hybrids (7a-l) were efficiently synthesized in excellent yields by the popular 'Fisher-Indole synthesis' approach. The structure elucidation of the target compounds was carried out by different spectral techniques including H-NMR, C-NMR, ESI Mass, and FTIR analysis. Additionally, the proposed structure of 7i was proved by single-crystal X-ray analysis.

Microwave-assisted synthesis, biological evaluation and molecular docking studies of new coumarin-based 1,2,3-triazoles.

Coumarin-based 1,4-disubstituted 1,2,3-triazole derivatives were synthesized using a highly efficient, eco-friendly protocol a copper(i)-catalyzed click reaction between various substituted arylazides and terminal alkynes. The synthetic route was easy to access and gave excellent yields under microwave irradiation conditions compared to the conventional heating route. The structures of all the compounds were characterized by IR, H NMR, C NMR spectroscopy and mass spectrometry.

Facile synthesis, characterization and enhanced catalytic reduction of 4-nitrophenol using NaBH by undoped and Sm, Gd, Hf doped LaO nanoparticles.

This work focuses on the synthesis of undoped and doped lanthanum oxide nanoparticles (LaO NPs) by a simple co-precipitation method for the catalytic reduction of 4-nitrophenol (4-NP) using NaBH as a reducing agent. Their optical properties, morphologies, structure, chemical compositions and electronic properties were carefully characterized by XRD, FTIR, SEM, TEM, PL and UV-visible absorption spectroscopy. The SEM and TEM images showed various shape morphologies and sizes of the particles.

Synthesis of 8',11'-dihydrospiro[cyclohexane-1,2'-oxepino[2,3-] chromen]-4'(3')-ones with ring closing metathesis as a key step.

A series of novel hybrid molecular entities incorporating various spiro chromanone scaffolds onto the benzannulated oxepine core moiety were synthesised using allylation, Claisen rearrangement, Kabbe condensation and Ring Closing Metathesis (RCM) as a key step. During the synthesis we found that the nitrogen functionality in the substrate influences significantly the catalyst load due to electronic effects. Several iterations have been carried out to achieve complete conversion to products 6a-6e.

1,2,3-Triazole-fused spirochromenes as potential anti-tubercular agents: synthesis and biological evaluation.

A facile and convenient approach has been designed for the synthesis of novel prototypes that possess the advantage of the two pharmacophores of chromene and 1,2,3-triazole in a single molecular backbone, were evaluated against H37Rv strain. The new analogues 1,2,3-triazole-fused spirochromenes were accomplished in four step synthetic strategy utilizing click chemistry ([3 + 2] Huisgen cycloaddition) in the ultimate step. The synthesized compounds were established based on the spectral data and X-ray crystal structure for 7a.