Green synthesis of heterocyclic alkenes using MCM 41 supported perchloric acid catalytic system: characterization and DFT studies.

Context: In this work, a series of heterocyclic alkenes were prepared by the reaction of 2-hydroxy-1-naphthaldehyde with various heterocyclic active methylene compounds via Knoevenagel condensation reaction using mesoporous silica, MCM 41, supported perchloric acid as an efficient green catalytic system under solvent-free conditions. A comparative study of the conventional method vs the green method was also reported with the same raw materials. H NMR, C NMR, IR, and mass spectroscopic techniques were used for the characterization of synthesized compounds.

Chitosan Catalyzed Novel Piperidinium Dicoumarol: Green Synthesis, X-ray Diffraction, Hirshfeld Surface and DFT Studies.

The novel piperidinium dicoumarol has been synthesized by the reaction of 3-formylchromone, 4-hydroxycoumarin, and piperidine under chitosan catalyzed solvent-free green conditions. FT-IR and NMR spectroscopy established the structure of dicoumarol, which was further confirmed by a single X-ray diffraction study. The single diffraction study has revealed the hydrogen bonding interactions, which were further validated by Hirshfeld surface analysis.

Photophysics of Dihydroquinazolinone Derivatives: Experimental and Theoretical Studies.

Herein, we report the synthesis of two dihydroquinazolinone derivative 2-(2-Hydroxy-naphthalen-1-yl)-2, 3-dihydro-1H-quinazolin-4-one (1) and 2-(3-Methyl-thiophen-2-yl)-2,3-dihydro-1H-quinazolin-4-one (2) by using 2-aminobenzamide, 2-hydroxybenzaldehyde and 3-methyl thiophene-2-carboxaldehyde. The synthesized compounds were characterized by 1H NMR, 13C NMR, FT-IR and its spectral, photophysical, intramolecular charge transfer characteristics were studied by absorption and emission spectroscopy. The synthesized compound exhibits significant changes in their photophysical properties depending on the solvent polarity.

Synthesis of 4-hydroxycoumarin heteroarylhybrids as potential antimicrobial agents.

A new series of 4-hydroxycoumarin derivatives 3a-d was synthesized by the reaction of 3-bromo-4-hydroxy coumarin 1 with various heteroaldehydes 2a-d in good yields. The synthesized compounds were characterized on the basis of their elemental and spectral (IR, (1)H-NMR and mass spectrometry) analysis. All target compounds were evaluated for their in-vitro antimicrobial activity against Streptococcus pyogenes, methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumonia, and Escherichia coli bacterial strains and fungal cultures of Candida albicans, Aspergillus fumigatus, Trichophyton mentagrophytes, and Penicillium marneffei by disk diffusion assay with slight modifications.